Measuring emittances and sigma matrices
International Nuclear Information System (INIS)
Rees, J.; Rivkin, L.
1984-03-01
The method used for measuring emittance at the SLAC Linac and the linear collider damping ring is described. The basis of the method is derived using one two-by-two matrix to specify the state of the input beam (sigma matrix) and another to describe the lens-drift transport system (R-matrix)
Measurement of the Jones matrix of liquid crystal displays using a common path interferometer
International Nuclear Information System (INIS)
Sarkadi, Tamás; Koppa, Pál
2011-01-01
We propose a robust interferometric method to measure the Jones matrix of polarization components, especially liquid crystal displays. Phase values are measured by a simple common path interferometer containing a birefringent crystal as beam splitter and a polarizer as beam combiner. This solution eliminates the sensitivity of traditional interferometric techniques to vibration, temperature variation or wavefront distortion. The proposed phase measurement method is applicable to the measurement of both spatially homogeneous and binary modulated states, thus the modulation transfer function and inter-pixel interference can also be studied. We demonstrate this technique by the measurement of a liquid crystal on silicon display. The resulting Jones matrix, as a function of displayed gray level, can be efficiently embedded in any numeric model of an optical system containing the analyzed spatial light modulator
DEFF Research Database (Denmark)
underrated, impact on the American structuralist school. This eight volume collection makes available the first editions of Jones' standard books, i.e. The Pronunciation of English (1909), An English Pronouncing Dictionary (1917) and An Outline of English Phonetics (1918). In addition, Jones' crucial...... pioneering works, now out of print for many decades, are made easily accessible to scholars once again. Numerous articles encompassing a variety of phonetic/phonological topics, for example, phonemic analysis, juncture, models of pronunciation, and historiography, are also included (converted where necessary...
Updating Stiffness and Hysteretic Damping Matrices Using Measured Modal Data
Directory of Open Access Journals (Sweden)
Jiashang Jiang
2018-01-01
Full Text Available A new direct method for the finite element (FE matrix updating problem in a hysteretic (or material damping model based on measured incomplete vibration modal data is presented. With this method, the optimally approximated stiffness and hysteretic damping matrices can be easily constructed. The physical connectivity of the original model is preserved and the measured modal data are embedded in the updated model. The numerical results show that the proposed method works well.
Updating Stiffness and Hysteretic Damping Matrices Using Measured Modal Data
Jiashang Jiang; Yongxin Yuan
2018-01-01
A new direct method for the finite element (FE) matrix updating problem in a hysteretic (or material) damping model based on measured incomplete vibration modal data is presented. With this method, the optimally approximated stiffness and hysteretic damping matrices can be easily constructed. The physical connectivity of the original model is preserved and the measured modal data are embedded in the updated model. The numerical results show that the proposed method works well.
Estimation of Fuzzy Measures Using Covariance Matrices in Gaussian Mixtures
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Nishchal K. Verma
2012-01-01
Full Text Available This paper presents a novel computational approach for estimating fuzzy measures directly from Gaussian mixtures model (GMM. The mixture components of GMM provide the membership functions for the input-output fuzzy sets. By treating consequent part as a function of fuzzy measures, we derived its coefficients from the covariance matrices found directly from GMM and the defuzzified output constructed from both the premise and consequent parts of the nonadditive fuzzy rules that takes the form of Choquet integral. The computational burden involved with the solution of λ-measure is minimized using Q-measure. The fuzzy model whose fuzzy measures were computed using covariance matrices found in GMM has been successfully applied on two benchmark problems and one real-time electric load data of Indian utility. The performance of the resulting model for many experimental studies including the above-mentioned application is found to be better and comparable to recent available fuzzy models. The main contribution of this paper is the estimation of fuzzy measures efficiently and directly from covariance matrices found in GMM, avoiding the computational burden greatly while learning them iteratively and solving polynomial equations of order of the number of input-output variables.
Analytical stiffness matrices with Green-Lagrange strain measure
DEFF Research Database (Denmark)
Pedersen, Pauli
2005-01-01
Separating the dependence on material and stress/strain state from the dependence on initial geometry, we obtain analytical secant and tangent stiffness matrices. For the case of a linear displacement triangle with uniform thickness and uniform constitutive behaviour closed-form results are listed...... a solution based on Green-Lagrange strain measure. The approach is especially useful in design optimization, because analytical sensitivity analysis then can be performed. The case of a three node triangular ring element for axisymmetric analysis involves small modifications and extension to four node...
Jones, Ernest Beachcroft; Kingham, Edward G; Radnai, Rudolf
1985-01-01
Jones' Instrument Technology, Volume 5: Automatic Instruments and Measuring Systems deals with general trends in automatic instruments and measuring systems. Specific examples are provided to illustrate the principles of such devices. A brief review of a considerable number of standards is undertaken, with emphasis on the IEC625 Interface System. Other relevant standards are reviewed, including the interface and backplane bus standards. This volume is comprised of seven chapters and begins with a short introduction to the principles of automatic measurements, classification of measuring system
Koltunud Indiana Jones / Kutt Kommel
Kommel, Kutt
2008-01-01
Steven Spielbergi neljas Indiana Jones'i film Harrison Fordiga nimiosas "Indiana Jones ja kristallpealuu kuningriik" ("Indiana Jones and the Kingdom of the Crystal Skull") : Ameerika Ühendriigid 2008
Directory of Open Access Journals (Sweden)
TANG Ying
2017-01-01
Full Text Available One of the research hotspots in the field of high-temperature alloys was to search the substitutional elements for Re in order to prepare the single-crystal Ni-based superalloys with less or even no Re addition. To find the elements with similar or even lower diffusion coefficients in comparison with that of Re was one of the effective strategies. In multicomponent alloys, the interdiffusivity matrix were used to comprehensively characterize the diffusion ability of any alloying elements. Therefore, accurate determination of the composition-dependant and temperature-dependent interdiffusivities matrices of different elements in γ and γ' phases of Ni-based superalloys was high priority. The paper briefly introduces of the status of the interdiffusivity matrices determination in Ni-based superalloys, and the methods for determining the interdiffusivities in multicomponent alloys, including the traditional Matano-Kirkaldy method and recently proposed numerical inverse method. Because the traditional Matano-Kirkaldy method is of low efficiency, the experimental reports on interdiffusivity matrices in ternary and higher order sub-systems of the Ni-based superalloys were very scarce in the literature. While the numerical inverse method newly proposed in our research group based on Fick's second law can be utilized for high-throughput measurement of accurate interdiffusivity matrices in alloys with any number of components. After that, the successful application of the numerical inverse method in the high-throughput measurement of interdiffusivity matrices in alloys is demonstrated in fcc (γ phase of the ternary Ni-Al-Ta system. Moreover, the validation of the resulting composition-dependant and temperature-dependent interdiffusivity matrices is also comprehensively made. Then, this paper summarizes the recent progress in the measurement of interdiffusivity matrices in γ and γ' phases of a series of core ternary Ni-based superalloys achieved in
Directory of Open Access Journals (Sweden)
R. Caballero-Águila
2014-01-01
Full Text Available The optimal least-squares linear estimation problem is addressed for a class of discrete-time multisensor linear stochastic systems subject to randomly delayed measurements with different delay rates. For each sensor, a different binary sequence is used to model the delay process. The measured outputs are perturbed by both random parameter matrices and one-step autocorrelated and cross correlated noises. Using an innovation approach, computationally simple recursive algorithms are obtained for the prediction, filtering, and smoothing problems, without requiring full knowledge of the state-space model generating the signal process, but only the information provided by the delay probabilities and the mean and covariance functions of the processes (signal, random parameter matrices, and noises involved in the observation model. The accuracy of the estimators is measured by their error covariance matrices, which allow us to analyze the estimator performance in a numerical simulation example that illustrates the feasibility of the proposed algorithms.
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Butrymowicz Dariusz
2016-09-01
Full Text Available The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed based on the modified single blow technique was presented and discussed in the paper. The methodology of this measurement approach dedicated to the matrix of the rotating regenerative gas heater was discussed in detail. The testing stand consisted of a dedicated experimental tunnel with auxiliary equipment and a measurement system are presented. Selected experimental results are presented and discussed for selected types of matrices of regenerative air preheaters for the wide range of Reynolds number of gas. The agreement between the theoretically predicted and measured temperature profiles was demonstrated. The exemplary dimensionless relationships between Colburn heat transfer factor, Darcy flow resistance factor and Reynolds number were presented for the investigated matrices of the regenerative gas heater.
A general method for measuring the scattering matrices of N-port systems
International Nuclear Information System (INIS)
Bizarro, J.P.; Pain, M.
1989-01-01
Arising from the need to test the multijunctions that will build up the JET (Joint European Torus) lower hybrid antenna, a general model to measure scattering matrices of microwave devices was developed. The model allows for devices with any number of ports and for the use of adaptors between the measuring system and the device under test. Its accuracy can be as good as 1% for waveguide components. (author)
Magnetoelectric Jones dichroism
International Nuclear Information System (INIS)
Andrews, D L; Daniels, G J; Stedman, G E
2003-01-01
Recent work on liquids has verified a novel magnetoelectrical birefringence predicted by Jones. Co-present static electric and magnetic fields generate a differential response to optical polarizations positively or negatively tilted against a plane orthogonal to the one containing the static field vectors. Reports indicated a dichroic counterpart; establishing its theory is the present aim. Results are trilinearly dependent on the irradiance, and the static electric and magnetic fields. For isotropic fluids a scalar quantifies propensity for Jones dichroism. In field-polarized fluids a second scalar also contributes; temperature dependence enables determination of both parameters. (letter to the editor)
International Nuclear Information System (INIS)
Jarlskog, C.
1985-06-01
The structure of the quark mass matrices in the Standard Electroweak Model is investigated. The commutator of the quark mass matrices is found to provide a conventional independent measure of CP-violation. The question of maximal CP-violation is discussed. The present experimental data indicate that CP is nowhere maximally violated. (author)
LAZAR STANKOV; KARL SCHWEIZER
2007-01-01
This paper examines the effects of complexity-enhancing manipulations of two cognitive tasks – Swaps and Triplet Numbers tests (Stankov, 2000) – on their relationship with Raven’s Progressive Matrices test representing aspects of fluid intelligence. The complexity manipulations involved four treatment levels, each requiring an increasing number of components and relationships among these components. The accuracy, speed of processing, and confidence measures were decomposed into experimental a...
Directory of Open Access Journals (Sweden)
Shun-ichi Amari
2014-04-01
Full Text Available Information geometry studies the dually flat structure of a manifold, highlighted by the generalized Pythagorean theorem. The present paper studies a class of Bregman divergences called the (ρ,τ-divergence. A (ρ,τ -divergence generates a dually flat structure in the manifold of positive measures, as well as in the manifold of positive-definite matrices. The class is composed of decomposable divergences, which are written as a sum of componentwise divergences. Conversely, a decomposable dually flat divergence is shown to be a (ρ,τ -divergence. A (ρ,τ -divergence is determined from two monotone scalar functions, ρ and τ. The class includes the KL-divergence, α-, β- and (α, β-divergences as special cases. The transformation between an affine parameter and its dual is easily calculated in the case of a decomposable divergence. Therefore, such a divergence is useful for obtaining the center for a cluster of points, which will be applied to classification and information retrieval in vision. For the manifold of positive-definite matrices, in addition to the dually flatness and decomposability, we require the invariance under linear transformations, in particular under orthogonal transformations. This opens a way to define a new class of divergences, called the (ρ,τ -structure in the manifold of positive-definite matrices.
Rishworth, Susan K
2012-01-01
The purpose of this historical article is to demonstrate, as the biography of Verina Morton Jones, MD, is uncovered, the difficulties inherent in researching original source material on the lives of 19th- and early 20th-century African American physicians as well as the great benefits derived from doing this research. The procedures used include basic archival research and close examination of published materials about her in the past, in conjunction with oral history. Original correspondence from Dr Morton Jones to her niece and nephew is used to illustrate events in her life and the thoughts and attitudes she expressed. Some of these thoughts and attitudes reflect those current situations in which African Americans found themselves, and others are quite unique, no doubt owing to her privileged position in the African American community. The principle conclusions reached include the great benefits derived from doing this kind of research, as difficult and time-consuming as that may be, with the enhanced knowledge and appreciation of the heritage of African American physicians, and insights into American social history during this period.
Development of a protocol to measure iron-55 in solid matrices in the environment
International Nuclear Information System (INIS)
Augeray, Céline; Magalie, Mouton; Nathalie, Broustet; Marie-France, Perdereau; Chloé, Laconici; Jeanne, Loyen; Corinne, Fayolle; Jean-Louis, Picolo
2015-01-01
The development of metrology of iron-55 in low-level radioactivity in environmental solid matrices was realised for conducting radioecological studies. A protocol was developed based on the adaptation of existing methods for the purification of iron-55 with selective chromatographic resin, which was then measured with liquid scintillation. The loss attached treatment chemical steps were quantified with elemental iron by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The tests were used to define the iron retention capacity of selective chromatographic resin, a key element in chemical treatment, and test sample size needed to reach the detection limit of 30 Bq kg −1 dry. The solid samples were analysed with the developed protocol. The activities obtained from iron-55 were below the detection limit of 30 Bq kg −1 dry. - Highlights: • To obtain the desired detection limit in environmental solid matrices, the choice of method was realised. • A protocol was thus developed with our resources to obtain a 30 Bq kg-1 dry detection limit. • The optimisation of the operating conditions is described and the activities obtained are presented
Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging
Directory of Open Access Journals (Sweden)
Zuzana eBurdikova
2015-03-01
Full Text Available Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g. pH, redox potential due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM. In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.
Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging.
Burdikova, Zuzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G; Panek, Jiri; Auty, Mark A E; Periasamy, Ammasi; Sheehan, Jeremiah J
2015-01-01
Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM). In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.
Indiana Jones ja kristallpealuu kuningriik / Jaanus Noormets
Noormets, Jaanus
2008-01-01
Steven Spielbergi neljas Indiana Jones'i film Harrison Fordiga nimiosas "Indiana Jones ja kristallpealuu kuningriik" ("Indiana Jones and the Kingdom of the Crystal Skull") : Ameerika Ühendriigid 2008
An experimental device for measurement of gas permeation in solid matrices
International Nuclear Information System (INIS)
De Salve, M.; Mazzi, E.; Zucchetti, M.
1996-01-01
The inventory in and the permeation through fusion reactor structures of hydrogen and its isotopes play an important role in the machine operation, evolution of material properties, and safety. An experimental and research activity for the determination of permeability (and derived parameters) of gases in solid matrices is described. It uses a gas permeation method, that basically consists in the measure of the time evolution of the gas pressure in a chamber in which vacuum has been previously made (downstream volume). This chamber is separated from another one, full of the gas in exam (upstream volume), by means of a membrane of the material under study. The experimental installation is described. The first stage of the experimental activity has dealt with the set-up of the device, the volume calibration, and the definition of the parameters range for which the installation can give reliable measurements. The subsequent stage of the activity has consisted in the measurement of the permeability, and then of the diffusion coefficient, of nitrogen in some materials at room temperature. Concurrently with the experimental activity, a model has been set-up and implemented in a computer code: this code permits to evaluate the time evolution of the pressure in the downstream chamber. With this code, using the measured parameters, the time evolution of the pressure experimentally measured has been satisfactorily reproduced. (author)
Tagging, Encoding, and Jones Optimality
DEFF Research Database (Denmark)
Danvy, Olivier; López, Pablo Ernesto Martínes
2003-01-01
A partial evaluator is said to be Jones-optimal if the result of specializing a self-interpreter with respect to a source program is textually identical to the source program, modulo renaming. Jones optimality has already been obtained if the self-interpreter is untyped. If the selfinterpreter...... is typed, however, residual programs are cluttered with type tags. To obtain the original source program, these tags must be removed. A number of sophisticated solutions have already been proposed. We observe, however, that with a simple representation shift, ordinary partial evaluation is already Jones...
Stabiilne Ashley Jones / Svea Suvi
Suvi, Svea
2006-01-01
Ameerika teleseriaali "Vaprad ja ilusad" ("The Bold and the Beautiful") osatäitja Ashley Jones (Bridget Forrester). Sama artikkel pealkirjaga "Uus Bridget" : Nädal, 30. jan. 2006, nr. 4, lk. 12 : ill
International Nuclear Information System (INIS)
Mantero Cabrera, J.
2014-01-01
: In radiological emergencies it's necessary a fast response from the laboratories in the quantification of certain radionuclides, in order to take decisions. In these cases, is the reaction time the key parameter to consider (without neglecting the quality of the measurement). In this work, it is shown a method for aqueous matrices that generates Pu and Am isotopes sources in one single day of work, to be measured subsequently by alpha spectrometry. The developed methodology has been validated through its application to reference samples and also taking part intercom- parison exercises, having in both cases, satisfactory results. This way, we check the validity of this fast method that let us generate in 24 hours (since the sample arrives our laboratory), one measurement with a Minimun Detectable Activity (MDA) of about 0.004Bq/L for Pu and Am isotopes in liquid matrices. [es
Tagging, Encoding, and Jones Optimality
DEFF Research Database (Denmark)
Danvy, Olivier; Lopez, Pablo E. Martinez
2003-01-01
A partial evaluator is said to be Jones-optimal if the result of specializing a self-interpreter with respect to a source program is textually identical to the source program, modulo renaming. Jones optimality has already been obtained if the self-interpreter is untyped. If the selfinterpreter...... is typed, however, residual programs are cluttered with type tags. To obtain the original source program, these tags must be removed. A number of sophisticated solutions have already been proposed. We observe, however, that with a simple representation shift, ordinary partial evaluation is already Jones......-optimal, modulo an encoding. The representation shift amounts to reading the type tags as constructors for higherorder abstract syntax. We substantiate our observation by considering a typed self-interpreter whose input syntax is higher-order. Specializing this interpreter with respect to a source program yields...
Measuring and modelling of diffusivities in carbohydrate-rich matrices during thin film drying
Perdana, J.A.; Sman, van der R.G.M.; Fox, M.B.; Boom, R.M.; Schutyser, M.A.I.
2014-01-01
Knowledge about moisture diffusivity in solid matrices is a key for understanding drying behaviour of for example probiotic or enzymatic formulations. This paper presents an experimental procedure to determine moisture diffusivity on the basis of thin film drying and gravimetric analysis in a
A new approach to radiative transfer theory using Jones's vectors. I
International Nuclear Information System (INIS)
Fymat, A.L.; Vasudevan, R.
1975-01-01
Radiative transfer of partially polarized radiation in an anisotropically scattering, inhomogeneous atmosphere containing arbitrary polydispersion of particles is described using Jones's amplitude vectors and matrices. This novel approach exploits the close analogy between the quantum mechanical states of spin 1/2 systems and the polarization states of electromagnetic radiation described by Jones's vector, and draws on the methodology of such spin 1/2 systems. The complete equivalence between the transport equation for Jones's vectors and the classical radiative transfer equation for Stokes's intensity vectors is demonstrated in two independent ways after deriving the transport equations for the polarization coherency matrices and for the quaternions corresponding to the Jones's vectors. A compact operator formulation of the theory is provided, and used to derive the necessary equations for both a local and a global description of the transport of Jones's vectors. Lastly, the integro-differential equations for the amplitude reflection and transmission matrices are derived, and related to the usual corresponding equations. The present formulation is the most succinct and the most convenient one for both theoretical and experimental studies. It yields a simpler analysis than the classical formulation since it reduces by a factor of two the dimensionality of transfer problems. It preserves information on phases, and thus can be used directly across the entire electromagnetic spectrum without any further conversion into intensities. (Auth.)
The Jones Family's Culture of Literacy
Johnson, Amy Suzanne
2010-01-01
This article considers the uses of literacy within the Jones family (all names are pseudonyms), an African American family who lives in the rural South of the United States. Drawing on life history data with three women in the Jones family--Harriet Jones (grandmother), Sally Harris (mother), and Lola Harris (granddaughter)--the author traces how…
Do America's Schools Need a "Dow Jones Index"?
Guthrie, James W.
1994-01-01
Discusses America's fascination with measuring education. Discusses the advantages and disadvantages of a single composite indicator, akin to the Dow Jones Index, to measure educational productivity. Describes progress in the California State Education Department in developing a composite index to measure student performance. (SR)
International Nuclear Information System (INIS)
Harrison, Jennifer J.; Zawadzki, Atun; Chisari, Robert; Wong, Henri K.Y.
2011-01-01
A technique for the isolation of thorium (Th), plutonium (Pu), americium (Am), uranium (U) and strontium (Sr) isotopes from various environmental matrices has been adapted from a previously published method specific to water samples (). Separation and isolation of the various elemental fractions from a single sub-sample is possible, thereby eliminating the need for multiple analyses. The technique involves sample dissolution, concentration via calcium phosphate co-precipitation, rapid column extraction using TEVA TM , TRU TM and Sr-Spec TM resin cartridges, alpha spectrometry for Th, Pu, U and Am and Cerenkov counting for Sr. Various standard reference materials were analysed and chemical yields are in the range of 70-80% for Th, Am, U and Sr and 50-60% for Pu. Sample sizes of up to 10 L for water, 5 g for dry soil and sediment and 10 g for dry vegetation and seaweed can be processed using this technique.
Energy Technology Data Exchange (ETDEWEB)
Harrison, Jennifer J., E-mail: jennifer.harrison@ansto.gov.au [Australian Nuclear Science and Technology Organisation, PMB 1, Menai NSW 2234 (Australia); Zawadzki, Atun; Chisari, Robert; Wong, Henri K.Y. [Australian Nuclear Science and Technology Organisation, PMB 1, Menai NSW 2234 (Australia)
2011-10-15
A technique for the isolation of thorium (Th), plutonium (Pu), americium (Am), uranium (U) and strontium (Sr) isotopes from various environmental matrices has been adapted from a previously published method specific to water samples (). Separation and isolation of the various elemental fractions from a single sub-sample is possible, thereby eliminating the need for multiple analyses. The technique involves sample dissolution, concentration via calcium phosphate co-precipitation, rapid column extraction using TEVA{sup TM}, TRU{sup TM} and Sr-Spec{sup TM} resin cartridges, alpha spectrometry for Th, Pu, U and Am and Cerenkov counting for Sr. Various standard reference materials were analysed and chemical yields are in the range of 70-80% for Th, Am, U and Sr and 50-60% for Pu. Sample sizes of up to 10 L for water, 5 g for dry soil and sediment and 10 g for dry vegetation and seaweed can be processed using this technique.
Measurements of matric and water potentials in unsaturated tuff at Yucca Mountain, Nevada
International Nuclear Information System (INIS)
Thamir, F.; McBride, C.M.
1985-01-01
Two types of instruments were installed in a borehole in order to monitor matric and water potentials of various hydrogeologic units consisting of tuff. The borehole was drilled as part of a study to provide information to the US Department of Energy for their use in evaluating Yucca Mountain, Nevada, for a repository for high-level radioactive waste. Heat-dissipation probes were used to monitor matric potentials and thermocouple psychrometers were used to monitor water potentials. Two major concerns regarding the use of these instruments in deep boreholes are: (1) the effect of length of the lead wires, and (2) the inability to recalibrate the instruments after installation. The length of the lead wire contributes to the source resistance and lead capacitance, which affects the signal settling time. Both instruments tested proved to be insensitive to lead-wire length, except when connected to smaller input-impedance data loggers. Thermocouple wires were more sensitive than heat-dissipation probe wires because of their greater resistance and quality of voltmeters used. Two thermocouple psychrometers were installed at every instrument station for backup and verification of data, because the instruments could not be recalibrated in situ. Multiple scanning rather than single-point scanning of the evaporation curve of a thermocouple psychrometer could give more reliable data, especially in differentiating between very wet and very dry environments. An isolated power supply needs to be used for each heat dissipation probe rather than a single power supply for a group of probes to avoid losing data from all probes when one probe malfunctions. This type of system is particularly desirable if the site is unattended by an operator for as long as a month. 20 refs., 13 figs., 2 tabs
Gamma spectrometric validation of measurements test of radionuclides in food matrices
International Nuclear Information System (INIS)
Rosa, Mychelle M.L.; Custodio, Luis G.; Bonifacio, Rodrigo L.; Taddei, Maria Helena T.
2013-01-01
In a testing laboratory the quality system encompasses a set of activities planned and systematic, which ensure the traceability process of an analysis, which is based on the standards NBR ISO/TEC 17025. With the need for analysis of radionuclides in food products to meet the requirements of import and export, accreditation of testing on this standard becomes increasingly necessary. The Gamma Spectrometry is a technique used for direct determination of radionuclides in different matrices, among them the food, being possible the simultaneous determination of different radionuclides in the same sample without the need for a chemical separation. In the process of Accreditation the methodology validation is an important step that includes testing accuracy, traceability, linearity and recovery. This paper describes the procedures used to validate the assay for determining radionuclides using gamma spectrometry in food. These procedures were performed through analysis of a certificated reference material by the International Atomic Energy Agency (IAEA Soil 327), analysis of samples of milk powder prepared from the doping with certified liquid standards also by the results obtained in the participation of tests of proficiency in analysis of environmental samples. (author)
Nuclear-magnetic-resonance quantum calculations of the Jones polynomial
International Nuclear Information System (INIS)
Marx, Raimund; Spoerl, Andreas; Pomplun, Nikolas; Schulte-Herbrueggen, Thomas; Glaser, Steffen J.; Fahmy, Amr; Kauffman, Louis; Lomonaco, Samuel; Myers, John M.
2010-01-01
The repertoire of problems theoretically solvable by a quantum computer recently expanded to include the approximate evaluation of knot invariants, specifically the Jones polynomial. The experimental implementation of this evaluation, however, involves many known experimental challenges. Here we present experimental results for a small-scale approximate evaluation of the Jones polynomial by nuclear magnetic resonance (NMR); in addition, we show how to escape from the limitations of NMR approaches that employ pseudopure states. Specifically, we use two spin-1/2 nuclei of natural abundance chloroform and apply a sequence of unitary transforms representing the trefoil knot, the figure-eight knot, and the Borromean rings. After measuring the nuclear spin state of the molecule in each case, we are able to estimate the value of the Jones polynomial for each of the knots.
Guts of surfaces and the colored Jones polynomial
Futer, David; Purcell, Jessica
2013-01-01
This monograph derives direct and concrete relations between colored Jones polynomials and the topology of incompressible spanning surfaces in knot and link complements. Under mild diagrammatic hypotheses, we prove that the growth of the degree of the colored Jones polynomials is a boundary slope of an essential surface in the knot complement. We show that certain coefficients of the polynomial measure how far this surface is from being a fiber for the knot; in particular, the surface is a fiber if and only if a particular coefficient vanishes. We also relate hyperbolic volume to colored Jones polynomials. Our method is to generalize the checkerboard decompositions of alternating knots. Under mild diagrammatic hypotheses, we show that these surfaces are essential, and obtain an ideal polyhedral decomposition of their complement. We use normal surface theory to relate the pieces of the JSJ decomposition of the complement to the combinatorics of certain surface spines (state graphs). Since state graphs have p...
Forefoot Adduction Is a Risk Factor for Jones Fracture.
Fleischer, Adam E; Stack, Rebecca; Klein, Erin E; Baker, Jeffrey R; Weil, Lowell; Weil, Lowell Scott
Jones fractures are among the most common fractures of the foot; however, much remains unknown about their etiology. The purpose of the present study was to further examine the risk factors of forefoot and hindfoot alignment on Jones fractures using an epidemiologic study design. We used a retrospective, matched, case-control study design. Cases consisted of patients with acute, isolated Jones fractures confirmed on plain film radiographs seen at our institute from January 2009 to December 2013. Patients presenting with pain unrelated to metatarsal fractures served as controls. Controls were matched to cases by age (±2 years), gender, and year of presentation. Weightbearing foot radiographs were assessed for 13 angular relationships by a single rater. Conditional multivariable logistic regression was used to identify important risk factors. Fifty patients with acute Jones fractures and 200 controls were included. The only significant variables in the final multivariable model were the metatarsus adductus angle (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.08 to 1.25) and fourth/fifth intermetatarsal angle (OR 0.69, 95% CI 0.57 to 0.83)-both measures of static forefoot adduction. The presence of metatarsus adductus (defined as >15°) on foot radiographs was associated with a 2.4 times greater risk of a Jones fracture (adjusted OR 2.4, 95% CI 1.2 to 4.8). We have concluded that the risk of Jones fracture increases with an adducted forefoot posture. In our population, which consisted primarily of patients presenting after a fall (10 of 50; 20%) or misstep/inversion injury (19 of 50; 38%), the hindfoot alignment appeared to be a less important factor. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
Burns, Malcolm; Wiseman, Gordon; Knight, Angus; Bramley, Peter; Foster, Lucy; Rollinson, Sophie; Damant, Andrew; Primrose, Sandy
2016-01-07
Following a report on a significant amount of horse DNA being detected in a beef burger product on sale to the public at a UK supermarket in early 2013, the Elliott report was published in 2014 and contained a list of recommendations for helping ensure food integrity. One of the recommendations included improving laboratory testing capacity and capability to ensure a harmonised approach for testing for food authenticity. Molecular biologists have developed exquisitely sensitive methods based on the polymerase chain reaction (PCR) or mass spectrometry for detecting the presence of particular nucleic acid or peptide/protein sequences. These methods have been shown to be specific and sensitive in terms of lower limits of applicability, but they are largely qualitative in nature. Historically, the conversion of these qualitative techniques into reliable quantitative methods has been beset with problems even when used on relatively simple sample matrices. When the methods are applied to complex sample matrices, as found in many foods, the problems are magnified resulting in a high measurement uncertainty associated with the result which may mean that the assay is not fit for purpose. However, recent advances in the technology and the understanding of molecular biology approaches have further given rise to the re-assessment of these methods for their quantitative potential. This review focuses on important issues for consideration when validating a molecular biology assay and the various factors that can impact on the measurement uncertainty of a result associated with molecular biology approaches used in detection of food fraud, with a particular focus on quantitative PCR-based and proteomics assays.
STS-98 Crew Interview: Tom Jones
2001-01-01
The STS-98 Mission Specialist Tom Jones is seen being interviewed. He answers questions about his inspiration to become an astronaut, his career path, and his training. He gives details on the mission's goals and significance, and the payload and hardware it brings to the International Space Station (ISS). Mr. Jones discusses his role in the mission's spacewalks and activities.
Krylov, Piotr
2017-01-01
This monograph is a comprehensive account of formal matrices, examining homological properties of modules over formal matrix rings and summarising the interplay between Morita contexts and K theory. While various special types of formal matrix rings have been studied for a long time from several points of view and appear in various textbooks, for instance to examine equivalences of module categories and to illustrate rings with one-sided non-symmetric properties, this particular class of rings has, so far, not been treated systematically. Exploring formal matrix rings of order 2 and introducing the notion of the determinant of a formal matrix over a commutative ring, this monograph further covers the Grothendieck and Whitehead groups of rings. Graduate students and researchers interested in ring theory, module theory and operator algebras will find this book particularly valuable. Containing numerous examples, Formal Matrices is a largely self-contained and accessible introduction to the topic, assuming a sol...
International Nuclear Information System (INIS)
Frechou, C.
2000-01-01
129 I, is a natural long-lived isotope, with a half-life of 15,7 million years, also artificially produced in nuclear power plant. It is then released in the liquid and gaseous effluents of the nuclear fuel reprocessing plants. 129 I is integrated in all biological compartments at different activity levels, depending on their distance from the emission source and their ability to metabolize iodine. Performances of the different 129 I and 129 I/ 127 I measurement techniques available: Radiochemical Neutron Activation Analysis, Accelerator Mass Spectrometry, direct γ-X spectrometry and liquid scintillation were evaluated. Associated radiochemical preparation steps of the two first techniques were optimized and adapted to the characteristics of the major environmental matrices. In a first step, the radiochemical protocols were developed and validated. In a second step, intercomparison exercises have been lead on various environmental samples presenting different 129 I activity levels. They showed the good agreement between the results given by the three techniques on different environmental matrices with activities between 0,2 and 200 Bq.kg -1 dry weight. As a conclusion, a methodology for the measurement of 129 I and 129 I/ 127 I ratio in environmental samples is proposed. It includes a decisional diagram taking into account the characteristics of the matrices, the detection limits and the answer delay. A study on the losses of 129 I during the calcination of an algae was lead by direct γ-X spectrometry and application studies were made to measure 129 I levels in different biological compartments issued from various locations: 129 I activity interspecific variation in different species of seaweeds from the French channel coast under the relative influence of La Hague, 129 I levels in bovine thyroids from the Cotentin area and 129 I in vegetal samples collected around the nuclear reprocessing plant of Marcoule. (author)
Averaging operations on matrices
Indian Academy of Sciences (India)
2014-07-03
Jul 3, 2014 ... Role of Positive Definite Matrices. • Diffusion Tensor Imaging: 3 × 3 pd matrices model water flow at each voxel of brain scan. • Elasticity: 6 × 6 pd matrices model stress tensors. • Machine Learning: n × n pd matrices occur as kernel matrices. Tanvi Jain. Averaging operations on matrices ...
Passive active neutron radioassay measurement uncertainty for combustible and glass waste matrices
International Nuclear Information System (INIS)
Blackwood, L.G.; Harker, Y.D.; Meachum, T.R.; Yoon, Woo Y.
1997-01-01
Using a modified statistical sampling and verification approach, total uncertainty of INEL's Passive Active Neutron (PAN) radioassay system was evaluated for combustible and glass content codes. Waste structure and content of 100 randomly selected drums in each the waste categories were computer modeled based on review of real-time radiography video tapes. Specific quantities of Pu were added to the drum models according to an experimental design. These drum models were then submitted to the Monte Carlo Neutron Photon code processing and subsequent calculations to produce simulated PAN system measurements. The reported Pu masses from the simulation runs were compared with the corresponding input masses. Analysis of the measurement errors produced uncertainty estimates. This paper presents results of the uncertainty calculations and compares them to previous reported results obtained for graphite waste
Zhang, Baohua; Han, Mei; Tan, Shuping; De Yang, Fu; Tan, Yunlong; Jiang, Shurong; Zhang, Xiangyang; Huang, Xu-Feng
2017-01-01
Using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), previous study showed significant gender differences for cognitive deficits in immediate and delayed memory in schizophrenia patients. However, RBANS does not include reasoning and problem solving, and social cognition. These cognitive functions can significantly affect the outcomes and daily life in patients. This study examined the gender differences of cognition using the measurement and treatment research to...
Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging
Zuzana eBurdikova; Zdenek eSvindrych; Jan ePala; Cian eHickey; Martin G. Wilkinson; Jiri ePanek; Mark A. E. Auty; Ammasi ePeriasamy; Jeremiah J. Sheehan
2015-01-01
Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a signi...
Measurement of pH micro-heterogeneity in natural cheese matrices by flourescence lifetime imaging
Burdikova, Suzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G.; Panek, Jiri; Auty, Mark A.E.; Periasamy, Ammasi; Sheehan, Jeremiah J.
2015-01-01
peer-reviewed Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level ther...
High-Dimensional Multivariate Repeated Measures Analysis with Unequal Covariance Matrices
Harrar, Solomon W.; Kong, Xiaoli
2015-01-01
In this paper, test statistics for repeated measures design are introduced when the dimension is large. By large dimension is meant the number of repeated measures and the total sample size grow together but either one could be larger than the other. Asymptotic distribution of the statistics are derived for the equal as well as unequal covariance cases in the balanced as well as unbalanced cases. The asymptotic framework considered requires proportional growth of the sample sizes and the dimension of the repeated measures in the unequal covariance case. In the equal covariance case, one can grow at much faster rate than the other. The derivations of the asymptotic distributions mimic that of Central Limit Theorem with some important peculiarities addressed with sufficient rigor. Consistent and unbiased estimators of the asymptotic variances, which make efficient use of all the observations, are also derived. Simulation study provides favorable evidence for the accuracy of the asymptotic approximation under the null hypothesis. Power simulations have shown that the new methods have comparable power with a popular method known to work well in low-dimensional situation but the new methods have shown enormous advantage when the dimension is large. Data from Electroencephalograph (EEG) experiment is analyzed to illustrate the application of the results. PMID:26778861
Bacterial Biofilms in Jones Tubes.
Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A
To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.
Gras, Ronda; Luong, Jim; Shellie, Robert A
2015-11-17
We introduce a technique for the direct measurement of elemental mercury in light hydrocarbons such as natural gas. We determined elemental mercury at the parts-per-trillion level with high precision [photometric detection (GC-UV) at 254 nm. Our approach requires a small sample volume (1 mL) and does not rely on any form of sample preconcentration. The GC-UV separation employs an inert divinylbenzene porous layer open tubular column set to separate mercury from other components in the sample matrix. We incorporated a 10-port gas-sampling valve in the GC-UV system, which enables automated sampling, as well as back flushing capability to enhance system cleanliness and sample throughput. Total analysis time is 98% over this range.
Estimating Depolarization with the Jones Matrix Quality Factor
Hilfiker, James N.; Hale, Jeffrey S.; Herzinger, Craig M.; Tiwald, Tom; Hong, Nina; Schöche, Stefan; Arwin, Hans
2017-11-01
Mueller matrix (MM) measurements offer the ability to quantify the depolarization capability of a sample. Depolarization can be estimated using terms such as the depolarization index or the average degree of polarization. However, these calculations require measurement of the complete MM. We propose an alternate depolarization metric, termed the Jones matrix quality factor, QJM, which does not require the complete MM. This metric provides a measure of how close, in a least-squares sense, a Jones matrix can be found to the measured Mueller matrix. We demonstrate and compare the use of QJM to other traditional calculations of depolarization for both isotropic and anisotropic depolarizing samples; including non-uniform coatings, anisotropic crystal substrates, and beetle cuticles that exhibit both depolarization and circular diattenuation.
On an entanglement measure in quantum physics: geometric aspects of density matrices
Energy Technology Data Exchange (ETDEWEB)
Franco, D.H.T.; Cima, O.M.D.; Silva, S.L.L. [Universidade Federal de Vicosa - UFV, MG (Brazil)
2013-07-01
Full text: The study of entanglement would be justified simply by its theoretical interest, given that this phenomenon since its inception, casts important questions on the basis of a fundamental character of the building that is quantum mechanics. Moreover,the entanglement has been an indispensable ingredient in the field of quantum computing (processing and transmission of information) and also in condensed matter physics (in the understanding of quantum phase transitions). In this work we present and discuss some ways to characterize both quantitatively and qualitatively entanglement. In particular, we aim to introduce and apply the method developed by Dahl et al. [1]. This method determines the distance from the nearest separable state of the state of interest, since this distance may be used to measure the degree of entanglement of the system of interest. We consider a separable state by state with only classical correlations, i.e a non-entangled, non-separable states which are said entangled. Quantum entanglement has been shown, also, a very useful tool in the study of superconductivity. We aim to study the relationship between the phase transition of superconductivity and the spin entanglement of the Cooper pairs. [1] G. Dahl, J. M. Leinaas, J. Myrheim, and E. Ovrum. Linear Algebra and its application, 420:711-725, 2007 (author)
Directory of Open Access Journals (Sweden)
Eliades J.
2012-04-01
Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.
He, Hao; Bustillo, Juan; Du, Yuhui; Yu, Qingbao; Jones, Thomas R.; Jiang, Tianzi; Calhoun, Vince D.; Sui, Jing
2015-03-01
The cognitive deficits of schizophrenia are largely resistant to current treatment, and are thus a life-long burden to patients. The MATRICS consensus cognitive battery (MCCB) provides a reliable and valid assessment of cognition across a comprehensive set of cognitive domains for schizophrenia. In resting-state fMRI, functional connectivity associated with MCCB has not yet been examined. In this paper, the interrelationships between MCCB and the abnormalities seen in two types of functional measures from resting-state fMRI—fractional amplitude of low frequency fluctuations (fALFF) and functional network connectivity (FNC) maps were investigated in data from 47 schizophrenia patients and 50 age-matched healthy controls. First, the fALFF maps were generated and decomposed by independent component analysis (ICA), and then the component showing the highest correlation with MCCB composite scores was selected. Second, the whole brain was separated into functional networks by group ICA, and the FNC maps were calculated. The FNC strengths with most significant correlations with MCCB were displayed and spatially overlapped with the fALFF component of interest. It demonstrated increased cognitive performance associated with higher fALFF values (intensity of regional spontaneous brain activity) in prefrontal regions, inferior parietal lobe (IPL) but lower ALFF values in thalamus, striatum, and superior temporal gyrus (STG). Interestingly, the FNC showing significant correlations with MCCB were in well agreement with the activated regions with highest z-values in fALFF component. Our results support the view that functional deficits in distributed cortico-striato-thalamic circuits and inferior parietal lobe may account for several aspects of cognitive impairment in schizophrenia.
Birefringence of cellotape: Jones representation and experimental analysis
International Nuclear Information System (INIS)
Belendez, Augusto; Frances, Jorge; Neipp, Cristian; Fernandez, Elena
2010-01-01
In this paper, we analyse a simple experiment to study the effects of polarized light. A simple optical system composed of a polarizer, a retarder (cellotape) and an analyser is used to study the effect on the polarization state of the light which impinges on the setup. The optical system is characterized by means of a Jones matrix, and a simple procedure based on Jones vectors is used to obtain an expression for the intensity after the light passes through the optical system. The light intensity is measured by a photodetector and the expression obtained theoretically is experimentally validated. By fitting the experimental intensity data, the value of the retardation introduced by the retarder can also be obtained.
Inverse m-matrices and ultrametric matrices
Dellacherie, Claude; San Martin, Jaime
2014-01-01
The study of M-matrices, their inverses and discrete potential theory is now a well-established part of linear algebra and the theory of Markov chains. The main focus of this monograph is the so-called inverse M-matrix problem, which asks for a characterization of nonnegative matrices whose inverses are M-matrices. We present an answer in terms of discrete potential theory based on the Choquet-Deny Theorem. A distinguished subclass of inverse M-matrices is ultrametric matrices, which are important in applications such as taxonomy. Ultrametricity is revealed to be a relevant concept in linear algebra and discrete potential theory because of its relation with trees in graph theory and mean expected value matrices in probability theory. Remarkable properties of Hadamard functions and products for the class of inverse M-matrices are developed and probabilistic insights are provided throughout the monograph.
Armstrong, Jenna L; Dills, Russell L; Yu, Jianbo; Yost, Michael G; Fenske, Richard A
2014-01-01
A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.
Dow Jones tugevdab oma koostist / Virge Lahe
Lahe, Virge
2008-01-01
USA tööstusettevõtteid koondav indeks Dow Jones vahetab nimekirjast välja kaks firmat ning lisab finants- ja kütusesektori osakaalu suurendamiseks Bank of America ja Chevroni. Vt. samas: Dow Jonesi tööstuskeskmisse lisandumine pole aktsiatele tiibu andnud; Dow Jonesi tööstuskeskmine
Magnetoelectric Jones spectroscopy of alkali atoms
International Nuclear Information System (INIS)
Chernushkin, V V; Mironova, P V; Ovsiannikov, V D
2008-01-01
The Jones effect in a medium of free atoms exposed to static electric and magnetic fields is a useful tool for determining details of an atomic structure. For atoms in their nS ground states irradiated by a monochromatic wave in resonance with a single-photon transition to an n' D state, the bilinear Jones effect is not shaded by the quadratic Kerr and Cotton-Mouton effects, nor by the linear in magnetic field Faraday effect. The position and shape of the amplitude resonance may provide information on spectroscopic properties of atomic levels. We generalize equations for the Jones-effect amplitude to the case of a doublet structure of energy levels and calculate corresponding parameters for alkali atoms. General equations are derived for the amplitude dependence on the relative orientation of the static electric and magnetic fields and on the angle between the static field and the major axis of the wave polarization vector. These equations demonstrate explicitly that the three bilinear-in-static-fields optical birefringence effects-(i) the Jones birefringence (in parallel fields), (ii) the linear birefringence and (iii) the directional birefringence (the last two in perpendicular fields)-correspond to particular cases of the bilinear-in-static-fields correction to the amplitude of Rayleigh forward scattering
Evaporation of Lennard-Jones fluids.
Cheng, Shengfeng; Lechman, Jeremy B; Plimpton, Steven J; Grest, Gary S
2011-06-14
Evaporation and condensation at a liquid/vapor interface are ubiquitous interphase mass and energy transfer phenomena that are still not well understood. We have carried out large scale molecular dynamics simulations of Lennard-Jones (LJ) fluids composed of monomers, dimers, or trimers to investigate these processes with molecular detail. For LJ monomers in contact with a vacuum, the evaporation rate is found to be very high with significant evaporative cooling and an accompanying density gradient in the liquid domain near the liquid/vapor interface. Increasing the chain length to just dimers significantly reduces the evaporation rate. We confirm that mechanical equilibrium plays a key role in determining the evaporation rate and the density and temperature profiles across the liquid/vapor interface. The velocity distributions of evaporated molecules and the evaporation and condensation coefficients are measured and compared to the predictions of an existing model based on kinetic theory of gases. Our results indicate that for both monatomic and polyatomic molecules, the evaporation and condensation coefficients are equal when systems are not far from equilibrium and smaller than one, and decrease with increasing temperature. For the same reduced temperature T/T(c), where T(c) is the critical temperature, these two coefficients are higher for LJ dimers and trimers than for monomers, in contrast to the traditional viewpoint that they are close to unity for monatomic molecules and decrease for polyatomic molecules. Furthermore, data for the two coefficients collapse onto a master curve when plotted against a translational length ratio between the liquid and vapor phase.
Melting of 2D monatomic solids: Lennard-Jones system
International Nuclear Information System (INIS)
Yi, Y.M.; Guo, Z.C.
1987-09-01
The Lennard-Jones interaction has been introduced into the Collins mix lattice of 2D liquids. By means of rigorous calculation of the total potential and the free area, the Gibbs functions for 2D liquid and solid have been derived. The melting line obtained from the phase transition equation agrees quite well with the result of recent computer simulation experiments. The obtained reduced temperature of the triple point T* t =0.438 agrees with the data measured in experiments of some inert gas monolayers adsorbed on graphite as well as in computer simulation experiments. (author). 11 refs, 7 figs, 3 tabs
A response to Dodds and Jones.
Purdy, Laura M
1989-01-01
In response to "Surrogacy and Autonomy," by Susan Dodds and Karen Jones in this issue of Bioethics, the author concedes that only a surrogacy practice stringently regulated by good counseling, escape clauses for pregnant women, and the prohibition of profit-making agencies will save women from exploitation, but she objects to singling out women for paternalistic "protection against themselves," and to defending women's autonomy to the extent of their right to behave in ways known to harm a fetus. Dodds and Jones' concerns about attitudes toward women, genetic bias, the concept of children as property, and the harm principle generated by surrogacy contracts are answered with arguments for why surrogacy should not be illegal.
Introduction into Hierarchical Matrices
Litvinenko, Alexander
2013-12-05
Hierarchical matrices allow us to reduce computational storage and cost from cubic to almost linear. This technique can be applied for solving PDEs, integral equations, matrix equations and approximation of large covariance and precision matrices.
Introduction into Hierarchical Matrices
Litvinenko, Alexander
2013-01-01
Hierarchical matrices allow us to reduce computational storage and cost from cubic to almost linear. This technique can be applied for solving PDEs, integral equations, matrix equations and approximation of large covariance and precision matrices.
Thermal decay of Lennard-Jones clusters
International Nuclear Information System (INIS)
Garzon, I.L.; Avalos-Borja, M.
1989-01-01
The decay mechanisms of argon clusters have been studied using molecular dynamics simulations and Lennard-Jones potentials. Heating up processes were applied to Ar 13 up to temperatures in the melting region. In this range of temperatures large fluctuations in the mean kinetic energy of the system are present and a sequential evaporation is observed. The thermal decay of these aggregates occurs in a time scale of nanoseconds. (orig.)
Evaporation of Lennard-Jones clusters
International Nuclear Information System (INIS)
Roman, C.E.; Garzon, I.L.
1991-01-01
Extensive molecular dynamics simulations have been done to study the evaporation of a 13-atom Lennard-Jones cluster. The survival probability and the evaporative lifetime are calculated as a function of the cluster total energy from a classical trajectory analysis. The results are interpreted in terms of the RRK theory of unimolecular dissociation. The calculation of the binding energy of the evaporated species from the evaporation rate and the average kinetic energy release is discussed. (orig.)
Ushenko, V. O.; Koval, G. D.; Ushenko, Yu. O.; Pidkamin, L. Y.; Sidor, M. I.; Vanchuliak, O.; Motrich, A. V.; Gorsky, M. P.; Meglinskiy, I.
2017-09-01
The paper presents the results of Jones-matrix mapping of uterine wall histological sections with second-degree and third-degree endometriosis. The technique of experimental measurement of coordinate distributions of the modulus and phase values of Jones matrix elements is suggested. Within the statistical and cross-correlation approaches the modulus and phase maps of Jones matrix images of optically thin biological layers of polycrystalline films of plasma and cerebrospinal fluid are analyzed. A set of objective parameters (statistical and generalized correlation moments), which are the most sensitive to changes in the phase of anisotropy, associated with the features of polycrystalline structure of uterine wall histological sections with second-degree and third-degree endometriosis are determined.
Matrices and linear transformations
Cullen, Charles G
1990-01-01
""Comprehensive . . . an excellent introduction to the subject."" - Electronic Engineer's Design Magazine.This introductory textbook, aimed at sophomore- and junior-level undergraduates in mathematics, engineering, and the physical sciences, offers a smooth, in-depth treatment of linear algebra and matrix theory. The major objects of study are matrices over an arbitrary field. Contents include Matrices and Linear Systems; Vector Spaces; Determinants; Linear Transformations; Similarity: Part I and Part II; Polynomials and Polynomial Matrices; Matrix Analysis; and Numerical Methods. The first
Freezing of Lennard-Jones-type fluids
International Nuclear Information System (INIS)
Khrapak, Sergey A.; Chaudhuri, Manis; Morfill, Gregor E.
2011-01-01
We put forward an approximate method to locate the fluid-solid (freezing) phase transition in systems of classical particles interacting via a wide range of Lennard-Jones-type potentials. This method is based on the constancy of the properly normalized second derivative of the interaction potential (freezing indicator) along the freezing curve. As demonstrated recently it yields remarkably good agreement with previous numerical simulation studies of the conventional 12-6 Lennard-Jones (LJ) fluid [S.A.Khrapak, M.Chaudhuri, G.E.Morfill, Phys. Rev. B 134, 052101 (2010)]. In this paper, we test this approach using a wide range of the LJ-type potentials, including LJ n-6 and exp-6 models, and find that it remains sufficiently accurate and reliable in reproducing the corresponding freezing curves, down to the triple-point temperatures. One of the possible application of the method--estimation of the freezing conditions in complex (dusty) plasmas with ''tunable'' interactions--is briefly discussed.
Return to Play and Performance After Jones Fracture in National Basketball Association Athletes
Begly, John P.; Guss, Michael; Ramme, Austin J.; Karia, Raj; Meislin, Robert J.
2015-01-01
Background: Basketball players are at risk for foot injuries, including Jones fractures. It is unknown how this injury affects the future play and performance of athletes. Hypothesis: National Basketball Association (NBA) players who sustain Jones fractures of the base of the fifth metatarsal have high rates of return to play and do not experience a decrease in performance on return to competition when compared with preinjury and with control-matched peers. Study Design: Retrospective cohort study. Level of Evidence: Level 5. Methods: Data on 26 elite basketball players with Jones fractures over 19 NBA seasons (1994-1995 to 2012-2013) were obtained from injury reports, press releases, player profiles, and online public databases. Variables included age, body mass index (BMI), player position, experience, and surgical treatment. Individual season statistics pre- and postinjury were collected. Twenty-six controls were identified by matched player position, age, and performance statistics. Results: The mean age at the time of injury was 24.8 years, mean BMI was 24.7 kg/m2, and the mean experience prior to injury was 4.1 NBA seasons. Return to previous level of competition was achieved by 85% of athletes. There was no change in player efficiency rating (PER) when pre- and postinjury performance was compared. When compared with controls, no decline in PER measured performance was identified. Conclusion: The majority of NBA players sustaining a Jones fracture return to their preinjury level of competition. These elite athletes demonstrate no decrease in performance on their return to play. Clinical Relevance: Jones fractures are well-studied injuries in terms of etiology, diagnosis, and management. However, the effect of these injuries on future performance of athletes is unknown. Using the findings of our study, orthopaedic surgeons may be better prepared to counsel and educate elite athletes who sustain a Jones fracture. PMID:26627111
Return to Play and Performance After Jones Fracture in National Basketball Association Athletes.
Begly, John P; Guss, Michael; Ramme, Austin J; Karia, Raj; Meislin, Robert J
2016-07-01
Basketball players are at risk for foot injuries, including Jones fractures. It is unknown how this injury affects the future play and performance of athletes. National Basketball Association (NBA) players who sustain Jones fractures of the base of the fifth metatarsal have high rates of return to play and do not experience a decrease in performance on return to competition when compared with preinjury and with control-matched peers. Retrospective cohort study. Level 5. Data on 26 elite basketball players with Jones fractures over 19 NBA seasons (1994-1995 to 2012-2013) were obtained from injury reports, press releases, player profiles, and online public databases. Variables included age, body mass index (BMI), player position, experience, and surgical treatment. Individual season statistics pre- and postinjury were collected. Twenty-six controls were identified by matched player position, age, and performance statistics. The mean age at the time of injury was 24.8 years, mean BMI was 24.7 kg/m(2), and the mean experience prior to injury was 4.1 NBA seasons. Return to previous level of competition was achieved by 85% of athletes. There was no change in player efficiency rating (PER) when pre- and postinjury performance was compared. When compared with controls, no decline in PER measured performance was identified. The majority of NBA players sustaining a Jones fracture return to their preinjury level of competition. These elite athletes demonstrate no decrease in performance on their return to play. Jones fractures are well-studied injuries in terms of etiology, diagnosis, and management. However, the effect of these injuries on future performance of athletes is unknown. Using the findings of our study, orthopaedic surgeons may be better prepared to counsel and educate elite athletes who sustain a Jones fracture. © 2015 The Author(s).
Robert T. Jones, One of a Kind
Vincenti, Walter G.
2005-01-01
His contemporaries saw R.T. Jones as one of the notably creative aerodynamicists of the twentieth century. This essay reviews his remarkable life and career, including his years as a farm-country boy, college dropout, and fledgling airplane designer in Missouri, his time as an elevator operator and self-directed student in Washington, D.C., and his long professional career as an aerodynamicist at the Langley and Ames Aeronautical Laboratories and Stanford University. The focus in his career is on his fundamental discovery of the benefits of sweepback for the wings of high-speed airplanes. This includes speculation about his highly intuitive thought processes in arriving at his creative ideas. I also give an account of his work on blood flow and the mechanical heart, his avocational accomplishments as a maker of telescopes and violins, and his philosophical interest in human affairs.
Obituary: Frank Culver Jones, 1932-2007
Ormes, Johnathan F.; Streitmatter, Robert E.
2007-12-01
Frank C. Jones, an emeritus theoretical physicist at NASA, died May 2, 2007 at age 74 after a struggle with a rare form of cancer. He died at his home in Silver Spring, Maryland, surrounded by his family. Frank was born July 30, 1932 in Fort Worth, Texas, the oldest of three boys. His parents were Kenneth Hugh and Nancy Culver Jones. Frank's father was a lawyer, and his grandfather was a Methodist minister. Frank graduated from Rice University in 1954 and earned a master's degree in 1955 and a doctorate in 1961, both in physics, from the University of Chicago. He did his graduate work with Prof. John Simpson. Dr. Jones began his professional career as an instructor in physics at Princeton University before joining NASA's Goddard Space Flight Center in 1963 as a National Research Council associate. He subsequently became a member of the Theory Division and the Laboratory for High Energy Astrophysics. His area of expertise was the origin, transport, and electromagnetic interactions of cosmic rays. His particular focus was the stochastic physics related to the diffusion of particles in random fields, plasma turbulence, and the shock acceleration of charged particles in collisionless plasmas. From 1993 to 1995, Frank was head of Goddard's Theoretical High Energy Astrophysics Office and continued to serve as Head of the Theory group. In 2003 he served as Acting Chief of the Laboratory for High Energy Astrophysics. He retired in 2005 and continued his affiliation with NASA as an emeritus scientist at Goddard until his death. As a youngster, Frank showed the signs of curiosity and initiative that indicated he might become an experimentalist. At the memorial service for Frank, his brother related the stories of how Frank had rigged a hidden microphone to play through the family television as his brother courted a young woman on the front porch swing, and how one of Frank's early chemistry experiments caused all the family silverware to turn black. Although Frank started
International Nuclear Information System (INIS)
Camp, D.C.; Wang, Tzu-Fang; Martz, H.E.
1992-01-01
Preliminary minimum detectable levels (MDLS) of selected actinide isotopes have been determined in full-scale, 55-gallon drums filled with a range of mock-waste materials from combustibles (0.14 g/CM 3 ) to sand (1.7 g/CM 3 ). Measurements were recorded from 100 to 10,000 seconds with selected actinide sources located in these drums at an edge position, on the center axis of a drum and midway between these two positions. Measurements were also made with a 166 Ho source to evaluate the attenuation of these mock-matrix materials as a function of energy. By knowing where the source activity is located within a drum, our preliminary results show that a simply collimated 90% HPGE detector can differentiate between TRU (>100 nCi/g) and LLW amounts of 239 Pu in only 100s of measurement time and with sufficient accuracy in both low and medium density, low Z materials. Other actinides measured so far include 235 U, 241 Am, and 244 Cm. These measurements begin to establish the probable MDLs achievable in the nondestructive assays of real waste drums when using active and passive CT. How future measurements may differ from these preliminary measurements is also discussed
Indian Academy of Sciences (India)
IAS Admin
harmonic analysis and complex analysis, in ... gebra describes not only the study of linear transforma- tions and .... special case of the Jordan canonical form of matrices. ..... Richard Bronson, Schaum's Outline Series Theory And Problems Of.
Imaginando Palmares: a obra de Gayl Jones
Directory of Open Access Journals (Sweden)
Stelamaris Coser
2005-01-01
Full Text Available http://dx.doi.org/10.1590/S0104-026X2005000300010 O longo poema narrativo Song for Anninho (1981, da escritora negra Gayl Jones (Estados Unidos, interfere na narrativa da história colonial brasileira ao resgatar a figura feminina na República de Palmares, reescrever a saga de resistência dos palmaristas do ponto de vista imaginário de uma mulher negra do século XVII e, através dela, reinventar o cotidiano, os amores, as disputas e os sonhos das pessoas comuns que integravam o quilombo. O texto reflete sobre a verdade histórica, o aspecto construído de documentos, as seleções e exclusões da linguagem, e a importância do relato oral para o conhecimento de vivências e identidades à margem da história oficial. Nessa versão especial, o relato dramático do sonho, da luta e da destruição do mais famoso quilombo brasileiro usa a imaginação literária para expandir a memória e os arquivos de um dos fatos mais importantes da história das Américas, contribuindo para estimular o diálogo interamericano e iluminar a diáspora africana no Brasil e no continente.
Antimony measurements in environmental matrices
DEFF Research Database (Denmark)
Maher, William A.; Krikowa, Frank; Foster, Simon D.
2018-01-01
of the oxidation of Sb(iii) to Sb(v) and the formation of artefact Sb species. The analysis of solid samples using X-ray absorption spectroscopy should be considered as it has been shown to discriminate between Sb(iii) and Sb(v) as well as Sb minerals, oxides and adsorbed Sb species....
High and Crazy Niggers: Anti-Rationalism in Leroi Jones
Brown, Lloyd W.
1974-01-01
Suggests that the assumption that the theme of anti-rationalism in Jones is an attack on reason as such and that such a theme rests on an exclusive commitment to the irrational needs to be tested. (Author/AM)
Shelley Jones: Helping Ugandan girls stay in school | IDRC ...
International Development Research Centre (IDRC) Digital Library (Canada)
Shelley Jones with her Masters of Education students debating gender issues ... early pregnancies, limited family support, or educational gender discrimination.” ... Girls' Secondary Education in Uganda: Assessing Policy within the Women's ...
Entanglement entropy and the colored Jones polynomial
Balasubramanian, Vijay; DeCross, Matthew; Fliss, Jackson; Kar, Arjun; Leigh, Robert G.; Parrikar, Onkar
2018-05-01
We study the multi-party entanglement structure of states in Chern-Simons theory created by performing the path integral on 3-manifolds with linked torus boundaries, called link complements. For gauge group SU(2), the wavefunctions of these states (in a particular basis) are the colored Jones polynomials of the corresponding links. We first review the case of U(1) Chern-Simons theory where these are stabilizer states, a fact we use to re-derive an explicit formula for the entanglement entropy across a general link bipartition. We then present the following results for SU(2) Chern-Simons theory: (i) The entanglement entropy for a bipartition of a link gives a lower bound on the genus of surfaces in the ambient S 3 separating the two sublinks. (ii) All torus links (namely, links which can be drawn on the surface of a torus) have a GHZ-like entanglement structure — i.e., partial traces leave a separable state. By contrast, through explicit computation, we test in many examples that hyperbolic links (namely, links whose complements admit hyperbolic structures) have W-like entanglement — i.e., partial traces leave a non-separable state. (iii) Finally, we consider hyperbolic links in the complexified SL(2,C) Chern-Simons theory, which is closely related to 3d Einstein gravity with a negative cosmological constant. In the limit of small Newton constant, we discuss how the entanglement structure is controlled by the Neumann-Zagier potential on the moduli space of hyperbolic structures on the link complement.
Chuck Jones lahkus, tema kangelased elavad edasi / Neeme Korv
Korv, Neeme, 1974-
2002-01-01
Suri Chuck Jones (1912-2002), kuulus USA animafilmirežissöör, kelle animasari "Tom & Jerry" on praegugi Eestis väga populaarne. Ta on loonud enam kui 300 animafilmi, saanud 3 Oscarit ning 1996. aastal ka elutöö Oscari. Eesti lapsed nägid nõukogude ajal esmakordselt Chuck Jones'i loomingut Raivo Järvi lastesaadetes "Laupäeval koos isaga"
Phase diagram of a modified Lennard-Jones system
International Nuclear Information System (INIS)
Sakagami, Takahiro; Fuchizaki, Kazuhiro
2010-01-01
The well-known Lennard-Jones potential is modified in such a way that it smoothly vanishes at a certain distance. A system whose interparticle interaction is given by such a potential is referred to as a modified Lennard-Jones system, and is served as a standard system describing simple solids and fluids. A phase diagram is determined based on the free energies obtained through thermodynamic integration.
Suharwardy, Zain
2013-01-01
This paper attempts to examine the performance of six countries spanning from Asia and the Middle East. Countries are selected from the Dow Jones Islamic Market Index and the focus is kept to only choose countries that have an active Dow Jones Islamic Market Country Index along with a parallel Dow Jones Conventional Country Index. Further break down is made by comparing the country performances to their respective Dow Jones regional index’s (Dow Jones Asia Index and the Dow Jones MENA) in ord...
Chemiluminescence in cryogenic matrices
Lotnik, S. V.; Kazakov, Valeri P.
1989-04-01
The literature data on chemiluminescence (CL) in cryogenic matrices have been classified and correlated for the first time. The role of studies on phosphorescence and CL at low temperatures in the development of cryochemistry is shown. The features of low-temperature CL in matrices of nitrogen and inert gases (fine structure of spectra, matrix effects) and the data on the mobility and reactivity of atoms and radicals at very low temperatures are examined. The trends in the development of studies on CL in cryogenic matrices, such as the search for systems involving polyatomic molecules and extending the forms of CL reactions, are followed. The reactions of active nitrogen with hydrocarbons that are accompanied by light emission and CL in the oxidation of carbenes at T >= 77 K are examined. The bibliography includes 112 references.
Matrices in Engineering Problems
Tobias, Marvin
2011-01-01
This book is intended as an undergraduate text introducing matrix methods as they relate to engineering problems. It begins with the fundamentals of mathematics of matrices and determinants. Matrix inversion is discussed, with an introduction of the well known reduction methods. Equation sets are viewed as vector transformations, and the conditions of their solvability are explored. Orthogonal matrices are introduced with examples showing application to many problems requiring three dimensional thinking. The angular velocity matrix is shown to emerge from the differentiation of the 3-D orthogo
Schmidt-Hieltjes, Yvonne; Elshof, Clemens; Roovers, Lian; Ruinemans-Koerts, Janneke
2016-05-01
The aim of our study was to analyse whether the κ/λ free light chain ratio reference range for screening for Bence Jones proteinuria should be dependent on the estimated glomerular filtration rate (eGFR). The serum κ/λ free light chain ratio, eGFR, serum M-protein and Bence Jones protein were measured in 544 patients for whom Bence Jones protein analysis was ordered. In the population of patients without Bence Jones proteinuria or a M-protein (n = 402), there is no gradual increase in κ/λ free light chain ratio with diminishing eGFR. The κ/λ free light chain ratio in this group was 0.56-1.86 (95% interval). With this diagnostic reference range of the κ/λ ratio, 105 of the 110 patients with Bence Jones protein could be identified correctly. Only five patients with Bence Jones proteinuria (free light chain ratio was measured without the presence of Bence Jones proteinuria. A κ/λ free light chain ratio in serum can be used safely and efficiently to select urine samples which should be analysed for Bence Jones proteinuria with an electrophoresis/immunofixation technique. Using this diagnostic reference range, the number of urine samples which should be analysed by electrophoresis/immunofixation could be reduced by 74%. The diagnostic reference interval can be determined best in a group of patients for whom Bence Jones analysis is indicated. For calculation of this reference range, the eGFR value does not need to be taken into account. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Infinite matrices and sequence spaces
Cooke, Richard G
2014-01-01
This clear and correct summation of basic results from a specialized field focuses on the behavior of infinite matrices in general, rather than on properties of special matrices. Three introductory chapters guide students to the manipulation of infinite matrices, covering definitions and preliminary ideas, reciprocals of infinite matrices, and linear equations involving infinite matrices.From the fourth chapter onward, the author treats the application of infinite matrices to the summability of divergent sequences and series from various points of view. Topics include consistency, mutual consi
Evaluation of linkages between equity indices : evidence from İstanbul Stock Exchange and Dow Jones
Ertan, Aytekin
2009-01-01
Ankara : The Department of Management, Bilkent Univiversity, 2009. Thesis (Master's) -- Bilkent University, 2009. Includes bibliographical references leaves 30-33. This study investigates the linkage between the major stock market indices of Turkey (ISE National 100) and USA (Dow Jones Industrial Average). Main purpose of this research is to measure the interdependence and cointegration between these indices and figure out the significance and the direction of short run r...
2014-04-01
materials, the affinity ligand would need identification , as well as chemistries that graft the affinity ligand onto the surface of magnetic...ACTIVE CAPTURE MATRICES FOR THE DETECTION/ IDENTIFICATION OF PHARMACEUTICALS...6 As shown in Figure 2.3-1a, the spectra exhibit similar baselines and the spectral peaks lineup . Under these circumstances, the spectral
NEWS: John Goronwy Jones (1920-1999)
Jennison, Brenda M.
2000-05-01
John Goronwy Jones Gron Jones, as he was known to all, was a champion of Physics Education and his death, shortly before his eightieth birthday, robbed physics teachers of a colleague who fought many battles on their behalf. He was not shy of taking issue with anyone in authority who might be putting forward policies which would harm his great love: Physics Education and Physics Teaching. His photograph shows a man with an impish grin, looking friend and foe alike straight in the eye, before delivering the death blow to an argument which was founded on less than common sense. At other times he would listen patiently to the woes of colleagues before offering them fatherly/grandfatherly advice so that whoever was on the receiving end would go away feeling better for the encounter. Gron was born in Swansea and educated at Lewis Boys Grammar School in Glamorgan before entering University College Cardiff first of all as a mathematician before graduating in Physics in 1941. After his war service in the RAF, working on signals and radar development, he returned to do an MSc in X-ray crystallography before completing a PGCE in Bristol. What then passed for teacher training in all institutions left him wary of returning to train teachers himself but after 14 years spent teaching physics in three schools he returned to Cardiff and began a 25 year career in teacher training. He and his two colleagues, Clifford Othen (chemistry) and Douglas Hillier (biology) built up the Cardiff Science Centre as a focus for initial and in-service science teacher training in South Wales. The triumvirate was well known and a power to be reckoned with. They created links between the University Science Departments and the Schools. Gron knew the local schools and their physics teachers intimately. Cardiff became a focus for science education both nationally and internationally. He was a frequent attender at both ICPE (International Commission for Physics Education) and GIREP (International Physics
Sparse Matrices in Frame Theory
DEFF Research Database (Denmark)
Lemvig, Jakob; Krahmer, Felix; Kutyniok, Gitta
2014-01-01
Frame theory is closely intertwined with signal processing through a canon of methodologies for the analysis of signals using (redundant) linear measurements. The canonical dual frame associated with a frame provides a means for reconstruction by a least squares approach, but other dual frames...... yield alternative reconstruction procedures. The novel paradigm of sparsity has recently entered the area of frame theory in various ways. Of those different sparsity perspectives, we will focus on the situations where frames and (not necessarily canonical) dual frames can be written as sparse matrices...
Introduction to matrices and vectors
Schwartz, Jacob T
2001-01-01
In this concise undergraduate text, the first three chapters present the basics of matrices - in later chapters the author shows how to use vectors and matrices to solve systems of linear equations. 1961 edition.
International Nuclear Information System (INIS)
Kim, Soon-Chul; Lee, Song Hi
2004-01-01
A density functional perturbation approximation (DFPT), which is based both on the fundamental-measure theory (FMT) to the hard-sphere repulsion and on the weighted-density approximations (WDAs) to the attractive contribution, has been proposed for studying the structural properties of model fluids with an attractive part of the potential. The advantage of the present theory is the simplicity of the calculation of the weight function due to the attractive contribution. It has been applied to predict the equilibrium particle density distributions and adsorption isotherms of Lennard-Jones fluids at interfaces. The theoretical results show that the present theory describes quite well the adsorption isotherms of a Lennard-Jones ethane in a graphite slit pore as well as the equilibrium particle density distributions of a Lennard-Jones fluid near a planar slit pore
Bapat, Ravindra B
2014-01-01
This new edition illustrates the power of linear algebra in the study of graphs. The emphasis on matrix techniques is greater than in other texts on algebraic graph theory. Important matrices associated with graphs (for example, incidence, adjacency and Laplacian matrices) are treated in detail. Presenting a useful overview of selected topics in algebraic graph theory, early chapters of the text focus on regular graphs, algebraic connectivity, the distance matrix of a tree, and its generalized version for arbitrary graphs, known as the resistance matrix. Coverage of later topics include Laplacian eigenvalues of threshold graphs, the positive definite completion problem and matrix games based on a graph. Such an extensive coverage of the subject area provides a welcome prompt for further exploration. The inclusion of exercises enables practical learning throughout the book. In the new edition, a new chapter is added on the line graph of a tree, while some results in Chapter 6 on Perron-Frobenius theory are reo...
Scaling of the dynamics of flexible Lennard-Jones chains
DEFF Research Database (Denmark)
Veldhorst, Arno; Dyre, Jeppe C.; Schrøder, Thomas
2015-01-01
The previous paper [A. A. Veldhorst et al., J. Chem. Phys. 141, 054904 (2014)] demonstrated that the isomorph theory explains the scaling properties of a liquid of flexible chains consisting of ten Lennard-Jones particles connected by rigid bonds. We here investigate the same model with harmonic......, dynamics, and the excess entropy are invariant. The Lennard-Jones chain liquid with harmonic bondsdoes have curves in the phase diagram along which the structure and dynamics are invariant. The excess entropy is not invariant on these curves, which we refer to as “pseudoisomorphs.” In particular......, this means that Rosenfeld’s excess-entropy scaling (the dynamics being a function of excess entropy only) does not apply for the Lennard-Jones chain with harmonic bonds...
Cluster fusion algorithm: application to Lennard-Jones clusters
DEFF Research Database (Denmark)
Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter
2006-01-01
paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry...
Cluster fusion algorithm: application to Lennard-Jones clusters
DEFF Research Database (Denmark)
Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter
2008-01-01
paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry...
Hierarchical quark mass matrices
International Nuclear Information System (INIS)
Rasin, A.
1998-02-01
I define a set of conditions that the most general hierarchical Yukawa mass matrices have to satisfy so that the leading rotations in the diagonalization matrix are a pair of (2,3) and (1,2) rotations. In addition to Fritzsch structures, examples of such hierarchical structures include also matrices with (1,3) elements of the same order or even much larger than the (1,2) elements. Such matrices can be obtained in the framework of a flavor theory. To leading order, the values of the angle in the (2,3) plane (s 23 ) and the angle in the (1,2) plane (s 12 ) do not depend on the order in which they are taken when diagonalizing. We find that any of the Cabbibo-Kobayashi-Maskawa matrix parametrizations that consist of at least one (1,2) and one (2,3) rotation may be suitable. In the particular case when the s 13 diagonalization angles are sufficiently small compared to the product s 12 s 23 , two special CKM parametrizations emerge: the R 12 R 23 R 12 parametrization follows with s 23 taken before the s 12 rotation, and vice versa for the R 23 R 12 R 23 parametrization. (author)
The 'golden' matrices and a new kind of cryptography
International Nuclear Information System (INIS)
Stakhov, A.P.
2007-01-01
We consider a new class of square matrices called the 'golden' matrices. They are a generalization of the classical Fibonacci Q-matrix for continuous domain. The 'golden' matrices can be used for creation of a new kind of cryptography called the 'golden' cryptography. The method is very fast and simple for technical realization and can be used for cryptographic protection of digital signals (telecommunication and measurement systems)
Not Fully Developed Turbulence in the Dow Jones Index
Trincado, Estrella; Vindel, Jose María
2013-08-01
The shape of the curves relating the scaling exponents of the structure functions to the order of these functions is shown to distinguish the Dow Jones index from other stock market indices. We conclude from the shape differences that the information-loss rate for the Dow Jones index is reduced at smaller time scales, while it grows for other indices. This anomaly is due to the construction of the index, in particular to its dependence on a single market parameter: price. Prices are subject to turbulence bursts, which act against full development of turbulence.
Imaginando Palmares: a obra de Gayl Jones Imagining Palmares: the work of Gayl Jones
Directory of Open Access Journals (Sweden)
Stelamaris Coser
2005-12-01
Full Text Available O longo poema narrativo Song for Anninho (1981, da escritora negra Gayl Jones (Estados Unidos, interfere na narrativa da história colonial brasileira ao resgatar a figura feminina na República de Palmares, reescrever a saga de resistência dos palmaristas do ponto de vista imaginário de uma mulher negra do século XVII e, através dela, reinventar o cotidiano, os amores, as disputas e os sonhos das pessoas comuns que integravam o quilombo. O texto reflete sobre a verdade histórica, o aspecto construído de documentos, as seleções e exclusões da linguagem, e a importância do relato oral para o conhecimento de vivências e identidades à margem da história oficial. Nessa versão especial, o relato dramático do sonho, da luta e da destruição do mais famoso quilombo brasileiro usa a imaginação literária para expandir a memória e os arquivos de um dos fatos mais importantes da história das Américas, contribuindo para estimular o diálogo interamericano e iluminar a diáspora africana no Brasil e no continente.The long narrative poem Song for Anninho (1981, written by black U.S. writer Gayl Jones, interferes in the narrative of Brazilian colonial history as it highlights the female presence in the Republic of Palmares, rewrites the tale of resistance from the point of view of a black woman in the 17th Century, and, through her, reinvents the everyday lives, loves, disputes, and dreams of common people in the quilombo. The text reflects about historical truth, the constructed character of documents, selections and exclusions in language, and the importance of oral accounts to give visibility to experiences and identities marginalized by official history. In this special version, the dramatic report of the dreams, struggles, and destruction of the most famous Brazilian quilombo uses literary imagination to expand the memory and the archives of one of the most important facts in the history of the Americas, contributing to stimulate
Bayesian Nonparametric Clustering for Positive Definite Matrices.
Cherian, Anoop; Morellas, Vassilios; Papanikolopoulos, Nikolaos
2016-05-01
Symmetric Positive Definite (SPD) matrices emerge as data descriptors in several applications of computer vision such as object tracking, texture recognition, and diffusion tensor imaging. Clustering these data matrices forms an integral part of these applications, for which soft-clustering algorithms (K-Means, expectation maximization, etc.) are generally used. As is well-known, these algorithms need the number of clusters to be specified, which is difficult when the dataset scales. To address this issue, we resort to the classical nonparametric Bayesian framework by modeling the data as a mixture model using the Dirichlet process (DP) prior. Since these matrices do not conform to the Euclidean geometry, rather belongs to a curved Riemannian manifold,existing DP models cannot be directly applied. Thus, in this paper, we propose a novel DP mixture model framework for SPD matrices. Using the log-determinant divergence as the underlying dissimilarity measure to compare these matrices, and further using the connection between this measure and the Wishart distribution, we derive a novel DPM model based on the Wishart-Inverse-Wishart conjugate pair. We apply this model to several applications in computer vision. Our experiments demonstrate that our model is scalable to the dataset size and at the same time achieves superior accuracy compared to several state-of-the-art parametric and nonparametric clustering algorithms.
Free energy of the Lennard-Jones solid
Hoef, van der M.A.
2000-01-01
We have determined a simple expression for the absolute Helmholtz free energy of the fcc Lennard-Jones solid from molecular dynamics simulations. The pressure and energy data from these simulations have been fitted to a simple functional form (18 parameters) for densities ranging from around
The homological content of the Jones representations at $q = -1$
DEFF Research Database (Denmark)
Egsgaard, Jens Kristian; Fuglede Jørgensen, Søren
We generalize a discovery of Kasahara and show that the Jones representations of braid groups, when evaluated at $q = -1$, are related to the action on homology of a branched double cover of the underlying punctured disk. As an application, we prove for a large family of pseudo-Anosov mapping...
Topological quantum information, virtual Jones polynomials and Khovanov homology
International Nuclear Information System (INIS)
Kauffman, Louis H
2011-01-01
In this paper, we give a quantum statistical interpretation of the bracket polynomial state sum 〈K〉, the Jones polynomial V K (t) and virtual knot theory versions of the Jones polynomial, including the arrow polynomial. We use these quantum mechanical interpretations to give new quantum algorithms for these Jones polynomials. In those cases where the Khovanov homology is defined, the Hilbert space C(K) of our model is isomorphic with the chain complex for Khovanov homology with coefficients in the complex numbers. There is a natural unitary transformation U:C(K) → C(K) such that 〈K〉 = Trace(U), where 〈K〉 denotes the evaluation of the state sum model for the corresponding polynomial. We show that for the Khovanov boundary operator ∂:C(K) → C(K), we have the relationship ∂U + U∂ = 0. Consequently, the operator U acts on the Khovanov homology, and we obtain a direct relationship between the Khovanov homology and this quantum algorithm for the Jones polynomial. (paper)
Scaling of the dynamics of flexible Lennard-Jones chains
DEFF Research Database (Denmark)
Veldhorst, Arno; Dyre, J. C.; Schrøder, Thomas
2014-01-01
functions of excess entropy) which has been observed in simulations of both molecular and polymeric systems. Doing molecular dynamics simulations of flexible Lennard-Jones chains (LJC) with rigid bonds, we here provide the first detailed test of the isomorph theory applied to flexible chain molecules. We...
Highlight: Dr David Butler-Jones on fighting pandemics | CRDI ...
International Development Research Centre (IDRC) Digital Library (Canada)
15 avr. 2016 ... Dr David Butler-Jones, professor in the Faculty of Medicine at the University of Manitoba and former Chief Medical Health Officer of Canada, delivered a lecture on lessons learned from the 2009 flu pandemic in Canada. He also commented on India's draft National Health Policy 2015 at the India ...
Public lecture | "Science and society" by Bob Jones | 22 May
2014-01-01
Public lecture: "Science and society: the impact of computing at CERN on society" by Bob Jones 22 May at 7.30 p.m. Globe of Science and Innovation Lecture in English, translated in French. Entrance free. Limited number of seats. Reservation essential: +41 22 767 76 76 or cern.reception@cern.ch
Highlight: Dr David Butler-Jones on fighting pandemics | IDRC ...
International Development Research Centre (IDRC) Digital Library (Canada)
2016-04-15
Apr 15, 2016 ... In the context of developing countries, Butler-Jones drew attention to the importance of public healthcare teams of doctors and paramedics, data, and accreditation standards in identifying appropriate interventions. There is a need to explore the public-private nexus, traditional medicines, and public health ...
A note on Valeriana jatamansi Jones (Caprifoliaceae s.l.)
Mabberley, D.J.; Noltie, H.J.
2014-01-01
The tangled arguments around the names of jatamansi drug plants are examined and the correct synonymies and typifications for Nardostachys jatamansi (D.Don) DC. and V. jatamansi Jones (both Caprifoliaceae s.l.) are provided. The conservation status of the former, and the need for further work on the
C. Rick Jones Is IRPA Keynote Lecturer on Stakeholder Engagement
International Nuclear Information System (INIS)
Strom, Daniel J.
2008-01-01
At the recent IRPA 12 Conference in Buenos Aires, Argentina, C. Rick Jones gave the keynote lecture 'Stakeholder Engagement in Practice - Now Is the Time to Act' This was one of the very best talks at the conference, covering IRPA's draft 'Guiding Principles for Radiation Protection Professionals on Stakeholder Engagement'
Thermal conductivity of the Lennard-Jones chain fluid model.
Galliero, Guillaume; Boned, Christian
2009-12-01
Nonequilibrium molecular dynamics simulations have been performed to estimate, analyze, and correlate the thermal conductivity of a fluid composed of short Lennard-Jones chains (up to 16 segments) over a large range of thermodynamic conditions. It is shown that the dilute gas contribution to the thermal conductivity decreases when the chain length increases for a given temperature. In dense states, simulation results indicate that the residual thermal conductivity of the monomer increases strongly with density, but is weakly dependent on the temperature. Compared to the monomer value, it has been noted that the residual thermal conductivity of the chain was slightly decreasing with its length. Using these results, an empirical relation, including a contribution due to the critical enhancement, is proposed to provide an accurate estimation of the thermal conductivity of the Lennard-Jones chain fluid model (up to 16 segments) over the domain 0.8values of the Lennard-Jones chain fluid model merge on the same "universal" curve when plotted as a function of the excess entropy. Furthermore, it is shown that the reduced configurational thermal conductivity of the Lennard-Jones chain fluid model is approximately proportional to the reduced excess entropy for all fluid states and all chain lengths.
Shelley Jones — Aider les jeunes Ougandaises à poursuivre leurs ...
International Development Research Centre (IDRC) Digital Library (Canada)
18 nov. 2014 ... ... d'entre elles abandonnent l'école à cause de leur cycle menstruel. ... Shelley Jones with her Masters of Education students debating gender issues ... limité ou à la discrimination sexospécifique en matière d'éducation.
Equilibrium spherically curved two-dimensional Lennard-Jones systems
Voogd, J.M.; Sloot, P.M.A.; van Dantzig, R.
2005-01-01
To learn about basic aspects of nano-scale spherical molecular shells during their formation, spherically curved two-dimensional N-particle Lennard-Jones systems are simulated, studying curvature evolution paths at zero-temperature. For many N-values (N < 800) equilibrium configu- rations are traced
Energy Technology Data Exchange (ETDEWEB)
Loche, F
2006-10-15
In the framework of radioactive waste drums control, difficulties arise in the nondestructive measurement of fissile mass ({sup 235}U, {sup 239}Pu..) by Active Neutron Interrogation (ANI), when dealing with matrices containing materials (Cl, H...) influencing the neutron flux. The idea is to use the neutron capture reaction (n,{gamma}) to determine the matrix composition to adjust the ANI calibration coefficient value. This study, dealing with 118 litres, homogeneous drums of density less than 0,4 and composed of chlorinated and/or hydrogenated materials, leads to build abacus linking the {gamma} ray peak areas to the ANI calibration coefficient. Validation assays of these abacus show a very good agreement between the corrected and true fissile masses for hydrogenated matrices (max. relative standard deviation: 23 %) and quite good for chlorinated and hydrogenated matrices (58 %). The developed correction method improves the measured values. It may be extended to 0,45 density, heterogeneous drums. (author)
M Wedderburn, J H
1934-01-01
It is the organization and presentation of the material, however, which make the peculiar appeal of the book. This is no mere compendium of results-the subject has been completely reworked and the proofs recast with the skill and elegance which come only from years of devotion. -Bulletin of the American Mathematical Society The very clear and simple presentation gives the reader easy access to the more difficult parts of the theory. -Jahrbuch über die Fortschritte der Mathematik In 1937, the theory of matrices was seventy-five years old. However, many results had only recently evolved from sp
Schneider, Hans
1989-01-01
Linear algebra is one of the central disciplines in mathematics. A student of pure mathematics must know linear algebra if he is to continue with modern algebra or functional analysis. Much of the mathematics now taught to engineers and physicists requires it.This well-known and highly regarded text makes the subject accessible to undergraduates with little mathematical experience. Written mainly for students in physics, engineering, economics, and other fields outside mathematics, the book gives the theory of matrices and applications to systems of linear equations, as well as many related t
Intermittency and random matrices
Sokoloff, Dmitry; Illarionov, E. A.
2015-08-01
A spectacular phenomenon of intermittency, i.e. a progressive growth of higher statistical moments of a physical field excited by an instability in a random medium, attracted the attention of Zeldovich in the last years of his life. At that time, the mathematical aspects underlying the physical description of this phenomenon were still under development and relations between various findings in the field remained obscure. Contemporary results from the theory of the product of independent random matrices (the Furstenberg theory) allowed the elaboration of the phenomenon of intermittency in a systematic way. We consider applications of the Furstenberg theory to some problems in cosmology and dynamo theory.
Dimension from covariance matrices.
Carroll, T L; Byers, J M
2017-02-01
We describe a method to estimate embedding dimension from a time series. This method includes an estimate of the probability that the dimension estimate is valid. Such validity estimates are not common in algorithms for calculating the properties of dynamical systems. The algorithm described here compares the eigenvalues of covariance matrices created from an embedded signal to the eigenvalues for a covariance matrix of a Gaussian random process with the same dimension and number of points. A statistical test gives the probability that the eigenvalues for the embedded signal did not come from the Gaussian random process.
Forecasting Covariance Matrices: A Mixed Frequency Approach
DEFF Research Database (Denmark)
Halbleib, Roxana; Voev, Valeri
This paper proposes a new method for forecasting covariance matrices of financial returns. The model mixes volatility forecasts from a dynamic model of daily realized volatilities estimated with high-frequency data with correlation forecasts based on daily data. This new approach allows for flexi......This paper proposes a new method for forecasting covariance matrices of financial returns. The model mixes volatility forecasts from a dynamic model of daily realized volatilities estimated with high-frequency data with correlation forecasts based on daily data. This new approach allows...... for flexible dependence patterns for volatilities and correlations, and can be applied to covariance matrices of large dimensions. The separate modeling of volatility and correlation forecasts considerably reduces the estimation and measurement error implied by the joint estimation and modeling of covariance...
Energy Technology Data Exchange (ETDEWEB)
Mantero Cabrera, J.
2014-07-01
: In radiological emergencies it's necessary a fast response from the laboratories in the quantification of certain radionuclides, in order to take decisions. In these cases, is the reaction time the key parameter to consider (without neglecting the quality of the measurement). In this work, it is shown a method for aqueous matrices that generates Pu and Am isotopes sources in one single day of work, to be measured subsequently by alpha spectrometry. The developed methodology has been validated through its application to reference samples and also taking part intercom- parison exercises, having in both cases, satisfactory results. This way, we check the validity of this fast method that let us generate in 24 hours (since the sample arrives our laboratory), one measurement with a Minimun Detectable Activity (MDA) of about 0.004Bq/L for Pu and Am isotopes in liquid matrices. [Spanish] En situaciones de emergencia radiológica es muy común la necesidad de dar una respuesta rápida por parte de los laboratorios en la cuantificación de ciertos radionucleidos, de cara a la toma de decisiones. En estos casos, el tiempo de reacción es una variable fundamental a considerar (aunque obviamente sin dejar de lado la calidad en el resultado de la medida). En este trabajo se presenta un método para matrices acuosas que permite generar en una única jornada de trabajo, las fuentes de medida necesarias en la detección de isótopos de Pu y Am para ser medidas con posterioridad por espectrometría alfa. La metodología puesta a punto ha sido validada mediante su aplicación a muestras de referencia y mediante la participación en ejercicios de intercomparación, en ambos casos, con resultados satisfactorios. Queda así demostrada la validez de este método rápido que nos permite generar en 24 horas desde la recepción de la muestra, una medida en nuestros sistemas con una Actividad Mínima Detectable (AMD) de 0.004 Bq/L tanto para isótopos de Pu (238Pu, 239+240Pu) como de
2010-04-21
... meeting would be beneficial. If we determine that one would aid this rulemaking, we will hold one at a... to the shows, as well as providing additional time should they run over the scheduled period. The... running east along the shoreline of Jones Beach State Park to approximate position 40[deg]35'49'' N, 073...
Indiana Jones on tagasi ja näitab, kuidas käituda / Kristiina Davidjants
Davidjants, Kristiina, 1974-
2008-01-01
22 mail esilinastub Steven Spielbergi järjekordne Indiana Jones'i film, kaasstsenaristiks ja produtsendiks George Lucas ja Harrison Fordiga nimiosas "Indiana Jones ja kristallpealuu kuningriik" ("Indiana Jones and the Kingdom of the Crystal Skull"). Saaga varasemast kolmest filmist
International Nuclear Information System (INIS)
Smith, D.L.
1987-03-01
Attention is called to the considerable sensitivity of many uncertainty calculations to the magnitude of the long-ranged correlations which appear in covariance matrices. If such correlations do exist, they must be included in order to properly assess the impact of the uncertainties in the data. If, however, certain assumed long-range correlations are unrealistic, then analyses involving such correlation information are almost certain to produce misleading results. The issue is discussed in general terms, and its importance is illustrated by examples based in part on recent work from this laboratory. Some practical suggestions are offered for dealing with the matter of correlations in instances where the available information is incomplete. 23 refs., 2 figs., 1 tab
Complex Wedge-Shaped Matrices: A Generalization of Jacobi Matrices
Czech Academy of Sciences Publication Activity Database
Hnětynková, Iveta; Plešinger, M.
2015-01-01
Roč. 487, 15 December (2015), s. 203-219 ISSN 0024-3795 R&D Projects: GA ČR GA13-06684S Keywords : eigenvalues * eigenvector * wedge-shaped matrices * generalized Jacobi matrices * band (or block) Krylov subspace methods Subject RIV: BA - General Mathematics Impact factor: 0.965, year: 2015
Generalisations of Fisher Matrices
Directory of Open Access Journals (Sweden)
Alan Heavens
2016-06-01
Full Text Available Fisher matrices play an important role in experimental design and in data analysis. Their primary role is to make predictions for the inference of model parameters—both their errors and covariances. In this short review, I outline a number of extensions to the simple Fisher matrix formalism, covering a number of recent developments in the field. These are: (a situations where the data (in the form of ( x , y pairs have errors in both x and y; (b modifications to parameter inference in the presence of systematic errors, or through fixing the values of some model parameters; (c Derivative Approximation for LIkelihoods (DALI - higher-order expansions of the likelihood surface, going beyond the Gaussian shape approximation; (d extensions of the Fisher-like formalism, to treat model selection problems with Bayesian evidence.
Energy Technology Data Exchange (ETDEWEB)
Fukuma, Masafumi; Sugishita, Sotaro; Umeda, Naoya [Department of Physics, Kyoto University,Kitashirakawa Oiwake-cho, Kyoto 606-8502 (Japan)
2015-07-17
We propose a class of models which generate three-dimensional random volumes, where each configuration consists of triangles glued together along multiple hinges. The models have matrices as the dynamical variables and are characterized by semisimple associative algebras A. Although most of the diagrams represent configurations which are not manifolds, we show that the set of possible diagrams can be drastically reduced such that only (and all of the) three-dimensional manifolds with tetrahedral decompositions appear, by introducing a color structure and taking an appropriate large N limit. We examine the analytic properties when A is a matrix ring or a group ring, and show that the models with matrix ring have a novel strong-weak duality which interchanges the roles of triangles and hinges. We also give a brief comment on the relationship of our models with the colored tensor models.
VanderLaan Circulant Type Matrices
Directory of Open Access Journals (Sweden)
Hongyan Pan
2015-01-01
Full Text Available Circulant matrices have become a satisfactory tools in control methods for modern complex systems. In the paper, VanderLaan circulant type matrices are presented, which include VanderLaan circulant, left circulant, and g-circulant matrices. The nonsingularity of these special matrices is discussed by the surprising properties of VanderLaan numbers. The exact determinants of VanderLaan circulant type matrices are given by structuring transformation matrices, determinants of well-known tridiagonal matrices, and tridiagonal-like matrices. The explicit inverse matrices of these special matrices are obtained by structuring transformation matrices, inverses of known tridiagonal matrices, and quasi-tridiagonal matrices. Three kinds of norms and lower bound for the spread of VanderLaan circulant and left circulant matrix are given separately. And we gain the spectral norm of VanderLaan g-circulant matrix.
DEFF Research Database (Denmark)
Rombouts, Jeroen V.K.; Stentoft, Lars; Violante, Francesco
innovation for a Laplace innovation assumption improves the pricing in a smaller way. Apart from investigating directly the value of model sophistication in terms of dollar losses, we also use the model condence set approach to statistically infer the set of models that delivers the best pricing performance.......We assess the predictive accuracy of a large number of multivariate volatility models in terms of pricing options on the Dow Jones Industrial Average. We measure the value of model sophistication in terms of dollar losses by considering a set 248 multivariate models that differer...
The Kauffman bracket and the Jones polynomial in quantum gravity
International Nuclear Information System (INIS)
Griego, J.
1996-01-01
In the loop representation the quantum states of gravity are given by knot invariants. From general arguments concerning the loop transform of the exponential of the Chern-Simons form, a certain expansion of the Kauffman bracket knot polynomial can be formally viewed as a solution of the Hamiltonian constraint with a cosmological constant in the loop representation. The Kauffman bracket is closely related to the Jones polynomial. In this paper the operation of the Hamiltonian on the power expansions of the Kauffman bracket and Jones polynomials is analyzed. It is explicitly shown that the Kauffman bracket is a formal solution of the Hamiltonian constraint to third order in the cosmological constant. We make use of the extended loop representation of quantum gravity where the analytic calculation can be thoroughly accomplished. Some peculiarities of the extended loop calculus are considered and the significance of the results to the case of the conventional loop representation is discussed. (orig.)
Diagonalization of the mass matrices
International Nuclear Information System (INIS)
Rhee, S.S.
1984-01-01
It is possible to make 20 types of 3x3 mass matrices which are hermitian. We have obtained unitary matrices which could diagonalize each mass matrix. Since the three elements of mass matrix can be expressed in terms of the three eigenvalues, msub(i), we can also express the unitary matrix in terms of msub(i). (Author)
Enhancing Understanding of Transformation Matrices
Dick, Jonathan; Childrey, Maria
2012-01-01
With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…
Tubo de Lester-Jones: indicações e resultados Lester-Jones tube: indications and results
Directory of Open Access Journals (Sweden)
Walberto Passos Junior
2004-12-01
Full Text Available OBJETIVO: Avaliar as indicações, resultados e complicações advindas do seu uso. MÉTODOS: Avaliaram-se retrospectivamente 25 pacientes submetidos a 27 conjuntivorrinostomias com colocação de tubo de Lester-Jones. Foram estudados os dados do portador, a etiologia da afecção e as complicações que ocorreram no intra e no pós-operatório. Os dados foram avaliados segundo a freqüência de ocorrência. RESULTADOS: O tubo de Lester-Jones foi usado igualmente em ambos os sexos, mais em indivíduos abaixo dos 10 ou acima dos 50 anos de idade. As causas mais freqüentes para utilização foram a idiopática ou a agenesia congênita de pontos e canalículos. Houve melhora dos sintomas em 88% dos pacientes. Complicações ocorreram em 59,25% dos casos, dentre as quais: extrusão (40,74% e a migração (14,8% do tubo. CONCLUSÃO: Apesar das complicações observadas, o índice de cura com a utilização do tubo de Lester-Jones é alto, sendo boa opção para o tratamento das obstruções lacrimais altas.PURPOSE: To evaluate the results and the complications occurring with this procedure. METHODS: The authors retrospectively reviewed charts of 25 patients (27 lacrimal viers with upper lacrimal system obstruction who underwent conjunctivorhinostomy and Lester-Jones tube bypass. The patients were evaluated according to gender, causative factors and the com plications during and after surgery. The data were submitted to statistical analysis. RESULTS: The Lester-Jones bypass tube was used in both sexes and most frequently in patients under 10 or above 50 years. The most common obstructive factor was unknown and congenital agenesis. Eighty-eight per cent of the patients had no epiphora at the end of the treatment. Complications occurred in 59.25% of the patients, most of them related to tube extrusion (40.74% or migration (14.8%. The authors concluded that the Lester-Jones bypass tube is a good option to treat the upper lacrimal obstruction, in spite
Phase diagram of a Lennard-Jones solid
International Nuclear Information System (INIS)
Choi, Y.; Ree, T.; Ree, F.H.
1993-01-01
A phase diagram of a Lennard-Jones solid at kT/ε≥0.8 is constructed by our recent perturbation theory. It shows the stability of the face-centered-cubic phase except within a small pressure and temperature domain, where the hexagonal-close packed phase may occur. The theory predicts anharmonic contributions to the Helmholtz free energy (important to the crystal stability) in good agreement with Monte Carlo data
Marine geophysics. By E.J.W. Jones
Digital Repository Service at National Institute of Oceanography (India)
Rao, D.G.
.Earth-Science Reviews 52 2001 381–384 www.elsevier.comrlocaterearscirev Book reviews Marine Geophysics E.J.W. Jones, University College, London, UK, Wiley, Chichester, West Sussex PO19IUD, England, 1999, 466 pp. As a practicing marine geophysicist working... principles, theory, state-of-the-art instruments, latest techniques in data acquisition, processing and interpretation. The book contains 16 chapters, in which the author has done commendable job in presenting the best examples of case studies in critical...
Technical considerations for surgical intervention of Jones fractures.
Mendicino, Robert W; Hentges, Matthew J; Mendicino, Michael R; Catanzariti, Alan R
2013-01-01
Jones fractures are a common injury treated by foot and ankle surgeons. Surgical intervention is recommended because of the high rate of delayed union, nonunion, and repeat fracture, when treated conservatively. Percutaneous intramedullary screw fixation is commonly used in the treatment of these fractures. We present techniques that can increase the surgical efficiency and decrease the complications associated with percutaneous delivery of internal fixation. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
Hierarchical matrices algorithms and analysis
Hackbusch, Wolfgang
2015-01-01
This self-contained monograph presents matrix algorithms and their analysis. The new technique enables not only the solution of linear systems but also the approximation of matrix functions, e.g., the matrix exponential. Other applications include the solution of matrix equations, e.g., the Lyapunov or Riccati equation. The required mathematical background can be found in the appendix. The numerical treatment of fully populated large-scale matrices is usually rather costly. However, the technique of hierarchical matrices makes it possible to store matrices and to perform matrix operations approximately with almost linear cost and a controllable degree of approximation error. For important classes of matrices, the computational cost increases only logarithmically with the approximation error. The operations provided include the matrix inversion and LU decomposition. Since large-scale linear algebra problems are standard in scientific computing, the subject of hierarchical matrices is of interest to scientists ...
Intrinsic character of Stokes matrices
Gagnon, Jean-François; Rousseau, Christiane
2017-02-01
Two germs of linear analytic differential systems x k + 1Y‧ = A (x) Y with a non-resonant irregular singularity are analytically equivalent if and only if they have the same eigenvalues and equivalent collections of Stokes matrices. The Stokes matrices are the transition matrices between sectors on which the system is analytically equivalent to its formal normal form. Each sector contains exactly one separating ray for each pair of eigenvalues. A rotation in S allows supposing that R+ lies in the intersection of two sectors. Reordering of the coordinates of Y allows ordering the real parts of the eigenvalues, thus yielding triangular Stokes matrices. However, the choice of the rotation in x is not canonical. In this paper we establish how the collection of Stokes matrices depends on this rotation, and hence on a chosen order of the projection of the eigenvalues on a line through the origin.
Early Experience with the StopLoss Jones Tube.
Bagdonaite, Laura; Pearson, Andrew R
2015-06-01
Extrusion is the most common reason for failure after Jones tube placement. The StopLoss Jones tube (SLJT) is a new innovation in Jones tubes that incorporates a flexible silicone internal flange to resist extrusion. We present our early experience of using this new tube and associated introducer system. We retrospectively analysed the case notes of a single surgeon consecutive series of patients having SLJT placement from November 2011 to November 2013. 29 SLJTs were placed in 25 eyes of 19 patients. Tube follow-up ranged from 1-25 months (mean 10 months) with a total of 291 tube-months. The indications for SLJT placement were: previous LJT complications (52%), failed canalicular-DCR surgery (31%), primary placement for inoperable canalicular occlusion (14%) and patent non-functioning DCR (3%). Tube length ranged from 10-16 mm. The tube introducer system was simple and effective and there were no intra-operative complications. The tube extrusion rate was 0%. Complications occurred in 5 tubes: 1 was too long, and 4 others (14%) developed conjunctival overgrowth/medial tube migration. Patient satisfaction with the tube was: 86% fully satisfied, 10% was moderately satisfied, 3% not satisfied. The overall final surgical success rate at last follow-up was 92%. In this short follow-up initial study the SLJT is simple to use and has a high rate of success and patient satisfaction. The addition of the internal silicone flange appears to prevent the previously common problem of extrusion.
A Viola-Jones based hybrid face detection framework
Murphy, Thomas M.; Broussard, Randy; Schultz, Robert; Rakvic, Ryan; Ngo, Hau
2013-12-01
Improvements in face detection performance would benefit many applications. The OpenCV library implements a standard solution, the Viola-Jones detector, with a statistically boosted rejection cascade of binary classifiers. Empirical evidence has shown that Viola-Jones underdetects in some instances. This research shows that a truncated cascade augmented by a neural network could recover these undetected faces. A hybrid framework is constructed, with a truncated Viola-Jones cascade followed by an artificial neural network, used to refine the face decision. Optimally, a truncation stage that captured all faces and allowed the neural network to remove the false alarms is selected. A feedforward backpropagation network with one hidden layer is trained to discriminate faces based upon the thresholding (detection) values of intermediate stages of the full rejection cascade. A clustering algorithm is used as a precursor to the neural network, to group significant overlappings. Evaluated on the CMU/VASC Image Database, comparison with an unmodified OpenCV approach shows: (1) a 37% increase in detection rates if constrained by the requirement of no increase in false alarms, (2) a 48% increase in detection rates if some additional false alarms are tolerated, and (3) an 82% reduction in false alarms with no reduction in detection rates. These results demonstrate improved face detection and could address the need for such improvement in various applications.
Energy Technology Data Exchange (ETDEWEB)
Rosa, Mychelle M.L.; Custodio, Luis G.; Bonifacio, Rodrigo L.; Taddei, Maria Helena T., E-mail: mychelle@cnen.gov.br, E-mail: Igcustodio@hotmail.com, E-mail: rodrigo@cnen.gov.br, E-mail: mhtaddei@cnen.gov [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), de Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas
2013-10-01
In a testing laboratory the quality system encompasses a set of activities planned and systematic, which ensure the traceability process of an analysis, which is based on the standards NBR ISO/TEC 17025. With the need for analysis of radionuclides in food products to meet the requirements of import and export, accreditation of testing on this standard becomes increasingly necessary. The Gamma Spectrometry is a technique used for direct determination of radionuclides in different matrices, among them the food, being possible the simultaneous determination of different radionuclides in the same sample without the need for a chemical separation. In the process of Accreditation the methodology validation is an important step that includes testing accuracy, traceability, linearity and recovery. This paper describes the procedures used to validate the assay for determining radionuclides using gamma spectrometry in food. These procedures were performed through analysis of a certificated reference material by the International Atomic Energy Agency (IAEA Soil 327), analysis of samples of milk powder prepared from the doping with certified liquid standards also by the results obtained in the participation of tests of proficiency in analysis of environmental samples. (author)
Deterministic matrices matching the compressed sensing phase transitions of Gaussian random matrices
Monajemi, Hatef; Jafarpour, Sina; Gavish, Matan; Donoho, David L.; Ambikasaran, Sivaram; Bacallado, Sergio; Bharadia, Dinesh; Chen, Yuxin; Choi, Young; Chowdhury, Mainak; Chowdhury, Soham; Damle, Anil; Fithian, Will; Goetz, Georges; Grosenick, Logan; Gross, Sam; Hills, Gage; Hornstein, Michael; Lakkam, Milinda; Lee, Jason; Li, Jian; Liu, Linxi; Sing-Long, Carlos; Marx, Mike; Mittal, Akshay; Monajemi, Hatef; No, Albert; Omrani, Reza; Pekelis, Leonid; Qin, Junjie; Raines, Kevin; Ryu, Ernest; Saxe, Andrew; Shi, Dai; Siilats, Keith; Strauss, David; Tang, Gary; Wang, Chaojun; Zhou, Zoey; Zhu, Zhen
2013-01-01
In compressed sensing, one takes samples of an N-dimensional vector using an matrix A, obtaining undersampled measurements . For random matrices with independent standard Gaussian entries, it is known that, when is k-sparse, there is a precisely determined phase transition: for a certain region in the (,)-phase diagram, convex optimization typically finds the sparsest solution, whereas outside that region, it typically fails. It has been shown empirically that the same property—with the same phase transition location—holds for a wide range of non-Gaussian random matrix ensembles. We report extensive experiments showing that the Gaussian phase transition also describes numerous deterministic matrices, including Spikes and Sines, Spikes and Noiselets, Paley Frames, Delsarte-Goethals Frames, Chirp Sensing Matrices, and Grassmannian Frames. Namely, for each of these deterministic matrices in turn, for a typical k-sparse object, we observe that convex optimization is successful over a region of the phase diagram that coincides with the region known for Gaussian random matrices. Our experiments considered coefficients constrained to for four different sets , and the results establish our finding for each of the four associated phase transitions. PMID:23277588
Special matrices of mathematical physics stochastic, circulant and Bell matrices
Aldrovandi, R
2001-01-01
This book expounds three special kinds of matrices that are of physical interest, centering on physical examples. Stochastic matrices describe dynamical systems of many different types, involving (or not) phenomena like transience, dissipation, ergodicity, nonequilibrium, and hypersensitivity to initial conditions. The main characteristic is growth by agglomeration, as in glass formation. Circulants are the building blocks of elementary Fourier analysis and provide a natural gateway to quantum mechanics and noncommutative geometry. Bell polynomials offer closed expressions for many formulas co
Gorre, Elsa; Owens, Kevin G
2016-11-01
In this work an attenuated total reflection Fourier transform infrared (FT-IR) absorption based method is used to measure the solubility of two matrix-assisted laser desorption-ionization (MALDI) matrices in a few pure solvents and mixtures of acetonitrile and water using low microliter amounts of solution. Results from a method that averages the values obtained from multiple calibration curves created by manual peak picking are compared to those predicted using a partial least squares (PLS) chemometrics approach. The PLS method provided solubility values that were in good agreement with the manual method with significantly greater ease of analysis. As a test, the solubility of adipic acid in acetone was measured using the two methods of analysis, and the values are in good agreement with solubility values reported in literature. The solubilities of the MALDI matrices α-cyano-4-hydroxy cinnamic acid (CHCA) and sinapinic acid (SA) were measured in a series of mixtures made from acetonitrile (ACN) and water; surprisingly, the results show a highly nonlinear trend. While both CHCA and SA show solubility values of less than 10 mg/mL in the pure solvents, the solubility value for SA increases to 56.3 mg/mL in a 75:25 v/v ACN:water mixture. This can have a significant effect on the matrix-to-analyte ratios in the MALDI experiment when sample protocols call for preparation of a saturated solution of the matrix in the chosen solvent system. © The Author(s) 2016.
The invariant theory of matrices
Concini, Corrado De
2017-01-01
This book gives a unified, complete, and self-contained exposition of the main algebraic theorems of invariant theory for matrices in a characteristic free approach. More precisely, it contains the description of polynomial functions in several variables on the set of m\\times m matrices with coefficients in an infinite field or even the ring of integers, invariant under simultaneous conjugation. Following Hermann Weyl's classical approach, the ring of invariants is described by formulating and proving the first fundamental theorem that describes a set of generators in the ring of invariants, and the second fundamental theorem that describes relations between these generators. The authors study both the case of matrices over a field of characteristic 0 and the case of matrices over a field of positive characteristic. While the case of characteristic 0 can be treated following a classical approach, the case of positive characteristic (developed by Donkin and Zubkov) is much harder. A presentation of this case...
Quantum matrices in two dimensions
International Nuclear Information System (INIS)
Ewen, H.; Ogievetsky, O.; Wess, J.
1991-01-01
Quantum matrices in two-dimensions, admitting left and right quantum spaces, are classified: they fall into two families, the 2-parametric family GL p,q (2) and a 1-parametric family GL α J (2). Phenomena previously found for GL p,q (2) hold in this general situation: (a) powers of quantum matrices are again quantum and (b) entries of the logarithm of a two-dimensional quantum matrix form a Lie algebra. (orig.)
Four crystal forms of a Bence-Jones protein
Energy Technology Data Exchange (ETDEWEB)
Makino, Debora L.; Henschen-Edman, Agnes H.; McPherson, Alexander, E-mail: amcphers@uci.edu [Molecular Biology and Biochemistry, University of California, Irvine, 560 Steinhaus Hall, Irvine, CA 92697-3900 (United States)
2005-01-01
Four crystal forms have been grown and characterized by X-ray diffraction of a Bence-Jones protein collected from the urine of a multiple myeloma patient more than 40 y ago. The trigonal crystal form may shed some light on the formation of fibrils common to certain storage diseases. Four crystal forms have been grown and characterized by X-ray diffraction of a Bence-Jones protein collected from the urine of a multiple myeloma patient more than 40 years ago. Closely related tetragonal and orthorhombic forms belonging to space groups P4{sub 3}2{sub 1}2 and P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = b = 68.7, c = 182.1 and a = 67.7, b = 69.4, c = 87.3 Å, diffract to 1.5 and 1.9 Å, respectively. Two closely related trigonal forms, both belonging to space group P3{sub 1}21 with unit-cell parameters a = b = 154.3 Å but differing by a doubling of the c axis, one 46.9 Å and the other 94.0 Å, diffract to 2.9 and 2.6 Å resolution, respectively. The trigonal crystal of short c-axis length shows a positive indication of twinning. The trigonal crystal of longer c axis, which appeared only after eight months of incubation at room temperature, is likely to be composed of proteolytically degraded molecules and unlike the other crystal forms contains two entire Bence-Jones dimers in the asymmetric unit. This latter crystal form may shed some light on the formation of fibrils common to certain storage diseases.
Four crystal forms of a Bence-Jones protein
International Nuclear Information System (INIS)
Makino, Debora L.; Henschen-Edman, Agnes H.; McPherson, Alexander
2004-01-01
Four crystal forms have been grown and characterized by X-ray diffraction of a Bence-Jones protein collected from the urine of a multiple myeloma patient more than 40 y ago. The trigonal crystal form may shed some light on the formation of fibrils common to certain storage diseases. Four crystal forms have been grown and characterized by X-ray diffraction of a Bence-Jones protein collected from the urine of a multiple myeloma patient more than 40 years ago. Closely related tetragonal and orthorhombic forms belonging to space groups P4 3 2 1 2 and P2 1 2 1 2 1 , with unit-cell parameters a = b = 68.7, c = 182.1 and a = 67.7, b = 69.4, c = 87.3 Å, diffract to 1.5 and 1.9 Å, respectively. Two closely related trigonal forms, both belonging to space group P3 1 21 with unit-cell parameters a = b = 154.3 Å but differing by a doubling of the c axis, one 46.9 Å and the other 94.0 Å, diffract to 2.9 and 2.6 Å resolution, respectively. The trigonal crystal of short c-axis length shows a positive indication of twinning. The trigonal crystal of longer c axis, which appeared only after eight months of incubation at room temperature, is likely to be composed of proteolytically degraded molecules and unlike the other crystal forms contains two entire Bence-Jones dimers in the asymmetric unit. This latter crystal form may shed some light on the formation of fibrils common to certain storage diseases
Radiation damage in an amorphous Lennard-Jones solid
International Nuclear Information System (INIS)
Chaki, T.K.; Li, J.C.M.
1985-01-01
A molecular-dynamics simulation of radiation damage in an amorphous Lennard-Jones solid has been undertaken. A three-dimensional structure of 685 atoms with periodic boundary conditions was used. An atom was injected inward from the middle of one surface, and as it lost its energy its velocity and position were recorded. The temperature profile around the injection direction was also calculated. The amorphous structure was examined before and after irradiation by calculating the volume distribution of the Voronoi polyhedra and its time evolution. The production of vacancies and interstitials was observed. The interstitials were found to disappear rapidly, and the vacancies slowly. (author)
Information geometry of density matrices and state estimation
International Nuclear Information System (INIS)
Brody, Dorje C
2011-01-01
Given a pure state vector |x) and a density matrix ρ-hat, the function p(x|ρ-hat)= defines a probability density on the space of pure states parameterised by density matrices. The associated Fisher-Rao information measure is used to define a unitary invariant Riemannian metric on the space of density matrices. An alternative derivation of the metric, based on square-root density matrices and trace norms, is provided. This is applied to the problem of quantum-state estimation. In the simplest case of unitary parameter estimation, new higher-order corrections to the uncertainty relations, applicable to general mixed states, are derived. (fast track communication)
Manin matrices and Talalaev's formula
International Nuclear Information System (INIS)
Chervov, A; Falqui, G
2008-01-01
In this paper we study properties of Lax and transfer matrices associated with quantum integrable systems. Our point of view stems from the fact that their elements satisfy special commutation properties, considered by Yu I Manin some 20 years ago at the beginning of quantum group theory. These are the commutation properties of matrix elements of linear homomorphisms between polynomial rings; more explicitly these read: (1) elements of the same column commute; (2) commutators of the cross terms are equal: [M ij , M kl ] [M kj , M il ] (e.g. [M 11 , M 22 ] = [M 21 , M 12 ]). The main aim of this paper is twofold: on the one hand we observe and prove that such matrices (which we call Manin matrices in short) behave almost as well as matrices with commutative elements. Namely, the theorems of linear algebra (e.g., a natural definition of the determinant, the Cayley-Hamilton theorem, the Newton identities and so on and so forth) have a straightforward counterpart in the case of Manin matrices. On the other hand, we remark that such matrices are somewhat ubiquitous in the theory of quantum integrability. For instance, Manin matrices (and their q-analogs) include matrices satisfying the Yang-Baxter relation 'RTT=TTR' and the so-called Cartier-Foata matrices. Also, they enter Talalaev's remarkable formulae: det(∂ z -L gaudin (z)), det(1-e -∂z T Yangian (z)) for the 'quantum spectral curve', and appear in the separation of variables problem and Capelli identities. We show that theorems of linear algebra, after being established for such matrices, have various applications to quantum integrable systems and Lie algebras, e.g. in the construction of new generators in Z(U crit (gl-hat n )) (and, in general, in the construction of quantum conservation laws), in the Knizhnik-Zamolodchikov equation, and in the problem of Wick ordering. We propose, in the appendix, a construction of quantum separated variables for the XXX-Heisenberg system
On reflectionless equi-transmitting matrices
Directory of Open Access Journals (Sweden)
Pavel Kurasov
2014-01-01
Full Text Available Reflectionless equi-transmitting unitary matrices are studied in connection to matching conditions in quantum graphs. All possible such matrices of size 6 are described explicitly. It is shown that such matrices form 30 six-parameter families intersected along 12 five-parameter families closely connected to conference matrices.
Spectra of sparse random matrices
International Nuclear Information System (INIS)
Kuehn, Reimer
2008-01-01
We compute the spectral density for ensembles of sparse symmetric random matrices using replica. Our formulation of the replica-symmetric ansatz shares the symmetries of that suggested in a seminal paper by Rodgers and Bray (symmetry with respect to permutation of replica and rotation symmetry in the space of replica), but uses a different representation in terms of superpositions of Gaussians. It gives rise to a pair of integral equations which can be solved by a stochastic population-dynamics algorithm. Remarkably our representation allows us to identify pure-point contributions to the spectral density related to the existence of normalizable eigenstates. Our approach is not restricted to matrices defined on graphs with Poissonian degree distribution. Matrices defined on regular random graphs or on scale-free graphs, are easily handled. We also look at matrices with row constraints such as discrete graph Laplacians. Our approach naturally allows us to unfold the total density of states into contributions coming from vertices of different local coordinations and an example of such an unfolding is presented. Our results are well corroborated by numerical diagonalization studies of large finite random matrices
Free probability and random matrices
Mingo, James A
2017-01-01
This volume opens the world of free probability to a wide variety of readers. From its roots in the theory of operator algebras, free probability has intertwined with non-crossing partitions, random matrices, applications in wireless communications, representation theory of large groups, quantum groups, the invariant subspace problem, large deviations, subfactors, and beyond. This book puts a special emphasis on the relation of free probability to random matrices, but also touches upon the operator algebraic, combinatorial, and analytic aspects of the theory. The book serves as a combination textbook/research monograph, with self-contained chapters, exercises scattered throughout the text, and coverage of important ongoing progress of the theory. It will appeal to graduate students and all mathematicians interested in random matrices and free probability from the point of view of operator algebras, combinatorics, analytic functions, or applications in engineering and statistical physics.
Chequered surfaces and complex matrices
International Nuclear Information System (INIS)
Morris, T.R.; Southampton Univ.
1991-01-01
We investigate a large-N matrix model involving general complex matrices. It can be reinterpreted as a model of two hermitian matrices with specific couplings, and as a model of positive definite hermitian matrices. Large-N perturbation theory generates dynamical triangulations in which the triangles can be chequered (i.e. coloured so that neighbours are opposite colours). On a sphere there is a simple relation between such triangulations and those generated by the single hermitian matrix model. For the torus (and a quartic potential) we solve the counting problem for the number of triangulations that cannot be quechered. The critical physics of chequered triangulations is the same as that of the hermitian matrix model. We show this explicitly by solving non-perturbatively pure two-dimensional ''chequered'' gravity. The interpretative framework given here applies to a number of other generalisations of the hermitian matrix model. (orig.)
The BQP-hardness of approximating the Jones polynomial
Energy Technology Data Exchange (ETDEWEB)
Aharonov, Dorit; Arad, Itai, E-mail: itaia@cs.huji.ac.il [Department of Computer Science and Engineering, Hebrew University, Jerusalem (Israel)
2011-03-15
A celebrated important result due to Freedman et al (2002 Commun. Math. Phys. 227 605-22) states that providing additive approximations of the Jones polynomial at the kth root of unity, for constant k=5 and k{>=}7, is BQP-hard. Together with the algorithmic results of Aharonov et al (2005) and Freedman et al (2002 Commun. Math. Phys. 227 587-603), this gives perhaps the most natural BQP-complete problem known today and motivates further study of the topic. In this paper, we focus on the universality proof; we extend the result of Freedman et al (2002) to ks that grow polynomially with the number of strands and crossings in the link, thus extending the BQP-hardness of Jones polynomial approximations to all values to which the AJL algorithm applies (Aharonov et al 2005), proving that for all those values, the problems are BQP-complete. As a side benefit, we derive a fairly elementary proof of the Freedman et al density result, without referring to advanced results from Lie algebra representation theory, making this important result accessible to a wider audience in the computer science research community. We make use of two general lemmas we prove, the bridge lemma and the decoupling lemma, which provide tools for establishing the density of subgroups in SU(n). Those tools seem to be of independent interest in more general contexts of proving the quantum universality. Our result also implies a completely classical statement, that the multiplicative approximations of the Jones polynomial, at exactly the same values, are P-hard, via a recent result due to Kuperberg (2009 arXiv:0908.0512). Since the first publication of those results in their preliminary form (Aharonov and Arad 2006 arXiv:quant-ph/0605181), the methods we present here have been used in several other contexts (Aharonov and Arad 2007 arXiv:quant-ph/0702008; Peter and Stephen 2008 Quantum Inf. Comput. 8 681). The present paper is an improved and extended version of the results presented by Aharonov and
The BQP-hardness of approximating the Jones polynomial
International Nuclear Information System (INIS)
Aharonov, Dorit; Arad, Itai
2011-01-01
A celebrated important result due to Freedman et al (2002 Commun. Math. Phys. 227 605-22) states that providing additive approximations of the Jones polynomial at the kth root of unity, for constant k=5 and k≥7, is BQP-hard. Together with the algorithmic results of Aharonov et al (2005) and Freedman et al (2002 Commun. Math. Phys. 227 587-603), this gives perhaps the most natural BQP-complete problem known today and motivates further study of the topic. In this paper, we focus on the universality proof; we extend the result of Freedman et al (2002) to ks that grow polynomially with the number of strands and crossings in the link, thus extending the BQP-hardness of Jones polynomial approximations to all values to which the AJL algorithm applies (Aharonov et al 2005), proving that for all those values, the problems are BQP-complete. As a side benefit, we derive a fairly elementary proof of the Freedman et al density result, without referring to advanced results from Lie algebra representation theory, making this important result accessible to a wider audience in the computer science research community. We make use of two general lemmas we prove, the bridge lemma and the decoupling lemma, which provide tools for establishing the density of subgroups in SU(n). Those tools seem to be of independent interest in more general contexts of proving the quantum universality. Our result also implies a completely classical statement, that the multiplicative approximations of the Jones polynomial, at exactly the same values, are P-hard, via a recent result due to Kuperberg (2009 arXiv:0908.0512). Since the first publication of those results in their preliminary form (Aharonov and Arad 2006 arXiv:quant-ph/0605181), the methods we present here have been used in several other contexts (Aharonov and Arad 2007 arXiv:quant-ph/0702008; Peter and Stephen 2008 Quantum Inf. Comput. 8 681). The present paper is an improved and extended version of the results presented by Aharonov and Arad
Loop diagrams without γ matrices
International Nuclear Information System (INIS)
McKeon, D.G.C.; Rebhan, A.
1993-01-01
By using a quantum-mechanical path integral to compute matrix elements of the form left-angle x|exp(-iHt)|y right-angle, radiative corrections in quantum-field theory can be evaluated without encountering loop-momentum integrals. In this paper we demonstrate how Dirac γ matrices that occur in the proper-time ''Hamiltonian'' H lead to the introduction of a quantum-mechanical path integral corresponding to a superparticle analogous to one proposed recently by Fradkin and Gitman. Direct evaluation of this path integral circumvents many of the usual algebraic manipulations of γ matrices in the computation of quantum-field-theoretical Green's functions involving fermions
Immanant Conversion on Symmetric Matrices
Directory of Open Access Journals (Sweden)
Purificação Coelho M.
2014-01-01
Full Text Available Letr Σn(C denote the space of all n χ n symmetric matrices over the complex field C. The main objective of this paper is to prove that the maps Φ : Σn(C -> Σn (C satisfying for any fixed irre- ducible characters X, X' -SC the condition dx(A +aB = dχ·(Φ(Α + αΦ(Β for all matrices A,В ε Σ„(С and all scalars a ε C are automatically linear and bijective. As a corollary of the above result we characterize all such maps Φ acting on ΣИ(С.
Glass of monatomic Lennard-Jones system at nanoscale
International Nuclear Information System (INIS)
Vo Van Hoang
2010-01-01
Structure and stability of glass of monatomic Lennard-Jones (LJ) system at nanoscale compared with those of the bulk counterparts have been studied using the classical molecular dynamics (MD) method. Models have been obtained by cooling from the melts. Structure of the systems was analyzed via radial distribution function (RDF), interatomic distances, the Honeycutt-Andersen analysis and coordination number distributions. Surface and core structures of LJ nanoparticles have been analyzed in details. Density dependence and cooling rate effects on structure of the systems have been found and discussed. In addition, size dependence of structure and properties of nanoparticles has been analyzed in detail. Indeed, we found glass formation in monatomic LJ systems; however, their stability is not high. Evolution of structure and thermodynamics of the systems upon cooling from the melts was found. We also discussed annealing-induced crystallization of LJ glass.
Robin Huws Jones (United Kingdom, President 1976- 1980
Directory of Open Access Journals (Sweden)
2008-07-01
Full Text Available Robin Huws Jones, President of the International Association of Schools of Social Work from 1976 to 1980, lived a life of challenge and change. Born in Wales in 1909, he often remarked that learning to speak Welsh at age two was such a challenge that he didn’t bother to learn English until he was six. The death of his mother when he was three led to the first of many changes in a life that was not easy in the formative years. Robin remained in the care of his father while his sister became the ward of two aunts. With his father, a draper’sassistant, he left Wales to live in a crowded boarding house in Liverpool.
Phase behavior of the 38-atom Lennard-Jones cluster
International Nuclear Information System (INIS)
Sehgal, Ray M.; Maroudas, Dimitrios; Ford, David M.
2014-01-01
We have developed a coarse-grained description of the phase behavior of the isolated 38-atom Lennard-Jones cluster (LJ 38 ). The model captures both the solid-solid polymorphic transitions at low temperatures and the complex cluster breakup and melting transitions at higher temperatures. For this coarse model development, we employ the manifold learning technique of diffusion mapping. The outcome of the diffusion mapping analysis over a broad temperature range indicates that two order parameters are sufficient to describe the cluster's phase behavior; we have chosen two such appropriate order parameters that are metrics of condensation and overall crystallinity. In this well-justified coarse-variable space, we calculate the cluster's free energy landscape (FEL) as a function of temperature, employing Monte Carlo umbrella sampling. These FELs are used to quantify the phase behavior and onsets of phase transitions of the LJ 38 cluster
Water in the presence of inert Lennard-Jones obstacles
Kurtjak, Mario; Urbic, Tomaz
2014-04-01
Water confined by the presence of a 'sea' of inert obstacles was examined. In the article, freely mobile two-dimensional Mercedes-Benz (MB) water put to a disordered, but fixed, matrix of Lennard-Jones disks was studied by the Monte Carlo computer simulations. For the MB water molecules in the matrix of Lennard-Jones disks, we explored the structures, hydrogen-bond-network formation and thermodynamics as a function of temperature and size and density of matrix particles. We found that the structure of model water is perturbed by the presence of the obstacles. Density of confined water, which was in equilibrium with the bulk water, was smaller than the density of the bulk water and the temperature dependence of the density of absorbed water did not show the density anomaly in the studied temperature range. The behaviour observed as a consequence of confinement is similar to that of increasing temperature, which can for a matrix lead to a process similar to capillary evaporation. At the same occupancy of space, smaller matrix molecules cause higher destruction effect on the absorbed water molecules than the bigger ones. We have also tested the hypothesis that at low matrix densities the obstacles induce an increased ordering and 'hydrogen bonding' of the MB model molecules, relative to pure fluid, while at high densities the obstacles reduce MB water structuring, as they prevent the fluid to form good 'hydrogen-bonding' networks. However, for the size of matrix molecules similar to that of water, we did not observe this effect.
A Lennard-Jones-like perspective on first order transitions in biological helices
DEFF Research Database (Denmark)
Oskolkov, Nikolay N.; Bohr, Jakob
2013-01-01
Helical structures with Lennard-Jones self-interactions are studied for optimal conformations. For this purpose, their self-energy is analyzed for extrema with respect to the geometric parameters of the helices. It is found that Lennard-Jones helices exhibit a first order phase transition from...
Effect of money supply on the Dow Jones Industrial Average stock index
Directory of Open Access Journals (Sweden)
Martin Širůček
2012-01-01
Full Text Available This focus of this paper are the effects and implications of a change in the money supply for share price indices in the USA during 1959–2011. The money supply will be measured by the M2 and MZM aggregates (money with zero maturity. The US stock market is represented by the Dow Jones Industrial Average index. The objective of this paper is to find, describe and evaluate the effects of changes to the money supply (M2 and MZM on the US stock market. A partial objective of this paper is to determine whether a change in the monetary aggregate shows in the stock index immediately or with a delay of several weeks. Another aim is to determine whether asset prices influence the money supply.
On families of anticommuting matrices
Czech Academy of Sciences Publication Activity Database
Hrubeš, Pavel
2016-01-01
Roč. 493, March 15 (2016), s. 494-507 ISSN 0024-3795 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : anticommuting matrices * sum-of-squares formulas Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2016 http://www.sciencedirect.com/science/article/pii/S0024379515007296
On families of anticommuting matrices
Czech Academy of Sciences Publication Activity Database
Hrubeš, Pavel
2016-01-01
Roč. 493, March 15 (2016), s. 494-507 ISSN 0024-3795 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : anticommuting matrices * sum -of-squares formulas Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2016 http://www.sciencedirect.com/science/article/pii/S0024379515007296
Arnold, Tim; Schönbächler, Maria; Rehkämper, Mark; Dong, Schuofei; Zhao, Fang-Jie; Kirk, Guy J D; Coles, Barry J; Weiss, Dominik J
2010-12-01
Analysis of naturally occurring isotopic variations is a promising tool for investigating Zn transport and cycling in geological and biological settings. Here, we present the recently installed double-spike (DS) technique at the MAGIC laboratories at Imperial College London. The procedure improves on previous published DS methods in terms of ease of measurement and precisions obtained. The analytical method involves addition of a (64)Zn-(67)Zn double-spike to the samples prior to digestion, separation of Zn from the sample matrix by ion exchange chromatography, and isotopic analysis by multiple-collector inductively coupled plasma mass spectrometry. The accuracy and reproducibility of the method were validated by analyses of several in-house and international elemental reference materials. Multiple analyses of pure Zn standard solutions consistently yielded a reproducibility of about ±0.05‰ (2 SD) for δ(66)Zn, and comparable precisions were obtained for analyses of geological and biological materials. Highly fractionated Zn standards analyzed by DS and standard sample bracketing yield slightly varying results, which probably originate from repetitive fractionation events during manufacture of the standards. However, the δ(66)Zn values (all reported relative to JMC Lyon Zn) for two less fractionated in-house Zn standard solutions, Imperial Zn (0.10 ± 0.08‰: 2 SD) and London Zn (0.08 ± 0.04‰), are within uncertainties to data reported with different mass spectrometric techniques and instruments. Two standard reference materials, blend ore BCR 027 and ryegrass BCR 281, were also measured, and the δ(66)Zn were found to be 0.25 ± 0.06‰ (2 SD) and 0.40 ± 0.09‰, respectively. Taken together, these standard measurements ascertain that the double-spike methodology is suitable for accurate and precise Zn isotope analyses of a wide range of natural samples. The newly installed technique was consequently applied to soil samples and soil leachates to
International Nuclear Information System (INIS)
SIDDIQUE, N.; Rahman, A.; Waheed, S.; Wasim, M.; Daud, M.; Ahmad, S.
2006-03-01
A Quality Assessment Programme (QAP) was initiated by the US, Department of Energy (DOE) in 1998 to establish credibility of radionuclide measurements in contaminated environmental samples, i.e. soil, vegetation and air filters. In this context best-known and pertinent laboratories around the world were identified and invited to participate in this programme. To evaluate the performance of these prestigious laboratories, the Miniature Neutron Source Reactor (MNSR) Neutron Activation Analysis (NAA) Laboratory at NCD, PINSTECH, which is an IAEA declared Regional Resource Unit (IAEA-RRU), along with 76 other laboratories were asked to take part in a regular proficiency exercise. In this report, the performance of the NAA Laboratory throughout the QAP programme (1998-2004) is presented is detail, describing the procedures employed, the problems encountered and the improvement and expertise gained from participating in this assessment programme. (author)
Deterministic matrices matching the compressed sensing phase transitions of Gaussian random matrices
Monajemi, Hatef; Jafarpour, Sina; Gavish, Matan; Donoho, David L.; Ambikasaran, Sivaram; Bacallado, Sergio; Bharadia, Dinesh; Chen, Yuxin; Choi, Young; Chowdhury, Mainak; Chowdhury, Soham; Damle, Anil; Fithian, Will; Goetz, Georges; Grosenick, Logan
2012-01-01
In compressed sensing, one takes samples of an N-dimensional vector using an matrix A, obtaining undersampled measurements . For random matrices with independent standard Gaussian entries, it is known that, when is k-sparse, there is a precisely determined phase transition: for a certain region in the (,)-phase diagram, convex optimization typically finds the sparsest solution, whereas outside that region, it typically fails. It has been shown empirically that the same property—with the ...
Determination of coefficient matrices for ARMA model
International Nuclear Information System (INIS)
Tran Dinh Tri.
1990-10-01
A new recursive algorithm for determining coefficient matrices of ARMA model from measured data is presented. The Yule-Walker equations for the case of ARMA model are derived from the ARMA innovation equation. The recursive algorithm is based on choosing appropriate form of the operator functions and suitable representation of the (n+1)-th order operator functions according to ones with the lower order. Two cases, when the order of the AR part is equal to one of the MA part, and the optimal case, were considered. (author) 5 refs
The modified Gauss diagonalization of polynomial matrices
International Nuclear Information System (INIS)
Saeed, K.
1982-10-01
The Gauss algorithm for diagonalization of constant matrices is modified for application to polynomial matrices. Due to this modification the diagonal elements become pure polynomials rather than rational functions. (author)
Double stochastic matrices in quantum mechanics
International Nuclear Information System (INIS)
Louck, J.D.
1997-01-01
The general set of doubly stochastic matrices of order n corresponding to ordinary nonrelativistic quantum mechanical transition probability matrices is given. Lande's discussion of the nonquantal origin of such matrices is noted. Several concrete examples are presented for elementary and composite angular momentum systems with the focus on the unitary symmetry associated with such systems in the spirit of the recent work of Bohr and Ulfbeck. Birkhoff's theorem on doubly stochastic matrices of order n is reformulated in a geometrical language suitable for application to the subset of quantum mechanical doubly stochastic matrices. Specifically, it is shown that the set of points on the unit sphere in cartesian n'-space is subjective with the set of doubly stochastic matrices of order n. The question is raised, but not answered, as to what is the subset of points of this unit sphere that correspond to the quantum mechanical transition probability matrices, and what is the symmetry group of this subset of matrices
Virial expansion for almost diagonal random matrices
Yevtushenko, Oleg; Kravtsov, Vladimir E.
2003-08-01
Energy level statistics of Hermitian random matrices hat H with Gaussian independent random entries Higeqj is studied for a generic ensemble of almost diagonal random matrices with langle|Hii|2rangle ~ 1 and langle|Hi\
Agricultural matrices affect ground ant assemblage composition inside forest fragments.
Directory of Open Access Journals (Sweden)
Diego Santana Assis
Full Text Available The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates; sugarcane (3; and pasture (3. At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart. Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.
Agricultural matrices affect ground ant assemblage composition inside forest fragments.
Assis, Diego Santana; Dos Santos, Iracenir Andrade; Ramos, Flavio Nunes; Barrios-Rojas, Katty Elena; Majer, Jonathan David; Vilela, Evaldo Ferreira
2018-01-01
The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices) on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates); sugarcane (3); and pasture (3). At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart). Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.
Physical properties of the Schur complement of local covariance matrices
International Nuclear Information System (INIS)
Haruna, L F; Oliveira, M C de
2007-01-01
General properties of global covariance matrices representing bipartite Gaussian states can be decomposed into properties of local covariance matrices and their Schur complements. We demonstrate that given a bipartite Gaussian state ρ 12 described by a 4 x 4 covariance matrix V, the Schur complement of a local covariance submatrix V 1 of it can be interpreted as a new covariance matrix representing a Gaussian operator of party 1 conditioned to local parity measurements on party 2. The connection with a partial parity measurement over a bipartite quantum state and the determination of the reduced Wigner function is given and an operational process of parity measurement is developed. Generalization of this procedure to an n-partite Gaussian state is given, and it is demonstrated that the n - 1 system state conditioned to a partial parity projection is given by a covariance matrix such that its 2 x 2 block elements are Schur complements of special local matrices
Phenomenological mass matrices with a democratic warp
International Nuclear Information System (INIS)
Kleppe, A.
2018-01-01
Taking into account all available data on the mass sector, we obtain unitary rotation matrices that diagonalize the quark matrices by using a specific parametrization of the Cabibbo-Kobayashi-Maskawa mixing matrix. In this way, we find mass matrices for the up- and down-quark sectors of a specific, symmetric form, with traces of a democratic texture.
International Nuclear Information System (INIS)
Jarlskog, C.; Stockholm Univ.; Bergen Univ.
1985-01-01
In the standard electroweak model, with three families, a one-to-one correspondence between certain determinants involving quark mass matrices (m and m' for charge 2/3 and -1/3 quarks respectively) and the presence/absence of CP violation is given. In an arbitrary basis for mass matrices, the quantity Im det[mm + , m'm' + ] appropriately normalized is introduced as a measure of CP violation. By this measure, CP is not maximally violated in any transition in Nature. Finally, constraints on quark mass matrices are derived from experiment. Any model of mass matrices, with the ambition to explain Nature, must satisfy these conditions. (orig.)
Vere-Jones' self-similar branching model
International Nuclear Information System (INIS)
Saichev, A.; Sornette, D.
2005-01-01
Motivated by its potential application to earthquake statistics as well as for its intrinsic interest in the theory of branching processes, we study the exactly self-similar branching process introduced recently by Vere-Jones. This model extends the ETAS class of conditional self-excited branching point-processes of triggered seismicity by removing the problematic need for a minimum (as well as maximum) earthquake size. To make the theory convergent without the need for the usual ultraviolet and infrared cutoffs, the distribution of magnitudes m ' of daughters of first-generation of a mother of magnitude m has two branches m ' ' >m with exponent β+d, where β and d are two positive parameters. We investigate the condition and nature of the subcritical, critical, and supercritical regime in this and in an extended version interpolating smoothly between several models. We predict that the distribution of magnitudes of events triggered by a mother of magnitude m over all generations has also two branches m ' ' >m with exponent β+h, with h=d√(1-s), where s is the fraction of triggered events. This corresponds to a renormalization of the exponent d into h by the hierarchy of successive generations of triggered events. For a significant part of the parameter space, the distribution of magnitudes over a full catalog summed over an average steady flow of spontaneous sources (immigrants) reproduces the distribution of the spontaneous sources with a single branch and is blind to the exponents β,d of the distribution of triggered events. Since the distribution of earthquake magnitudes is usually obtained with catalogs including many sequences, we conclude that the two branches of the distribution of aftershocks are not directly observable and the model is compatible with real seismic catalogs. In summary, the exactly self-similar Vere-Jones model provides an attractive new approach to model triggered seismicity, which alleviates delicate questions on the role of
Energy Technology Data Exchange (ETDEWEB)
Frechou, C
2000-07-01
{sup 129}I, is a natural long-lived isotope, with a half-life of 15,7 million years, also artificially produced in nuclear power plant. It is then released in the liquid and gaseous effluents of the nuclear fuel reprocessing plants. {sup 129}I is integrated in all biological compartments at different activity levels, depending on their distance from the emission source and their ability to metabolize iodine. Performances of the different {sup 129}I and {sup 129}I/{sup 127}I measurement techniques available: Radiochemical Neutron Activation Analysis, Accelerator Mass Spectrometry, direct {gamma}-X spectrometry and liquid scintillation were evaluated. Associated radiochemical preparation steps of the two first techniques were optimized and adapted to the characteristics of the major environmental matrices. In a first step, the radiochemical protocols were developed and validated. In a second step, intercomparison exercises have been lead on various environmental samples presenting different {sup 129}I activity levels. They showed the good agreement between the results given by the three techniques on different environmental matrices with activities between 0,2 and 200 Bq.kg{sup -1} dry weight. As a conclusion, a methodology for the measurement of {sup 129}I and {sup 129}I/{sup 127}I ratio in environmental samples is proposed. It includes a decisional diagram taking into account the characteristics of the matrices, the detection limits and the answer delay. A study on the losses of {sup 129}I during the calcination of an algae was lead by direct {gamma}-X spectrometry and application studies were made to measure {sup 129}I levels in different biological compartments issued from various locations: {sup 129}I activity interspecific variation in different species of seaweeds from the French channel coast under the relative influence of La Hague, {sup 129}I levels in bovine thyroids from the Cotentin area and {sup 129}I in vegetal samples collected around the nuclear
International Nuclear Information System (INIS)
Bombardelli, Diego
2016-01-01
In these notes we review the S-matrix theory in (1+1)-dimensional integrable models, focusing mainly on the relativistic case. Once the main definitions and physical properties are introduced, we discuss the factorization of scattering processes due to integrability. We then focus on the analytic properties of the two-particle scattering amplitude and illustrate the derivation of the S-matrices for all the possible bound states using the so-called bootstrap principle. General algebraic structures underlying the S-matrix theory and its relation with the form factors axioms are briefly mentioned. Finally, we discuss the S-matrices of sine-Gordon and SU (2), SU (3) chiral Gross–Neveu models. (topical review)
Synthesised standards in natural matrices
International Nuclear Information System (INIS)
Olsen, D.G.
1980-01-01
The problem of securing the most reliable standards for the accurate analysis of radionuclides is discussed in the paper and in the comment on the paper. It is contended in the paper that the best standards can be created by quantitative addition of accurately known spiking solutions into carefully selected natural matrices. On the other hand it is argued that many natural materials can be successfully standardized for numerous trace constituents. Both points of view are supported with examples. (U.K.)
Lacerda, Kássio André; Lameiras, Fernando Soares; Silva, Viviane Viana
2007-01-01
In this study, non-radioactive iodine was incorporated in two types of biodegradable hydroxyapatite-based porous matrices (HA and HACL) through impregnation process from sodium iodine aqueous solutions with varying concentrations (0.5 and 1.0 mol/L) . The results revealed that both systems presented a high capacity of incorporating iodine into their matrices. The quantity of incorporated iodine was measured through Neutron Activation Analysis (NAA). The porous ceramic matrices based on hydrox...
Contact angle of sessile drops in Lennard-Jones systems.
Becker, Stefan; Urbassek, Herbert M; Horsch, Martin; Hasse, Hans
2014-11-18
Molecular dynamics simulations are used for studying the contact angle of nanoscale sessile drops on a planar solid wall in a system interacting via the truncated and shifted Lennard-Jones potential. The entire range between total wetting and dewetting is investigated by varying the solid-fluid dispersive interaction energy. The temperature is varied between the triple point and the critical temperature. A correlation is obtained for the contact angle in dependence of the temperature and the dispersive interaction energy. Size effects are studied by varying the number of fluid particles at otherwise constant conditions, using up to 150,000 particles. For particle numbers below 10,000, a decrease of the contact angle is found. This is attributed to a dependence of the solid-liquid surface tension on the droplet size. A convergence to a constant contact angle is observed for larger system sizes. The influence of the wall model is studied by varying the density of the wall. The effective solid-fluid dispersive interaction energy at a contact angle of θ = 90° is found to be independent of temperature and to decrease linearly with the solid density. A correlation is developed that describes the contact angle as a function of the dispersive interaction, the temperature, and the solid density. The density profile of the sessile drop and the surrounding vapor phase is described by a correlation combining a sigmoidal function and an oscillation term.
Modified Kenneth Jones criteria for diagnosing tuberculous meningitis in children
International Nuclear Information System (INIS)
Anwar, M.; Ahmad, A.; Ahmad, F.; Mazhar, A.
2010-01-01
To evaluate accuracy of modified Kenneth Jones scoring criteria (MKJSC) as a screening tool to diagnose tuberculous meningitis in children. Study Design: Cross-sectional study. Place and Duration of Study: Paediatric Medicine, Unit-I, Bahawal Victoria Hospital, Bahawalpur, from May 2006 to March 2007. Methodology: A total of 100 children admitted through emergency in Paediatric Medicine, Unit-I, were included who were having fever and features suggestive of central nervous system (CNS) infection. Lumbar puncture was done in all patients after written consent. Findings of lumbar puncture were taken as gold standard for the diagnosis of TBM. MKJSC was applied on each patient and accuracy determined against the gold standard. Results: Out of 100 children, 47 were diagnosed as TBM on the basis of CSF results. All children had scored 0-7 or above according to MKJSC. A score 1-2, 3-4, 5-6 and 7 or more was obtained in 23, 25, 30 and 22 children respectively. Children who had scored 5 or more received ATT. Accuracy of MKJSC was calculated to be 91%. Conclusion: MKJSC is a simple and accurate tool to improve tuberculous meningitis case detection rate in children. (author)
Longitudinal and bulk viscosities of Lennard-Jones fluids
Tankeshwar, K.; Pathak, K. N.; Ranganathan, S.
1996-12-01
Expressions for the longitudinal and bulk viscosities have been derived using Green Kubo formulae involving the time integral of the longitudinal and bulk stress autocorrelation functions. The time evolution of stress autocorrelation functions are determined using the Mori formalism and a memory function which is obtained from the Mori equation of motion. The memory function is of hyperbolic secant form and involves two parameters which are related to the microscopic sum rules of the respective autocorrelation function. We have derived expressions for the zeroth-, second-and fourth- order sum rules of the longitudinal and bulk stress autocorrelation functions. These involve static correlation functions up to four particles. The final expressions for these have been put in a form suitable for numerical calculations using low- order decoupling approximations. The numerical results have been obtained for the sum rules of longitudinal and bulk stress autocorrelation functions. These have been used to calculate the longitudinal and bulk viscosities and time evolution of the longitudinal stress autocorrelation function of the Lennard-Jones fluids over wide ranges of densities and temperatures. We have compared our results with the available computer simulation data and found reasonable agreement.
Jones index, secret sharing and total quantum dimension
Fiedler, Leander; Naaijkens, Pieter; Osborne, Tobias J.
2017-02-01
We study the total quantum dimension in the thermodynamic limit of topologically ordered systems. In particular, using the anyons (or superselection sectors) of such models, we define a secret sharing scheme, storing information invisible to a malicious party, and argue that the total quantum dimension quantifies how well we can perform this task. We then argue that this can be made mathematically rigorous using the index theory of subfactors, originally due to Jones and later extended by Kosaki and Longo. This theory provides us with a ‘relative entropy’ of two von Neumann algebras and a quantum channel, and we argue how these can be used to quantify how much classical information two parties can hide form an adversary. We also review the total quantum dimension in finite systems, in particular how it relates to topological entanglement entropy. It is known that the latter also has an interpretation in terms of secret sharing schemes, although this is shown by completely different methods from ours. Our work provides a different and independent take on this, which at the same time is completely mathematically rigorous. This complementary point of view might be beneficial, for example, when studying the stability of the total quantum dimension when the system is perturbed.
Vacancy behavior in a compressed fcc Lennard-Jones crystal
International Nuclear Information System (INIS)
Beeler, J.R. Jr.
1981-12-01
This computer experiment study concerns the determination of the stable vacancy configuration in a compressed fcc Lennard-Jones crystal and the migration of this defect in a compressed crystal. Isotropic and uniaxial compression stress conditions were studied. The isotropic and uniaxial compression magnitudes employed were 0.94 less than or equal to eta less than or equal to 1.5, and 1.0 less than or equal to eta less than or equal to 1.5, respectively. The site-centered vacancy (SCV) was the stable vacancy configuration whenever cubic symmetry was present. This includes all of the isotropic compression cases and the particular uniaxial compression case (eta = √2) that give a bcc structure. In addition, the SCV was the stable configuration for uniaxial compression eta 1.20, the SV-OP is an extended defect and, therefore, a saddle point for SV-OP migration could not be determined. The mechanism for the transformation from the SCV to the SV-OP as the stable form at eta = 1.29 appears to be an alternating sign [101] and/or [011] shear process
The Jones polynomial as a new invariant of topological fluid dynamics
International Nuclear Information System (INIS)
Ricca, Renzo L; Liu, Xin
2014-01-01
A new method based on the use of the Jones polynomial, a well-known topological invariant of knot theory, is introduced to tackle and quantify topological aspects of structural complexity of vortex tangles in ideal fluids. By re-writing the Jones polynomial in terms of helicity, the resulting polynomial becomes then function of knot topology and vortex circulation, providing thus a new invariant of topological fluid dynamics. Explicit computations of the Jones polynomial for some standard configurations, including the Whitehead link and the Borromean rings (whose linking numbers are zero), are presented for illustration. In the case of a homogeneous, isotropic tangle of vortex filaments with same circulation, the new Jones polynomial reduces to some simple algebraic expression, that can be easily computed by numerical methods. This shows that this technique may offer a new setting and a powerful tool to detect and compute topological complexity and to investigate relations with energy, by tackling fundamental aspects of turbulence research. (paper)
The impact of modifying the Jones Act on US coastal shipping.
2014-06-01
The study assesses exempt coastal shipping defined as exempted from the US-built stipulation of the : Jones Act, operating with functional crews and exempted from Harbor Maintenance Tax (HMT). The : study focuses on two research questions: (a) the im...
Symmetric webs, Jones-Wenzl recursions and q-Howe duality
DEFF Research Database (Denmark)
Rose, David; Tubbenhauer, Daniel
We define and study the category of symmetric sl2-webs. This category is a combinatorial description of the category of all finite dimensional quantum sl2-modules. Explicitly, we show that (the additive closure of) the symmetric sl2-spider is (braided monoidally) equivalent to the latter. Our mai...... tool is a quantum version of symmetric Howe duality. As a corollary of our construction, we provide new insight into Jones-Wenzl projectors and the colored Jones polynomials....
Are there Long-Run Diversification Gains from the Dow Jones Islamic Finance Index?
Mehmet Balcilar; Charl Jooste; Shawkat Hammoudeh; Rangan Gupta; Vassilios Babalos
2014-01-01
We compare nonlinear cointegration tests with the standard cointegration tests in studying the relationship of the Dow Jones Islamic finance index with three other conventional equity market indices. Our results show that there is a long-run nonlinear cointegrating relationship between the Dow Jones Islamic stock market index and other conventional stock market indices. Our findings rely on a battery of standard tests as well as on the Bierens and Martins (2010) test that investigates time-va...
Staging Henry Fielding: The Author-Narrator in Tom Jones On Screen
Løfaldli, Eli
2017-01-01
As recent adaptation theory has shown, classic-novel adaptation typically sets issues connected to authorship and literal and figurative ownership into play. This key feature of such adaptations is also central to the screen versions of Henry Fielding’s Tom Jones (1749). In much of Fielding’s fiction, the narrator, typically understood as an embodiment of Fielding himself, is a particularly prominent presence. The author-narrator in Tom Jones is no exception: not only is his presence strongly...
The Inverse of Banded Matrices
2013-01-01
indexed entries all zeros. In this paper, generalizing a method of Mallik (1999) [5], we give the LU factorization and the inverse of the matrix Br,n (if it...r ≤ i ≤ r, 1 ≤ j ≤ r, with the remaining un-indexed entries all zeros. In this paper generalizing a method of Mallik (1999) [5...matrices and applications to piecewise cubic approximation, J. Comput. Appl. Math. 8 (4) (1982) 285–288. [5] R.K. Mallik , The inverse of a lower
Fusion algebra and fusing matrices
International Nuclear Information System (INIS)
Gao Yihong; Li Miao; Yu Ming.
1989-09-01
We show that the Wilson line operators in topological field theories form a fusion algebra. In general, the fusion algebra is a relation among the fusing (F) matrices. In the case of the SU(2) WZW model, some special F matrix elements are found in this way, and the remaining F matrix elements are then determined up to a sign. In addition, the S(j) modular transformation of the one point blocks on the torus is worked out. Our results are found to agree with those obtained from the quantum group method. (author). 24 refs
Transfer matrices for multilayer structures
International Nuclear Information System (INIS)
Baquero, R.
1988-08-01
We consider four of the transfer matrices defined to deal with multilayer structures. We deduce algorithms to calculate them numerically, in a simple and neat way. We illustrate their application to semi-infinite systems using SGFM formulae. These algorithms are of fast convergence and allow a calculation of bulk-, surface- and inner-layers band structure in good agreement with much more sophisticated calculations. Supermatrices, interfaces and multilayer structures can be calculated in this way with a small computational effort. (author). 10 refs
Orthogonal polynomials and random matrices
Deift, Percy
2000-01-01
This volume expands on a set of lectures held at the Courant Institute on Riemann-Hilbert problems, orthogonal polynomials, and random matrix theory. The goal of the course was to prove universality for a variety of statistical quantities arising in the theory of random matrix models. The central question was the following: Why do very general ensembles of random n {\\times} n matrices exhibit universal behavior as n {\\rightarrow} {\\infty}? The main ingredient in the proof is the steepest descent method for oscillatory Riemann-Hilbert problems.
Regulatory restrictions and energy: The impact of the Jones Act on spot gasoline prices
International Nuclear Information System (INIS)
Gius, Mark
2013-01-01
The purpose of the present study is to estimate the effects of the Jones Act on spot gasoline prices. Although the Jones Act pertains to the domestic shipment of all types of goods, the present study will only focus on gasoline. The present study will use data obtained from the Energy Information Administration in order to determine if the price of gasoline declined during Jones Act waiver periods. Looking at daily prices, the results regarding the effects of the Jones Act on spot gasoline prices are mixed. When using a t-test, the results indicated either that there was no significant difference or that prices were actually higher during the waiver periods. When using a first-order autoregressive model, it was found that prices were lower during the 2005 waiver period but higher during the 2012 waiver. Given these inconclusive results, it is not possible to conclude that the Jones Act restrictions contribute to higher gasoline prices. - Highlights: • I examine the effect of the Jones Act on spot gasoline prices. • I use daily price data over a seven year period. • I find that the results are mixed. • For the Hurricane Katrina waiver, prices fell, but for the Hurricane Sandy waiver, prices rose
Viscous hydrophilic injection matrices for serial crystallography
Directory of Open Access Journals (Sweden)
Gabriela Kovácsová
2017-07-01
Full Text Available Serial (femtosecond crystallography at synchrotron and X-ray free-electron laser (XFEL sources distributes the absorbed radiation dose over all crystals used for data collection and therefore allows measurement of radiation damage prone systems, including the use of microcrystals for room-temperature measurements. Serial crystallography relies on fast and efficient exchange of crystals upon X-ray exposure, which can be achieved using a variety of methods, including various injection techniques. The latter vary significantly in their flow rates – gas dynamic virtual nozzle based injectors provide very thin fast-flowing jets, whereas high-viscosity extrusion injectors produce much thicker streams with flow rates two to three orders of magnitude lower. High-viscosity extrusion results in much lower sample consumption, as its sample delivery speed is commensurate both with typical XFEL repetition rates and with data acquisition rates at synchrotron sources. An obvious viscous injection medium is lipidic cubic phase (LCP as it is used for in meso membrane protein crystallization. However, LCP has limited compatibility with many crystallization conditions. While a few other viscous media have been described in the literature, there is an ongoing need to identify additional injection media for crystal embedding. Critical attributes are reliable injection properties and a broad chemical compatibility to accommodate samples as heterogeneous and sensitive as protein crystals. Here, the use of two novel hydrogels as viscous injection matrices is described, namely sodium carboxymethyl cellulose and the thermo-reversible block polymer Pluronic F-127. Both are compatible with various crystallization conditions and yield acceptable X-ray background. The stability and velocity of the extruded stream were also analysed and the dependence of the stream velocity on the flow rate was measured. In contrast with previously characterized injection media, both new
Noisy covariance matrices and portfolio optimization II
Pafka, Szilárd; Kondor, Imre
2003-03-01
Recent studies inspired by results from random matrix theory (Galluccio et al.: Physica A 259 (1998) 449; Laloux et al.: Phys. Rev. Lett. 83 (1999) 1467; Risk 12 (3) (1999) 69; Plerou et al.: Phys. Rev. Lett. 83 (1999) 1471) found that covariance matrices determined from empirical financial time series appear to contain such a high amount of noise that their structure can essentially be regarded as random. This seems, however, to be in contradiction with the fundamental role played by covariance matrices in finance, which constitute the pillars of modern investment theory and have also gained industry-wide applications in risk management. Our paper is an attempt to resolve this embarrassing paradox. The key observation is that the effect of noise strongly depends on the ratio r= n/ T, where n is the size of the portfolio and T the length of the available time series. On the basis of numerical experiments and analytic results for some toy portfolio models we show that for relatively large values of r (e.g. 0.6) noise does, indeed, have the pronounced effect suggested by Galluccio et al. (1998), Laloux et al. (1999) and Plerou et al. (1999) and illustrated later by Laloux et al. (Int. J. Theor. Appl. Finance 3 (2000) 391), Plerou et al. (Phys. Rev. E, e-print cond-mat/0108023) and Rosenow et al. (Europhys. Lett., e-print cond-mat/0111537) in a portfolio optimization context, while for smaller r (around 0.2 or below), the error due to noise drops to acceptable levels. Since the length of available time series is for obvious reasons limited in any practical application, any bound imposed on the noise-induced error translates into a bound on the size of the portfolio. In a related set of experiments we find that the effect of noise depends also on whether the problem arises in asset allocation or in a risk measurement context: if covariance matrices are used simply for measuring the risk of portfolios with a fixed composition rather than as inputs to optimization, the
Hypercyclic Abelian Semigroups of Matrices on Cn
International Nuclear Information System (INIS)
Ayadi, Adlene; Marzougui, Habib
2010-07-01
We give a complete characterization of existence of dense orbit for any abelian semigroup of matrices on C n . For finitely generated semigroups, this characterization is explicit and is used to determine the minimal number of matrices in normal form over C which forms a hypercyclic abelian semigroup on C n . In particular, we show that no abelian semigroup generated by n matrices on C n can be hypercyclic. (author)
Lambda-matrices and vibrating systems
Lancaster, Peter; Stark, M; Kahane, J P
1966-01-01
Lambda-Matrices and Vibrating Systems presents aspects and solutions to problems concerned with linear vibrating systems with a finite degrees of freedom and the theory of matrices. The book discusses some parts of the theory of matrices that will account for the solutions of the problems. The text starts with an outline of matrix theory, and some theorems are proved. The Jordan canonical form is also applied to understand the structure of square matrices. Classical theorems are discussed further by applying the Jordan canonical form, the Rayleigh quotient, and simple matrix pencils with late
Liquid-vapour phase behaviour of a polydisperse Lennard-Jones fluid
International Nuclear Information System (INIS)
Wilding, Nigel B; Sollich, Peter
2005-01-01
We describe a simulation study of the liquid-vapour phase behaviour of a model polydisperse fluid. Particle interactions are given by a Lennard-Jones potential in which polydispersity features both in the particle sizes and the amplitude of their interactions. We address the computational problem of accurately locating the cloud curve for such a system using Monte Carlo simulations within the grand canonical ensemble. The strongly nonlinear variation of the fractional volumes of the phases across the coexistence region precludes naive extrapolation to determine the cloud point density. Instead we propose an improved estimator for the cloud point location and use scaling arguments to predicts its finite-size behaviour. Excellent agreement is found with the simulation results. Application of the method reveals that the measured cloud curve is highly sensitive to the presence of large particles, even when they are extremely rare. This finding is expected to have implications for the reproducibility of experimentally measured phase diagrams in colloids and polymers
Georgescu, Ionuţ; Mandelshtam, Vladimir A
2012-10-14
The theory of self-consistent phonons (SCP) was originally developed to address the anharmonic effects in condensed matter systems. The method seeks a harmonic, temperature-dependent Hamiltonian that provides the "best fit" for the physical Hamiltonian, the "best fit" being defined as the one that optimizes the Helmholtz free energy at a fixed temperature. The present developments provide a scalable O(N) unified framework that accounts for anharmonic effects in a many-body system, when it is probed by either thermal (ℏ → 0) or quantum fluctuations (T → 0). In these important limits, the solution of the nonlinear SCP equations can be reached in a manner that requires only the multiplication of 3N × 3N matrices, with no need of diagonalization. For short range potentials, such as Lennard-Jones, the Hessian, and other related matrices are highly sparse, so that the scaling of the matrix multiplications can be reduced from O(N(3)) to ~O(N). We investigate the role of quantum effects by continuously varying the de-Boer quantum delocalization parameter Λ and report the N-Λ (T = 0), and also the classical N-T (Λ = 0) phase diagrams for sizes up to N ~ 10(4). Our results demonstrate that the harmonic approximation becomes inadequate already for such weakly quantum systems as neon clusters, or for classical systems much below the melting temperatures.
Pathological rate matrices: from primates to pathogens
Directory of Open Access Journals (Sweden)
Knight Rob
2008-12-01
Full Text Available Abstract Background Continuous-time Markov models allow flexible, parametrically succinct descriptions of sequence divergence. Non-reversible forms of these models are more biologically realistic but are challenging to develop. The instantaneous rate matrices defined for these models are typically transformed into substitution probability matrices using a matrix exponentiation algorithm that employs eigendecomposition, but this algorithm has characteristic vulnerabilities that lead to significant errors when a rate matrix possesses certain 'pathological' properties. Here we tested whether pathological rate matrices exist in nature, and consider the suitability of different algorithms to their computation. Results We used concatenated protein coding gene alignments from microbial genomes, primate genomes and independent intron alignments from primate genomes. The Taylor series expansion and eigendecomposition matrix exponentiation algorithms were compared to the less widely employed, but more robust, Padé with scaling and squaring algorithm for nucleotide, dinucleotide, codon and trinucleotide rate matrices. Pathological dinucleotide and trinucleotide matrices were evident in the microbial data set, affecting the eigendecomposition and Taylor algorithms respectively. Even using a conservative estimate of matrix error (occurrence of an invalid probability, both Taylor and eigendecomposition algorithms exhibited substantial error rates: ~100% of all exonic trinucleotide matrices were pathological to the Taylor algorithm while ~10% of codon positions 1 and 2 dinucleotide matrices and intronic trinucleotide matrices, and ~30% of codon matrices were pathological to eigendecomposition. The majority of Taylor algorithm errors derived from occurrence of multiple unobserved states. A small number of negative probabilities were detected from the Pad�� algorithm on trinucleotide matrices that were attributable to machine precision. Although the Pad
Directory of Open Access Journals (Sweden)
Amir Saadaoui
2015-02-01
Full Text Available In the course of the recent global crisis, the stock shocks are distributed and transmitted from their homes in the developed stock market to emerging stock markets. By supporting the development of emerging stock markets, this study aims to see the transmission of volatility between the Dow Jones stock index and the Dow Jones emerging Islamic stock indiex. In this study we have divided the period into three, periods, before, during and after this crisis to demonstrate the resilience of the Islamic market index in response to the global financial crisis. Another aim of this study is to provide a new guide line for investors in emerging stock market before making investment decisions. The data are daily, going from 02/01/2005 until 31/12/2012. To measure the transmission we used bivariate BEKK-GARCH and DCC-GARCH model. The result shows that there is a transmission mainly during the crisis period which means that the crisis affects all the financial assets whether Islamic or not. The same result also shows the preference to invest in both Islamic and classical stock indexes since they are less risky.
Quantum Hilbert matrices and orthogonal polynomials
DEFF Research Database (Denmark)
Andersen, Jørgen Ellegaard; Berg, Christian
2009-01-01
Using the notion of quantum integers associated with a complex number q≠0 , we define the quantum Hilbert matrix and various extensions. They are Hankel matrices corresponding to certain little q -Jacobi polynomials when |q|<1 , and for the special value they are closely related to Hankel matrice...
The construction of factorized S-matrices
International Nuclear Information System (INIS)
Chudnovsky, D.V.
1981-01-01
We study the relationships between factorized S-matrices given as representations of the Zamolodchikov algebra and exactly solvable models constructed using the Baxter method. Several new examples of symmetric and non-symmetric factorized S-matrices are proposed. (orig.)
Skew-adjacency matrices of graphs
Cavers, M.; Cioaba, S.M.; Fallat, S.; Gregory, D.A.; Haemers, W.H.; Kirkland, S.J.; McDonald, J.J.; Tsatsomeros, M.
2012-01-01
The spectra of the skew-adjacency matrices of a graph are considered as a possible way to distinguish adjacency cospectral graphs. This leads to the following topics: graphs whose skew-adjacency matrices are all cospectral; relations between the matchings polynomial of a graph and the characteristic
On Investigating GMRES Convergence using Unitary Matrices
Czech Academy of Sciences Publication Activity Database
Duintjer Tebbens, Jurjen; Meurant, G.; Sadok, H.; Strakoš, Z.
2014-01-01
Roč. 450, 1 June (2014), s. 83-107 ISSN 0024-3795 Grant - others:GA AV ČR(CZ) M100301201; GA MŠk(CZ) LL1202 Institutional support: RVO:67985807 Keywords : GMRES convergence * unitary matrices * unitary spectra * normal matrices * Krylov residual subspace * Schur parameters Subject RIV: BA - General Mathematics Impact factor: 0.939, year: 2014
Patel, Mayara Paim; Henriques, José Fernando Castanha; Freitas, Karina Maria Salvatore; Grec, Roberto Henrique da Costa
2014-01-01
The aim of this study was to cephalometrically assess the skeletal and dentoalveolar effects of Class II malocclusion treatment performed with the Jones Jig appliance followed by fixed appliances. The sample comprised 25 patients with Class II malocclusion treated with the Jones Jig appliance followed by fixed appliances, at a mean initial age of 12.90 years old. The mean time of the entire orthodontic treatment was 3.89 years. The distalization phase lasted for 0.85 years, after which the fixed appliance was used for 3.04 years. Cephalograms were used at initial (T1), post-distalization (T2) and final phases of treatment (T3). For intragroup comparison of the three phases evaluated, dependent ANOVA and Tukey tests were used. Jones Jig appliance did not interfere in the maxillary and mandibular component and did not change maxillomandibular relationship. Jones Jig appliance promoted distalization of first molars with anchorage loss, mesialization and significant extrusion of first and second premolars, as well as a significant increase in anterior face height at the end of treatment. The majority of adverse effects that occur during intraoral distalization are subsequently corrected during corrective mechanics. Buccal inclination and protrusion of mandibular incisors were identified. By the end of treatment, correction of overjet and overbite was observed. Jones Jig appliance promoted distalization of first molars with anchorage loss represented by significant mesial movement and extrusion of first and second premolars, in addition to a significant increase in anterior face height.
Exact Inverse Matrices of Fermat and Mersenne Circulant Matrix
Directory of Open Access Journals (Sweden)
Yanpeng Zheng
2015-01-01
Full Text Available The well known circulant matrices are applied to solve networked systems. In this paper, circulant and left circulant matrices with the Fermat and Mersenne numbers are considered. The nonsingularity of these special matrices is discussed. Meanwhile, the exact determinants and inverse matrices of these special matrices are presented.
Phase diagram of power law and Lennard-Jones systems: Crystal phases
International Nuclear Information System (INIS)
Travesset, Alex
2014-01-01
An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists with the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed
Magnetoelectric Jones birefringence and dichroism in a medium of free atoms
International Nuclear Information System (INIS)
Mironova, P V; Ovsiannikov, V D; Chernushkin, V V
2006-01-01
Theoretical treatment of the magnetoelectric Jones birefringence and dichroism is developed through the bilinearity in static electric and magnetic field dipole-forbidden corrections to the amplitude of Rayleigh scattering. In particular cases of orientation of the static fields relative to the polarization and wave vectors of monochromatic radiation, the amplitude determines corrections to the refractive index of atomic gas responsible for (i) the Jones birefringence and dichroism (ii) linear birefringence and dichroism and (iii) directional anisotropy for the monochromatic wave. The analytical equations and numerical data for the indicated corrections, calculated for alkaline-earth-like atoms, determine optimal conditions for observing the effects in vapours. For resonance on 1 D 2 state essential enhancement is discovered in the frequency dependence for the ratio of refractive index anisotropy of the Jones effect to the square-root product of corresponding anisotropies determining the Kerr and Cotton-Mouton effects
Adhesion and metabolic activity of human corneal cells on PCL based nanofiber matrices
Energy Technology Data Exchange (ETDEWEB)
Stafiej, Piotr; Küng, Florian [Department of Ophthalmology, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen (Germany); Institute of Polymer Materials, Universität Erlangen-Nürnberg, Martensstraße 7, 91054 Erlangen (Germany); Thieme, Daniel; Czugala, Marta; Kruse, Friedrich E. [Department of Ophthalmology, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen (Germany); Schubert, Dirk W. [Institute of Polymer Materials, Universität Erlangen-Nürnberg, Martensstraße 7, 91054 Erlangen (Germany); Fuchsluger, Thomas A., E-mail: thomas.fuchsluger@uk-erlangen.de [Department of Ophthalmology, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen (Germany)
2017-02-01
In this work, polycaprolactone (PCL) was used as a basic polymer for electrospinning of random and aligned nanofiber matrices. Our aim was to develop a biocompatible substrate for ophthalmological application to improve wound closure in defects of the cornea as replacement for human amniotic membrane. We investigated whether blending the hydrophobic PCL with poly (glycerol sebacate) (PGS) or chitosan (CHI) improves the biocompatibility of the matrices for cell expansion. Human corneal epithelial cells (HCEp) and human corneal keratocytes (HCK) were used for in vitro biocompatibility studies. After optimization of the electrospinning parameters for all blends, scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and water contact angle were used to characterize the different matrices. Fluorescence staining of the F-actin cytoskeleton of the cells was performed to analyze the adherence of the cells to the different matrices. Metabolic activity of the cells was measured by cell counting kit-8 (CCK-8) for 20 days to compare the biocompatibility of the materials. Our results show the feasibility of producing uniform nanofiber matrices with and without orientation for the used blends. All materials support adherence and proliferation of human corneal cell lines with oriented growth on aligned matrices. Although hydrophobicity of the materials was lowered by blending PCL, no increase in biocompatibility or proliferation, as was expected, could be measured. All tested matrices supported the expansion of human corneal cells, confirming their potential as substrates for biomedical applications. - Highlights: • PCL was blended with chitosan and poly(glycerol sebacate) for electrospinning. • Biocompatibility was proven with two human corneal cell lines. • Both cell lines adhered and proliferated on random and aligned nanofiber matrices. • Cytoskeletal orientation is shown on aligned nanofiber matrices.
Community Detection for Correlation Matrices
Directory of Open Access Journals (Sweden)
Mel MacMahon
2015-04-01
Full Text Available A challenging problem in the study of complex systems is that of resolving, without prior information, the emergent, mesoscopic organization determined by groups of units whose dynamical activity is more strongly correlated internally than with the rest of the system. The existing techniques to filter correlations are not explicitly oriented towards identifying such modules and can suffer from an unavoidable information loss. A promising alternative is that of employing community detection techniques developed in network theory. Unfortunately, this approach has focused predominantly on replacing network data with correlation matrices, a procedure that we show to be intrinsically biased because of its inconsistency with the null hypotheses underlying the existing algorithms. Here, we introduce, via a consistent redefinition of null models based on random matrix theory, the appropriate correlation-based counterparts of the most popular community detection techniques. Our methods can filter out both unit-specific noise and system-wide dependencies, and the resulting communities are internally correlated and mutually anticorrelated. We also implement multiresolution and multifrequency approaches revealing hierarchically nested subcommunities with “hard” cores and “soft” peripheries. We apply our techniques to several financial time series and identify mesoscopic groups of stocks which are irreducible to a standard, sectorial taxonomy; detect “soft stocks” that alternate between communities; and discuss implications for portfolio optimization and risk management.
Community Detection for Correlation Matrices
MacMahon, Mel; Garlaschelli, Diego
2015-04-01
A challenging problem in the study of complex systems is that of resolving, without prior information, the emergent, mesoscopic organization determined by groups of units whose dynamical activity is more strongly correlated internally than with the rest of the system. The existing techniques to filter correlations are not explicitly oriented towards identifying such modules and can suffer from an unavoidable information loss. A promising alternative is that of employing community detection techniques developed in network theory. Unfortunately, this approach has focused predominantly on replacing network data with correlation matrices, a procedure that we show to be intrinsically biased because of its inconsistency with the null hypotheses underlying the existing algorithms. Here, we introduce, via a consistent redefinition of null models based on random matrix theory, the appropriate correlation-based counterparts of the most popular community detection techniques. Our methods can filter out both unit-specific noise and system-wide dependencies, and the resulting communities are internally correlated and mutually anticorrelated. We also implement multiresolution and multifrequency approaches revealing hierarchically nested subcommunities with "hard" cores and "soft" peripheries. We apply our techniques to several financial time series and identify mesoscopic groups of stocks which are irreducible to a standard, sectorial taxonomy; detect "soft stocks" that alternate between communities; and discuss implications for portfolio optimization and risk management.
E-tailing in Australia: A preliminary analysis of David Jones
Directory of Open Access Journals (Sweden)
Jun Xu
2017-06-01
Full Text Available Compared with other countries, especially China, United States, United Kingdom, Japan and Germany, Australiars online retail fall behind in terms of both its sale and percentage contribution to the total retail. This paper analyses David Jones, which is typical of large department store chains, and Australian e-tailing environment as a case study to identify enablers for and obstacle to the advancement of e-tailing in Australia. Based on the analysis, the paper provides David Jones with recommendations on internal improvement, supply chain, customer relationship, and adoption of emerging technologies. Future research will be conducted to investigate if the recommendations are also applicable for other Australian retailers.
Fairy tales? Marion Jones, C.J. Hunter and the framing of doping in American newspapers
DEFF Research Database (Denmark)
Pfister, Gertrud Ursula; Gems, Gerald
2015-01-01
This article deals with the images, metaphors and narratives in the media coverage of doping in the United States. It presents a case study with a focus on Marion Jones, the most celebrated track athlete of the turn of the millennium, and her husband, C.J. Hunter, a shot put world champion...... under suspicion. At the same time, the 2000 Olympics can be considered a watershed in American anti-doping policy. The media portrayed Jones and Hunter as the Beauty and the Beast or Svengali and his victim, using a famous fairy tale and a well-known novel to capture attention, label the protagonists...
Occurrence of pathotypes of Ascochyta pinodes (Jones in the Olsztyn district
Directory of Open Access Journals (Sweden)
Helena Furgał-Węgrzycka
2013-12-01
Full Text Available The causal agent of leaf and pods spot-pot of peas and field peas in the Olsztyn district was the fungus Ascochyta pinodes (Jones. Investigated isolates of A. pinoides different by macroscopic and microscopic features. From diseased leaves and pods of peas and field peas saprophytic fungi were also obtained. Among them Alternaria alternata, Cladosporium cladosporioides, Epicoccum purpurascens, Stemphylium botryosum, Sordaria fimicola and mycelia sterilia were dominant. In the study on the identification and distribution of pathotypes of A. pinodes (Jones six pathotypes were identified among which pathotypes 3 dominated. The identified pathotypes differed by macroscopic and microscopic features.
Simulation of depositions of a Lennard-Jones cluster on a crystalline surface
International Nuclear Information System (INIS)
Saitoh, Kuniyasu; Hayakawa, Hisao
2009-01-01
Depositions of amorphous Lennard-Jones clusters on a crystalline surface are numerically investigated. From the results of the molecular dynamics simulation, we found that the deposited clusters exhibit a transition from multilayered adsorption to monolayered adsorption at a critical incident speed. Employing the energy conservation law, we can explain the behavior of the ratio of the number of atoms adsorbed on the substrate to the cluster size. The boundary shape of the deposited cluster depends strongly on the incident speed, and some unstable modes grow during the spread of the deposited cluster on the substrate. We also discuss the wettability between different Lennard-Jones atoms. (author)
The Antitriangular Factorization of Saddle Point Matrices
Pestana, J.
2014-01-01
Mastronardi and Van Dooren [SIAM J. Matrix Anal. Appl., 34 (2013), pp. 173-196] recently introduced the block antitriangular ("Batman") decomposition for symmetric indefinite matrices. Here we show the simplification of this factorization for saddle point matrices and demonstrate how it represents the common nullspace method. We show that rank-1 updates to the saddle point matrix can be easily incorporated into the factorization and give bounds on the eigenvalues of matrices important in saddle point theory. We show the relation of this factorization to constraint preconditioning and how it transforms but preserves the structure of block diagonal and block triangular preconditioners. © 2014 Society for Industrial and Applied Mathematics.
Polynomial sequences generated by infinite Hessenberg matrices
Directory of Open Access Journals (Sweden)
Verde-Star Luis
2017-01-01
Full Text Available We show that an infinite lower Hessenberg matrix generates polynomial sequences that correspond to the rows of infinite lower triangular invertible matrices. Orthogonal polynomial sequences are obtained when the Hessenberg matrix is tridiagonal. We study properties of the polynomial sequences and their corresponding matrices which are related to recurrence relations, companion matrices, matrix similarity, construction algorithms, and generating functions. When the Hessenberg matrix is also Toeplitz the polynomial sequences turn out to be of interpolatory type and we obtain additional results. For example, we show that every nonderogative finite square matrix is similar to a unique Toeplitz-Hessenberg matrix.
Synchronous correlation matrices and Connes’ embedding conjecture
Energy Technology Data Exchange (ETDEWEB)
Dykema, Kenneth J., E-mail: kdykema@math.tamu.edu [Department of Mathematics, Texas A& M University, College Station, Texas 77843-3368 (United States); Paulsen, Vern, E-mail: vern@math.uh.edu [Department of Mathematics, University of Houston, Houston, Texas 77204 (United States)
2016-01-15
In the work of Paulsen et al. [J. Funct. Anal. (in press); preprint arXiv:1407.6918], the concept of synchronous quantum correlation matrices was introduced and these were shown to correspond to traces on certain C*-algebras. In particular, synchronous correlation matrices arose in their study of various versions of quantum chromatic numbers of graphs and other quantum versions of graph theoretic parameters. In this paper, we develop these ideas further, focusing on the relations between synchronous correlation matrices and microstates. We prove that Connes’ embedding conjecture is equivalent to the equality of two families of synchronous quantum correlation matrices. We prove that if Connes’ embedding conjecture has a positive answer, then the tracial rank and projective rank are equal for every graph. We then apply these results to more general non-local games.
Discrete canonical transforms that are Hadamard matrices
International Nuclear Information System (INIS)
Healy, John J; Wolf, Kurt Bernardo
2011-01-01
The group Sp(2,R) of symplectic linear canonical transformations has an integral kernel which has quadratic and linear phases, and which is realized by the geometric paraxial optical model. The discrete counterpart of this model is a finite Hamiltonian system that acts on N-point signals through N x N matrices whose elements also have a constant absolute value, although they do not form a representation of that group. Those matrices that are also unitary are Hadamard matrices. We investigate the manifolds of these N x N matrices under the Sp(2,R) equivalence imposed by the model, and find them to be on two-sided cosets. By means of an algorithm we determine representatives that lead to collections of mutually unbiased bases.
ESTIMATION OF FUNCTIONALS OF SPARSE COVARIANCE MATRICES.
Fan, Jianqing; Rigollet, Philippe; Wang, Weichen
High-dimensional statistical tests often ignore correlations to gain simplicity and stability leading to null distributions that depend on functionals of correlation matrices such as their Frobenius norm and other ℓ r norms. Motivated by the computation of critical values of such tests, we investigate the difficulty of estimation the functionals of sparse correlation matrices. Specifically, we show that simple plug-in procedures based on thresholded estimators of correlation matrices are sparsity-adaptive and minimax optimal over a large class of correlation matrices. Akin to previous results on functional estimation, the minimax rates exhibit an elbow phenomenon. Our results are further illustrated in simulated data as well as an empirical study of data arising in financial econometrics.
The Antitriangular Factorization of Saddle Point Matrices
Pestana, J.; Wathen, A. J.
2014-01-01
Mastronardi and Van Dooren [SIAM J. Matrix Anal. Appl., 34 (2013), pp. 173-196] recently introduced the block antitriangular ("Batman") decomposition for symmetric indefinite matrices. Here we show the simplification of this factorization for saddle
Procedure for the analysis of americium in complex matrices
International Nuclear Information System (INIS)
Knab, D.
1978-02-01
A radioanalytical procedure for the analysis of americium in complex matrices has been developed. Clean separations of americium can be obtained from up to 100 g of sample ash, regardless of the starting material. The ability to analyze large masses of material provides the increased sensitivity necessary to detect americium in many environmental samples. The procedure adequately decontaminates from rare earth elements and natural radioactive nuclides that interfere with the alpha spectrometric measurements
Estimating correlation and covariance matrices by weighting of market similarity
Michael C. M\\"unnix; Rudi Sch\\"afer; Oliver Grothe
2010-01-01
We discuss a weighted estimation of correlation and covariance matrices from historical financial data. To this end, we introduce a weighting scheme that accounts for similarity of previous market conditions to the present one. The resulting estimators are less biased and show lower variance than either unweighted or exponentially weighted estimators. The weighting scheme is based on a similarity measure which compares the current correlation structure of the market to the structures at past ...
Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Miura, Masahiro; Yasuno, Yoshiaki
2016-04-01
This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients' eyes can be obtained.
International Nuclear Information System (INIS)
Lin, T.; Bian, X.F.; Jiang, J.
2006-01-01
Two metallic bulk glasses, Cu 60 Zr 30 Ti 10 and Cu 47 Ti 33 Zr 11 Ni 8 Si 1 , with a diameter of 3 mm were prepared by copper mold casting method. Dilatometric measurement was carried out on the two glassy alloys to obtain information about the average nearest-neighbour distance r 0 and the effective depth of pair potential V 0 . By assuming a Lennard-Jones potential, r 0 and V 0 were calculated to be 0.28 nm and 0.16 eV for Cu 60 Zr 30 Ti 10 and 0.27 nm and 0.13 eV for Cu 47 Ti 33 Zr 11 Ni 8 Si 1 , respectively. It was found that the glassy alloy Cu 60 Zr 30 Ti 10 was more stable than Cu 47 Ti 33 Zr 11 Ni 8 Si 1 against heating from both experiment and calculation
Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Miura, Masahiro; Yasuno, Yoshiaki
2016-01-01
This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients’ eyes can be obtained. PMID:27446673
Flux Jacobian Matrices For Equilibrium Real Gases
Vinokur, Marcel
1990-01-01
Improved formulation includes generalized Roe average and extension to three dimensions. Flux Jacobian matrices derived for use in numerical solutions of conservation-law differential equations of inviscid flows of ideal gases extended to real gases. Real-gas formulation of these matrices retains simplifying assumptions of thermodynamic and chemical equilibrium, but adds effects of vibrational excitation, dissociation, and ionization of gas molecules via general equation of state.
Supercritical fluid extraction behaviour of polymer matrices
International Nuclear Information System (INIS)
Sujatha, K.; Kumar, R.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.
2007-01-01
Organic compounds present in polymeric matrices such as neoprene, surgical gloves and PVC were co-extracted during the removal of uranium using supercritical fluid extraction (SFE) technique. Hence SFE studies of these matrices were carried out to establish the extracted species using HPLC, IR and mass spectrometry techniques. The initial study indicated that uranium present in the extract could be purified from the co-extracted organic species. (author)
Käsitsi tegemise võlu / David Jones ; intervjueerinud Kai Lobjakas
Jones, David, 1953-
2010-01-01
10. Kohila keraamikasümpoosionil osalenud briti keraamik ja teoreetik David Jones endast, rakutehnikast, huvist põletamisega seonduvate teemade vastu, Kohila sümpoosioni raames tehtust, keraamika õpetamisest Inglismaal, käsitöö ja keraamika positsioonist praegu ja tulevikus jm.
Flexible equation of state for a hard sphere and Lennard–Jones fluid ...
Indian Academy of Sciences (India)
Equation of state; Lennard–Jones potential; hard-sphere potential; liquid mixture; computer simulation. ... deviation than Barker–Henderson BH2 for LJ fluids, and results are much closer to molecular dynamics (MD) simulations than expectations and reproduce the existing simulation data and present EoS for LJ potential, ...
RISM theory distribution functions for Lennard--Jones interaction site fluids
International Nuclear Information System (INIS)
Johnson, E.; Hazoume, R.P.
1978-01-01
Reference interaction site model (RISM) theory distribution functions for Lennard-Jones interaction site fluids are discussed. The comparison with computer simulation results suggests that these distribution functions are as accurate as RISM distribution functions for fused hard sphere molecular fluids
On the localisation of antigenic determinants in a Bence Jones protein
Eyk, H.G. van; Myszkowska, K.
1967-01-01
1. 1. The presence of a low molecular weight protein (1.2 S), having antigenic determinants in common with the homologous Bence Jones protein (3.4 S), has been observed in the urine of a patient with multiple myeloma. Its amino acid composition and α-NH2-terminal amino acid residue make it likely
"Armastuse retsepti" tippkokk Zeta Jones ei oska muna keeta / Triin Tael
Tael, Triin
2007-01-01
Scott Hicksi romantiline komöödiafilm "Armastuse retsept" ("No Reservations"), mille peaosas Walesist pärit näitlejanna Catherine Zeta Jones. Näitlejanna muljeid oma rolliks ettevalmistustest, mille hulka käis ka praktika pärisrestoranis
Formation of global energy minimim structures in the growth process of Lennard-Jones clusters
DEFF Research Database (Denmark)
Solov'yov, Ilia; Koshelev, Andrey; Shutovich, Andrey
2003-01-01
that in this way all known global minimum structures of the Lennard-Jones (LJ) clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic numbers sequence for the clusters of noble gases atoms and compare...
Fusion process of Lennard-Jones clusters: global minima and magic numbers formation
DEFF Research Database (Denmark)
Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter
2004-01-01
We present a new theoretical framework for modeling the fusion process of Lennard–Jones (LJ) clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing paths up to the cluster size of 150 atoms...
Enhancing Undergraduates' Capabilities through Team-Based Competitions: The Edward Jones Challenge
Umble, Elisabeth J.; Umble, Michael; Artz, Kendall
2008-01-01
The Edward Jones Company recently initiated financial sponsorship of team-based competitions in six undergraduate business core classes at Baylor University. The challenges were chosen to take place in an introductory freshman business class, Managerial Accounting, Principles of Marketing, Corporate Finance, Operations Management, and Strategic…
Application of the RISM theory to Lennard-Jones interaction site molecular fluids
International Nuclear Information System (INIS)
Johnson, E.; Hazoume, R.P.
1979-01-01
It seems that reference interaction site model (RISM) theory atom--atom distribution functions have been obtained directly from the RISM equations only for fused hard sphere molecular fluids. RISM distribution functions for Lennard-Jones interaction site fluids are presented. Results presented suggest that these distribution functions are as accurate as RISM distribution functions for fused hard sphere molecular fluids
PHYTOREMEDIATION OF DREDGED SEDIMENTS: A CASE STUDY AT THE JONES ISLAND CDF
The Jones Island Confined Disposal Facility (CDF) is a 44 acre in-lake area that receives dredged material from Milwaukee Harbor and the surrounding waterways. Some of those materials are contaminated with industrial waste and urban run-off. The CDF is nearing the end of its desi...
RASW : a Run-time Adaptive Sliding Window to Improve Viola-Jones object detection.
Comaschi, F.; Stuijk, S.; Basten, T.; Corporaal, H.
2013-01-01
Abstract—In recent years accurate algorithms for detecting objects in images have been developed. Among these algorithms, the object detection scheme proposed by Viola and Jones gained great popularity, especially after the release of high-quality face classifiers by the OpenCV group. However, as
2010-07-26
..., Sharon Pennsylvania Print Plant a Subsidiary of News Corporation, West Middlesex, Pennsylvania; Notice of..., Sharon Pennsylvania Print Plant, a subsidiary of News Corporation, West Middlesex, Pennsylvania, was... between Dow Jones & Company, West Middlesex, Pennsylvania, and any Konica facility. The petitioner did not...
The Game TV Plays: Or, Why an English Teacher Came to Hate Barnaby Jones.
Shaw, Patrick W.
The message of current popular television shows in which the hero is, or appears to be, a dumb clod (e.g., Archie Bunker, Fred Sanford, Columbo, and Barnaby Jones), apparently is that corruption may be equated with articulation, wealth, and education, while virtue may be equated with poverty and, often, illiteracy. Unfortunately, the effect of…
2012-10-01
... Collection; Comment Request; Coastal Zone Management Act Walter B. Jones and NOAA Excellence Awards AGENCY... approved information collection. The 1990 reauthorization of the Coastal Zone Management Act (CZMA) authorized an awards program to ``implement a program to promote excellence in coastal zone management by...
Machine News and Volatility: The Dow Jones Industrial Average and the TRNA Sentiment Series
D.E. Allen (David); A.K. Singh (Abhay)
2014-01-01
markdownabstract__Abstract__ This paper features an analysis of the relationship between the volatility of the Dow Jones Industrial Average (DJIA) Index and a sentiment news series using daily data obtained from the Thomson Reuters News Analytics (TRNA) provided by SIRCA (The Securities Industry
Atomic size effect on the formation of ionized cluster beam epitaxy in Lennard-Jones systems
International Nuclear Information System (INIS)
Hsieh Horngming; Averback, R.S.
1991-01-01
Ionized cluster beam deposition is studied by molecular dynamics simulations in which the atomic size of incident cluster atoms is different from the size of substrate atoms. Lennard-Jones interatomic potentials are used for the two-component system. The results provide the morphologies of the overlayers for various atomic sizes and are compared to simulation results of molecular beam epitaxy. (orig.)
Baron, Christopher; Hamlin, Christopher
2015-01-01
Between 1906 and 1909 the biologist Ronald Ross and the classicist W.H.S. Jones pioneered interdisciplinary research in biology and history in advancing the claim that malaria had been crucial in the decline of golden-age Greece (fourth century BCE). The idea had originated with Ross, winner of the Nobel Prize for demonstrating the importance of…
Energy Technology Data Exchange (ETDEWEB)
Lacerda, Kassio Andre; Lameiras, Fernando Soares [Centro de Desenvolvimento da Tecnologia Nuclear, (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Viviane Viana [Centro de Desenvolvimento da Tecnologia Nuclear, (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Universidade Vale do Rio Verde de Tres Coracoes, MG (Brazil)
2007-07-15
In this study, non-radioactive iodine was incorporated in two types of biodegradable hydroxyapatite-based porous matrices (HA and HACL) through impregnation process from sodium iodine aqueous solutions with varying concentrations (0.5 and 1.0 mol/L) . The results revealed that both systems presented a high capacity of incorporating iodine into their matrices. The quantity of incorporated iodine was measured through Neutron Activation Analysis (NAA). The porous ceramic matrices based on hydroxyapatite demonstrated a great potential for uses in low dose rate (LDR) brachytherapy. (author)
Schur Complement Inequalities for Covariance Matrices and Monogamy of Quantum Correlations.
Lami, Ludovico; Hirche, Christoph; Adesso, Gerardo; Winter, Andreas
2016-11-25
We derive fundamental constraints for the Schur complement of positive matrices, which provide an operator strengthening to recently established information inequalities for quantum covariance matrices, including strong subadditivity. This allows us to prove general results on the monogamy of entanglement and steering quantifiers in continuous variable systems with an arbitrary number of modes per party. A powerful hierarchical relation for correlation measures based on the log-determinant of covariance matrices is further established for all Gaussian states, which has no counterpart among quantities based on the conventional von Neumann entropy.
Detecting macroeconomic phases in the Dow Jones Industrial Average time series
Wong, Jian Cheng; Lian, Heng; Cheong, Siew Ann
2009-11-01
In this paper, we perform statistical segmentation and clustering analysis of the Dow Jones Industrial Average (DJI) time series between January 1997 and August 2008. Modeling the index movements and log-index movements as stationary Gaussian processes, we find a total of 116 and 119 statistically stationary segments respectively. These can then be grouped into between five and seven clusters, each representing a different macroeconomic phase. The macroeconomic phases are distinguished primarily by their volatilities. We find that the US economy, as measured by the DJI, spends most of its time in a low-volatility phase and a high-volatility phase. The former can be roughly associated with economic expansion, while the latter contains the economic contraction phase in the standard economic cycle. Both phases are interrupted by a moderate-volatility market correction phase, but extremely-high-volatility market crashes are found mostly within the high-volatility phase. From the temporal distribution of various phases, we see a high-volatility phase from mid-1998 to mid-2003, and another starting mid-2007 (the current global financial crisis). Transitions from the low-volatility phase to the high-volatility phase are preceded by a series of precursor shocks, whereas the transition from the high-volatility phase to the low-volatility phase is preceded by a series of inverted shocks. The time scale for both types of transitions is about a year. We also identify the July 1997 Asian Financial Crisis to be the trigger for the mid-1998 transition, and an unnamed May 2006 market event related to corrections in the Chinese markets to be the trigger for the mid-2007 transition.
Ochenjele, George; Ho, Bryant; Switaj, Paul J; Fuchs, Daniel; Goyal, Nitin; Kadakia, Anish R
2015-03-01
Jones fractures occur in the relatively avascular metadiaphyseal junction of the fifth metatarsal (MT), which predisposes these fractures to delayed union and nonunion. Operative treatment with intramedullary (IM) screw fixation is recommended in certain cases. Incorrect screw selection can lead to refractures, nonunion, and cortical blowout fractures. A better understanding of the anatomy of the fifth MT could aid in preoperative planning, guide screw size selection, and minimize complications. We retrospectively identified foot computed tomographic (CT) scans of 119 patients that met inclusion criteria. Using interactive 3-dimensional (3-D) models, the following measurements were calculated: MT length, "straight segment length" (distance from the base of the MT to the shaft curvature), and canal diameter. The diaphysis had a lateroplantar curvature where the medullary canal began to taper. The average straight segment length was 52 mm, and corresponded to 68% of the overall length of the MT from its proximal end. The medullary canal cross-section was elliptical rather than circular, with widest width in the sagittal plane and narrowest in coronal plane. The average coronal canal diameter at the isthmus was 5.0 mm. A coronal diameter greater than 4.5 mm at the isthmus was present in 81% of males and 74% of females. To our knowledge, this is the first anatomic description of the fifth metatarsal based on 3-D imaging. Excessive screw length could be avoided by keeping screw length less than 68% of the length of the fifth metatarsal. A greater than 4.5 mm diameter screw might be needed to provide adequate fixation for most study patients since the isthmus of the medullary canal for most were greater than 4.5 mm. Our results provide an improved understanding of the fifth metatarsal anatomy to guide screw diameter and length selection to maximize screw fixation and minimize complications. © The Author(s) 2014.
Prevalence of Jones Fracture Repair and Impact on Short-Term NFL Participation.
Tu, Leigh-Anne; Knapik, Derrick M; Sheehan, Joseph; Salata, Michael J; Voos, James E
2018-01-01
Elite American football athletes are at high risk for Jones fractures. Fixation is recommended to minimize nonunion and allow early return to play. The purpose of this investigation was to evaluate the prevalence of Jones fracture repair in athletes invited to the National Football League (NFL) Combine and the impact of fracture repair on short-term NFL participation compared to athletes with no history of repair. A total of 1311 athletes participating in the Combine from 2012 to 2015 were evaluated. Athletes with history of Jones fracture repair were identified. Athlete demographic information was collected while physical examination findings were recorded. Radiographs were evaluated to determine fixation type and the presence of nonunion. Future participation in the NFL was evaluated based on draft status, games played, and games started in the athlete's first season following the Combine. Fixation was performed for 41 Jones fractures in 40 athletes (3.1%). The highest prevalence was in defensive linemen (n = 10 athletes), with the greatest rate in tight ends (5.1%, n = 4 of 79 athletes). Intramedullary screw fixation was used for all fractures. Incomplete bony union was present in 3 (8%) fractures. Athletes with a history of repair were not at significant risk for going undrafted ( P = .61), playing ( P = .23), or starting ( P = .76) fewer NFL games compared to athletes with no history of repair during athletes' first NFL season. Athletes with a history of Jones fracture repair were not at significant risk of going undrafted or for diminished participation during their first season in the NFL. Level IV, case series.
Substituted amylose matrices for oral drug delivery
International Nuclear Information System (INIS)
Moghadam, S H; Wang, H W; El-Leithy, E Saddar; Chebli, C; Cartilier, L
2007-01-01
High amylose corn starch was used to obtain substituted amylose (SA) polymers by chemically modifying hydroxyl groups by an etherification process using 1,2-epoxypropanol. Tablets for drug-controlled release were prepared by direct compression and their release properties assessed by an in vitro dissolution test (USP XXIII no 2). The polymer swelling was characterized by measuring gravimetrically the water uptake ability of polymer tablets. SA hydrophilic matrix tablets present sequentially a burst effect, typical of hydrophilic matrices, and a near constant release, typical of reservoir systems. After the burst effect, surface pores disappear progressively by molecular association of amylose chains; this allows the creation of a polymer layer acting as a diffusion barrier and explains the peculiar behaviour of SA polymers. Several formulation parameters such as compression force, drug loading, tablet weight and insoluble diluent concentration were investigated. On the other hand, tablet thickness, scanning electron microscope analysis and mercury intrusion porosimetry showed that the high crushing strength values observed for SA tablets were due to an unusual melting process occurring during tabletting although the tablet external layer went only through densification, deformation and partial melting. In contrast, HPMC tablets did not show any traces of a melting process
LIBS analysis of artificial calcified tissues matrices.
Kasem, M A; Gonzalez, J J; Russo, R E; Harith, M A
2013-04-15
In most laser-based analytical methods, the reproducibility of quantitative measurements strongly depends on maintaining uniform and stable experimental conditions. For LIBS analysis this means that for accurate estimation of elemental concentration, using the calibration curves obtained from reference samples, the plasma parameters have to be kept as constant as possible. In addition, calcified tissues such as bone are normally less "tough" in their texture than many samples, especially metals. Thus, the ablation process could change the sample morphological features rapidly, and result in poor reproducibility statistics. In the present work, three artificial reference sample sets have been fabricated. These samples represent three different calcium based matrices, CaCO3 matrix, bone ash matrix and Ca hydroxyapatite matrix. A comparative study of UV (266 nm) and IR (1064 nm) LIBS for these three sets of samples has been performed under similar experimental conditions for the two systems (laser energy, spot size, repetition rate, irradiance, etc.) to examine the wavelength effect. The analytical results demonstrated that UV-LIBS has improved reproducibility, precision, stable plasma conditions, better linear fitting, and the reduction of matrix effects. Bone ash could be used as a suitable standard reference material for calcified tissue calibration using LIBS with a 266 nm excitation wavelength. Copyright © 2013 Elsevier B.V. All rights reserved.
Probing the Topology of Density Matrices
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Charles-Edouard Bardyn
2018-02-01
Full Text Available The mixedness of a quantum state is usually seen as an adversary to topological quantization of observables. For example, exact quantization of the charge transported in a so-called Thouless adiabatic pump is lifted at any finite temperature in symmetry-protected topological insulators. Here, we show that certain directly observable many-body correlators preserve the integrity of topological invariants for mixed Gaussian quantum states in one dimension. Our approach relies on the expectation value of the many-body momentum-translation operator and leads to a physical observable—the “ensemble geometric phase” (EGP—which represents a bona fide geometric phase for mixed quantum states, in the thermodynamic limit. In cyclic protocols, the EGP provides a topologically quantized observable that detects encircled spectral singularities (“purity-gap” closing points of density matrices. While we identify the many-body nature of the EGP as a key ingredient, we propose a conceptually simple, interferometric setup to directly measure the latter in experiments with mesoscopic ensembles of ultracold atoms.
Protein matrices for wound dressings =
Vasconcelos, Andreia Joana Costa
Fibrous proteins such as silk fibroin (SF), keratin (K) and elastin (EL) are able to mimic the extracellular matrix (ECM) that allows their recognition under physiological conditions. The impressive mechanical properties, the environmental stability, in combination with their biocompatibility and control of morphology, provide an important basis to use these proteins in biomedical applications like protein-based wound dressings. Along time the concept of wound dressings has changed from the traditional dressings such as honey or natural fibres, used just to protect the wound from external factors, to the interactive dressings of the present. Wounds can be classified in acute that heal in the expected time frame, and chronic, which fail to heal because the orderly sequence of events is disrupted at one or more stages of the healing process. Moreover, chronic wound exudates contain high levels of tissue destructive proteolytic enzymes such as human neutrophil elastase (HNE) that need to be controlled for a proper healing. The aim of this work is to exploit the self-assemble properties of silk fibroin, keratin and elastin for the development of new protein materials to be used as wound dressings: i) evaluation of the blending effect on the physical and chemical properties of the materials; ii) development of materials with different morphologies; iii) assessment of the cytocompatibility of the protein matrices; iv) ultimately, study the ability of the developed protein matrices as wound dressings through the use of human chronic wound exudate; v) use of innovative short peptide sequences that allow to target the control of high levels of HNE found on chronic wounds. Chapter III reports the preparation of silk fibroin/keratin (SF/K) blend films by solvent casting evaporation. Two solvent systems, aqueous and acidic, were used for the preparation of films from fibroin and keratin extracted from the respective silk and wool fibres. The effect of solvent system used was
MERSENNE AND HADAMARD MATRICES CALCULATION BY SCARPIS METHOD
Directory of Open Access Journals (Sweden)
N. A. Balonin
2014-05-01
Full Text Available Purpose. The paper deals with the problem of basic generalizations of Hadamard matrices associated with maximum determinant matrices or not optimal by determinant matrices with orthogonal columns (weighing matrices, Mersenne and Euler matrices, ets.; calculation methods for the quasi-orthogonal local maximum determinant Mersenne matrices are not studied enough sufficiently. The goal of this paper is to develop the theory of Mersenne and Hadamard matrices on the base of generalized Scarpis method research. Methods. Extreme solutions are found in general by minimization of maximum for absolute values of the elements of studied matrices followed by their subsequent classification according to the quantity of levels and their values depending on orders. Less universal but more effective methods are based on structural invariants of quasi-orthogonal matrices (Silvester, Paley, Scarpis methods, ets.. Results. Generalizations of Hadamard and Belevitch matrices as a family of quasi-orthogonal matrices of odd orders are observed; they include, in particular, two-level Mersenne matrices. Definitions of section and layer on the set of generalized matrices are proposed. Calculation algorithms for matrices of adjacent layers and sections by matrices of lower orders are described. Approximation examples of the Belevitch matrix structures up to 22-nd critical order by Mersenne matrix of the third order are given. New formulation of the modified Scarpis method to approximate Hadamard matrices of high orders by lower order Mersenne matrices is proposed. Williamson method is described by example of one modular level matrices approximation by matrices with a small number of levels. Practical relevance. The efficiency of developing direction for the band-pass filters creation is justified. Algorithms for Mersenne matrices design by Scarpis method are used in developing software of the research program complex. Mersenne filters are based on the suboptimal by
Likelihood Approximation With Hierarchical Matrices For Large Spatial Datasets
Litvinenko, Alexander
2017-09-03
We use available measurements to estimate the unknown parameters (variance, smoothness parameter, and covariance length) of a covariance function by maximizing the joint Gaussian log-likelihood function. To overcome cubic complexity in the linear algebra, we approximate the discretized covariance function in the hierarchical (H-) matrix format. The H-matrix format has a log-linear computational cost and storage O(kn log n), where the rank k is a small integer and n is the number of locations. The H-matrix technique allows us to work with general covariance matrices in an efficient way, since H-matrices can approximate inhomogeneous covariance functions, with a fairly general mesh that is not necessarily axes-parallel, and neither the covariance matrix itself nor its inverse have to be sparse. We demonstrate our method with Monte Carlo simulations and an application to soil moisture data. The C, C++ codes and data are freely available.
A Brief Historical Introduction to Matrices and Their Applications
Debnath, L.
2014-01-01
This paper deals with the ancient origin of matrices, and the system of linear equations. Included are algebraic properties of matrices, determinants, linear transformations, and Cramer's Rule for solving the system of algebraic equations. Special attention is given to some special matrices, including matrices in graph theory and electrical…
Raven's matrices and working memory: a dual-task approach.
Rao, K Venkata; Baddeley, Alan
2013-01-01
Raven's Matrices Test was developed as a "pure" measure of Spearman's concept of general intelligence, g. Subsequent research has attempted to specify the processes underpinning performance, some relating it to the concept of working memory and proposing a crucial role for the central executive, with the nature of other components currently unclear. Up to this point, virtually all work has been based on correlational analysis of number of correct solutions, sometimes related to possible strategies. We explore the application to this problem of the concurrent task methodology used widely in developing the concept of multicomponent working memory. Participants attempted to solve problems from the matrices under baseline conditions, or accompanied by backward counting or verbal repetition tasks, assumed to disrupt the central executive and phonological loop components of working memory, respectively. As in other uses of this method, number of items correct showed little effect, while solution time measures gave very clear evidence of an important role for the central executive, but no evidence for phonological loop involvement. We conclude that this and related concurrent task techniques hold considerable promise for the analysis of Raven's matrices and potentially for other established psychometric tests.
Savenkov, S M
2002-01-01
Using the Mueller matrix representation in the basis of the matrices of amplitude and phase anisotropies, a generalized solution of the inverse problem of polarimetry for deterministic objects on the base of incomplete Mueller matrices, which have been measured by method of three input polarization, is obtained.
International Nuclear Information System (INIS)
Savenkov, S.M.; Oberemok, Je.A.
2002-01-01
Using the Mueller matrix representation in the basis of the matrices of amplitude and phase anisotropies, a generalized solution of the inverse problem of polarimetry for deterministic objects on the base of incomplete Mueller matrices, which have been measured by method of three input polarization, is obtained
International Nuclear Information System (INIS)
Wei Yi; Fyodorov, Yan V
2008-01-01
Given any fixed N x N positive semi-definite diagonal matrix G ≥ 0 we derive the explicit formula for the density of complex eigenvalues for random matrices A of the form A=U√G where the random unitary matrices U are distributed on the group U(N) according to the Haar measure. (fast track communication)
Random matrices and random difference equations
International Nuclear Information System (INIS)
Uppuluri, V.R.R.
1975-01-01
Mathematical models leading to products of random matrices and random difference equations are discussed. A one-compartment model with random behavior is introduced, and it is shown how the average concentration in the discrete time model converges to the exponential function. This is of relevance to understanding how radioactivity gets trapped in bone structure in blood--bone systems. The ideas are then generalized to two-compartment models and mammillary systems, where products of random matrices appear in a natural way. The appearance of products of random matrices in applications in demography and control theory is considered. Then random sequences motivated from the following problems are studied: constant pulsing and random decay models, random pulsing and constant decay models, and random pulsing and random decay models
Quantum Entanglement and Reduced Density Matrices
Purwanto, Agus; Sukamto, Heru; Yuwana, Lila
2018-05-01
We investigate entanglement and separability criteria of multipartite (n-partite) state by examining ranks of its reduced density matrices. Firstly, we construct the general formula to determine the criterion. A rank of origin density matrix always equals one, meanwhile ranks of reduced matrices have various ranks. Next, separability and entanglement criterion of multipartite is determined by calculating ranks of reduced density matrices. In this article we diversify multipartite state criteria into completely entangled state, completely separable state, and compound state, i.e. sub-entangled state and sub-entangledseparable state. Furthermore, we also shorten the calculation proposed by the previous research to determine separability of multipartite state and expand the methods to be able to differ multipartite state based on criteria above.
Advanced incomplete factorization algorithms for Stiltijes matrices
Energy Technology Data Exchange (ETDEWEB)
Il`in, V.P. [Siberian Division RAS, Novosibirsk (Russian Federation)
1996-12-31
The modern numerical methods for solving the linear algebraic systems Au = f with high order sparse matrices A, which arise in grid approximations of multidimensional boundary value problems, are based mainly on accelerated iterative processes with easily invertible preconditioning matrices presented in the form of approximate (incomplete) factorization of the original matrix A. We consider some recent algorithmic approaches, theoretical foundations, experimental data and open questions for incomplete factorization of Stiltijes matrices which are {open_quotes}the best{close_quotes} ones in the sense that they have the most advanced results. Special attention is given to solving the elliptic differential equations with strongly variable coefficients, singular perturbated diffusion-convection and parabolic equations.
DEFF Research Database (Denmark)
D'ovidio, Francesco; Bohr, Henrik; Lindgård, Per-Anker
2005-01-01
We study the propagation of solitons along the hydrogen bonds of an alpha helix. Modeling the hydrogen and peptide bonds with Lennard-Jones potentials, we show that the solitons can appear spontaneously and have long lifetimes. Remarkably, even if no explicit solution is known for the Lennard-Jones...... potential, the solitons can be characterized analytically with a good quantitative agreement using formulas for a Toda potential with parameters fitted to the Lennard-Jones potential. We also discuss and show the robustness of the family of periodic solutions called cnoidal waves, corresponding to phonons...
Energy Technology Data Exchange (ETDEWEB)
Baudry, G.
2003-11-15
In the field of the measurement of low masses of fissile material ({sup 235}U, {sup 239}Pu, {sup 241}Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density {<=} 0,4 g/cm{sup 3}) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the
Tereshin, Alexander A.; Usilin, Sergey A.; Arlazarov, Vladimir V.
2018-04-01
This paper aims to study the problem of multi-class object detection in video stream with Viola-Jones cascades. An adaptive algorithm for selecting Viola-Jones cascade based on greedy choice strategy in solution of the N-armed bandit problem is proposed. The efficiency of the algorithm on the problem of detection and recognition of the bank card logos in the video stream is shown. The proposed algorithm can be effectively used in documents localization and identification, recognition of road scene elements, localization and tracking of the lengthy objects , and for solving other problems of rigid object detection in a heterogeneous data flows. The computational efficiency of the algorithm makes it possible to use it both on personal computers and on mobile devices based on processors with low power consumption.
Density functional study of the pressure tensor for inhomogeneous Lennard—Jones fluids
International Nuclear Information System (INIS)
Sun Zong-Li; Liu Zhi-Cheng; Kang Yan-Shuang; Ma Heng-Xin; Kang Yan-Mei
2012-01-01
Based on classical density functional theory, an expression of the pressure tensor for inhomogeneous fluids is presented. This takes into account greater correlation between particles, especially for systems that are geometrically confined or involve an interface. The density and pressure components of Lennard-Jones fluids confined in hard and softened nano-cavities are calculated. A comparison between the results of this work and IK expression suggests that the agreement depends on temperature. The interfacial tension for hard sphere fluids agrees well with the Monte Carlo result when the bulk density is not too large. The results of the solid-fluid interfacial tension for Lennard—Jones fluids demonstrate that different types of external potentials modulate the interfacial tension in different manners. (condensed matter: structural, mechanical, and thermal properties)
Molecular dynamics study of the hydration of Lennard-Jones solutes
International Nuclear Information System (INIS)
Geiger, A.; Rahman, A.; Stillinger, F.H.
1979-01-01
In order to clarify the nature of hydrophobic interactions in water, we have used the molecular dynamics simulation method to study a system comprising two Lennard-Jones solute particles and 214 water molecules. Although the solutes were placed initially in contact, forces in the system drive them slightly apart to permit formation of vertex-sharing solvent ''cages.'' Definite orientational preferences have been observed for water molecules in the first solvation layer around the Lennard-Jones solutes; these preferences are loosely reminiscent of structure in clathrates. Nevertheless, substantial local disorder is obviously present. The dynamical data show that translational and rotational motions of solvation--sheath water molecules are perceptibly slower (by at least 20%) than those in pure bulk water
Volatility Transmission between Dow Jones Stock Index and Emerging Bond Index
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Amir Saadaoui
2016-04-01
Full Text Available In this paper, we use a bivariate GARCH model to estimate simultaneously of the mean and the conditional variance between the Dow Jones stock index and some emerging bond indices. We used the DCC-GARCH model to graphically demonstrate the peaks of the volatility transmission. We examined this transmission using daily returns between July, 30, 2009 and January, 18, 2011 extracted from Datastream. Our results demonstrate that there is a significant transmission of shocks and volatility between the Dow Jones stock index and bond indices of the emerging countries. The results also confirm the idea that the crisis was transmitted from the United States to the emerging countries due to foreign investment made in these countries.
Collision kernels in the eikonal approximation for Lennard-Jones interaction potential
International Nuclear Information System (INIS)
Zielinska, S.
1985-03-01
The velocity changing collisions are conveniently described by collisional kernels. These kernels depend on an interaction potential and there is a necessity for evaluating them for realistic interatomic potentials. Using the collision kernels, we are able to investigate the redistribution of atomic population's caused by the laser light and velocity changing collisions. In this paper we present the method of evaluating the collision kernels in the eikonal approximation. We discuss the influence of the potential parameters Rsub(o)sup(i), epsilonsub(o)sup(i) on kernel width for a given atomic state. It turns out that unlike the collision kernel for the hard sphere model of scattering the Lennard-Jones kernel is not so sensitive to changes of Rsub(o)sup(i) as the previous one. Contrary to the general tendency of approximating collisional kernels by the Gaussian curve, kernels for the Lennard-Jones potential do not exhibit such a behaviour. (author)
Acute Plasma Cell Leukemia Associated with Bence-Jones Proteinuria: A case Report
Directory of Open Access Journals (Sweden)
M. Morshed
1972-07-01
Full Text Available Acute plasma cell leukemia with Bence-Jones proteinuria is reported in a 60 year old lranien male with a 25 day history of acute onset of fever. weakness, weight loss, diarrhea and bloody stools. The patient was noted to be cachectic and anemic. He had purpuric and petechial skin lesions, generalized lymphadenopathy and splenomegaly. Up to 80% immature plasma cells were present in the peripheral blood and the platelet count was 10,000. Bone marrow was hypercellular and that most of it was composed of immature plasma cells. Serum electrophoresis showed increased beta globulins and Bence-Jones protein was strongly positive in the urine. The patient died after nine days in uremic coma with haemorrhagic diathesis. Auto psy showed wide spread infi ltra tion of plasmocytes and plasmocytoblasts in all organs.
Wishart and anti-Wishart random matrices
International Nuclear Information System (INIS)
Janik, Romuald A; Nowak, Maciej A
2003-01-01
We provide a compact exact representation for the distribution of the matrix elements of the Wishart-type random matrices A † A, for any finite number of rows and columns of A, without any large N approximations. In particular, we treat the case when the Wishart-type random matrix contains redundant, non-random information, which is a new result. This representation is of interest for a procedure for reconstructing the redundant information hidden in Wishart matrices, with potential applications to numerous models based on biological, social and artificial intelligence networks
Topological expansion of the chain of matrices
International Nuclear Information System (INIS)
Eynard, B.; Ferrer, A. Prats
2009-01-01
We solve the loop equations to all orders in 1/N 2 , for the Chain of Matrices matrix model (with possibly an external field coupled to the last matrix of the chain). We show that the topological expansion of the free energy, is, like for the 1 and 2-matrix model, given by the symplectic invariants of [19]. As a consequence, we find the double scaling limit explicitly, and we discuss modular properties, large N asymptotics. We also briefly discuss the limit of an infinite chain of matrices (matrix quantum mechanics).
Partitioning sparse rectangular matrices for parallel processing
Energy Technology Data Exchange (ETDEWEB)
Kolda, T.G.
1998-05-01
The authors are interested in partitioning sparse rectangular matrices for parallel processing. The partitioning problem has been well-studied in the square symmetric case, but the rectangular problem has received very little attention. They will formalize the rectangular matrix partitioning problem and discuss several methods for solving it. They will extend the spectral partitioning method for symmetric matrices to the rectangular case and compare this method to three new methods -- the alternating partitioning method and two hybrid methods. The hybrid methods will be shown to be best.
Fluctuations and thermodynamic response functions in a Lennard-Jones solid
International Nuclear Information System (INIS)
Li, M.; Johnson, W.L.
1992-01-01
Thermodynamic response functions of a nearest-neighbor Lennard-Jones solid--heat capacity, thermal-expansion coefficient, compressibility, and elastic constants--are calculated directly from fluctuations using molecular-dynamics simulations. The algorithm used is the earlier Parrinello-Rahman molecular dynamics modified to take into account symmetry and rotation invariance of the system under investigation. The convergence is very fast and results are in good agreement with existing Monte Carlo and molecular-dynamics results
Melting in Two-Dimensional Lennard-Jones Systems: Observation of a Metastable Hexatic Phase
International Nuclear Information System (INIS)
Chen, K.; Kaplan, T.; Mostoller, M.
1995-01-01
Large scale molecular dynamics simulations of two-dimensional melting have been carried out using a recently revised Parrinello-Rahman scheme on massively parallel supercomputers. A metastable state is observed between the solid and liquid phases in Lennard-Jones systems of 36 864 and 102 400 atoms. This intermediate state shows the characteristics of the hexatic phase predicted by the theory of Kosterlitz, Thouless, Halperin, Nelson, and Young
Dynamics of an assembly of finite-size Lennard-Jones spheres
International Nuclear Information System (INIS)
Singh, P.
1996-01-01
The time-averaged Fourier spectra of the number density, velocity, and force fields are obtained numerically for an assembly of spherical particles interacting via the Lennard-Jones potential. The magnitude spectra determine the dominant wave numbers, and the phase difference between the Lennard-Jones force and number density spectra determines the nature of the particle dynamics. The latter is used to show that for every wave number k there is a critical frequency ω c (k), such that when ω c (k) the phase difference is π/2 and when ω approx-gt ω c (k) the phase difference is -π/2. The ratio of the frequency and the wave number at which the phase difference changes sign is used to define an effective sound speed for the particle system. The effective sound speed is shown to be a function of the dimensionless wave number, and is locally minimum at the same dimensionless wave numbers for which the static structure factor is minimum. It is also shown that the dynamical response of the particle system for waves with speeds greater than the effective sound speed is similar to the response of the hyperbolic systems of equations, and for waves with speeds smaller than the effective sound speed the response is similar to the response of the elliptic systems. The convection effects are shown to be of the same order of magnitude as the Lennard-Jones forces, and the change of type of the equations from hyperbolic to elliptic occurs when the magnitude of the convection term is comparable to the magnitude of the Lennard-Jones force term. It is also shown that the change of type cannot occur in a theory where the convection term is neglected. copyright 1996 The American Physical Society
Stability of relaxed Lennard-Jones models made of 500 to 6000 atoms
International Nuclear Information System (INIS)
Raoult, B.; Farges, J.; Feraudy, M.F. de; Torchet, G.
1989-01-01
We present a study of the stability of clusters models made of a number N of atoms in the range 500 to 6000 atoms, freely interacting through the Lennard-Jones potential. The potential energy per atom, calculated for relaxed models, shows that stable models belong to an icosahedral sequence when N<1600 and to a decahedral sequence beyond. A coexistence size range of both structures is discussed in connection with experimental results on argon clusters in free jet expansions. (orig.)
Effect of Energy Polydispersity on the Nature of Lennard-Jones Liquids
Ingebrigtsen, Trond S.; Tanaka, Hajime
2016-01-01
In the companion paper [T. S. Ingebrigtsen and H. Tanaka, J. Phys. Chem. B 119, 11052 (2015)] the effect of size polydispersity on the nature of Lennard-Jones (LJ) liquids, which represent most molecular liquids without hydrogen bonds, was studied. More specifically, it was shown that even highly size polydisperse LJ liquids are Roskilde-simple (RS) liquids. RS liquids are liquids with strong correlation between constant volume equilibrium fluctuations of virial and potential energy and are s...
International Nuclear Information System (INIS)
Sun Zong-Li; Kang Yan-Shuang
2011-01-01
Classical density functional theory is used to study the associating Lennard—Jones fluids in contact with spherical hard wall of different curvature radii. The interfacial properties including contact density and fluid-solid interfacial tension are investigated. The influences of associating energy, curvature of hard wall and the bulk density of fluids on these properties are analyzed in detail. The results may provide helpful clues to understand the interfacial properties of other complex fluids. (condensed matter: structure, mechanical and thermal properties)
Lake Holocene Use of Wetland Habitats in Central California: A Reply to Jones
Hildebrandt, William R
1997-01-01
In this volume, Terry Jones (1997) provided a thorough critique of my summary (also in this volume [Hildebrandt 1977a]) of prehistoric hunter- gatherer adaptations in the southern Santa Clara Valley, California (also see Hildebrandt and Mikkelsen 1993). His review identified a variety of issues that warrant additional consideration, particularly those pertaining to settlement chronology, paleoenvironmental change, and Late Holocene subsistence intensification. I appreciate his comments, as my...
Idiosyncratic risk in the Dow Jones Eurostoxx50 Index
Daly, Kevin; Vo, Vinh
2008-07-01
Recent evidence by Campbell et al. [J.Y. Campbell, M. Lettau B.G. Malkiel, Y. Xu, Have individual stocks become more volatile? An empirical exploration of idiosyncratic risk, The Journal of Finance (February) (2001)] shows an increase in firm-level volatility and a decline of the correlation among stock returns in the US. In relation to the Euro-Area stock markets, we find that both aggregate firm-level volatility and average stock market correlation have trended upwards. We estimate a linear model of the market risk-return relationship nested in an EGARCH(1, 1)-M model for conditional second moments. We then show that traditional estimates of the conditional risk-return relationship, that use ex-post excess-returns as the conditioning information set, lead to joint tests of the theoretical model (usually the ICAPM) and of the Efficient Market Hypothesis in its strong form. To overcome this problem we propose alternative measures of expected market risk based on implied volatility extracted from traded option prices and we discuss the conditions under which implied volatility depends solely on expected risk. We then regress market excess-returns on lagged market implied variance computed from implied market volatility to estimate the relationship between expected market excess-returns and expected market risk.We investigate whether, as predicted by the ICAPM, the expected market risk is the main factor in explaining the market risk premium and the latter is independent of aggregate idiosyncratic risk.
Pendeteksian Bagian Tubuh Manusia untuk Filter Pornografi dengan Metode Viola-Jones
Directory of Open Access Journals (Sweden)
Benny Senjaya
2012-06-01
Full Text Available Information Technology does help people to get information promptly anytime and anywhere. Unfortunately, the information gathered from the Internet does not always come out positive. Some information can be destructive, such as porn images. To mitigate this problem, the study aims to create a desktop application that could detect parts of human body which can be expanded in the future to become an image filter application for pornography. The detection methodology in this study is Viola-Jones method which provides a complete framework for extracting and recognizing image features. A combination of Viola-Jones method with Haar-like features, integral image, boosting algorithm, and cascade classifier provide a robust detector for the application. First, several parts of the human body are chosen to be detected as the data training using the Viola-Jones method. Then, another set of images (similar body parts but different images are run through the application to be recognized. The result shows 86.25% of successful detection. The failures are identified and show that the inputted data are completely different with the data training.
Metastability, spectrum, and eigencurrents of the Lennard-Jones-38 network
International Nuclear Information System (INIS)
Cameron, Maria K.
2014-01-01
We develop computational tools for spectral analysis of stochastic networks representing energy landscapes of atomic and molecular clusters. Physical meaning and some properties of eigenvalues, left and right eigenvectors, and eigencurrents are discussed. We propose an approach to compute a collection of eigenpairs and corresponding eigencurrents describing the most important relaxation processes taking place in the system on its way to the equilibrium. It is suitable for large and complex stochastic networks where pairwise transition rates, given by the Arrhenius law, vary by orders of magnitude. The proposed methodology is applied to the network representing the Lennard-Jones-38 cluster created by Wales's group. Its energy landscape has a double funnel structure with a deep and narrow face-centered cubic funnel and a shallower and wider icosahedral funnel. However, the complete spectrum of the generator matrix of the Lennard-Jones-38 network has no appreciable spectral gap separating the eigenvalue corresponding to the escape from the icosahedral funnel. We provide a detailed description of the escape process from the icosahedral funnel using the eigencurrent and demonstrate a superexponential growth of the corresponding eigenvalue. The proposed spectral approach is compared to the methodology of the Transition Path Theory. Finally, we discuss whether the Lennard-Jones-38 cluster is metastable from the points of view of a mathematician and a chemical physicist, and make a connection with experimental works
Analytic Debye-Grüneisen equation of state for a generalized Lennard-Jones solids
Institute of Scientific and Technical Information of China (English)
孙久勋; 吴强; 蔡灵仓; 经福谦
2003-01-01
The approximate method to treat the practical quantum anharmonic solids proposed by Hardy,Lacks and Shukla is reformulated with explicit physical meanings.It is shown that the quantum effect is important at low temperature,it can be treated in the harmonic framework; and the anharmonic effect is important at high temperature and tends to zero at low temperature,it can be treated by using a classical approximation.The alternative formulation is easier for various applications,and is applied to a Debye-Gruneisen solid with the generalized Lennard-Jones intermolecular interaction.The expressions for the Debye temperature and Gruneisen parameter as a function of volume are analytically derived.The analytic equation of state is applied to predict the thermodynamic properties of solid xenon at normal-pressure with the nearest-neighbour Lennard-Jones interaction,and is further applied to research the properties of solid xenon and krypton at high pressure by using an all-neighbour Lennard-Jones interaction.The theoretical results are in agreement with the experiments.
Mutability and Deformity: Models of the Body and the Art of Edward Burne-Jones
Directory of Open Access Journals (Sweden)
Caroline Arscott
2008-10-01
Full Text Available This essay discusses the alternatives that emerged in the Victorian period to a perfect and regular neoclassical conception of the heroic male body. It charts the evolving fascination with mutable forms, whether heroic or monstrous, imagined first of all in the 1850s in terms of a body conceived of as bolted together or modified by the fusion of organic and inorganic substances. The early work of Burne-Jones is discussed in relation to investigations of cell structure and mechanical inventions in the Great Exhibition of 1851 such as the 'Expanding Model of a Man' invented by Count Dunin. Arscott also discusses the cybernetic implications of Burne-Jones's gouache, 'The Merciful Knight' (1863. Later works of Burne-Jones, in particular 'Perseus and the Graiae' (1878 and the reworked composition 'Love Among the Ruins' (1894, are discussed in terms of a turn towards a sense of the spread and mutation of organic being through and beyond the self. Arscott considers this alongside contemporary investigations of the role of bacilli in disease, looking at leprosy and the heroisation of the Leper Priest of Molokai, Father Damien in the 1880s and 1890s. In the late-Victorian period, Arscott concludes, monstrous distortion was imagined as the unpredictable and unruly proliferation of the organic by the organism in both its vital and morbid states.
Revised Jones Criteria For The Diagnosis of Acute Rheumatic Fever (AHA 2015 - An Indian Perspective
Directory of Open Access Journals (Sweden)
KV Sahasranam
2015-07-01
Full Text Available Acute Rheumatic Fever (ARF is still a major problem in some developing and low middle income countries though the incidence and prevalence has remarkably reduced in North America and Europe. Ever since T. Duckett Jones in 1944 proposed the Jones criteria, it was modified and later revised by the American Heart Association (AHA in 1992. This was reconfirmed in and AHA sponsored Work shop in 2002. No modification or change was suggested after the introduction of Doppler Echocardiography (DE for the diagnosis of clinical and "subclinical carditis". When a clinical diagnosis by the clinician fails to show evidence of carditis, DE may pick up cases of "subclinical carditis". Moreover, previous recommendations did not include the Classification of Recommendations (Class I, II a, II b, and III and Levels of Evidence (Levels A, B and C. Recently, however, a scientific statement from the American Heart Association (AHA has published an update to the Jones criteria including the use of DE in the diagnosis of ARF.
Jones, Simon
2005-01-01
Pärnus telekommunikatsiooni- ja infofoorumil viibiv innovatsiooniekspert vastab küsimustele, mis puudutavad tema hinnangut Eesti teadus- ja arendustegevusele, tehnoloogia kasutamist sotsiaalprobleemide lahendamisel ning Eesti varustamist tasuta internetiühendusega. Lisa: Simon Jones
Schweitzer, Simon D.
2006-01-01
Vorliegender Index erschließt die nicht-ersten Titelbestandteile der in Dilwyn Jones: An index of ancient Egyptian titles, epithets and phrases of the Old Kingdom. Oxford : Archaeopress, 2000, verzettelten Titel und Epitheta des Alten Reiches.
National Research Council Canada - National Science Library
Fulton, Larry
1998-01-01
.... ̂Product 2 - "Bayne-Jones Army Community Hospital Web Site," a strategic Internet web site for marketing health and wellness, the TRICARE medical network, the Joint Readiness Training Center Surgeon's...
National Oceanic and Atmospheric Administration, Department of Commerce — Meteorological data were collected using meteorological sensors from the USS JOHN PAUL JONES in the Northeast Pacific Ocean. Data were collected and recorded into...
Hierarchical matrix approximation of large covariance matrices
Litvinenko, Alexander; Genton, Marc G.; Sun, Ying
2015-01-01
We approximate large non-structured Matérn covariance matrices of size n×n in the H-matrix format with a log-linear computational cost and storage O(kn log n), where rank k ≪ n is a small integer. Applications are: spatial statistics, machine learning and image analysis, kriging and optimal design.
Theoretical origin of quark mass matrices
International Nuclear Information System (INIS)
Mohapatra, R.N.
1987-01-01
This paper presents the theoretical origin of specific quark mass matrices in the grand unified theories. The author discusses the first natural derivation of the Stech-type mass matrix in unified gauge theories. A solution to the strong CP-problem is provided
Malware Analysis Using Visualized Image Matrices
Directory of Open Access Journals (Sweden)
KyoungSoo Han
2014-01-01
Full Text Available This paper proposes a novel malware visual analysis method that contains not only a visualization method to convert binary files into images, but also a similarity calculation method between these images. The proposed method generates RGB-colored pixels on image matrices using the opcode sequences extracted from malware samples and calculates the similarities for the image matrices. Particularly, our proposed methods are available for packed malware samples by applying them to the execution traces extracted through dynamic analysis. When the images are generated, we can reduce the overheads by extracting the opcode sequences only from the blocks that include the instructions related to staple behaviors such as functions and application programming interface (API calls. In addition, we propose a technique that generates a representative image for each malware family in order to reduce the number of comparisons for the classification of unknown samples and the colored pixel information in the image matrices is used to calculate the similarities between the images. Our experimental results show that the image matrices of malware can effectively be used to classify malware families both statically and dynamically with accuracy of 0.9896 and 0.9732, respectively.
Moment matrices, border bases and radical computation
B. Mourrain; J.B. Lasserre; M. Laurent (Monique); P. Rostalski; P. Trebuchet (Philippe)
2013-01-01
htmlabstractIn this paper, we describe new methods to compute the radical (resp. real radical) of an ideal, assuming it complex (resp. real) variety is nte. The aim is to combine approaches for solving a system of polynomial equations with dual methods which involve moment matrices and
Moment matrices, border bases and radical computation
Lasserre, J.B.; Laurent, M.; Mourrain, B.; Rostalski, P.; Trébuchet, P.
2013-01-01
In this paper, we describe new methods to compute the radical (resp. real radical) of an ideal, assuming its complex (resp. real) variety is finite. The aim is to combine approaches for solving a system of polynomial equations with dual methods which involve moment matrices and semi-definite
Moment matrices, border bases and radical computation
B. Mourrain; J.B. Lasserre; M. Laurent (Monique); P. Rostalski; P. Trebuchet (Philippe)
2011-01-01
htmlabstractIn this paper, we describe new methods to compute the radical (resp. real radical) of an ideal, assuming it complex (resp. real) variety is nte. The aim is to combine approaches for solving a system of polynomial equations with dual methods which involve moment matrices and
Malware analysis using visualized image matrices.
Han, KyoungSoo; Kang, BooJoong; Im, Eul Gyu
2014-01-01
This paper proposes a novel malware visual analysis method that contains not only a visualization method to convert binary files into images, but also a similarity calculation method between these images. The proposed method generates RGB-colored pixels on image matrices using the opcode sequences extracted from malware samples and calculates the similarities for the image matrices. Particularly, our proposed methods are available for packed malware samples by applying them to the execution traces extracted through dynamic analysis. When the images are generated, we can reduce the overheads by extracting the opcode sequences only from the blocks that include the instructions related to staple behaviors such as functions and application programming interface (API) calls. In addition, we propose a technique that generates a representative image for each malware family in order to reduce the number of comparisons for the classification of unknown samples and the colored pixel information in the image matrices is used to calculate the similarities between the images. Our experimental results show that the image matrices of malware can effectively be used to classify malware families both statically and dynamically with accuracy of 0.9896 and 0.9732, respectively.
Generation speed in Raven's Progressive Matrices Test
Verguts, T.; Boeck, P. De; Maris, E.G.G.
1999-01-01
In this paper, we investigate the role of response fluency on a well-known intelligence test, Raven's (1962) Advanced Progressive Matrices (APM) test. Critical in solving this test is finding rules that govern the items. Response fluency is conceptualized as generation speed or the speed at which a
Inversion of General Cyclic Heptadiagonal Matrices
Directory of Open Access Journals (Sweden)
A. A. Karawia
2013-01-01
Full Text Available We describe a reliable symbolic computational algorithm for inverting general cyclic heptadiagonal matrices by using parallel computing along with recursion. The computational cost of it is operations. The algorithm is implementable to the Computer Algebra System (CAS such as MAPLE, MATLAB, and MATHEMATICA. Two examples are presented for the sake of illustration.
Hierarchical matrix approximation of large covariance matrices
Litvinenko, Alexander
2015-11-30
We approximate large non-structured Matérn covariance matrices of size n×n in the H-matrix format with a log-linear computational cost and storage O(kn log n), where rank k ≪ n is a small integer. Applications are: spatial statistics, machine learning and image analysis, kriging and optimal design.
Computing the Jones index of quadratic permutation endomorphisms of O2
DEFF Research Database (Denmark)
Szymanski, Wojciech; Conti, Roberto
2009-01-01
We compute the index of the type III1/2 factors arising from endomorphisms of the Cuntz algebra O2 associated to the rank-two permutation matrices. Udgivelsesdato: January......We compute the index of the type III1/2 factors arising from endomorphisms of the Cuntz algebra O2 associated to the rank-two permutation matrices. Udgivelsesdato: January...
Reinisch, S; Schweiger, K; Pablik, E; Collet-Fenetrier, B; Peyrin-Biroulet, L; Alfaro, I; Panés, J; Moayyedi, P; Reinisch, W
2016-09-01
The Lennard-Jones criteria are considered the gold standard for diagnosing Crohn's disease (CD) and include the items granuloma, macroscopic discontinuity, transmural inflammation, fibrosis, lymphoid aggregates and discontinuous inflammation on histology. The criteria have never been subjected to a formal validation process. To develop a validated and improved diagnostic index based on the items of Lennard-Jones criteria. Included were 328 adult patients with long-standing CD (median disease duration 10 years) from three centres and classified as 'established', 'probable' or 'non-CD' by Lennard-Jones criteria at time of diagnosis. Controls were patients with ulcerative colitis (n = 170). The performance of each of the six diagnostic items of Lennard-Jones criteria was modelled by logistic regression and a new index based on stepwise backward selection and cut-offs was developed. The diagnostic value of the new index was analysed by comparing sensitivity, specificity and accuracy vs. Lennard-Jones criteria. By Lennard-Jones criteria 49% (n = 162) of CD patients would have been diagnosed as 'non-CD' at time of diagnosis (sensitivity/specificity/accuracy, 'established' CD: 0.34/0.99/0.67; 'probable' CD: 0.51/0.95/0.73). A new index was derived from granuloma, fibrosis, transmural inflammation and macroscopic discontinuity, but excluded lymphoid aggregates and discontinuous inflammation on histology. Our index provided improved diagnostic accuracy for 'established' and 'probable' CD (sensitivity/specificity/accuracy, 'established' CD: 0.45/1/0.72; 'probable' CD: 0.8/0.85/0.82), including the subgroup isolated colonic CD ('probable' CD, new index: 0.73/0.85/0.79; Lennard-Jones criteria: 0.43/0.95/0.69). We developed an index based on items of Lennard-Jones criteria providing improved diagnostic accuracy for the differential diagnosis between CD and UC. © 2016 John Wiley & Sons Ltd.
Characterization of a New Heat Dissipation Matric Potential Sensor
Directory of Open Access Journals (Sweden)
Rolf Krebs
2013-01-01
Full Text Available Soil moisture sensors can help to reduce the amount of water needed for irrigation. In this paper we describe the PlantCare soil moisture sensor as a new type of heat dissipation sensor, its calibration and the correction for temperature changes. With the PlantCare sensor it is possible to measure the matric potential indirectly to monitor or control irrigation. This sensor is based on thermal properties of a synthetic felt. After a defined heating phase the cooling time to a threshold temperature is a function of the water content in the synthetic felt. The water content in this porous matrix is controlled by the matric potential in the surrounding soil. Calibration measurements have shown that the sensor is most sensitive to −400 hPa and allows lower sensitivity measurements to −800 hPa. The disturbing effect of the temperature change during the measurement on the cooling time can be corrected by a linear function and the differences among sensors are minimized by a two point calibration.
Dissimilarities of reduced density matrices and eigenstate thermalization hypothesis
He, Song; Lin, Feng-Li; Zhang, Jia-ju
2017-12-01
We calculate various quantities that characterize the dissimilarity of reduced density matrices for a short interval of length ℓ in a two-dimensional (2D) large central charge conformal field theory (CFT). These quantities include the Rényi entropy, entanglement entropy, relative entropy, Jensen-Shannon divergence, as well as the Schatten 2-norm and 4-norm. We adopt the method of operator product expansion of twist operators, and calculate the short interval expansion of these quantities up to order of ℓ9 for the contributions from the vacuum conformal family. The formal forms of these dissimilarity measures and the derived Fisher information metric from contributions of general operators are also given. As an application of the results, we use these dissimilarity measures to compare the excited and thermal states, and examine the eigenstate thermalization hypothesis (ETH) by showing how they behave in high temperature limit. This would help to understand how ETH in 2D CFT can be defined more precisely. We discuss the possibility that all the dissimilarity measures considered here vanish when comparing the reduced density matrices of an excited state and a generalized Gibbs ensemble thermal state. We also discuss ETH for a microcanonical ensemble thermal state in a 2D large central charge CFT, and find that it is approximately satisfied for a small subsystem and violated for a large subsystem.
On Skew Circulant Type Matrices Involving Any Continuous Fibonacci Numbers
Directory of Open Access Journals (Sweden)
Zhaolin Jiang
2014-01-01
inverse matrices of them by constructing the transformation matrices. Furthermore, the maximum column sum matrix norm, the spectral norm, the Euclidean (or Frobenius norm, and the maximum row sum matrix norm and bounds for the spread of these matrices are given, respectively.
Waller, Niels G
2016-01-01
For a fixed set of standardized regression coefficients and a fixed coefficient of determination (R-squared), an infinite number of predictor correlation matrices will satisfy the implied quadratic form. I call such matrices fungible correlation matrices. In this article, I describe an algorithm for generating positive definite (PD), positive semidefinite (PSD), or indefinite (ID) fungible correlation matrices that have a random or fixed smallest eigenvalue. The underlying equations of this algorithm are reviewed from both algebraic and geometric perspectives. Two simulation studies illustrate that fungible correlation matrices can be profitably used in Monte Carlo research. The first study uses PD fungible correlation matrices to compare penalized regression algorithms. The second study uses ID fungible correlation matrices to compare matrix-smoothing algorithms. R code for generating fungible correlation matrices is presented in the supplemental materials.
Evolutionary Games with Randomly Changing Payoff Matrices
Yakushkina, Tatiana; Saakian, David B.; Bratus, Alexander; Hu, Chin-Kun
2015-06-01
Evolutionary games are used in various fields stretching from economics to biology. In most of these games a constant payoff matrix is assumed, although some works also consider dynamic payoff matrices. In this article we assume a possibility of switching the system between two regimes with different sets of payoff matrices. Potentially such a model can qualitatively describe the development of bacterial or cancer cells with a mutator gene present. A finite population evolutionary game is studied. The model describes the simplest version of annealed disorder in the payoff matrix and is exactly solvable at the large population limit. We analyze the dynamics of the model, and derive the equations for both the maximum and the variance of the distribution using the Hamilton-Jacobi equation formalism.
An algorithmic characterization of P-matricity
Ben Gharbia , Ibtihel; Gilbert , Jean Charles
2013-01-01
International audience; It is shown that a matrix M is a P-matrix if and only if, whatever is the vector q, the Newton-min algorithm does not cycle between two points when it is used to solve the linear complementarity problem 0 ≤ x ⊥ (Mx+q) ≥ 0.; Nous montrons dans cet article qu'une matrice M est une P-matrice si, et seulement si, quel que soit le vecteur q, l'algorithme de Newton-min ne fait pas de cycle de deux points lorsqu'il est utilisé pour résoudre le problème de compl\\émentarité lin...
Introduction to random matrices theory and practice
Livan, Giacomo; Vivo, Pierpaolo
2018-01-01
Modern developments of Random Matrix Theory as well as pedagogical approaches to the standard core of the discipline are surprisingly hard to find in a well-organized, readable and user-friendly fashion. This slim and agile book, written in a pedagogical and hands-on style, without sacrificing formal rigor fills this gap. It brings Ph.D. students in Physics, as well as more senior practitioners, through the standard tools and results on random matrices, with an eye on most recent developments that are not usually covered in introductory texts. The focus is mainly on random matrices with real spectrum. The main guiding threads throughout the book are the Gaussian Ensembles. In particular, Wigner’s semicircle law is derived multiple times to illustrate several techniques (e.g., Coulomb gas approach, replica theory). Most chapters are accompanied by Matlab codes (stored in an online repository) to guide readers through the numerical check of most analytical results.
Teaching Fourier optics through ray matrices
International Nuclear Information System (INIS)
Moreno, I; Sanchez-Lopez, M M; Ferreira, C; Davis, J A; Mateos, F
2005-01-01
In this work we examine the use of ray-transfer matrices for teaching and for deriving some topics in a Fourier optics course, exploiting the mathematical simplicity of ray matrices compared to diffraction integrals. A simple analysis of the physical meaning of the elements of the ray matrix provides a fast derivation of the conditions to obtain the optical Fourier transform. We extend this derivation to fractional Fourier transform optical systems, and derive the order of the transform from the ray matrix. Some examples are provided to stress this point of view, both with classical and with graded index lenses. This formulation cannot replace the complete explanation of Fourier optics provided by the wave theory, but it is a complementary tool useful to simplify many aspects of Fourier optics and to relate them to geometrical optics
The recurrence sequences via Sylvester matrices
Karaduman, Erdal; Deveci, Ömür
2017-07-01
In this work, we define the Pell-Jacobsthal-Slyvester sequence and the Jacobsthal-Pell-Slyvester sequence by using the Slyvester matrices which are obtained from the characteristic polynomials of the Pell and Jacobsthal sequences and then, we study the sequences defined modulo m. Also, we obtain the cyclic groups and the semigroups from the generating matrices of these sequences when read modulo m and then, we derive the relationships among the orders of the cyclic groups and the periods of the sequences. Furthermore, we redefine Pell-Jacobsthal-Slyvester sequence and the Jacobsthal-Pell-Slyvester sequence by means of the elements of the groups and then, we examine them in the finite groups.
Joint Matrices Decompositions and Blind Source Separation
Czech Academy of Sciences Publication Activity Database
Chabriel, G.; Kleinsteuber, M.; Moreau, E.; Shen, H.; Tichavský, Petr; Yeredor, A.
2014-01-01
Roč. 31, č. 3 (2014), s. 34-43 ISSN 1053-5888 R&D Projects: GA ČR GA102/09/1278 Institutional support: RVO:67985556 Keywords : joint matrices decomposition * tensor decomposition * blind source separation Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 5.852, year: 2014 http://library.utia.cas.cz/separaty/2014/SI/tichavsky-0427607.pdf
Tensor Permutation Matrices in Finite Dimensions
Christian, Rakotonirina
2005-01-01
We have generalised the properties with the tensor product, of one 4x4 matrix which is a permutation matrix, and we call a tensor commutation matrix. Tensor commutation matrices can be constructed with or without calculus. A formula allows us to construct a tensor permutation matrix, which is a generalisation of tensor commutation matrix, has been established. The expression of an element of a tensor commutation matrix has been generalised in the case of any element of a tensor permutation ma...
Fast Approximate Joint Diagonalization Incorporating Weight Matrices
Czech Academy of Sciences Publication Activity Database
Tichavský, Petr; Yeredor, A.
2009-01-01
Roč. 57, č. 3 (2009), s. 878-891 ISSN 1053-587X R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : autoregressive processes * blind source separation * nonstationary random processes Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.212, year: 2009 http://library.utia.cas.cz/separaty/2009/SI/tichavsky-fast approximate joint diagonalization incorporating weight matrices.pdf
Photoluminescence of nanocrystals embedded in oxide matrices
International Nuclear Information System (INIS)
Estrada, C.; Gonzalez, J.A.; Kunold, A.; Reyes-Esqueda, J.A.; Pereyra, P.
2006-12-01
We used the theory of finite periodic systems to explain the photoluminescence spectra dependence on the average diameter of nanocrystals embedded in oxide matrices. Because of the broad matrix band gap, the photoluminescence response is basically determined by isolated nanocrystals and sequences of a few of them. With this model we were able to reproduce the shape and displacement of the experimentally observed photoluminescence spectra. (author)
Equiangular tight frames and unistochastic matrices
Czech Academy of Sciences Publication Activity Database
Goyeneche, D.; Turek, Ondřej
2017-01-01
Roč. 50, č. 24 (2017), č. článku 245304. ISSN 1751-8113 R&D Projects: GA ČR GA17-01706S Institutional support: RVO:61389005 Keywords : equiangular tight frames * unistochastic matrices * SIC POVM Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 1.857, year: 2016
Simplifications of rational matrices by using UML
Tasić, Milan B.; Stanimirović, Ivan P.
2013-01-01
The simplification process on rational matrices consists of simplifying each entry represented by a rational function. We follow the classic approach of dividing the numerator and denominator polynomials by their common GCD polynomial, and provide the activity diagram in UML for this process. A rational matrix representation as the quotient of a polynomial matrix and a polynomial is also discussed here and illustrated via activity diagrams. Also, a class diagram giving the links between the c...
Hierarchical matrix approximation of large covariance matrices
Litvinenko, Alexander
2015-01-07
We approximate large non-structured covariance matrices in the H-matrix format with a log-linear computational cost and storage O(n log n). We compute inverse, Cholesky decomposition and determinant in H-format. As an example we consider the class of Matern covariance functions, which are very popular in spatial statistics, geostatistics, machine learning and image analysis. Applications are: kriging and optimal design
Hierarchical matrix approximation of large covariance matrices
Litvinenko, Alexander
2015-01-05
We approximate large non-structured covariance matrices in the H-matrix format with a log-linear computational cost and storage O(nlogn). We compute inverse, Cholesky decomposition and determinant in H-format. As an example we consider the class of Matern covariance functions, which are very popular in spatial statistics, geostatistics, machine learning and image analysis. Applications are: kriging and op- timal design.
PHAGOCYTOSIS AND REMODELING OF COLLAGEN MATRICES
Abraham, Leah C.; Dice, J Fred.; Lee, Kyongbum; Kaplan, David L.
2007-01-01
The biodegradation of collagen and the deposition of new collagen-based extracellular matrices are of central importance in tissue remodeling and function. Similarly, for collagen-based biomaterials used in tissue engineering, the degradation of collagen scaffolds with accompanying cellular infiltration and generation of new extracellular matrix is critical for integration of in vitro grown tissues in vivo. In earlier studies we observed significant impact of collagen structure on primary lun...
Preconditioners for regularized saddle point matrices
Czech Academy of Sciences Publication Activity Database
Axelsson, Owe
2011-01-01
Roč. 19, č. 2 (2011), s. 91-112 ISSN 1570-2820 Institutional research plan: CEZ:AV0Z30860518 Keywords : saddle point matrices * preconditioning * regularization * eigenvalue clustering Subject RIV: BA - General Mathematics Impact factor: 0.533, year: 2011 http://www.degruyter.com/view/j/jnma.2011.19.issue-2/jnum.2011.005/jnum.2011.005. xml
Hierarchical matrix approximation of large covariance matrices
Litvinenko, Alexander; Genton, Marc G.; Sun, Ying; Tempone, Raul
2015-01-01
We approximate large non-structured covariance matrices in the H-matrix format with a log-linear computational cost and storage O(n log n). We compute inverse, Cholesky decomposition and determinant in H-format. As an example we consider the class of Matern covariance functions, which are very popular in spatial statistics, geostatistics, machine learning and image analysis. Applications are: kriging and optimal design
Hierarchical matrix approximation of large covariance matrices
Litvinenko, Alexander; Genton, Marc G.; Sun, Ying; Tempone, Raul
2015-01-01
We approximate large non-structured covariance matrices in the H-matrix format with a log-linear computational cost and storage O(nlogn). We compute inverse, Cholesky decomposition and determinant in H-format. As an example we consider the class of Matern covariance functions, which are very popular in spatial statistics, geostatistics, machine learning and image analysis. Applications are: kriging and op- timal design.
Staging Henry Fielding: The Author-Narrator in Tom Jones On Screen
Directory of Open Access Journals (Sweden)
Eli Løfaldli
2017-06-01
Full Text Available As recent adaptation theory has shown, classic-novel adaptation typically sets issues connected to authorship and literal and figurative ownership into play. This key feature of such adaptations is also central to the screen versions of Henry Fielding’s Tom Jones (1749. In much of Fielding’s fiction, the narrator, typically understood as an embodiment of Fielding himself, is a particularly prominent presence. The author-narrator in Tom Jones is no exception: not only is his presence strongly felt throughout the novel, but through a variety of means, ‘The History of Tom Jones, A Foundling’ is also distinctly marked as being under his control and ownership. The two adaptations of Fielding’s novel, a 1963 film and a 1997 television series, both retain the figure of the author-narrator, but differ greatly in their handling of this device and its consequent thematic ramifications. Although the 1963 film de-emphasises Henry Fielding’s status as proprietor of the story, the author-narrator as represented in the film’s voiceover commentary is a figure of authority and authorial control. In contrast, the 1997 adaptation emphasises Fielding’s ownership of the narrative and even includes the author-narrator as a character in the series, but this ownership is undermined by the irreverent treatment to which he is consistently subjected. The representations of Henry Fielding in the form of the author-narrator in both adaptations are not only indicative of shifting conceptions of authorship, but also of the important interplay between authorship, ownership and adaptation more generally.
Yan, Rongliang; Qu, Jiafu; Cao, Lihai; Liu, Hongda; Chen, Jianghua; Gao, Yan; Peng, Yi
2018-05-01
To summarize the effectiveness of mini locking plate combined with Kirschner wire in treatment of comminuted Jones fracture. Between January 2011 and October 2016, 25 cases with comminuted Jones fracture were treated with mini locking plate combined with Kirschner wire. There were 9 males and 16 females with an average age of 31.4 years (range, 16-66 years). The fractures located on the left side in 11 cases and on the right side in 14 cases. The causes of injury included spraining in 21 cases, falling down in 3 cases, and bruise in 1 case. The bone fragment of all cases was more than 3 pieces. The fracture line was mostly Y-shape or T-shape. Twelve of them were combined with other fractures. The time from injury to operation was 1-9 days (mean, 5 days). The mini locking plate and Kirschner wire were removed at 9-12 months postoperatively. At 12 months postoperatively, the pain was evaluated by the visual analogue scale (VAS) score, and the function by the American Orthopaedic Foot & Ankle Society (AOFAS) score. All incisions healed by first intention. All cases were followed up 12-36 months with an average of 21.7 months. Fracture union was observed in all patients without complications such as nonunion, delayed union, and malunion. The fracture union time was 8-12 weeks (mean, 9.4 weeks). At 12 months postoperatively, the VAS score was 1.15±0.87; the AOFAS score was 89.45±6.24, and the results were excellent in 14 cases, good in 9 cases, fair in 1 case, and poor in 1 case, with an excellent and good rate of 92%. The procedure of mini locking plate combined with Kirschner wire for comminuted Jones fracture has such advantages as convenient operation, more rigid fixation, high rate of fracture healing, and good functional recovery in foot.
Numerical simulation of pool boiling of a Lennard-Jones liquid
Inaoka, Hajime
2013-09-01
We performed a numerical simulation of pool boiling by a molecular dynamics model. In the simulation, a liquid composed of Lennard-Jones particles in a uniform gravitational field is heated by a heat source at the bottom of the system. The model successfully reproduces the change in regimes of boiling from nucleate boiling to film boiling with the increase of the heat source temperature. We present the pool boiling curve by the model, whose general behavior is consistent with those observed in experiments of pool boiling. © 2013 Elsevier B.V. All rights reserved.
Numerical simulation of pool boiling of a Lennard-Jones liquid
Inaoka, Hajime; Ito, Nobuyasu
2013-01-01
We performed a numerical simulation of pool boiling by a molecular dynamics model. In the simulation, a liquid composed of Lennard-Jones particles in a uniform gravitational field is heated by a heat source at the bottom of the system. The model successfully reproduces the change in regimes of boiling from nucleate boiling to film boiling with the increase of the heat source temperature. We present the pool boiling curve by the model, whose general behavior is consistent with those observed in experiments of pool boiling. © 2013 Elsevier B.V. All rights reserved.
Cell-model prediction of the melting of a Lennard-Jones solid
International Nuclear Information System (INIS)
Holian, B.L.
1980-01-01
The classical free energy of the Lennard-Jones 6-12 solid is computed from a single-particle anharmonic cell model with a correction to the entropy given by the classical correlational entropy of quasiharmonic lattice dynamics. The free energy of the fluid is obtained from the Hansen-Ree analytic fit to Monte Carlo equation-of-state calculations. The resulting predictions of the solid-fluid coexistence curves by this corrected cell model of the solid are in excellent agreement with the computer experiments
Third-order WKBJ eigenvalues for Lennard-Jones and Varshni V potentials
International Nuclear Information System (INIS)
Kesarwani, R.N.; Varshni, Y.P.
1978-01-01
The WKBJ method is applied to the third order for obtaining the eigenvalues for the fifth potential of Varshni, and the relevant integrals are analytically evaluated. Numerical results are obtained for the Lennard-Jones Potential, which is a special case of the Varshni V potential, and are compared to the results of Harrison and Bernstein obtained by a numerical integration of the wave equation. Error estimates are made. It is shown that for diatomic potentials, the Langer correction is not needed if the WKBJ approximation is carried to second and higher orders. (author)
Self-diffusion coefficients of the metastable Lennard-Jones vapor
International Nuclear Information System (INIS)
Nie Chu; Zhou Youhua; Marlow, W H; Hassan, Y A
2008-01-01
Self-diffusion coefficients of a metastable Lennard-Jones vapor were obtained using the memory function formalism and the frequency moments of the velocity autocorrelation function at reduced temperatures from 0.75 to 1.0. The radial density distribution functions used to evaluate the second, fourth and sixth frequency moments of the velocity autocorrelation function were obtained from the restricted canonical ensemble Monte Carlo simulation (Corti and Debenedetti 1994 Chem. Eng. Sci. 49 2717). The self-diffusion coefficients at reduced temperature 0.75 do not vary monotonically as the density increases, and for the other three temperatures the self-diffusion coefficients vary normally
Self-diffusion coefficients of the metastable Lennard-Jones vapor
Energy Technology Data Exchange (ETDEWEB)
Nie Chu; Zhou Youhua [School of Physics and Information Engineering, Jianghan University, Wuhan 430056 (China); Marlow, W H; Hassan, Y A [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843 (United States)], E-mail: yhzhou@jhun.edu.cn
2008-10-15
Self-diffusion coefficients of a metastable Lennard-Jones vapor were obtained using the memory function formalism and the frequency moments of the velocity autocorrelation function at reduced temperatures from 0.75 to 1.0. The radial density distribution functions used to evaluate the second, fourth and sixth frequency moments of the velocity autocorrelation function were obtained from the restricted canonical ensemble Monte Carlo simulation (Corti and Debenedetti 1994 Chem. Eng. Sci. 49 2717). The self-diffusion coefficients at reduced temperature 0.75 do not vary monotonically as the density increases, and for the other three temperatures the self-diffusion coefficients vary normally.
Evidence of hexatic phase formation in two-dimensional Lennard-Jones binary arrays
International Nuclear Information System (INIS)
Li, M.; Johnson, W.L.; Goddard, W.A. III
1996-01-01
We report evidence of the hexatic phase formation in Lennard-Jones binary substitutional random arrays from isothermal-isobaric molecular-dynamics simulations. The hexatic phase is analogous to those predicted in Kosterlitz-Thouless theory of melting that is characterized by short-range translational order and quasi-long-range orientational order. At the crystal to hexatic phase transition, dislocation pairs are observed to unbind into isolated dislocations. Further disordering of the hexatic phase, however, does not lead to dissociation of dislocations into disclinations. Instead, the dislocations become clustered and form dislocation networks which results in formation of amorphous phases. copyright 1996 The American Physical Society
Crystallisation of a Lennard-Jones fluid by large scale molecular dynamics simulation
International Nuclear Information System (INIS)
Snook, I.
1998-01-01
Full text: The evolution of the structure of a large system of atoms interacting via a Lennard-Jones pair potential was simulated by the use of the Molecular Dynamics computer simulation technique. The system was initially equilibrated in the one phase region of the phase diagram at a temperature above critical then a temperature quench was performed which placed the system in a region were the single fluid phase was unstable. Quenches to below the triple point temperature gave rise to crystallisation The mechanism and final morphology is shown to depend strongly on the starting conditions e.g. the starting density
The potential energy landscape in the Lennard-Jones binary mixture model
International Nuclear Information System (INIS)
Sampoli, M; Benassi, P; Eramo, R; Angelani, L; Ruocco, G
2003-01-01
The potential energy landscape in the Kob-Andersen Lennard-Jones binary mixture model has been studied carefully from the liquid down to the supercooled regime, from T = 2 down to 0.46. One thousand independent configurations along the time evolution locus have been examined at each temperature investigated. From the starting configuration, we searched for the nearest saddle (or quasi-saddle) and minimum of the potential energy. The vibrational densities of states for the starting and the two derived configurations have been evaluated. Besides the number of negative eigenvalues of the saddles other quantities show some signature of the approach of the dynamical arrest temperature
Molecular dynamics studies of the dynamics of supercooled Lennard-Jones liquids
International Nuclear Information System (INIS)
De Leeuw, S.W.; Brakkee, M.J.D.
1990-01-01
Results are presented of molecular dynamics experiments, in which the Lennard-Jones liquid is cooled isobarically into the metastable temperature region below the freezing temperature. The variation of the density-density and transverse current correlation functions with temperature is studied. We observed a power-law behaviour for the temperature dependence of dynamical properties (viscosity and coefficienty of self-diffusion) with an exponent in good agreement with prediction of mode coupling theories and recent experimental results. (author). 23 refs, 5 figs
Nonlinear transport processes and fluid dynamics: Cylindrical Couette flow of Lennard-Jones fluids
International Nuclear Information System (INIS)
Khayat, R.E.; Eu, B.C.
1988-01-01
In this paper we report on calculations of flow profiles for cylindrical Couette flow of a Lennard-Jones fluid. The flow is subjected to a temperature gradient and thermoviscous effects are taken into consideration. We apply the generalized fluid dynamic equations which are provided by the modified moment method for the Boltzmann equation reported previously. The results of calculations are in good agreement with the Monte Carlo direct simulation method by K. Nanbu [Phys. Fluids 27, 2632 (1984)] for most of Knudsen numbers for which the simulation data are available
Group inverses of M-matrices and their applications
Kirkland, Stephen J
2013-01-01
Group inverses for singular M-matrices are useful tools not only in matrix analysis, but also in the analysis of stochastic processes, graph theory, electrical networks, and demographic models. Group Inverses of M-Matrices and Their Applications highlights the importance and utility of the group inverses of M-matrices in several application areas. After introducing sample problems associated with Leslie matrices and stochastic matrices, the authors develop the basic algebraic and spectral properties of the group inverse of a general matrix. They then derive formulas for derivatives of matrix f
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M. Fiori
2005-04-01
Full Text Available A disease symptomatically similar to that caused by Erwinia carotovora occurred on “Cuore di Bue” and “Cencara” tomato plants grafted on “Beaufort” and “He-Man”, or ungrafted, in greenhouses in Sardinia (Italy. Symptoms were: dark brown/black longitudinal stem lesions, soft stem rot, pith breakdown of the stems, hollow stems, vascular tissue discoloration, wilting and collapse of the plants. Numerous bacterial colonies from stem tissues were isolated on yeast extract salts (YS medium. Seven isolates (DPP As-1, DPP As-2, DPP As-3, DPP As-14, DPP Pu6, DPP Pu7 e DPP Pu8 were selected on the basis of their ability to cause rot on potato pieces and a hypersensitivity reaction in “White burley” tobacco leaves. Pathogenicity tests revealed that five of these isolates infected artichoke, basil, dwarf bean, fennel, marrow, melon, pepper, eggplant, grafted and ungrafted tomato, and white cabbage. Of the remaining two isolates, one (DPP As-1 did not infect white cabbage, and the other (DPP Pu8 did not infect basil, marrow or white cabbage. Phenotypic properties and ELISA, also performed on naturally infected tissues, revealed that all the isolates were E. c. ssp. carotovora (Jones Bergey et al. PCR-RFLP analysis placed two (DPP As-2 and DPP As-3 of the seven isolates in RFLP group 8. Five isolates belonged to a hitherto unknown RFLP group. Prevention and control measures for this disease are suggested.
Algumas considerações sobre o termo afânise a partir de E. Jones e J. Lacan
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Daniela Scheinkman Chatelard
2001-12-01
Full Text Available Em sua primeira parte, este artigo propõe-se a retomar e a desenvolver o termo afânise, tal como foi forjado por Ernest Jones. Na segunda parte, trata-se de acrescentar a importância dada por Jacques Lacan a este termo: do registro do puro desaparecimento do desejo, em sua relação com a castração, como foi sustentado por E. Jones, passamos ao registro do desaparecimento do sujeito, enquanto sujeito dividido e desejante. Para isso, recorremos ao exemplo do personagem literário, Hamlet, da tragédia de Shakespeare.Some considerations about the aphanisis term from E. Jones and J. Lacan. The aim of the article in its first part is to retake and to develop the term aphanisis, such as forged by Ernest Jones. In its second part, the purpose is to add to this term the importance given by Jacques Lacan : from the register of the pure disappearing of desire in its relation to castration, as supported by Jones, we will pass on to the register of the disappearing of the subject, while in the form of a divided and desiring subject. Therefore, we will use the example of the literary character, Hamlet, taken from Shakespeare's tragedy.
Phase Diagram of Kob-Andersen-Type Binary Lennard-Jones Mixtures
Pedersen, Ulf R.; Schrøder, Thomas B.; Dyre, Jeppe C.
2018-04-01
The binary Kob-Andersen (KA) Lennard-Jones mixture is the standard model for computational studies of viscous liquids and the glass transition. For very long simulations, the viscous KA system crystallizes, however, by phase separating into a pure A particle phase forming a fcc crystal. We present the thermodynamic phase diagram for KA-type mixtures consisting of up to 50% small (B ) particles showing, in particular, that the melting temperature of the standard KA system at liquid density 1.2 is 1.028(3) in A particle Lennard-Jones units. At large B particle concentrations, the system crystallizes into the CsCl crystal structure. The eutectic corresponding to the fcc and CsCl structures is cutoff in a narrow interval of B particle concentrations around 26% at which the bipyramidal orthorhombic PuBr3 structure is the thermodynamically stable phase. The melting temperature's variation with B particle concentration at two constant pressures, as well as at the constant density 1.2, is estimated from simulations at pressure 10.19 using isomorph theory. Our data demonstrate approximate identity between the melting temperature and the onset temperature below which viscous dynamics appears. Finally, the nature of the solid-liquid interface is briefly discussed.
International Nuclear Information System (INIS)
Vorob'ev, V.S.
2003-01-01
We suggest a concept of multiple disordering scaling of the crystalline state. Such a scaling procedure applied to a crystal leads to the liquid and (in low density limit) gas states. This approach provides an explanation to a high value of configuration (common) entropy of liquefied noble gases, which can be deduced from experimental data. We use the generalized nearest-neighbor approach to calculate free energy and pressure of the Lennard-Jones systems after performing this scaling procedure. These thermodynamic functions depend on one parameter characterizing the disordering only. Condensed states of the system (liquid and solid) correspond to small values of this parameter. When this parameter tends to unity, we get an asymptotically exact equation of state for a gas involving the second virial coefficient. A reasonable choice of the values for the disordering parameter (ranging between zero and unity) allows us to find the lines of coexistence between different phase states in the Lennard-Jones systems, which are in a good agreement with the available experimental data
Glass transitions in one-, two-, three-, and four-dimensional binary Lennard-Jones systems
Energy Technology Data Exchange (ETDEWEB)
Bruening, Ralf; St-Onge, Denis A; Patterson, Steve [Physics Department, Mount Allison University, Sackville, NB, E4L 1E6 (Canada); Kob, Walter [Laboratoire des Colloides, Verres et Nanomateriaux, UMR5587, Universite Montpellier II and CNRS, 34095 Montpellier Cedex (France)], E-mail: rbruening@mta.ca
2009-01-21
We investigate the calorimetric liquid-glass transition by performing simulations of a binary Lennard-Jones mixture in one through four dimensions. Starting at a high temperature, the systems are cooled to T = 0 and heated back to the ergodic liquid state at constant rates. Glass transitions are observed in two, three and four dimensions as a hysteresis between the cooling and heating curves. This hysteresis appears in the energy and pressure diagrams, and the scanning rate dependence of the area and height of the hysteresis can be described using power laws. The one-dimensional system does not experience a glass transition but its specific heat curve resembles the shape of the D{>=}2 results in the supercooled liquid regime above the glass transition. As D increases, the radial distribution functions reflect reduced geometric constraints. Nearest neighbor distances become smaller with increasing D due to interactions between nearest and next-nearest neighbors. Simulation data for the glasses are compared with crystal and melting data obtained with a Lennard-Jones system with only one type of particle and we find that with increasing D crystallization becomes increasingly more difficult.
Energy Technology Data Exchange (ETDEWEB)
Barbante, Paolo [Dipartimento di Matematica, Politecnico di Milano - Piazza Leonardo da Vinci 32 - 20133 Milano (Italy); Frezzotti, Aldo; Gibelli, Livio [Dipartimento di Scienze e Tecnologie Aerospaziali, Politecnico di Milano - Via La Masa 34 - 20156 Milano (Italy)
2014-12-09
The unsteady evaporation of a thin planar liquid film is studied by molecular dynamics simulations of Lennard-Jones fluid. The obtained results are compared with the predictions of a diffuse interface model in which capillary Korteweg contributions are added to hydrodynamic equations, in order to obtain a unified description of the liquid bulk, liquid-vapor interface and vapor region. Particular care has been taken in constructing a diffuse interface model matching the thermodynamic and transport properties of the Lennard-Jones fluid. The comparison of diffuse interface model and molecular dynamics results shows that, although good agreement is obtained in equilibrium conditions, remarkable deviations of diffuse interface model predictions from the reference molecular dynamics results are observed in the simulation of liquid film evaporation. It is also observed that molecular dynamics results are in good agreement with preliminary results obtained from a composite model which describes the liquid film by a standard hydrodynamic model and the vapor by the Boltzmann equation. The two mathematical model models are connected by kinetic boundary conditions assuming unit evaporation coefficient.
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Bagavad Gita
2014-01-01
Full Text Available Gingival fibromatosis is characterized by gingival tissue overgrowth of a firm and fibrotic nature. The growth is slow and progressive and is drug-induced, idiopathic, or hereditary in etiology. It occurs isolated or frequently as a component of various syndromes. Our patient presented with the complaint of gingival enlargement associated with progressive deafness, characteristic of Jones syndrome. This case report is important and unique since it is the first known one to have a Jones syndrome-like presentation without a family history. A male patient aged 14 years reported with the chief complaint of swelling of gums and progressive hearing loss in both ears for the past one year. There was no family history or history of drug intake. Enlargement was generalized, fibrotic and bulbous, involving the free and attached gingiva, extending up to the middle 1/3 rd of the crown. Investigations such as pure tone audiogram, impedance audiometry, and Tone decay test concluded that there was severe right and moderate left sensorineural hearing loss. The case was diagnosed to be idiopathic, generalized gingival fibromatosis with progressive hearing loss. The gingival overgrowth was managed by gingivectomy and periodic review. The patient was advised to use high occlusion computer generated hearing aids for his deafness as it was not treatable by medicines or surgery. This unique case report once again emphasizes the heterogeneity of gingival fibromatosis, which can present in an atypical manner.
Icosahedral binary clusters of glass-forming Lennard-Jones binary alloy
International Nuclear Information System (INIS)
Iwamatsu, Masao
2007-01-01
It is widely believed that the local icosahedral structure is related to the formation of bulk metallic glasses (BMGs). Specifically the existence of 13-atom icosahedral cluster in undercooled liquid is imagined to play a key role to initiate the glass formation as the seed of amorphous structure or to block the nucleation of regular crystal as the impurity. The existence of 13-atom icosahedral clusters in one-component liquids was predicted more than half a century ago by Frank from his total energy calculation for isolated clusters. In BMG alloys, however, the situation is less clear. In this report, we present the lowest-energy structures of 13-atom Lennard-Jones binary cluster calculated from the modified space-fixed genetic algorithm. We study, in particular, the artificial Lennard-Jones potential designed by Kob and Andersen [W. Kob, H.C. Andersen, Phys. Rev. E 51 (1995) 4626] that is known to form BMG. Curiously, the lowest-energy structures of 13-atom cluster are non-icosahedral for almost all compositions. Our result suggests that the existence of the icosahedral cluster is not a necessary condition but only a sufficient condition for glass formation
Binding energy of large icosahedral and cuboctahedral Lennard-Jones clusters
International Nuclear Information System (INIS)
Northby, J.A.; Xie, J.
1989-01-01
It is widely believed that the lowest energy configurations for small rare gas clusters have icosahedral symmetry. This contrasts with the bulk crystal structures which have cuboctahedral fcc symmetry. It is of interest to understand the transition between this finite and bulk behavior. To model this transition in rare gas clusters we have undertaken optimization studies within the Lennard-Jones pair potential model. Using a combination of Monte Carlo and Partan Search optimization methods, the lowest energy relaxed structures of Lennard-Jones clusters having icosahedral and cuboctahedral symmetry were found. Studies were performed for complete shell clusters ranging in size from one shell having 13 atoms to 14 shells having 10,179 atoms. It was found that the icosahedral structures are lower in energy than the cuboctahedral structures for cluster sizes having 13 shells or fewer. Additional studies were performed using the more accurate Aziz-Chen [HFD-C] pair potential parameterized for argon. The conclusions appear to be relatively insensitive to the form of the potential. (orig.)
An accurate expression for radial distribution function of the Lennard-Jones fluid
International Nuclear Information System (INIS)
Morsali, Ali; Goharshadi, Elaheh K.; Ali Mansoori, G.; Abbaspour, Mohsen
2005-01-01
A simple and accurate expression for radial distribution function (RDF) of the Lennard-Jones fluid is presented. The expression explicitly states the RDF as a continuous function of reduced interparticle distance, temperature, and density. It satisfies the limiting conditions of zero density and infinite distance imposed by statistical thermodynamics. The distance dependence of this expression is expressed by an equation which contains 11 adjustable parameters. These parameters are fitted to 353 RDF data, obtained by molecular dynamics calculations, and then expressed as functions of reduced distance, temperature and density. This expression, having a total of 65 constants, reproduces the RDF data with an average root-mean-squared deviation of 0.0152 for the range of state variables of 0.5= * = * = * =ρσ 3 are reduced temperature and density, respectively). The expression predicts the pressure and the internal energy of the Lennard-Jones fluid with an uncertainty that is comparable to that obtained directly from the molecular dynamics simulations
The fish and fisheries of Jones Bank and the wider Celtic Sea
Martinez, I.; Ellis, J. R.; Scott, B.; Tidd, A.
2013-10-01
The Celtic Sea is a diverse fishing ground that supports important commercial fisheries for a range of demersal fish, large and small-bodied pelagic fish and a variety of cephalopods and other shellfish. A regional overview of the main commercial fish stocks of the Celtic Sea and of the fish that occur in the vicinity of Jones Bank are provided through analyses of landings data from English and Welsh vessels, and from scientific trawl surveys. Dedicated smaller scale sampling via trawl surveys combined with baited cameras on and around the Jones Bank were also analysed to investigate the importance of sandbank habitats with attention paid to the differences in the species occurring on the top of the bank in comparison to adjacent off-bank habitats. Official landing statistics for UK (English and Welsh) vessels indicated that the predominant commercial demersal species in ICES Divisions VIIg,h (in terms of quantities landed) were anglerfish, megrim, pollack and skates (Rajidae). There were, however, regional differences in the distribution of fish and fisheries, and the area surrounding Jones Bank (ICES Rectangles 28E1 and 28E2) supports fisheries for megrim, anglerfish, skates, hake, ling and turbot, with otter trawl, gillnet and beam trawl the main gears used. Recent survey data collected with GOV (Grande Ouverture Verticale) trawl from the Celtic Sea (ICES Divisions VIIe-h, 2007-2010) were used to highlight the broad scale distribution of the main fish assemblages in the Celtic Sea. Analyses of the fish and cephalopod catches from these surveys indicated that there were four broad assemblages in the area, including (i) a region around the Cornwall (which will also be partly influenced by the necessity to use rockhopper ground gear on these rough grounds), (ii) the shallower regions of the north-western Celtic Sea (including parts of the Bristol Channel), (iii) the deeper parts of the outer shelf and (iv) the central Celtic Sea. These data also provided
Algebraic Graph Theory Morphisms, Monoids and Matrices
Knauer, Ulrich
2011-01-01
This is a highly self-contained book about algebraic graph theory which iswritten with a view to keep the lively and unconventional atmosphere of a spoken text to communicate the enthusiasm the author feels about this subject. The focus is on homomorphisms and endomorphisms, matrices and eigenvalues. Graph models are extremely useful for almost all applications and applicators as they play an important role as structuring tools. They allow to model net structures -like roads, computers, telephones -instances of abstract data structures -likelists, stacks, trees -and functional or object orient
Coherence and extensions of stochastic matrices
Directory of Open Access Journals (Sweden)
Angelo Gilio
1995-11-01
Full Text Available In this paper a review of some general results on coherence of conditional probability assessments is given. Then, a necessary and sufficient condition on coherence of two finite families of discrete conditianal probability distributions, represented by two stochastic matrices P and Q, is obtained. Moreover, the possible extensions of the assessment (P,Q to the marginal distributions are examined and explicit formulas for them are given in some special case. Finally, a general algorithm to check coherence of (P,Q and to derive its extensions is proposed.
2D gravity and random matrices
International Nuclear Information System (INIS)
Zinn-Justin, J.
1990-01-01
Recent progress in 2D gravity coupled to d ≤ 1 matter, based on a representation of discrete gravity in terms of random matrices, is reported. The matrix problem can be solved in many cases by the introduction of suitable orthogonal polynomials. Alternatively in the continuum limit the orthogonal polynomial method can be shown to be equivalent to the construction of representation of the canonical commutation relations in terms of differential operators. In the case of pure gravity or discrete Ising-like matter the sum over topologies is reduced to the solution of non-linear differential equations. The d = 1 problem can be solved by semiclassical methods
Autonomous identification of matrices in the APNea system
International Nuclear Information System (INIS)
Hensley, D.
1995-01-01
The APNea System is a passive and active neutron assay device which features imaging to correct for nonuniform distributions of source material. Since the imaging procedure requires a detailed knowledge of both the detection efficiency and the thermal neutron flux for (sub)volumes of the drum of interest, it is necessary to identify which mocked-up matrix, to be used for detailed characterization studies, best matches the matrix of interest. A methodology referred to as the external matrix probe (EMP) has been established which links external measures of a drum matrix to those of mocked-up matrices. These measures by themselves are sufficient to identify the appropriate mock matrix, from which the necessary characterization data are obtained. This independent matrix identification leads to an autonomous determination of the required system response parameters for the assay analysis
Analytical Derivation of the Inverse Moments of One-Sided Correlated Gram Matrices With Applications
Elkhalil, Khalil
2016-02-03
This paper addresses the development of analytical tools for the computation of the inverse moments of random Gram matrices with one side correlation. Such a question is mainly driven by applications in signal processing and wireless communications wherein such matrices naturally arise. In particular, we derive closed-form expressions for the inverse moments and show that the obtained results can help approximate several performance metrics such as the average estimation error corresponding to the Best Linear Unbiased Estimator (BLUE) and the Linear Minimum Mean Square Error (LMMSE) estimator or also other loss functions used to measure the accuracy of covariance matrix estimates.
Empirically Determined Response Matrices for On-Line Orbit and Energy Correction at Jefferson Lab
International Nuclear Information System (INIS)
Leigh Harwood; Alicia Hofler; Michele Joyce; Valeri Lebedev; David Bryan
2001-01-01
Jefferson Lab uses feedback loops (less than 1 hertz update rate) to correct drifts in CEBAF's electron beam orbit and energy. Previous incarnations of these loops used response matrices that were computed by a numerical model of the machine. Jefferson Lab is transitioning this feedback system to use empirically determined response matrices whereby the software introduces small orbit or energy deviations using the loop's actuators and measures the system response with the loop's sensors. This method is in routine use for orbit correction. This paper will describe the orbit correction system and future plans to extend this method to energy correction
Reliability and Validity of Colored Progressive Matrices for 4-6 Age Children
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Ahmet Bildiren
2017-06-01
Full Text Available In this research, it was aimed to test the reliability and validity of Colored Progressive Matrices for children between the ages of 4 to 6 from 15 schools. The sample of the study consisted of 640 kindergarten children. Test-retest and parallel form were used for reliability analyses. For the validity analysis, the relations between the Colored Progressive Matrices Test and Bender Gestalt Visual Motor Sensitivity Test, WISC-R and TONI-3 tests were examined. The results showed that there was a significant relation between the test-retest results and the parallel forms in all the age groups. Validity analyses showed strong correlations between the Colored Progressive Matrices and all the other measures.
Energy Technology Data Exchange (ETDEWEB)
Singh, Harpreet; Arvind; Dorai, Kavita, E-mail: kavita@iisermohali.ac.in
2016-09-07
Estimation of quantum states is an important step in any quantum information processing experiment. A naive reconstruction of the density matrix from experimental measurements can often give density matrices which are not positive, and hence not physically acceptable. How do we ensure that at all stages of reconstruction, we keep the density matrix positive? Recently a method has been suggested based on maximum likelihood estimation, wherein the density matrix is guaranteed to be positive definite. We experimentally implement this protocol on an NMR quantum information processor. We discuss several examples and compare with the standard method of state estimation. - Highlights: • State estimation using maximum likelihood method was performed on an NMR quantum information processor. • Physically valid density matrices were obtained every time in contrast to standard quantum state tomography. • Density matrices of several different entangled and separable states were reconstructed for two and three qubits.
Directory of Open Access Journals (Sweden)
Ana Lucia Nicastri
2001-06-01
Full Text Available The aim of this investigation was to evaluate the endocytosis of two Bence-Jones proteins by renal cells in order to elucidate the interference of their physical and chemical characteristics on nephrotoxicity. Bence-Jones proteins (AK and GL were purified and isolated from the urine of two patients with multiple myeloma. The isotype of both proteins was characterised as being human monoclonal lambda light chain. The AK protein presented mainly an Ip>7.0, a high content of galactose and a low amount of sialic acid molecules. On the other hand, the GL protein presented a single band with an Ip of 4.3, a higher level of sialic acid and a reduced amount of galactose, in comparison with the AK protein. Baby Hamster Kidney (BHK cells were maintained in culture in bottles at 37ºC, using DMEM culture media supplemented with 10% of calf serum with a pH of 7.4. Once the monolayer was observed to be confluent, the BHK cells were incubated with the two proteins, dissolved in a serum-free medium for 1, 5, 15, 30, 60 minutes and 24 hours. Control cells were established omitting the incubation with Bence-Jones proteins, but maintaining all of the other conditions. After, this the cells were washed, trypsinised, centrifuged and fixed in a solution of 4% paraformaldehyde and 0.5% glutaraldehyde on a 0.1 M, pH 7.4 phosphate buffer. Cells were processed for immunocytochemical reactions by using protein A coupled with colloidal gold and further silver enhancement. Semi-thin sections of the pellets were obtained and submitted to the cytochemical reactions. Detection of labelling was made by using light microscopy. It was observed that GL protein tended to be directed towards a perinuclear position, whereas the AK protein tended to suffer lysosomal deviation, suggesting that there is a direct contribution of physical and chemical characteristics on intracellular direction taken by Bence-Jones proteins.O objetivo deste trabalho foi avaliar a endocitose de duas prote
DEFF Research Database (Denmark)
Cotterill, Rodney M J; Madsen, J.
1986-01-01
Sections of configuration space for Lennard-Jones matter were obtained by probing all the normal-mode energy profiles, following diagonalization of the dynamical matrix for a 240-particle system. For the crystal and sufficiently cold glass, these are single welled, whereas increasing numbers...... of double wells occur as the glass is warmed toward the fluid. This indicates that there might be a fundamental difference between the topologies of the constant-potential-energy hypersurfaces of crystalline and noncrystalline Lennard-Jones matter....
Energy Technology Data Exchange (ETDEWEB)
Wagner, C.
1996-12-31
In 1992, Wittum introduced the frequency filtering decompositions (FFD), which yield a fast method for the iterative solution of large systems of linear equations. Based on this method, the tangential frequency filtering decompositions (TFFD) have been developed. The TFFD allow the robust and efficient treatment of matrices with strongly varying coefficients. The existence and the convergence of the TFFD can be shown for symmetric and positive definite matrices. For a large class of matrices, it is possible to prove that the convergence rate of the TFFD and of the FFD is independent of the number of unknowns. For both methods, schemes for the construction of frequency filtering decompositions for unsymmetric matrices have been developed. Since, in contrast to Wittums`s FFD, the TFFD needs only one test vector, an adaptive test vector can be used. The TFFD with respect to the adaptive test vector can be combined with other iterative methods, e.g. multi-grid methods, in order to improve the robustness of these methods. The frequency filtering decompositions have been successfully applied to the problem of the decontamination of a heterogeneous porous medium by flushing.
Development of Abbreviated Nine-Item Forms of the Raven's Standard Progressive Matrices Test
Bilker, Warren B.; Hansen, John A.; Brensinger, Colleen M.; Richard, Jan; Gur, Raquel E.; Gur, Ruben C.
2012-01-01
The Raven's Standard Progressive Matrices (RSPM) is a 60-item test for measuring abstract reasoning, considered a nonverbal estimate of fluid intelligence, and often included in clinical assessment batteries and research on patients with cognitive deficits. The goal was to develop and apply a predictive model approach to reduce the number of items…
Critical statistics for non-Hermitian matrices
International Nuclear Information System (INIS)
Garcia-Garcia, A.M.; Verbaarschot, J.J.M.; Nishigaki, S.M.
2002-01-01
We introduce a generalized ensemble of non-Hermitian matrices interpolating between the Gaussian Unitary Ensemble, the Ginibre ensemble, and the Poisson ensemble. The joint eigenvalue distribution of this model is obtained by means of an extension of the Itzykson-Zuber formula to general complex matrices. Its correlation functions are studied both in the case of weak non-Hermiticity and in the case of strong non-Hermiticity. In the weak non-Hermiticity limit we show that the spectral correlations in the bulk of the spectrum display critical statistics: the asymptotic linear behavior of the number variance is already approached for energy differences of the order of the eigenvalue spacing. To lowest order, its slope does not depend on the degree of non-Hermiticity. Close the edge, the spectral correlations are similar to the Hermitian case. In the strong non-Hermiticity limit the crossover behavior from the Ginibre ensemble to the Poisson ensemble first appears close to the surface of the spectrum. Our model may be relevant for the description of the spectral correlations of an open disordered system close to an Anderson transition
Tensor Dictionary Learning for Positive Definite Matrices.
Sivalingam, Ravishankar; Boley, Daniel; Morellas, Vassilios; Papanikolopoulos, Nikolaos
2015-11-01
Sparse models have proven to be extremely successful in image processing and computer vision. However, a majority of the effort has been focused on sparse representation of vectors and low-rank models for general matrices. The success of sparse modeling, along with popularity of region covariances, has inspired the development of sparse coding approaches for these positive definite descriptors. While in earlier work, the dictionary was formed from all, or a random subset of, the training signals, it is clearly advantageous to learn a concise dictionary from the entire training set. In this paper, we propose a novel approach for dictionary learning over positive definite matrices. The dictionary is learned by alternating minimization between sparse coding and dictionary update stages, and different atom update methods are described. A discriminative version of the dictionary learning approach is also proposed, which simultaneously learns dictionaries for different classes in classification or clustering. Experimental results demonstrate the advantage of learning dictionaries from data both from reconstruction and classification viewpoints. Finally, a software library is presented comprising C++ binaries for all the positive definite sparse coding and dictionary learning approaches presented here.
Virial expansion for almost diagonal random matrices
International Nuclear Information System (INIS)
Yevtushenko, Oleg; Kravtsov, Vladimir E
2003-01-01
Energy level statistics of Hermitian random matrices H-circumflex with Gaussian independent random entries H i≥j is studied for a generic ensemble of almost diagonal random matrices with (vertical bar H ii vertical bar 2 ) ∼ 1 and (vertical bar H i≠j vertical bar 2 ) bF(vertical bar i - j vertical bar) parallel 1. We perform a regular expansion of the spectral form-factor K(τ) = 1 + bK 1 (τ) + b 2 K 2 (τ) + c in powers of b parallel 1 with the coefficients K m (τ) that take into account interaction of (m + 1) energy levels. To calculate K m (τ), we develop a diagrammatic technique which is based on the Trotter formula and on the combinatorial problem of graph edges colouring with (m + 1) colours. Expressions for K 1 (τ) and K 2 (τ) in terms of infinite series are found for a generic function F(vertical bar i - j vertical bar ) in the Gaussian orthogonal ensemble (GOE), the Gaussian unitary ensemble (GUE) and in the crossover between them (the almost unitary Gaussian ensemble). The Rosenzweig-Porter and power-law banded matrix ensembles are considered as examples
Generalized Eigenvalues for pairs on heritian matrices
Rublein, George
1988-01-01
A study was made of certain special cases of a generalized eigenvalue problem. Let A and B be nxn matrics. One may construct a certain polynomial, P(A,B, lambda) which specializes to the characteristic polynomial of B when A equals I. In particular, when B is hermitian, that characteristic polynomial, P(I,B, lambda) has real roots, and one can ask: are the roots of P(A,B, lambda) real when B is hermitian. We consider the case where A is positive definite and show that when N equals 3, the roots are indeed real. The basic tools needed in the proof are Shur's theorem on majorization for eigenvalues of hermitian matrices and the interlacing theorem for the eigenvalues of a positive definite hermitian matrix and one of its principal (n-1)x(n-1) minors. The method of proof first reduces the general problem to one where the diagonal of B has a certain structure: either diag (B) = diag (1,1,1) or diag (1,1,-1), or else the 2 x 2 principal minors of B are all 1. According as B has one of these three structures, we use an appropriate method to replace A by a positive diagonal matrix. Since it can be easily verified that P(D,B, lambda) has real roots, the result follows. For other configurations of B, a scaling and a continuity argument are used to prove the result in general.
Meet and Join Matrices in the Poset of Exponential Divisors
Indian Academy of Sciences (India)
... exponential divisor ( G C E D ) and the least common exponential multiple ( L C E M ) do not always exist. In this paper we embed this poset in a lattice. As an application we study the G C E D and L C E M matrices, analogues of G C D and L C M matrices, which are both special cases of meet and join matrices on lattices.
Generalized Perron--Frobenius Theorem for Nonsquare Matrices
Avin, Chen; Borokhovich, Michael; Haddad, Yoram; Kantor, Erez; Lotker, Zvi; Parter, Merav; Peleg, David
2013-01-01
The celebrated Perron--Frobenius (PF) theorem is stated for irreducible nonnegative square matrices, and provides a simple characterization of their eigenvectors and eigenvalues. The importance of this theorem stems from the fact that eigenvalue problems on such matrices arise in many fields of science and engineering, including dynamical systems theory, economics, statistics and optimization. However, many real-life scenarios give rise to nonsquare matrices. A natural question is whether the...
The Monte Carlo dynamics of a binary Lennard-Jones glass-forming mixture
International Nuclear Information System (INIS)
Berthier, L; Kob, W
2007-01-01
We use a standard Monte Carlo algorithm to study the slow dynamics of a binary Lennard-Jones glass-forming mixture at low temperature. We find that the Monte Carlo approach is by far the most efficient way to simulate a stochastic dynamics since the relaxation is about 10 times faster than in Brownian dynamics and about 30 times faster than in stochastic dynamics. Moreover, the average dynamical behaviour of the system is in quantitative agreement with that obtained using Newtonian dynamics, apart from at very short times where thermal vibrations are suppressed. We show, however, that dynamic fluctuations quantified by four-point dynamic susceptibilities do retain a dependence on the microscopic dynamics, as recently predicted theoretically
The effect of atom mismatch on the fragility of supercooled Lennard-Jones binary mixtures
International Nuclear Information System (INIS)
Sun Minhua; Sun Yongli; Wang Aiping; Ma Congxiao; Li Jiayun; Cheng Weidong; Liu Fang
2006-01-01
The shear viscosity of the well-known binary Lennard-Jones mixture is simulated under constant temperature and constant volume conditions (NVT) by a molecular-dynamics (MD) method. The effect of atomic size mismatch on the fragility parameter and glass-forming ability is studied. The fragility parameters calculated from shear viscosity data decrease with the increment of the atomic size mismatch. The value of the fragility changes from 168.963 to 22.976 when the mismatch changes from 0.023 to 0.25. It is shown that the fragility parameter is sensitive to the atomic size mismatch. The calculated pair distribution functions and mean square displacements indicate that the glass-forming ability increases with the atomic size mismatch
Dynamics of vacancies in two-dimensional Lennard-Jones crystals
Yao, Zhenwei; Olvera de La Cruz, Monica
2015-03-01
Vacancies represent an important class of crystallographic defects, and their behaviors can be strongly coupled with relevant material properties. We report the rich dynamics of vacancies in two-dimensional Lennard-Jones crystals in several thermodynamic states. Specifically, we numerically observe significantly faster diffusion of the 2-point vacancy with two missing particles in comparison with other types of vacancies; it opens the possibility of doping 2-point vacancies into atomic materials to enhance atomic migration. In addition, the resulting dislocations in the healing of a long vacancy suggest the intimate connection between vacancies and topological defects that may provide an extra dimension in the engineering of defects in extensive crystalline materials for desired properties. We thank the financial support from the U.S. Department of Commerce, National Institute of Standards and Technology, the Office of the Director of Defense Research and Engineering (DDR&E) and the Air Force Office of Scientific Research.
Theoretical prediction of crystallization kinetics of a supercooled Lennard-Jones fluid
Gunawardana, K. G. S. H.; Song, Xueyu
2018-05-01
The first order curvature correction to the crystal-liquid interfacial free energy is calculated using a theoretical model based on the interfacial excess thermodynamic properties. The correction parameter (δ), which is analogous to the Tolman length at a liquid-vapor interface, is found to be 0.48 ± 0.05 for a Lennard-Jones (LJ) fluid. We show that this curvature correction is crucial in predicting the nucleation barrier when the size of the crystal nucleus is small. The thermodynamic driving force (Δμ) corresponding to available simulated nucleation conditions is also calculated by combining the simulated data with a classical density functional theory. In this paper, we show that the classical nucleation theory is capable of predicting the nucleation barrier with excellent agreement to the simulated results when the curvature correction to the interfacial free energy is accounted for.
Thermal conductivity of the Lennard-Jones fluid: An empirical correlation
International Nuclear Information System (INIS)
Bugel, Mathilde; Galliero, Guillaume
2008-01-01
In this work, is presented an empirical correlation on the thermal conductivity of the Lennard-Jones fluid based on extensive non-equilibrium molecular dynamics simulations results (103 points). Finite size and cutoff radius effects are investigated and taken into account to develop the correlation. This last, composed of low-density, residual and critical enhancement contributions, is built for a wide range of thermodynamics states, even at the vicinity of the critical point, and yields an average absolute deviation of 1.29% compared to our simulations. In addition, a careful analysis of the different contributions to the microscopic flux is carried out which sheds light on the underlying mechanism of the results. Finally, are discussed the limitations of the proposed model when applied to real simple fluids and mixtures using a standard corresponding states scheme and the van der Waals one-fluid approximation
Platform for Manipulating Polarization Modes Realized with Jones Vectors in MATHEMATICA
Directory of Open Access Journals (Sweden)
Yong-Dae Choi
2015-06-01
Full Text Available The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.
John Paul Jones: An Overlooked Autopsy Finding that May Explain His Terminal Illness.
Hamrell, Burt B
2016-03-01
A finding in the autopsy of John Paul Jones, the American Revolutionary War naval hero, may explain his terminal illness. During his last 2 years, he had a persistent productive cough and dyspnea. Ten days before death, he developed rapidly progressive dependent edema and ascites. He died in France in 1792. His body, preserved in alcohol in a lead coffin, was, in 1905, removed to the United States. Glomerulonephritis was noted on an autopsy, performed in France, but there was no comment then or since about ventricular wall thickness being the same in both ventricles at 5-6 mm. Hypertrophy and dilatation with biventricular failure followed by tissue shrinkage during 113 years in alcohol could have resulted in these ventricular wall findings. Systemic hypertension and left ventricular failure are consistent with his respiratory symptoms complicated perhaps by pulmonary emboli, right ventricular failure with tricuspid regurgitation, peripheral congestion, and jaundice. © 2015 American Academy of Forensic Sciences.
Crystal phases of a glass-forming Lennard-Jones mixture
International Nuclear Information System (INIS)
Fernandez, Julian R.; Harrowell, Peter
2003-01-01
We compare the potential energy at zero temperature of a range of crystal structures for a glass-forming binary mixture of Lennard-Jones particles. The lowest-energy ordered state consists of coexisting phases of a single component face centered cubic structure and an equimolar cesium chloride structure. An infinite number of layered crystal structures are identified with energies close to this ground state. We demonstrate that the finite size increase of the energy of the coexisting crystal with incoherent interfaces is sufficient to destabilize this ordered phase in simulations of typical size. Two specific local coordination structures are identified as of possible structural significance in the amorphous state. We observe rapid crystal growth in the equimolar mixture
Simulasi Sifat Fisis Model Molekuler Dinamik Gas Argon dengan Potensial Lennard-Jones
Directory of Open Access Journals (Sweden)
Wira Bahari Nurdin
2014-01-01
Full Text Available DOWNLOAD PDFTelah dilakukan pembuatan dan pengujian suatu simulasi tentang sifat fisis gasargon dengan menggunakan dinamika molekuler menggunakan potensial Lennard-Jonesdalam sistem terisolasi (ensemble mikrokanonik. Jumlah molekul, energi total sistem danluas kotak simulasi telah divariasikan. Untuk menghitung perubahan posisi digunakanalgoritma Verlet. Sifat fisis yang ditentukan dalam simulasi adalah temperatur dan energitotal sistem untuk menentukan adanya fase transisi. Dari hasil simulasi, terdapatkesesuaian antara simulasi dengan gas argon dan tidak diperoleh adanya fase transisi.Kata kunci: Simulasi dinamika molekul, argon, potensial Lennard-Jones, ensemblemikrokanonik, algoritma Verlet
Molecular dynamics calculation of half-lives for thermal decay of Lennard-Jones clusters
International Nuclear Information System (INIS)
Smith, R.W.
1991-01-01
Molecular dynamics has been used with a Lenard-Jones (6-12) potential in order to study the decay behavior of neutral Argon clusters containing between 12 and 14 atoms. The clusters were heated to temperatures well above their melting points and then tracked in time via molecular dynamics until evaporation of one or more atoms was observed. In each simulation, the mode of evaporation, energy released during evaporation, and cluster lifetime were recorded. Results from roughly 2000 simulation histories were combined in order to compute statistically significant values of cluster half-lives and decay energies. It was found that cluster half-life decreases with increasing energy and that for a given value of excess energy (defined as E=(E tot -E gnd )/n), the 13 atom cluster is more stable against decay than clusters containing either 12 or 14 atoms. The dominant decay mechanism for all clusters was determined to be single atom emission. (orig.)
A molecular dynamics study of Lennard-Jones physisorption on W(100)
International Nuclear Information System (INIS)
Broughton, J.Q.
1980-01-01
The physisorption of Xe on W(100) was modeled by Lennard-Jones pair-wise interaction potentials and the dynamics of coverages ranging from one to four adlayers obtained by molecular dynamics simulation. At 115 K, the first two layers were well-ordered and each adsorbed with c(2 x 2) symmetry. Further adsorption produced a surface similar to that of a distorted Xe(100) face. In accord with the work of Broughton and Woodcock, the top layers of the three- and four-adlayer coverages were rough and had liquid-like diffusion coefficients. The potential energies of all layers other than the first were similar, thus corroborating one of the postulates of BET theory. Generally, the effect of adsorbing a layer was to reduce the entropy of all those beneath. (orig.)
Nagao, Tomoaki; Okura, Takafumi; Miyoshi, Ken-Ichi; Watanabe, Sanae; Manabe, Seiko; Kurata, Mie; Irita, Jun; Fukuoka, Tomikazu; Higaki, Jitsuo
2005-09-01
A 79-year-old woman was admitted to our hospital because of leg edema due to a nephrotic syndrome. Urinary and serum immunoelectrophoresis showed positive for the lambda type of Bence Jones protein. A bone marrow aspiration test revealed mild plasmacytosis (6.4% of the total cells). These findings confirmed her diagnosis of monoclonal gammopathy of undetermined significance (MGUS). Her renal biopsy specimen revealed mild mesangial cell proliferation and an increase in the mesangial matrix. Immunofluorescence studies showed positive staining for IgG, IgA, C3, and kappa and lambda light chains in the capillary wall and mesangium area. Electron microscopy showed that the electron deposits in the thickened basement membrane were formed by randomly arranged 16- to 18-nm nonbranching fibrils. A Congo red stain for amyloid was negative. These findings corresponded with the diagnosis of fibrillary glomerulonephritis. Therefore, this case showed a rare combination of fibrillary glomerulonephritis and MGUS.
Phase diagram and universality of the Lennard-Jones gas-liquid system
Watanabe, Hiroshi
2012-01-01
The gas-liquid phase transition of the three-dimensional Lennard-Jones particles system is studied by molecular dynamics simulations. The gas and liquid densities in the coexisting state are determined with high accuracy. The critical point is determined by the block density analysis of the Binder parameter with the aid of the law of rectilinear diameter. From the critical behavior of the gas-liquid coexisting density, the critical exponent of the order parameter is estimated to be β = 0.3285(7). Surface tension is estimated from interface broadening behavior due to capillary waves. From the critical behavior of the surface tension, the critical exponent of the correlation length is estimated to be ν = 0.63(4). The obtained values of β and ν are consistent with those of the Ising universality class. © 2012 American Institute of Physics.
Directory of Open Access Journals (Sweden)
Peter Irgens
2017-04-01
Full Text Available We present an field programmable gate arrays (FPGA based implementation of the popular Viola-Jones face detection algorithm, which is an essential building block in many applications such as video surveillance and tracking. Our implementation is a complete system level hardware design described in a hardware description language and validated on the affordable DE2-115 evaluation board. Our primary objective is to study the achievable performance with a low-end FPGA chip based implementation. In addition, we release to the public domain the entire project. We hope that this will enable other researchers to easily replicate and compare their results to ours and that it will encourage and facilitate further research and educational ideas in the areas of image processing, computer vision, and advanced digital design and FPGA prototyping.
Freezing and melting line invariants of the Lennard-Jones system
DEFF Research Database (Denmark)
Costigliola, Lorenzo; Schrøder, Thomas; Dyre, Jeppe C.
2016-01-01
The invariance of several structural and dynamical properties of the Lennard-Jones (LJ) system along the freezing and melting lines is interpreted in terms of isomorph theory. First the freezing/melting lines of the LJ system are shown to be approximated by isomorphs. Then we show...... that the invariants observed along the freezing and melting isomorphs are also observed on other isomorphs in the liquid and crystalline phases. The structure is probed by the radial distribution function and the structure factor and dynamics are probed by the mean-square displacement, the intermediate scattering...... function, and the shear viscosity. Studying these properties with reference to isomorph theory explains why the known single-phase melting criteria hold, e.g., the Hansen–Verlet and the Lindemann criteria, and why the Andrade equation for the viscosity at freezing applies, e.g., for most liquid metals. Our...
Jones, Brett D.; Skaggs, Gary
2016-01-01
This study provides validity evidence for the MUSIC Model of Academic Motivation Inventory (MUSIC Inventory; Jones, 2012), which measures college students' beliefs related to the five components of the MUSIC Model of Motivation (MUSIC model; Jones, 2009). The MUSIC model is a conceptual framework for five categories of teaching strategies (i.e.,…
Shear viscosity of the Lennard-Jones fluid near the triple point: Green-Kubo results
International Nuclear Information System (INIS)
Erpenbeck, J.J.
1988-01-01
The long-standing disagreement over the shear viscosity coefficient of the Lennard-Jones fluid near the triple point is reexamined through a series of very extensive Monte Carlo molecular-dynamics calculations of this transport coefficient based on the Green-Kubo theory. The stress autocorrelation function is shown to exhibit a slow decay, principally in the kinetic-potential and the potential-potential terms, which is large compared with the kinetic-kinetic long-time tail predicted by simple mode-coupling theory. Nonetheless, the viscosity coefficient, exclusive of any correction for this tail for times greater than are accessible numerically, is found to agree with that of Schoen and Hoheisel (who discounted the existence of such a tail) as well as nonequilibrium molecular-dynamics calculations. The large value of the viscosity coefficient found by Levesque and co-workers for 864 particles is brought into statistical agreement with the present results by a modest, but not unrealistic, increase in its statistical uncertainty. The pressure is found to exhibit an anomalous dependence on the size of the system, but the viscosity as well as the self-diffusion constant appear to be linear in the inverse of the number of particles, within the precision of our calculations. The viscosity coefficient, including a long-time-tail contribution based on the extended mode-coupling theory is (3.796 +- 0.068)σepsilon-c/m)/sup 1/2/ for the Lennard-Jones potential, fitted to a cubic spline, and (3.345 +- 0.068)σepsilon-c/m)/sup 1/2/ for the potential truncated at 2.5σ
Intrinsic Density Matrices of the Nuclear Shell Model
International Nuclear Information System (INIS)
Deveikis, A.; Kamuntavichius, G.
1996-01-01
A new method for calculation of shell model intrinsic density matrices, defined as two-particle density matrices integrated over the centre-of-mass position vector of two last particles and complemented with isospin variables, has been developed. The intrinsic density matrices obtained are completely antisymmetric, translation-invariant, and do not employ a group-theoretical classification of antisymmetric states. They are used for exact realistic density matrix expansion within the framework of the reduced Hamiltonian method. The procedures based on precise arithmetic for calculation of the intrinsic density matrices that involve no numerical diagonalization or orthogonalization have been developed and implemented in the computer code. (author). 11 refs., 2 tabs
Encapsulation of biological species in sol-gel matrices
International Nuclear Information System (INIS)
Finnie, K.S.; Bartlett, J.R.; Woolfrey, J.L.
2000-01-01
Two examples are given of the gelation of silica sols containing bio catalysts, resulting in their encapsulation in porous matrices. Urease was encapsulated in gels made from a mixture of TMOS and alkyltrimethoxysilane. Enzyme activities, monitored by measuring the rate of production of ammoniacal nitrogen as urea was decomposed, ranged up to 60% of that of the unencapsulated species. Anaerobic sulphate-reducing bacteria were encapsulated in a gel produced from colloidal silica, thus avoiding contact with alcohol. The detection of H 2 S produced in the doped gel indicated that the bacteria were able to continue normal metabolic function within the gel matrix. A gel initially doped with ∼ 5 x 10 5 cells cm -3 , exhibited an optimum sulphate reduction rate of 11 ug h -1 cm -3 ; this reduction rate was quickly re-established after storage of the gel for 14 weeks. Copyright (2000) The Australian Ceramic Society
Immobilization of radioactive waste in cement-based matrices
International Nuclear Information System (INIS)
Glasser, F.P.; Rahman, A.A.; Crawford, R.W.; McCulloch, C.E.; Angus, M.J.
1984-01-01
Tobermorite and xonotlite, two synthetic calcium silicate hydrates, improve the Cs retention of cement matrices for Cs, when incorporated at the 6 to 10% level. A kinetic and mechanistic scheme is presented for the reaction of fine grained, Cs-loaded clinoptilolite with cement. The Magnox waste form reacts quickly with cement, leading to an exchange of carbonate between waste form and cement components. Carbonation of cements leads to a marked improvement in their physical properties of Cs retentivity. Diffusion models are presented for cement systems whose variable parameters can readily be derived from experimental measurements. Predictions about scaled-up behaviour of large immobilized masses are applied to extrapolation of laboratory scale results to full-size masses. (author)
Weighted Low-Rank Approximation of Matrices and Background Modeling
Dutta, Aritra
2018-04-15
We primarily study a special a weighted low-rank approximation of matrices and then apply it to solve the background modeling problem. We propose two algorithms for this purpose: one operates in the batch mode on the entire data and the other one operates in the batch-incremental mode on the data and naturally captures more background variations and computationally more effective. Moreover, we propose a robust technique that learns the background frame indices from the data and does not require any training frames. We demonstrate through extensive experiments that by inserting a simple weight in the Frobenius norm, it can be made robust to the outliers similar to the $\\\\ell_1$ norm. Our methods match or outperform several state-of-the-art online and batch background modeling methods in virtually all quantitative and qualitative measures.
Weighted Low-Rank Approximation of Matrices and Background Modeling
Dutta, Aritra; Li, Xin; Richtarik, Peter
2018-01-01
We primarily study a special a weighted low-rank approximation of matrices and then apply it to solve the background modeling problem. We propose two algorithms for this purpose: one operates in the batch mode on the entire data and the other one operates in the batch-incremental mode on the data and naturally captures more background variations and computationally more effective. Moreover, we propose a robust technique that learns the background frame indices from the data and does not require any training frames. We demonstrate through extensive experiments that by inserting a simple weight in the Frobenius norm, it can be made robust to the outliers similar to the $\\ell_1$ norm. Our methods match or outperform several state-of-the-art online and batch background modeling methods in virtually all quantitative and qualitative measures.
DEFF Research Database (Denmark)
Friisberg, Ida Marie; Costigliola, Lorenzo; Dyre, Jeppe C.
2017-01-01
This paper investigates the relation between the density-scaling exponent γ and the virial potentialenergy coefficient R at several thermodynamic state points in three dimensions for the generalized (2n, n) Lennard-Jones (LJ) system for n = 4, 9, 12, 18, as well as for the standard n = 6 LJ syste...
Viscous Growth in Spinodal Decomposition of the Two-component Lennard-Jones Model in Two Dimensions
DEFF Research Database (Denmark)
Laradji, M.; Toxvaerd, S.; Mouritsen, Ole G.
1997-01-01
The dynamics of phase separation of a two-component Lennard-Jones model in three dimensions is investigated by means of large scale molecular dynamics simulation. A systematic study over a wide range of quench temperatures within the coexistence region shows that the binary system reaches...
2012-06-26
... proposed reservoirs from 6,225 feet to 7,330 feet; and (7) change the name of the project from ``Jones Canyon Pumped Storage Project'' to ``Oregon Winds Pumped Storage''. FERC Contact: Jennifer Harper, 202..., using the eComment system at http://www.ferc.gov/docs-filing/ecomment.asp . You must include your name...
D.E. Allen (David); M.J. McAleer (Michael); A.K. Singh (Abhay)
2016-01-01
textabstractThis paper features an analysis of the relationship between the DOW JONES Industrial Average Index (DJIA) and a sentiment news series using daily data obtained from the Thomson Reuters News Analytics (TRNA)1 provided by SIRCA (The Securities Industry Research Centre of the Asia Pacic).
2012-03-26
...'') requested that the Securities and Exchange Commission (``Commission'') issue to Edward Jones an exemption... subject to the conditions contained in this order, is exempt from the new issue lending restriction of... SECURITIES AND EXCHANGE COMMISSION [Release No. 34-66624] Order Granting an Application of Edward...
Equiangular tight frames and unistochastic matrices
International Nuclear Information System (INIS)
Goyeneche, Dardo; Turek, Ondřej
2017-01-01
We demonstrate that a complex equiangular tight frame composed of N vectors in dimension d , denoted ETF ( d , N ), exists if and only if a certain bistochastic matrix, univocally determined by N and d , belongs to a special class of unistochastic matrices. This connection allows us to find new complex ETFs in infinitely many dimensions and to derive a method to introduce non-trivial free parameters in ETFs. We present an explicit six-parametric family of complex ETF(6,16), which defines a family of symmetric POVMs. Minimal and maximal possible average entanglement of the vectors within this qubit–qutrit family are described. Furthermore, we propose an efficient numerical procedure to compute the unitary matrix underlying a unistochastic matrix, which we apply to find all existing classes of complex ETFs containing up to 20 vectors. (paper)
Colonization of bone matrices by cellular components
Shchelkunova, E. I.; Voropaeva, A. A.; Korel, A. V.; Mayer, D. A.; Podorognaya, V. T.; Kirilova, I. A.
2017-09-01
Practical surgery, traumatology, orthopedics, and oncology require bioengineered constructs suitable for replacement of large-area bone defects. Only rigid/elastic matrix containing recipient's bone cells capable of mitosis, differentiation, and synthesizing extracellular matrix that supports cell viability can comply with these requirements. Therefore, the development of the techniques to produce structural and functional substitutes, whose three-dimensional structure corresponds to the recipient's damaged tissues, is the main objective of tissue engineering. This is achieved by developing tissue-engineering constructs represented by cells placed on the matrices. Low effectiveness of carrier matrix colonization with cells and their uneven distribution is one of the major problems in cell culture on various matrixes. In vitro studies of the interactions between cells and material, as well as the development of new techniques for scaffold colonization by cellular components are required to solve this problem.
Computing with linear equations and matrices
International Nuclear Information System (INIS)
Churchhouse, R.F.
1983-01-01
Systems of linear equations and matrices arise in many disciplines. The equations may accurately represent conditions satisfied by a system or, more likely, provide an approximation to a more complex system of non-linear or differential equations. The system may involve a few or many thousand unknowns and each individual equation may involve few or many of them. Over the past 50 years a vast literature on methods for solving systems of linear equations and the associated problems of finding the inverse or eigenvalues of a matrix has been produced. These lectures cover those methods which have been found to be most useful for dealing with such types of problem. References are given where appropriate and attention is drawn to the possibility of improved methods for use on vector and parallel processors. (orig.)
Matrices over runtime systems at exascale
Agullo, Emmanuel
2012-11-01
The goal of Matrices Over Runtime Systems at Exascale (MORSE) project is to design dense and sparse linear algebra methods that achieve the fastest possible time to an accurate solution on large-scale multicore systems with GPU accelerators, using all the processing power that future high end systems can make available. In this poster, we propose a framework for describing linear algebra algorithms at a high level of abstraction and delegating the actual execution to a runtime system in order to design software whose performance is portable accross architectures. We illustrate our methodology on three classes of problems: dense linear algebra, sparse direct methods and fast multipole methods. The resulting codes have been incorporated into Magma, Pastix and ScalFMM solvers, respectively. © 2012 IEEE.
Sparse random matrices: The eigenvalue spectrum revisited
International Nuclear Information System (INIS)
Semerjian, Guilhem; Cugliandolo, Leticia F.
2003-08-01
We revisit the derivation of the density of states of sparse random matrices. We derive a recursion relation that allows one to compute the spectrum of the matrix of incidence for finite trees that determines completely the low concentration limit. Using the iterative scheme introduced by Biroli and Monasson [J. Phys. A 32, L255 (1999)] we find an approximate expression for the density of states expected to hold exactly in the opposite limit of large but finite concentration. The combination of the two methods yields a very simple geometric interpretation of the tails of the spectrum. We test the analytic results with numerical simulations and we suggest an indirect numerical method to explore the tails of the spectrum. (author)
From Pauli Matrices to Quantum Ito Formula
International Nuclear Information System (INIS)
Pautrat, Yan
2005-01-01
This paper answers important questions raised by the recent description, by Attal, of a robust and explicit method to approximate basic objects of quantum stochastic calculus on bosonic Fock space by analogues on the state space of quantum spin chains. The existence of that method justifies a detailed investigation of discrete-time quantum stochastic calculus. Here we fully define and study that theory and obtain in particular a discrete-time quantum Ito formula, which one can see as summarizing the commutation relations of Pauli matrices.An apparent flaw in that approximation method is the difference in the quantum Ito formulas, discrete and continuous, which suggests that the discrete quantum stochastic calculus differs fundamentally from the continuous one and is therefore not a suitable object to approximate subtle phenomena. We show that flaw is only apparent by proving that the continuous-time quantum Ito formula is actually a consequence of its discrete-time counterpart
Dirac matrices for Chern-Simons gravity
Energy Technology Data Exchange (ETDEWEB)
Izaurieta, Fernando; Ramirez, Ricardo; Rodriguez, Eduardo [Departamento de Matematica y Fisica Aplicadas, Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, 4090541 Concepcion (Chile)
2012-10-06
A genuine gauge theory for the Poincare, de Sitter or anti-de Sitter algebras can be constructed in (2n- 1)-dimensional spacetime by means of the Chern-Simons form, yielding a gravitational theory that differs from General Relativity but shares many of its properties, such as second order field equations for the metric. The particular form of the Lagrangian is determined by a rank n, symmetric tensor invariant under the relevant algebra. In practice, the calculation of this invariant tensor can be reduced to the computation of the trace of the symmetrized product of n Dirac Gamma matrices {Gamma}{sub ab} in 2n-dimensional spacetime. While straightforward in principle, this calculation can become extremely cumbersome in practice. For large enough n, existing computer algebra packages take an inordinate long time to produce the answer or plainly fail having used up all available memory. In this talk we show that the general formula for the trace of the symmetrized product of 2n Gamma matrices {Gamma}{sub ab} can be written as a certain sum over the integer partitions s of n, with every term being multiplied by a numerical cofficient {alpha}{sub s}. We then give a general algorithm that computes the {alpha}-coefficients as the solution of a linear system of equations generated by evaluating the general formula for different sets of tensors B{sup ab} with random numerical entries. A recurrence relation between different coefficients is shown to hold and is used in a second, 'minimal' algorithm to greatly speed up the computations. Runtime of the minimal algorithm stays below 1 min on a typical desktop computer for up to n = 25, which easily covers all foreseeable applications of the trace formula.
Scaling relation and regime map of explosive gas–liquid flow of binary Lennard-Jones particle system
Inaoka, Hajime
2012-02-01
We study explosive gasliquid flows caused by rapid depressurization using a molecular dynamics model of Lennard-Jones particle systems. A unique feature of our model is that it consists of two types of particles: liquid particles, which tend to form liquid droplets, and gas particles, which remain supercritical gaseous states under the depressurization realized by simulations. The system has a pipe-like structure similar to the model of a shock tube. We observed physical quantities and flow regimes in systems with various combinations of initial particle number densities and initial temperatures. It is observed that a physical quantity Q, such as pressure, at position z measured along a pipe-like system at time t follows a scaling relation Q(z,t)=Q(zt) with a scaling function Q(ζ). A similar scaling relation holds for time evolution of flow regimes in a system. These scaling relations lead to a regime map of explosive flows in parameter spaces of local physical quantities. The validity of the scaling relations of physical quantities means that physics of equilibrium systems, such as an equation of state, is applicable to explosive flows in our simulations, though the explosive flows involve highly nonequilibrium processes. In other words, if the breaking of the scaling relations is observed, it means that the explosive flows cannot be fully described by physics of equilibrium systems. We show the possibility of breaking of the scaling relations and discuss its implications in the last section. © 2011 Elsevier B.V. All rights reserved.
Directory of Open Access Journals (Sweden)
P. S. Timashev
2016-01-01
Full Text Available Aim. Controlled treatment of the physico-chemical and mechanical properties of a three-dimensional crosslinked matrix based on reactive chitosan. Materials and methods. The three-dimensional matrices were obtained using photosensitive composition based on allyl chitosan (5 wt%, poly(ethylene glycol diacrylate (8 wt% and the photoinitiator Irgacure 2959 (1 wt% by laser stereolithography setting. The kinetic swelling curves were constructed for structures in the base and salt forms of chitosan using gravimetric method and the contact angles were measured using droplet spreading. The supercritical fl uid setting (40 °C, 12 MPa was used to process matrices during 1.5 hours. Using nanohardness Piuma Nanoindenter we calculated values of Young’s modulus. The study of cytotoxicity was performed by direct contact with the culture of the NIH 3T3 mouse fi broblast cell line. Results. Architectonics of matrices fully repeats the program model. Matrices are uniform throughout and retain their shape after being transferred to the base form. Matrices compressed by 5% after treatment in supercritical carbon dioxide (scCO2 . The elastic modulus of matrices after scCO2 treatment is 4 times higher than the original matrix. The kinetic swelling curves have similar form. In this case the maximum degree of swelling for matrices in base form is 2–2.5 times greater than that of matrices in salt form. There was a surface hydrophobization after the material was transferred to the base form: the contact angle is 94°, and for the salt form it is 66°. The basic form absorbs liquid approximately 1.6 times faster. The fi lm thickness was increased in the area of contact with the liquid droplets after absorption by 133 and 87% for the base and the salt forms, respectively. Treatment of samples in scCO2 reduces their cytotoxicity from 2 degree of reaction (initial samples down to 1 degree of reaction. Conclusion. The use of supercritical carbon dioxide for scaffolds
Binary Positive Semidefinite Matrices and Associated Integer Polytopes
DEFF Research Database (Denmark)
Letchford, Adam N.; Sørensen, Michael Malmros
2012-01-01
We consider the positive semidefinite (psd) matrices with binary entries, along with the corresponding integer polytopes. We begin by establishing some basic properties of these matrices and polytopes. Then, we show that several families of integer polytopes in the literature-the cut, boolean qua...
CONVERGENCE OF POWERS OF CONTROLLABLE INTUITIONISTIC FUZZY MATRICES
Riyaz Ahmad Padder; P. Murugadas
2016-01-01
Convergences of powers of controllable intuitionistic fuzzy matrices have been stud¬ied. It is shown that they oscillate with period equal to 2, in general. Some equalities and sequences of inequalities about powers of controllable intuitionistic fuzzy matrices have been obtained.
Propositional matrices as alternative representation of truth values ...
African Journals Online (AJOL)
The paper considered the subject of representation of truth values in symbolic logic. An alternative representation was given based on the rows and columns properties of matrices, with the operations involving the logical connectives subjected to the laws of algebra of propositions. Matrices of various propositions detailing ...
The Modern Origin of Matrices and Their Applications
Debnath, L.
2014-01-01
This paper deals with the modern development of matrices, linear transformations, quadratic forms and their applications to geometry and mechanics, eigenvalues, eigenvectors and characteristic equations with applications. Included are the representations of real and complex numbers, and quaternions by matrices, and isomorphism in order to show…
Abel-grassmann's groupoids of modulo matrices
International Nuclear Information System (INIS)
Javaid, Q.; Awan, M.D.; Naqvi, S.H.A.
2016-01-01
The binary operation of usual addition is associative in all matrices over R. However, a binary operation of addition in matrices over Z/sub n/ of a nonassociative structures of AG-groupoids and AG-groups are defined and investigated here. It is shown that both these structures exist for every integer n >≥ 3. Various properties of these structures are explored like: (i) Every AG-groupoid of matrices over Z/sub n/ is transitively commutative AG-groupoid and is a cancellative AG-groupoid if n is prime. (ii) Every AG-groupoid of matrices over Z/sub n/ of Type-II is a T/sup 3/-AG-groupoid. (iii) An AG-groupoid of matrices over Z/sub n/ ; G /sub nAG/(t,u), is an AG-band, if t+u=1(mod n). (author)
Neutrino mass matrices with vanishing determinant
International Nuclear Information System (INIS)
Chauhan, Bhag C.; Pulido, Joao; Picariello, Marco
2006-01-01
We investigate the prospects for neutrinoless double beta decay, texture zeros. and equalities between neutrino mass matrix elements in scenarios with vanishing determinant mass matrices for vanishing and finite θ 13 mixing angles in normal and inverse mass hierarchies. For normal hierarchy and both zero and finite θ 13 it is found that neutrinoless double beta decay cannot be observed by any of the present or next generation experiments, while for inverse hierarchy it is, on the contrary, accessible to experiments. Regarding texture zeros and equalities between mass matrix elements, we find that in both normal and inverse hierarchies with θ 13 =0 no texture zeros nor any such equalities can exist apart from the obvious ones. For θ 13 ≠0 some texture zeros become possible. In normal hierarchy two texture zeros occur if 8.1x10 -2 ≤sinθ 13 ≤9.1x10 -2 while in inverse hierarchy three are possible, one with sinθ 13 ≥7x10 -3 and two others with sinθ 13 ≥0.18. All equalities between mass matrix elements are impossible with θ 13 ≠0
Calculating scattering matrices by wave function matching
International Nuclear Information System (INIS)
Zwierzycki, M.; Khomyakov, P.A.; Starikov, A.A.; Talanana, M.; Xu, P.X.; Karpan, V.M.; Marushchenko, I.; Brocks, G.; Kelly, P.J.; Xia, K.; Turek, I.; Bauer, G.E.W.
2008-01-01
The conductance of nanoscale structures can be conveniently related to their scattering properties expressed in terms of transmission and reflection coefficients. Wave function matching (WFM) is a transparent technique for calculating transmission and reflection matrices for any Hamiltonian that can be represented in tight-binding form. A first-principles Kohn-Sham Hamiltonian represented on a localized orbital basis or on a real space grid has such a form. WFM is based upon direct matching of the scattering-region wave function to the Bloch modes of ideal leads used to probe the scattering region. The purpose of this paper is to give a pedagogical introduction to WFM and present some illustrative examples of its use in practice. We briefly discuss WFM for calculating the conductance of atomic wires, using a real space grid implementation. A tight-binding muffin-tin orbital implementation very suitable for studying spin-dependent transport in layered magnetic materials is illustrated by looking at spin-dependent transmission through ideal and disordered interfaces. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Visualizing complex (hydrological) systems with correlation matrices
Haas, J. C.
2016-12-01
When trying to understand or visualize the connections of different aspects of a complex system, this often requires deeper understanding to start with, or - in the case of geo data - complicated GIS software. To our knowledge, correlation matrices have rarely been used in hydrology (e.g. Stoll et al., 2011; van Loon and Laaha, 2015), yet they do provide an interesting option for data visualization and analysis. We present a simple, python based way - using a river catchment as an example - to visualize correlations and similarities in an easy and colorful way. We apply existing and easy to use python packages from various disciplines not necessarily linked to the Earth sciences and can thus quickly show how different aquifers work or react, and identify outliers, enabling this system to also be used for quality control of large datasets. Going beyond earlier work, we add a temporal and spatial element, enabling us to visualize how a system reacts to local phenomena such as for example a river, or changes over time, by visualizing the passing of time in an animated movie. References: van Loon, A.F., Laaha, G.: Hydrological drought severity explained by climate and catchment characteristics, Journal of Hydrology 526, 3-14, 2015, Drought processes, modeling, and mitigation Stoll, S., Hendricks Franssen, H. J., Barthel, R., Kinzelbach, W.: What can we learn from long-term groundwater data to improve climate change impact studies?, Hydrology and Earth System Sciences 15(12), 3861-3875, 2011
Decellularized matrices for cardiovascular tissue engineering.
Moroni, Francesco; Mirabella, Teodelinda
2014-01-01
Cardiovascular disease (CVD) is one of the leading causes of death in the Western world. The replacement of damaged vessels and valves has been practiced since the 1950's. Synthetic grafts, usually made of bio-inert materials, are long-lasting and mechanically relevant, but fail when it comes to "biointegration". Decellularized matrices, instead, can be considered biological grafts capable of stimulating in vivo migration and proliferation of endothelial cells (ECs), recruitment and differentiation of mural cells, finally, culminating in the formation of a biointegrated tissue. Decellularization protocols employ osmotic shock, ionic and non-ionic detergents, proteolitic digestions and DNase/RNase treatments; most of them effectively eliminate the cellular component, but show limitations in preserving the native structure of the extracellular matrix (ECM). In this review, we examine the current state of the art relative to decellularization techniques and biological performance of decellularized heart, valves and big vessels. Furthermore, we focus on the relevance of ECM components, native and resulting from decellularization, in mediating in vivo host response and determining repair and regeneration, as opposed to graft corruption.
On some Toeplitz matrices and their inversions
Directory of Open Access Journals (Sweden)
S. Dutta
2014-10-01
Full Text Available In this article, using the difference operator B(a[m], we introduce a lower triangular Toeplitz matrix T which includes several difference matrices such as Δ(1,Δ(m,B(r,s,B(r,s,t, and B(r̃,s̃,t̃,ũ in different special cases. For any x ∈ w and m∈N0={0,1,2,…}, the difference operator B(a[m] is defined by (B(a[m]xk=ak(0xk+ak-1(1xk-1+ak-2(2xk-2+⋯+ak-m(mxk-m,(k∈N0 where a[m] = {a(0, a(1, …, a(m} and a(i = (ak(i for 0 ⩽ i ⩽ m are convergent sequences of real numbers. We use the convention that any term with negative subscript is equal to zero. The main results of this article relate to the determination and applications of the inverse of the Toeplitz matrix T.
Tiwari, Aviral Kumar; Albulescu, Claudiu Tiberiu; Yoon, Seong-Min
2017-10-01
This study challenges the efficient market hypothesis, relying on the Dow Jones sector Exchange-Traded Fund (ETF) indices. For this purpose, we use the generalized Hurst exponent and multifractal detrended fluctuation analysis (MF-DFA) methods, using daily data over the timespan from 2000 to 2015. We compare the sector ETF indices in terms of market efficiency between short- and long-run horizons, small and large fluctuations, and before and after the global financial crisis (GFC). Our findings can be summarized as follows. First, there is clear evidence that the sector ETF markets are multifractal in nature. We also find a crossover in the multifractality of sector ETF market dynamics. Second, the utilities and consumer goods sector ETF markets are more efficient compared with the financial and telecommunications sector ETF markets, in terms of price prediction. Third, there are noteworthy discrepancies in terms of market efficiency, between the short- and long-term horizons. Fourth, the ETF market efficiency is considerably diminished after the global financial crisis.
International Nuclear Information System (INIS)
Adebayo, G.A.; Anusionwu, B.C.; Njah, A.N.; Adeniran, O.J.; Mathew, B.; Sunmonu, R.S.
2009-01-01
Arising from the inability of theoretical calculations to give accurate descriptions of (shear) viscosity in rare gases at high densities, we investigated the likely cause of discrepancy between theory and experiments. Molecular Dynamics simulations were performed to calculate transport coefficients and collision frequency of rare gases at high densities and different temperatures using a Lennard-Jones modelled pair potential. The results, when compared with experiments show an underestimation of the viscosity calculated through the Green-Kubo formalism, but in agreement with some other calculations performed by other groups. In the present work the origin of the underestimation is considered. Analyses of the transport coefficients show a very high collision frequency which suggests an atom may spend much less time in the neighbourhood of the fields of force of another atom and that the distribution in the systems studied adjusts itself to a nearly Maxwellian type which resulted in a locally and temporarily slowly varying temperature. We show that the time spent in the fields of force is so small compared with relaxation time thereby leading to a possible reduction in local velocity auto-correlation between atoms. (author)
Single-site Lennard-Jones models via polynomial chaos surrogates of Monte Carlo molecular simulation
Energy Technology Data Exchange (ETDEWEB)
Kadoura, Ahmad, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa; Sun, Shuyu, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa [Computational Transport Phenomena Laboratory, The Earth Sciences and Engineering Department, The Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia); Siripatana, Adil, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa; Hoteit, Ibrahim, E-mail: ibrahim.hoteit@kaust.edu.sa [Earth Fluid Modeling and Predicting Group, The Earth Sciences and Engineering Department, The Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia); Knio, Omar, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa [Uncertainty Quantification Center, The Applied Mathematics and Computational Science Department, The Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)
2016-06-07
In this work, two Polynomial Chaos (PC) surrogates were generated to reproduce Monte Carlo (MC) molecular simulation results of the canonical (single-phase) and the NVT-Gibbs (two-phase) ensembles for a system of normalized structureless Lennard-Jones (LJ) particles. The main advantage of such surrogates, once generated, is the capability of accurately computing the needed thermodynamic quantities in a few seconds, thus efficiently replacing the computationally expensive MC molecular simulations. Benefiting from the tremendous computational time reduction, the PC surrogates were used to conduct large-scale optimization in order to propose single-site LJ models for several simple molecules. Experimental data, a set of supercritical isotherms, and part of the two-phase envelope, of several pure components were used for tuning the LJ parameters (ε, σ). Based on the conducted optimization, excellent fit was obtained for different noble gases (Ar, Kr, and Xe) and other small molecules (CH{sub 4}, N{sub 2}, and CO). On the other hand, due to the simplicity of the LJ model used, dramatic deviations between simulation and experimental data were observed, especially in the two-phase region, for more complex molecules such as CO{sub 2} and C{sub 2} H{sub 6}.
Nephrotoxicity of Bence-Jones proteins: interference in renal epithelial cell acidification
Directory of Open Access Journals (Sweden)
Nicastri A.L.
2002-01-01
Full Text Available The aim of the present study was to evaluate the acidification of the endosome-lysosome system of renal epithelial cells after endocytosis of two human immunoglobulin lambda light chains (Bence-Jones proteins, BJP obtained from patients with multiple myeloma. Renal epithelial cell handling of two BJP (neutral and acidic BJP was evaluated by rhodamine fluorescence. Renal cells (MDCK were maintained in culture and, when confluent, were incubated with rhodamine-labeled BJP for different periods of time. Photos were obtained with a fluorescence microscope (Axiolab-Zeiss. Labeling density was determined on slides with a densitometer (Shimadzu Dual-Wavelength Flying-Spot Scanner CS9000. Endocytosis of neutral and acidic BJP was correlated with acidic intracellular compartment distribution using acridine orange labeling. We compared the pattern of distribution after incubation of native neutral and acidic BJP and after complete deglycosylation of BJP by periodate oxidation. The subsequent alteration of pI converted neutral BJP to acidic BJP. There was a significant accumulation of neutral BJP in endocytic structures, reduced lysosomal acidification, and a diffuse pattern of acidification. This pattern was reversed after total deglycosylation and subsequent alteration of the pI to an acidic BJP. We conclude that the physicochemical characteristics of BJP interfere with intracellular acidification, possibly explaining the strong nephrotoxicity of neutral BJP. Lysosomal acidification is fundamental for adequate protein processing and catabolism.
A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images.
Xu, Yongzheng; Yu, Guizhen; Wang, Yunpeng; Wu, Xinkai; Ma, Yalong
2016-08-19
A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles' in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians.
A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images
Xu, Yongzheng; Yu, Guizhen; Wang, Yunpeng; Wu, Xinkai; Ma, Yalong
2016-01-01
A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles’ in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians. PMID:27548179
A test of the mean density approximation for Lennard-Jones mixtures with large size ratios
International Nuclear Information System (INIS)
Ely, J.F.
1986-01-01
The mean density approximation for mixture radial distribution functions plays a central role in modern corresponding-states theories. This approximation is reasonably accurate for systems that do not differ widely in size and energy ratios and which are nearly equimolar. As the size ratio increases, however, or if one approaches an infinite dilution of one of the components, the approximation becomes progressively worse, especially for the small molecule pair. In an attempt to better understand and improve this approximation, isothermal molecular dynamics simulations have been performed on a series of Lennard-Jones mixtures. Thermodynamic properties, including the mixture radial distribution functions, have been obtained at seven compositions ranging from 5 to 95 mol%. In all cases the size ratio was fixed at two and three energy ratios were investigated, 22 / 11 =0.5, 1.0, and 1.5. The results of the simulations are compared with the mean density approximation and a modification to integrals evaluated with the mean density approximation is proposed
A perturbed Lennard-Jones chain equation of state for liquid metals
Energy Technology Data Exchange (ETDEWEB)
Mousazadeh, M H; Marageh, M Ghanadi [AEOI, JIH Research Laboratory, 11365/8486, Tehran (Iran, Islamic Republic of)
2006-05-24
The perturbed Lennard-Jones chain (PLJC) equation of state is formulated based on first-order variational perturbation theory. The model uses two parameters for a monatomic system, segment size, {sigma}, and segment energy, {epsilon}/k. In this work, we employed the PLJC equation to calculate the liquid density of 26 metals, including alkali and alkali earth metals, iron, cobalt, nickel, copper, silver, gold, zinc, cadmium, mercury, aluminium, gallium, indium, thallium, tin, lead, antimony, and bismuth, for which accurate experimental data exist in the literature. The calculations cover a broad range of temperatures ranging from the melting point to close to the critical point and pressures ranging from the vapour-pressure curve up to pressures as high as 2000 bar. The average absolute deviation in the liquid density predicted by the PLJC equation of state in the saturation line compared with experimental data is 1.26%. Also, using the normal melting temperature and liquid density at melting point (T{sub m}, {rho}{sub m}) as input data for the estimation of the equation of state parameters provides a good correlation of liquid density at saturated and compressed pressures.
Thermodynamic equivalence between the Lennard-Jones and hard-core attractive Yukawa systems
International Nuclear Information System (INIS)
Kadiri, Y.; Albaki, R.; Bretonnet, J.L.
2008-01-01
The investigation of the thermodynamic properties of the Lennard-Jones (LJ) fluid is made by means of a system of particles interacting with a potential of hard-core plus attractive Yukawa tail (HCY). Due to the similarity between the LJ potential and the HCY potential in its overall form, it is worthwhile seeking to approximate the LJ potential in much the same way that the hard-sphere reference potential has been so used. The study consists in describing the thermodynamics of the LJ fluid in terms of the equivalent HCY system, whose the properties are known accurately, by means of mapping the thermodynamic quantities for the HCY potential parameters. The method is feasible owing to a convenient analytical expression of the Helmholtz free energy from the mean-spherical approximation expanded in power of the inverse temperature. Two different procedures are used to determine the parameters of the HCY potential as a function of the thermodynamic states: one is based on the simultaneous fits of pressure and internal energy of the LJ system and the other uses the concept of collision frequency. The reasonable homogeneity of the results in both procedures of mapping makes that the HCY potential is a very good reference system, whose the proposed theoretical expressions can be used confidently to predict the thermodynamic properties of more realistic potentials
Modeling Aggregation Processes of Lennard-Jones particles Via Stochastic Networks
Forman, Yakir; Cameron, Maria
2017-07-01
We model an isothermal aggregation process of particles/atoms interacting according to the Lennard-Jones pair potential by mapping the energy landscapes of each cluster size N onto stochastic networks, computing transition probabilities from the network for an N-particle cluster to the one for N+1, and connecting these networks into a single joint network. The attachment rate is a control parameter. The resulting network representing the aggregation of up to 14 particles contains 6427 vertices. It is not only time-irreversible but also reducible. To analyze its transient dynamics, we introduce the sequence of the expected initial and pre-attachment distributions and compute them for a wide range of attachment rates and three values of temperature. As a result, we find the configurations most likely to be observed in the process of aggregation for each cluster size. We examine the attachment process and conduct a structural analysis of the sets of local energy minima for every cluster size. We show that both processes taking place in the network, attachment and relaxation, lead to the dominance of icosahedral packing in small (up to 14 atom) clusters.
Spray flow-network flow transition of binary Lennard-Jones particle system
Inaoka, Hajime
2010-07-01
We simulate gas-liquid flows caused by rapid depressurization using a molecular dynamics model. The model consists of two types of Lennard-Jones particles, which we call liquid particles and gas particles. These two types of particles are distinguished by their mass and strength of interaction: a liquid particle has heavier mass and stronger interaction than a gas particle. By simulations with various initial number densities of these particles, we found that there is a transition from a spray flow to a network flow with an increase of the number density of the liquid particles. At the transition point, the size of the liquid droplets follows a power-law distribution, while it follows an exponential distribution when the number density of the liquid particles is lower than the critical value. The comparison between the transition of the model and that of models of percolation is discussed. The change of the average droplet size with the initial number density of the gas particles is also presented. © 2010 Elsevier B.V. All rights reserved.
Efficient Implementations of Molecular Dynamics Simulations for Lennard-Jones Systems
Watanabe, H.
2011-08-01
Efficient implementations of the classical molecular dynamics (MD) method for Lennard-Jones particle systems are considered. Not only general algorithms but also techniques that are efficient for some specific CPU architectures are also explained. A simple spatialdecomposition-based strategy is adopted for parallelization. By utilizing the developed code, benchmark simulations are performed on a HITACHI SR16000/J2 system consisting of IBM POWER6 processors which are 4.7 GHz at the National Institute for Fusion Science (NIFS) and an SGI Altix ICE 8400EX system consisting of Intel Xeon processors which are 2.93 GHz at the Institute for Solid State Physics (ISSP), the University of Tokyo. The parallelization efficiency of the largest run, consisting of 4.1 billion particles with 8192 MPI processes, is about 73% relative to that of the smallest run with 128 MPI processes at NIFS, and it is about 66% relative to that of the smallest run with 4 MPI processes at ISSP. The factors causing the parallel overhead are investigated. It is found that fluctuations of the execution time of each process degrade the parallel efficiency. These fluctuations may be due to the interference of the operating system, which is known as OS Jitter.
Directory of Open Access Journals (Sweden)
Xin Chao Liu
2013-01-01
Full Text Available The aim of this research was to determine chemical composition and insecticidal activities of the essential oil of Valeriana jatamansi Jones roots against booklice, Liposcelis bostrychophila Badonnel, and to isolate insecticidal constituents from the oil. Essential oil of V. jatamansi was obtained by hydrodistillation and analyzed by GC-MS. A total of 27 components in the essential oil were identified. The major compounds were patchoulol (24.3%, α-bulnesene (13.8%, isovaleric acid (12.9%, α-guaiene (8.7%, and 3-methylvaleric acid (8.4%. Based on bioactivity-guided fractionation, isovaleric acid, 3-methylvaleric acid, and patchoulol were isolated and identified as the active constituents. The essential oil exhibited contact toxicity against L. bostrychophila with an LC50 value of 236.4 μg/cm2. Patchoulol (LC50 = 61.35 μg/cm2 exhibited stronger acute toxicity than 3-methylvaleric acid (LC50 = 210.69 μg/cm2 against the booklice. The essential oil also possessed fumigant toxicity against L. bostrychophila with an LC50 value of 6.0 mg/L, while 3-methylvaleric acid and isovaleric acid had LC50 values of 5.53 mg/L and 5.67 mg/L against the booklice, respectively. The results indicated that the essential oil and its constituent compounds have potential to develop into natural insecticides or fumigants for control of insects in stored grains.
Pieprzyk, S.; Brańka, A. C.; Maćkowiak, Sz.; Heyes, D. M.
2018-03-01
The equation of state (EoS) of the Lennard-Jones fluid is calculated using a new set of molecular dynamics data which extends to higher temperature than in previous studies. The modified Benedict-Webb-Rubin (MBWR) equation, which goes up to ca. T ˜ 6, is reparametrized with new simulation data. A new analytic form for the EoS, which breaks the fluid range into two regions with different analytic forms and goes up to ca. T ≃ 35, is also proposed. The accuracy of the new formulas is at least as good as the MBWR fit and goes to much higher temperature allowing it to now encompass the Amagat line. The fitted formula extends into the high temperature range where the system can be well represented by inverse power potential scaling, which means that our specification of the equation of state covers the entire (ρ, T) plane. Accurate analytic fit formulas for the Boyle, Amagat, and inversion curves are presented. Parametrizations of the extrema loci of the isochoric, CV, and isobaric, CP, heat capacities are given. As found by others, a line maxima of CP terminates in the critical point region, and a line of minima of CP terminates on the freezing line. The line of maxima of CV terminates close to or at the critical point, and a line of minima of CV terminates to the right of the critical point. No evidence for a divergence in CV in the critical region is found.
Enhancement of the droplet nucleation in a dense supersaturated Lennard-Jones vapor
Energy Technology Data Exchange (ETDEWEB)
Zhukhovitskii, D. I., E-mail: dmr@ihed.ras.ru [Joint Institute of High Temperatures, Russian Academy of Sciences, Izhorskaya 13, Bd. 2, 125412 Moscow (Russian Federation)
2016-05-14
The vapor–liquid nucleation in a dense Lennard-Jones system is studied analytically and numerically. A solution of the nucleation kinetic equations, which includes the elementary processes of condensation/evaporation involving the lightest clusters, is obtained, and the nucleation rate is calculated. Based on the equation of state for the cluster vapor, the pre-exponential factor is obtained. The latter diverges as a spinodal is reached, which results in the nucleation enhancement. The work of critical cluster formation is calculated using the previously developed two-parameter model (TPM) of small clusters. A simple expression for the nucleation rate is deduced and it is shown that the work of cluster formation is reduced for a dense vapor. This results in the nucleation enhancement as well. To verify the TPM, a simulation is performed that mimics a steady-state nucleation experiments in the thermal diffusion cloud chamber. The nucleating vapor with and without a carrier gas is simulated using two different thermostats for the monomers and clusters. The TPM proves to match the simulation results of this work and of other studies.
A model-adaptivity method for the solution of Lennard-Jones based adhesive contact problems
Ben Dhia, Hachmi; Du, Shuimiao
2018-05-01
The surface micro-interaction model of Lennard-Jones (LJ) is used for adhesive contact problems (ACP). To address theoretical and numerical pitfalls of this model, a sequence of partitions of contact models is adaptively constructed to both extend and approximate the LJ model. It is formed by a combination of the LJ model with a sequence of shifted-Signorini (or, alternatively, -Linearized-LJ) models, indexed by a shift parameter field. For each model of this sequence, a weak formulation of the associated local ACP is developed. To track critical localized adhesive areas, a two-step strategy is developed: firstly, a macroscopic frictionless (as first approach) linear-elastic contact problem is solved once to detect contact separation zones. Secondly, at each shift-adaptive iteration, a micro-macro ACP is re-formulated and solved within the multiscale Arlequin framework, with significant reduction of computational costs. Comparison of our results with available analytical and numerical solutions shows the effectiveness of our global strategy.
Dodecagonal order in a two-dimensional Lennard-Jones system
International Nuclear Information System (INIS)
Leung, P.W.; Henley, C.L.; Chester, G.V.
1989-01-01
We investigate a two-dimensional Lennard-Jones mixture with the interaction parameters chosen so as to favor configurations where the large atoms form squares and equilateral triangles. Many such configurations are possible which by our choice of interactions are nearly degenerate in energy. It is hypothesized that a thermal equilibrium state with 12-fold orientational order exists. Several Monte Carlo simulations were performed to cool the system to a temperature approaching zero. The ordering process was studied by following the evolution of the configurations with temperature. The onset of ordering seemed to be very diffuse in space rather than nucleated at a point. The resulting configurations consist of squares and triangles, except for a few dislocations, and thus have perfect orientational order. We also characterized the deviation from ideal quasiperiodicity in terms of the ''phason strain''; this was analyzed both by fitting a linear relation between the physical space coordinates of the atoms and the corresponding ''perpendicular space'' coordinates, and also by calculating the diffraction peaks. The latter are shifted and broadened, relative to an ideal 12-fold diffraction pattern, as in real quasicrystals
Single-site Lennard-Jones models via polynomial chaos surrogates of Monte Carlo molecular simulation
Kadoura, Ahmad Salim
2016-06-01
In this work, two Polynomial Chaos (PC) surrogates were generated to reproduce Monte Carlo (MC) molecular simulation results of the canonical (single-phase) and the NVT-Gibbs (two-phase) ensembles for a system of normalized structureless Lennard-Jones (LJ) particles. The main advantage of such surrogates, once generated, is the capability of accurately computing the needed thermodynamic quantities in a few seconds, thus efficiently replacing the computationally expensive MC molecular simulations. Benefiting from the tremendous computational time reduction, the PC surrogates were used to conduct large-scale optimization in order to propose single-site LJ models for several simple molecules. Experimental data, a set of supercritical isotherms, and part of the two-phase envelope, of several pure components were used for tuning the LJ parameters (ε, σ). Based on the conducted optimization, excellent fit was obtained for different noble gases (Ar, Kr, and Xe) and other small molecules (CH4, N2, and CO). On the other hand, due to the simplicity of the LJ model used, dramatic deviations between simulation and experimental data were observed, especially in the two-phase region, for more complex molecules such as CO2 and C2 H6.
Spray flow-network flow transition of binary Lennard-Jones particle system
Inaoka, Hajime; Yukawa, Satoshi; Ito, Nobuyasu
2010-01-01
We simulate gas-liquid flows caused by rapid depressurization using a molecular dynamics model. The model consists of two types of Lennard-Jones particles, which we call liquid particles and gas particles. These two types of particles are distinguished by their mass and strength of interaction: a liquid particle has heavier mass and stronger interaction than a gas particle. By simulations with various initial number densities of these particles, we found that there is a transition from a spray flow to a network flow with an increase of the number density of the liquid particles. At the transition point, the size of the liquid droplets follows a power-law distribution, while it follows an exponential distribution when the number density of the liquid particles is lower than the critical value. The comparison between the transition of the model and that of models of percolation is discussed. The change of the average droplet size with the initial number density of the gas particles is also presented. © 2010 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Farid, A.; Iqbal, S.M.J.; Hanif, A.
2013-01-01
Background: Tuberculosis (TB) is a granulomatous disease caused by Mycobacterium tuberculosis. The gold standard for the diagnosis of tuberculosis is detection of Mycobacterium tubercle bacilli. However, clinical scoring systems are most widely used for the diagnosis of TB in children. Objective: To determine the diagnostic accuracy of modified Kenneth Jones scoring criteria (MKJSC) in conformed cases of tuberculosis. Methodology: This cross-sectional comparative study was conducted in the department of Paediatrics, King Edward Medical University / Mayo Hospital, Lahore from January to June 2007. One hundred children below 15 years of age were enrolled. They were diagnosed as suspected cases of TB on the basis of fever and cough for more than 15 days. MKJSC was applied and each child was subjected to confirmatory test for TB. Results: There was an overall male preponderance of 54%. The mean age of study population was 1.8 +- 0.7 years. Out of 100 children, 66% were diagnosed as TB cases (23 with confirmatory tests and 43 with MKJSC of 5 or more). Sensitivity, specificity, positive and negative predictive value of MKJSC was 73.91%, 44.16%, 28.33%, and 85% respectively. Diagnostic accuracy of MKJSC was 51%. Conclusion: Present study does not support the hypothesis that MKJSC is a good alternative to confirmatory tests to diagnose tuberculosis in children. However, MKJSC is a simple tool, which can be applied to improve the case detection rate in the absence of sophisticated tests. (author)
An application of viola jones method for face recognition for absence process efficiency
Rizki Damanik, Rudolfo; Sitanggang, Delima; Pasaribu, Hendra; Siagian, Hendrik; Gulo, Frisman
2018-04-01
Absence was a list of documents that the company used to record the attendance time of each employee. The most common problem in a fingerprint machine is the identification of a slow sensor or a sensor not recognizing a finger. The employees late to work because they get difficulties at fingerprint system, they need about 3 – 5 minutes to absence when the condition of finger is wet or not fit. To overcome this problem, this research tried to utilize facial recognition for attendance process. The method used for facial recognition was Viola Jones. Through the processing phase of the RGB face image was converted into a histogram equalization face image for the next stage of recognition. The result of this research was the absence process could be done less than 1 second with a maximum slope of ± 700 and a distance of 20-200 cm. After implement facial recognition the process of absence is more efficient, just take less 1 minute to absence.
Fowler's approximation for the surface tension and surface energy of Lennard-Jones fluids revisited
International Nuclear Information System (INIS)
Mulero, A; Galan, C; Cuadros, F
2003-01-01
We present a detailed study of the validity of Fowler's approximation for calculating the surface tension and the surface energy of Lennard-Jones fluids. To do so, we consider three different explicit analytical expressions for the radial distribution function (RDF), including one proposed by our research group, together with very accurate expressions for the liquid and vapour densities, also proposed by our group. The calculation of the surface tension from the direct correlation function using both the Percus-Yevick and the hypernetted-chain approximations is also considered. Finally, our results are compared with those obtained by other authors by computer simulations or through relevant theoretical approximations. In particular, we consider the analytical expression proposed by Kalikmanov and Hofmans (1994 J. Phys.: Condens. Matter 6 2207-14) for the surface tension. Our results indicate that the values for the surface energy in Fowler's approximation obtained by other authors are adequate, and can be calculated from the RDF models. For the surface tension, however, the values considered as valid in previous works seem to be incorrect. The correct values can be obtained from our model for the RDF or from the Kalikmanov and Hofmans expression with suitable inputs
International Nuclear Information System (INIS)
Hamady, Saleem; Hijazi, Abbas; Atwi, Ali
2013-01-01
An analytical expression for the Lennard–Jones interaction between nano-rods and an infinite flat solid surface is presented. Starting from the elementary Lennard–Jones interaction between two particles, and taking the shape of the nano-rod to be a filled cylinder of radius r and length L, the obtained expression was valid for arbitrary orientation of the nano-rod at variable elevation from the surface. By differentiating the potential with respect to the orientation and elevation we were able to extract the torque and force, respectively, exerted on the nano-rods when approaching a flat surface. The derivation is subjected to the assumption of additivity and approximated for some limiting case
International Nuclear Information System (INIS)
Mulero, A.; Cuadros, F; Faundez, C.A.
1999-01-01
Vapour-liquid equilibrium properties for both three- and two-dimensional Lennard-Jones fluids were obtained using simple cubic-in-density equations of state proposed by the authors. Results were compared with those obtained by other workers from computer simulations and also with results given by other more complex semi-theoretical or semi-empirical equations of state. In the three-dimensional case good agreement is found for all properties and all temperatures. In the two-dimensional case only the coexistence densities were compared, producing good agreement for low temperatures only. The present work is the first to give numerical data for the vapour-liquid equilibrium properties of Lennard-Jones fluids calculated from equations of state. Copyright (1999) CSIRO Australia
Gu, Rongbao; Shao, Yanmin
2016-07-01
In this paper, a new concept of multi-scales singular value decomposition entropy based on DCCA cross correlation analysis is proposed and its predictive power for the Dow Jones Industrial Average Index is studied. Using Granger causality analysis with different time scales, it is found that, the singular value decomposition entropy has predictive power for the Dow Jones Industrial Average Index for period less than one month, but not for more than one month. This shows how long the singular value decomposition entropy predicts the stock market that extends Caraiani's result obtained in Caraiani (2014). On the other hand, the result also shows an essential characteristic of stock market as a chaotic dynamic system.
Chain of matrices, loop equations and topological recursion
Orantin, Nicolas
2009-01-01
Random matrices are used in fields as different as the study of multi-orthogonal polynomials or the enumeration of discrete surfaces. Both of them are based on the study of a matrix integral. However, this term can be confusing since the definition of a matrix integral in these two applications is not the same. These two definitions, perturbative and non-perturbative, are discussed in this chapter as well as their relation. The so-called loop equations satisfied by integrals over random matrices coupled in chain is discussed as well as their recursive solution in the perturbative case when the matrices are Hermitean.
Approximate joint diagonalization and geometric mean of symmetric positive definite matrices.
Directory of Open Access Journals (Sweden)
Marco Congedo
Full Text Available We explore the connection between two problems that have arisen independently in the signal processing and related fields: the estimation of the geometric mean of a set of symmetric positive definite (SPD matrices and their approximate joint diagonalization (AJD. Today there is a considerable interest in estimating the geometric mean of a SPD matrix set in the manifold of SPD matrices endowed with the Fisher information metric. The resulting mean has several important invariance properties and has proven very useful in diverse engineering applications such as biomedical and image data processing. While for two SPD matrices the mean has an algebraic closed form solution, for a set of more than two SPD matrices it can only be estimated by iterative algorithms. However, none of the existing iterative algorithms feature at the same time fast convergence, low computational complexity per iteration and guarantee of convergence. For this reason, recently other definitions of geometric mean based on symmetric divergence measures, such as the Bhattacharyya divergence, have been considered. The resulting means, although possibly useful in practice, do not satisfy all desirable invariance properties. In this paper we consider geometric means of covariance matrices estimated on high-dimensional time-series, assuming that the data is generated according to an instantaneous mixing model, which is very common in signal processing. We show that in these circumstances we can approximate the Fisher information geometric mean by employing an efficient AJD algorithm. Our approximation is in general much closer to the Fisher information geometric mean as compared to its competitors and verifies many invariance properties. Furthermore, convergence is guaranteed, the computational complexity is low and the convergence rate is quadratic. The accuracy of this new geometric mean approximation is demonstrated by means of simulations.
Approximate joint diagonalization and geometric mean of symmetric positive definite matrices.
Congedo, Marco; Afsari, Bijan; Barachant, Alexandre; Moakher, Maher
2014-01-01
We explore the connection between two problems that have arisen independently in the signal processing and related fields: the estimation of the geometric mean of a set of symmetric positive definite (SPD) matrices and their approximate joint diagonalization (AJD). Today there is a considerable interest in estimating the geometric mean of a SPD matrix set in the manifold of SPD matrices endowed with the Fisher information metric. The resulting mean has several important invariance properties and has proven very useful in diverse engineering applications such as biomedical and image data processing. While for two SPD matrices the mean has an algebraic closed form solution, for a set of more than two SPD matrices it can only be estimated by iterative algorithms. However, none of the existing iterative algorithms feature at the same time fast convergence, low computational complexity per iteration and guarantee of convergence. For this reason, recently other definitions of geometric mean based on symmetric divergence measures, such as the Bhattacharyya divergence, have been considered. The resulting means, although possibly useful in practice, do not satisfy all desirable invariance properties. In this paper we consider geometric means of covariance matrices estimated on high-dimensional time-series, assuming that the data is generated according to an instantaneous mixing model, which is very common in signal processing. We show that in these circumstances we can approximate the Fisher information geometric mean by employing an efficient AJD algorithm. Our approximation is in general much closer to the Fisher information geometric mean as compared to its competitors and verifies many invariance properties. Furthermore, convergence is guaranteed, the computational complexity is low and the convergence rate is quadratic. The accuracy of this new geometric mean approximation is demonstrated by means of simulations.
Perwita, Ratnanggana Ausiyyah Mustika
2015-01-01
The experience that young people get has an effect to their personality and their problem solving. This is why older people tend to be more mature than the young people. In Diana Wynne Jones' Howl's Moving Castle, the main character has a development in her personality through experiences. Her experiences lead her to how she solves her problems while she unconsciously uses defense mechanism. In this case, in this study will be analyzed the characteristic of the main character, Sophie, when sh...
International Nuclear Information System (INIS)
Garcia, N.
1978-01-01
The GR method for solving the scattering equations of atoms from a hard corrugated surface is applied on accelerated particles above a hard corrugated surface and a hard corrugated surface with an attractive well. The solutions are given for the Rayleigh hypothesis that under the range of corrugation presented in this paper leads to the exact ones. Threshold resonances are studied observing that the appearance and disappearance of beams must be for a general theory with vertical tangent. The structure of the Lennard-Jones resonances given for the model mentioned above. For the first time it is stressed that Lennard-Jones resonances are not observed in metal surfaces in general, and, accordingly, they are unobserved in compact metallic surfaces. This is correlated with the fact that diffraction has not been observed. Both facts are due to the very weak corrugation of the gas-metal interaction potential. According to our results, the Lennard-Jones resonances in metals present greater difficulties to be observed experimentally. It is also noted that the absence of diffraction in compact metal surfaces is because they are almost plane and not because of the Debye-Waller effect. Finally, the lifetimes of the atoms at the crystal surfaces are calculated. These are larger, the smaller the incident energy and the larger the corrugation. But the lifetimes are particularly large at resonance conditions (10 -11 s). (Auth.)
Ab initio study of the atomic motion in liquid metal surfaces: comparison with Lennard-Jones systems
International Nuclear Information System (INIS)
Gonzalez, Luis E; Gonzalez, David J
2006-01-01
It is established that liquid metals exhibit surface layering at the liquid-vapour interface, while dielectric simple systems, like those interacting through Lennard-Jones potentials, show a monotonic decay from the liquid density to that of the vapour. First principles molecular dynamics simulations of the free liquid surface of several liquid metals (Li, Na, K, Rb, Cs, Mg, Ba, Al, Tl and Si), and the Na 3 K 7 alloy near their triple points have been performed in order to study the atomic motion at the interface, mainly at the outer layer. Comparison with the results of classical molecular dynamics simulations of a Lennard-Jones system shows interesting differences and similarities. The probability distribution function of the time of residence in a layer shows a peak at very short times and a long-lasting tail. The mean residence time in a layer increases when approaching the interfacial region, slightly in the Lennard-Jones system but strongly in the metallic systems. The motion within the layers, parallel to the interface, can be described as diffusion enhanced (strongly in the case of the outermost layer) with respect to the bulk, for both types of systems, despite its reduced dimensionality in metals
Modular Extracellular Matrices: Solutions for the Puzzle
Serban, Monica A.; Prestwich, Glenn D.
2008-01-01
The common technique of growing cells in two-dimensions (2-D) is gradually being replaced by culturing cells on matrices with more appropriate composition and stiffness, or by encapsulation of cells in three-dimensions (3-D). The universal acceptance of the new 3-D paradigm has been constrained by the absence of a commercially available, biocompatible material that offers ease of use, experimental flexibility, and a seamless transition from in vitro to in vivo applications. The challenge – the puzzle that needs a solution – is to replicate the complexity of the native extracellular matrix (ECM) environment with the minimum number of components necessary to allow cells to rebuild and replicate a given tissue. For use in drug discovery, toxicology, cell banking, and ultimately in reparative medicine, the ideal matrix would therefore need to be highly reproducible, manufacturable, approvable, and affordable. Herein we describe the development of a set of modular components that can be assembled into biomimetic materials that meet these requirements. These semi-synthetic ECMs, or sECMs, are based on hyaluronan derivatives that form covalently crosslinked, biodegradable hydrogels suitable for 3-D culture of primary and stem cells in vitro, and for tissue formation in vivo. The sECMs can be engineered to provide appropriate biological cues needed to recapitulate the complexity of a given ECM environment. Specific applications for different sECM compositions include stem cell expansion with control of differentiation, scar-free wound healing, growth factor delivery, cell delivery for osteochondral defect and liver repair, and development of vascularized tumor xenografts for personalized chemotherapy. PMID:18442709
Comparison of eigensolvers for symmetric band matrices.
Moldaschl, Michael; Gansterer, Wilfried N
2014-09-15
We compare different algorithms for computing eigenvalues and eigenvectors of a symmetric band matrix across a wide range of synthetic test problems. Of particular interest is a comparison of state-of-the-art tridiagonalization-based methods as implemented in Lapack or Plasma on the one hand, and the block divide-and-conquer (BD&C) algorithm as well as the block twisted factorization (BTF) method on the other hand. The BD&C algorithm does not require tridiagonalization of the original band matrix at all, and the current version of the BTF method tridiagonalizes the original band matrix only for computing the eigenvalues. Avoiding the tridiagonalization process sidesteps the cost of backtransformation of the eigenvectors. Beyond that, we discovered another disadvantage of the backtransformation process for band matrices: In several scenarios, a lot of gradual underflow is observed in the (optional) accumulation of the transformation matrix and in the (obligatory) backtransformation step. According to the IEEE 754 standard for floating-point arithmetic, this implies many operations with subnormal (denormalized) numbers, which causes severe slowdowns compared to the other algorithms without backtransformation of the eigenvectors. We illustrate that in these cases the performance of existing methods from Lapack and Plasma reaches a competitive level only if subnormal numbers are disabled (and thus the IEEE standard is violated). Overall, our performance studies illustrate that if the problem size is large enough relative to the bandwidth, BD&C tends to achieve the highest performance of all methods if the spectrum to be computed is clustered. For test problems with well separated eigenvalues, the BTF method tends to become the fastest algorithm with growing problem size.
MATXTST, Basic Operations for Covariance Matrices
International Nuclear Information System (INIS)
Geraldo, Luiz P.; Smith, Donald
1989-01-01
1 - Description of program or function: MATXTST and MATXTST1 perform the following operations for a covariance matrix: - test for singularity; - test for positive definiteness; - compute the inverse if the matrix is non-singular; - compute the determinant; - determine the number of positive, negative, and zero eigenvalues; - examine all possible 3 X 3 cross correlations within a sub-matrix corresponding to a leading principal minor which is non-positive definite. While the two programs utilize the same input, the calculational procedures employed are somewhat different and their functions are complementary. The available input options include: i) the full covariance matrix, ii) the basic variables plus the relative covariance matrix, or iii) uncertainties in the basic variables plus the correlation matrix. 2 - Method of solution: MATXTST employs LINPACK subroutines SPOFA and SPODI to test for positive definiteness and to perform further optional calculations. Subroutine SPOFA factors a symmetric matrix M using the Cholesky algorithm to determine the elements of a matrix R which satisfies the relation M=R'R, where R' is the transposed matrix of R. Each leading principal minor of M is tested until the first one is found which is not positive definite. MATXTST1 uses LINPACK subroutines SSICO, SSIFA, and SSIDI to estimate whether the matrix is near to singularity or not (SSICO), and to perform the matrix diagonalization process (SSIFA). The algorithm used in SSIFA is generalization of the Method of Lagrange Reduction. SSIDI is used to compute the determinant and inertia of the matrix. 3 - Restrictions on the complexity of the problem: Matrices of sizes up to 50 X 50 elements can be treated by present versions of the programs
Houser, Dorian S; Champagne, Cory D; Crocker, Daniel E; Kellar, Nicholas M; Cockrem, John; Romano, Tracy; Booth, Rebecca K; Wasser, Samuel K
2016-01-01
Knowledge regarding stress hormones and how they vary in response to seasonality, gender, age, and reproductive status for any marine mammal is limited. Furthermore, stress hormones may be measured in more than one matrix (e.g., feces, blood, blubber), but the relationships between levels of a given hormone across these matrices are unknown, further complicating the interpretations of hormones measured in samples collected from wild animals. A study is underway to address these issues in a population of bottlenose dolphins trained for voluntary participation in sample collections from different matrices and across season and time of day.
Two updating methods for dissipative models with non symmetric matrices
International Nuclear Information System (INIS)
Billet, L.; Moine, P.; Aubry, D.
1997-01-01
In this paper the feasibility of the extension of two updating methods to rotating machinery models is considered, the particularity of rotating machinery models is to use non-symmetric stiffness and damping matrices. It is shown that the two methods described here, the inverse Eigen-sensitivity method and the error in constitutive relation method can be adapted to such models given some modification.As far as inverse sensitivity method is concerned, an error function based on the difference between right hand calculated and measured Eigen mode shapes and calculated and measured Eigen values is used. Concerning the error in constitutive relation method, the equation which defines the error has to be modified due to the non definite positiveness of the stiffness matrix. The advantage of this modification is that, in some cases, it is possible to focus the updating process on some specific model parameters. Both methods were validated on a simple test model consisting in a two-bearing and disc rotor system. (author)
Joint Estimation of Multiple Precision Matrices with Common Structures.
Lee, Wonyul; Liu, Yufeng
Estimation of inverse covariance matrices, known as precision matrices, is important in various areas of statistical analysis. In this article, we consider estimation of multiple precision matrices sharing some common structures. In this setting, estimating each precision matrix separately can be suboptimal as it ignores potential common structures. This article proposes a new approach to parameterize each precision matrix as a sum of common and unique components and estimate multiple precision matrices in a constrained l 1 minimization framework. We establish both estimation and selection consistency of the proposed estimator in the high dimensional setting. The proposed estimator achieves a faster convergence rate for the common structure in certain cases. Our numerical examples demonstrate that our new estimator can perform better than several existing methods in terms of the entropy loss and Frobenius loss. An application to a glioblastoma cancer data set reveals some interesting gene networks across multiple cancer subtypes.
Systems of Differential Equations with Skew-Symmetric, Orthogonal Matrices
Glaister, P.
2008-01-01
The solution of a system of linear, inhomogeneous differential equations is discussed. The particular class considered is where the coefficient matrix is skew-symmetric and orthogonal, and where the forcing terms are sinusoidal. More general matrices are also considered.
Finiteness properties of congruence classes of infinite matrices
Eggermont, R.H.
2014-01-01
We look at spaces of infinite-by-infinite matrices, and consider closed subsets that are stable under simultaneous row and column operations. We prove that up to symmetry, any of these closed subsets is defined by finitely many equations.
Flexible Bayesian Dynamic Modeling of Covariance and Correlation Matrices
Lan, Shiwei; Holbrook, Andrew; Fortin, Norbert J.; Ombao, Hernando; Shahbaba, Babak
2017-01-01
Modeling covariance (and correlation) matrices is a challenging problem due to the large dimensionality and positive-definiteness constraint. In this paper, we propose a novel Bayesian framework based on decomposing the covariance matrix
Discrimination Power of Polynomial-Based Descriptors for Graphs by Using Functional Matrices.
Dehmer, Matthias; Emmert-Streib, Frank; Shi, Yongtang; Stefu, Monica; Tripathi, Shailesh
2015-01-01
In this paper, we study the discrimination power of graph measures that are based on graph-theoretical matrices. The paper generalizes the work of [M. Dehmer, M. Moosbrugger. Y. Shi, Encoding structural information uniquely with polynomial-based descriptors by employing the Randić matrix, Applied Mathematics and Computation, 268(2015), 164-168]. We demonstrate that by using the new functional matrix approach, exhaustively generated graphs can be discriminated more uniquely than shown in the mentioned previous work.
Procrustes Problems for General, Triangular, and Symmetric Toeplitz Matrices
Directory of Open Access Journals (Sweden)
Juan Yang
2013-01-01
Full Text Available The Toeplitz Procrustes problems are the least squares problems for the matrix equation AX=B over some Toeplitz matrix sets. In this paper the necessary and sufficient conditions are obtained about the existence and uniqueness for the solutions of the Toeplitz Procrustes problems when the unknown matrices are constrained to the general, the triangular, and the symmetric Toeplitz matrices, respectively. The algorithms are designed and the numerical examples show that these algorithms are feasible.
An introduction to the theory of canonical matrices
Turnbull, H W
2004-01-01
Thorough and self-contained, this penetrating study of the theory of canonical matrices presents a detailed consideration of all the theory's principal features. Topics include elementary transformations and bilinear and quadratic forms; canonical reduction of equivalent matrices; subgroups of the group of equivalent transformations; and rational and classical canonical forms. The final chapters explore several methods of canonical reduction, including those of unitary and orthogonal transformations. 1952 edition. Index. Appendix. Historical notes. Bibliographies. 275 problems.
Dynamical correlations for circular ensembles of random matrices
International Nuclear Information System (INIS)
Nagao, Taro; Forrester, Peter
2003-01-01
Circular Brownian motion models of random matrices were introduced by Dyson and describe the parametric eigenparameter correlations of unitary random matrices. For symmetric unitary, self-dual quaternion unitary and an analogue of antisymmetric Hermitian matrix initial conditions, Brownian dynamics toward the unitary symmetry is analyzed. The dynamical correlation functions of arbitrary number of Brownian particles at arbitrary number of times are shown to be written in the forms of quaternion determinants, similarly as in the case of Hermitian random matrix models
Complementary Set Matrices Satisfying a Column Correlation Constraint
Wu, Di; Spasojevic, Predrag
2006-01-01
Motivated by the problem of reducing the peak to average power ratio (PAPR) of transmitted signals, we consider a design of complementary set matrices whose column sequences satisfy a correlation constraint. The design algorithm recursively builds a collection of $2^{t+1}$ mutually orthogonal (MO) complementary set matrices starting from a companion pair of sequences. We relate correlation properties of column sequences to that of the companion pair and illustrate how to select an appropriate...
Open vessel microwave digestion of food matrices (T6)
International Nuclear Information System (INIS)
Rhodes, L.; LeBlanc, G.
2002-01-01
Full text: Advancements in the field of open vessel microwave digestion continue to provide solutions for industries requiring acid digestion of large sample sizes. Those interesting in digesting food matrices are particularly interested in working with large amounts of sample and then diluting small final volumes. This paper will show the advantages of instantaneous regent addition and post-digestion evaporation when performing an open vessel digestion and evaporation methods for various food matrices will be presented along with analyte recovery data. (author)
Quantum Algorithms for Weighing Matrices and Quadratic Residues
van Dam, Wim
2000-01-01
In this article we investigate how we can employ the structure of combinatorial objects like Hadamard matrices and weighing matrices to device new quantum algorithms. We show how the properties of a weighing matrix can be used to construct a problem for which the quantum query complexity is ignificantly lower than the classical one. It is pointed out that this scheme captures both Bernstein & Vazirani's inner-product protocol, as well as Grover's search algorithm. In the second part of the ar...
Asymptotic Distribution of Eigenvalues of Weakly Dilute Wishart Matrices
Energy Technology Data Exchange (ETDEWEB)
Khorunzhy, A. [Institute for Low Temperature Physics (Ukraine)], E-mail: khorunjy@ilt.kharkov.ua; Rodgers, G. J. [Brunel University, Uxbridge, Department of Mathematics and Statistics (United Kingdom)], E-mail: g.j.rodgers@brunel.ac.uk
2000-03-15
We study the eigenvalue distribution of large random matrices that are randomly diluted. We consider two random matrix ensembles that in the pure (nondilute) case have a limiting eigenvalue distribution with a singular component at the origin. These include the Wishart random matrix ensemble and Gaussian random matrices with correlated entries. Our results show that the singularity in the eigenvalue distribution is rather unstable under dilution and that even weak dilution destroys it.
International Nuclear Information System (INIS)
Lee, Song Hi
2010-01-01
We presented a molecular dynamics (MD) simulation study of friction behavior between two very massive Brownian particles (BPs) oriented along the z axis with BP centers at -R 12 /2 and R 12 /2 in a Lennard-Jones solvent as a function of the inter-particle separation, R 12 . In order to fix the BPs in space an MD simulation method with the mass of the BP as 10 90 g/mol was employed in which the total momentum of the system was conserved. The cross friction coefficients of x- and y-components are nearly insensitive to R 12 but that of z-component varies with R 12 in good accord with the simple hydrodynamic approximation. On the other hand, the self-friction coefficients are estimated as a very small difference from the single particle friction coefficients, ξ 0 , at all inter-particle separations which agrees with the simple hydrodynamic approximation. Consequently ξ (-) xx is nearly independent of R 12 and equal to its asymptotic value of twice the single particle friction coefficient, and the other relative friction, ξ (-) zz , is in good agreement with the simple hydrodynamic approximation. Molecular theory of Brownian motion of a single heavy particle in a fluid had received a considerable attention in earlier years. After molecular dynamics (MD) simulation technique was utilized, this subject has been widely studied by a variety of MD simulation methods. The common issues here were about the long time behavior of the force and velocity autocorrelation functions, the system size dependent friction coefficient of a massive Brownian particle, and test of the Stokes-Einstein law
P. Smetacek
2012-01-01
Two hundred and forty three species of butterflies recorded from Jones Estate, Uttarakhand between 1951 and 2010 are reported. The ongoing rapid urbanization of Jones Estate micro-watershed will destroy the habitat of 49 species of wildlife protected under Indian law, as well as several species of narrow endemic moths and butterflies. The only known Indian habitat for the butterfly Lister’s Hairstreak Pamela dudgeoni will be destroyed. The effect on the water flow of both the Bhimtal and Sa...
Inference for High-dimensional Differential Correlation Matrices.
Cai, T Tony; Zhang, Anru
2016-01-01
Motivated by differential co-expression analysis in genomics, we consider in this paper estimation and testing of high-dimensional differential correlation matrices. An adaptive thresholding procedure is introduced and theoretical guarantees are given. Minimax rate of convergence is established and the proposed estimator is shown to be adaptively rate-optimal over collections of paired correlation matrices with approximately sparse differences. Simulation results show that the procedure significantly outperforms two other natural methods that are based on separate estimation of the individual correlation matrices. The procedure is also illustrated through an analysis of a breast cancer dataset, which provides evidence at the gene co-expression level that several genes, of which a subset has been previously verified, are associated with the breast cancer. Hypothesis testing on the differential correlation matrices is also considered. A test, which is particularly well suited for testing against sparse alternatives, is introduced. In addition, other related problems, including estimation of a single sparse correlation matrix, estimation of the differential covariance matrices, and estimation of the differential cross-correlation matrices, are also discussed.
On-Chip Neural Data Compression Based On Compressed Sensing With Sparse Sensing Matrices.
Zhao, Wenfeng; Sun, Biao; Wu, Tong; Yang, Zhi
2018-02-01
On-chip neural data compression is an enabling technique for wireless neural interfaces that suffer from insufficient bandwidth and power budgets to transmit the raw data. The data compression algorithm and its implementation should be power and area efficient and functionally reliable over different datasets. Compressed sensing is an emerging technique that has been applied to compress various neurophysiological data. However, the state-of-the-art compressed sensing (CS) encoders leverage random but dense binary measurement matrices, which incur substantial implementation costs on both power and area that could offset the benefits from the reduced wireless data rate. In this paper, we propose two CS encoder designs based on sparse measurement matrices that could lead to efficient hardware implementation. Specifically, two different approaches for the construction of sparse measurement matrices, i.e., the deterministic quasi-cyclic array code (QCAC) matrix and -sparse random binary matrix [-SRBM] are exploited. We demonstrate that the proposed CS encoders lead to comparable recovery performance. And efficient VLSI architecture designs are proposed for QCAC-CS and -SRBM encoders with reduced area and total power consumption.
Estimated correlation matrices and portfolio optimization
Pafka, Szilárd; Kondor, Imre
2004-11-01
Correlations of returns on various assets play a central role in financial theory and also in many practical applications. From a theoretical point of view, the main interest lies in the proper description of the structure and dynamics of correlations, whereas for the practitioner the emphasis is on the ability of the models to provide adequate inputs for the numerous portfolio and risk management procedures used in the financial industry. The theory of portfolios, initiated by Markowitz, has suffered from the “curse of dimensions” from the very outset. Over the past decades a large number of different techniques have been developed to tackle this problem and reduce the effective dimension of large bank portfolios, but the efficiency and reliability of these procedures are extremely hard to assess or compare. In this paper, we propose a model (simulation)-based approach which can be used for the systematical testing of all these dimensional reduction techniques. To illustrate the usefulness of our framework, we develop several toy models that display some of the main characteristic features of empirical correlations and generate artificial time series from them. Then, we regard these time series as empirical data and reconstruct the corresponding correlation matrices which will inevitably contain a certain amount of noise, due to the finiteness of the time series. Next, we apply several correlation matrix estimators and dimension reduction techniques introduced in the literature and/or applied in practice. As in our artificial world the only source of error is the finite length of the time series and, in addition, the “true” model, hence also the “true” correlation matrix, are precisely known, therefore in sharp contrast with empirical studies, we can precisely compare the performance of the various noise reduction techniques. One of our recurrent observations is that the recently introduced filtering technique based on random matrix theory performs
Uranium and thorium phosphate based matrices; syntheses, characterizations and lixiviation
International Nuclear Information System (INIS)
Dacheux, N.
1995-03-01
In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO 2 )(PO 4 ) 2 , U 2 O(PO 4 ) 2 , UC1PO 4 ,H 2 O, and Th 4 (PO 4 ) 4 , U 2 O 3 P 2 O 7 and Th 3 (PO 4 ) 4 . Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO 2 )(PO 4 ) 2 has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new mixed valence uranium phosphate in which U 4+ and UO 2 2+ ions are ordered in pairs along parallel chains according to a new type of arrangement. Reaction mechanism, starting from UC1PO 4 , 4H 2 O and based on redox processes of uranium in solid state was set up. From two main matrices U(UO 2 )(PO 4 ) 2 and Th 4 (PO 4 ) 4 P 2 O 7 , solid solutions were studied. They consist of replacement of U(IV) by Th(IV) and reversely. The leaching tests on pure, loaded and doped matrices were performed in terms of storage time, pH of solutions, and determined by the use of solids labelled with 230 U or by the measurement of uranyl concentration by Laser-Induced Time-Resolved Spectrofluorometry. Average concentration of uranium in the liquid phase is around 10 -4 M to 10 -6 M. Taking into account the very low solubilities of the studied phosphate ceramics, we estimated their chemical performances promising as an answer to the important nuclear waste problem, if we compare them to the glasses used at the present time. (author). 47 figs., 23 tabs., 6 appendixes
Copper ion implantation of polycarbonate matrices: Morphological and structural properties
Energy Technology Data Exchange (ETDEWEB)
Resta, V., E-mail: vincenzo.resta@le.infn.it; Quarta, G.; Maruccio, L.; Calcagnile, L.
2014-07-15
The implantation of 1 MeV {sup 63}Cu{sup +} ions in polycarbonate (PC) matrices has been carried out in order to evaluate the morphological and structural modifications induced in the polymer as a function of the ion fluence in the range 5 × 10{sup 13} ions cm{sup −2} to 1 × 10{sup 17} ions cm{sup −2}. Atomic Force Microscopy analysis reveals a significant roughness increase of the polymer surface only for fluences higher than 5 × 10{sup 16} ions cm{sup −2} with the presence of hillock structures which surface density increases with increasing the ion fluence. X-ray Diffraction measurements of PC implanted with fluences in the range between 5 × 10{sup 15} at cm{sup −2} and 5 × 10{sup 16} at cm{sup −2} reveal an increase of the disorder inside the PC matrix, as a consequence of the damaging process induced by the ion irradiation. Evidences about the presence of exotic phase structures ascribed to both cubic Cu{sub 2}O and cubic Cu have been found.
Stress evolution of Ge nanocrystals in dielectric matrices
Bahariqushchi, Rahim; Raciti, Rosario; Emre Kasapoğlu, Ahmet; Gür, Emre; Sezen, Meltem; Kalay, Eren; Mirabella, Salvatore; Aydinli, A.
2018-05-01
Germanium nanocrystals (Ge NCs) embedded in single and multilayer silicon oxide and silicon nitride matrices have been synthesized using plasma enhanced chemical vapor deposition followed by conventional furnace annealing or rapid thermal processing in N2 ambient. Compositions of the films were determined by Rutherford backscattering spectrometry and x-ray photoelectron spectroscopy. The formation of NCs under suitable process conditions was observed with high resolution transmission electron microscope micrographs and Raman spectroscopy. Stress measurements were done using Raman shifts of the Ge optical phonon line at 300.7 cm-1. The effect of the embedding matrix and annealing methods on Ge NC formation were investigated. In addition to Ge NCs in single layer samples, the stress on Ge NCs in multilayer samples was also analyzed. Multilayers of Ge NCs in a silicon nitride matrix separated by dielectric buffer layers to control the size and density of NCs were fabricated. Multilayers consisted of SiN y :Ge ultrathin films sandwiched between either SiO2 or Si3N4 by the proper choice of buffer material. We demonstrated that it is possible to tune the stress state of Ge NCs from compressive to tensile, a desirable property for optoelectronic applications. We also observed that there is a correlation between the stress and the crystallization threshold in which the compressive stress enhances the crystallization, while the tensile stress suppresses the process.
Melting Behavior of Organic Nanocrystals Grown in Sol-gel Matrices
International Nuclear Information System (INIS)
Sanz, N.; Boudet, A.; Ibanez, A.
2002-01-01
We have characterized the thermal stability of organic nanocrystals grown in the pores of sol-gel matrices. The structure has been measured with transmission electron microscopy (TEM) analysis. Depending on the nature of organic molecules and sol-gel matrices, we have modified the dye-matrix interactions and the interfacial structure between nanocrystals and gel-glasses. When the dye-matrix interactions are weak (Van der Waals' bonds), the corresponding interfacial structure observed by TEM is sharp and the nanocrystals melt below the bulk melting point. On the other hand, when the dye-matrix interactions are strong (hydrogen bonds), the interfacial structure is fuzzy and a great superheating of organic nanocrystals is observed in comparison to the bulk melting point of the dye
International Nuclear Information System (INIS)
Bartosova, A.; Rajec, P.; Reich, M.
2003-01-01
A sorbent based on Aliquat 336 anchored on hydrophobised silica gel support as an ion exchanger was prepared. Prepared sorbent was suitable for separation of technetium-99 from environmental matrices. The sorbent properties, sorption characteristic and distribution coefficient of 99 mTcO 4 - in various medium was studied. The chemical yield of Tc during separation process was determined using 99m Tc tracer and gamma measurement. Typical sorption recoveries of Tc for this sorbent from 0.1 M HNO 3 were more than 98 %. Typical desorption recoveries using 8 M HNO 3 were in the range 92 - 96 %. The commercial TEVA Spec resin from Eichrom Industries for comparison purpose was used as well. It was found that the prepared sorbent is suitable for separation of technetium from environmental matrices. (authors)
On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices
Pestana, Jennifer
2014-01-01
Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.
International Nuclear Information System (INIS)
Chudnovsky, D.V.; Chudnovsky, G.V.
1980-01-01
We consider semi-classical approximation to factorized S-matrices. We show that this new class of matrices, called s-matrices, defines Hamiltonian structures for isospectral deformation equations. Concrete examples of factorized s-matrices are constructed and they are used to define Hamiltonian structure for general two-dimensional isospectral deformation systems. (orig.)
International Nuclear Information System (INIS)
Ates, Zeliha; Gueven, Olgun
2010-01-01
Radiation-induced molecular imprinting of D-glucose onto poly(2-hydroxyethyl methacrylate) matrix was achieved to create three-dimensional cavities to recognize and bind D-glucose. The optimization of imprinting capability of matrices was achieved by investigating the effects of various parameters such as the type and amount of crosslinking agent, type of solvent, template to monomer ratio and total absorbed dose. Crosslinking agents with increasing chain lengths and different flexibilities were used in an attempt to elucidate the impact of relevant imprint parameters on the effectiveness of imprinting technique. The absorbed dose varied from 1 to 15 kGy. Cavity sizes of MIPs were measured by positron annihilation lifetime (PAL) experiments. Control matrices were synthesized with exactly the same composition in the absence of D-glucose. Separation of D-glucose has been shown to be successfully achieved in HPLC columns filled with MIPs whereas no separation was observed for non-imprint matrices.
Properties of Organic Liquids when Simulated with Long-Range Lennard-Jones Interactions.
Fischer, Nina M; van Maaren, Paul J; Ditz, Jonas C; Yildirim, Ahmet; van der Spoel, David
2015-07-14
In order to increase the accuracy of classical computer simulations, existing methodologies may need to be adapted. Hitherto, most force fields employ a truncated potential function to model van der Waals interactions, sometimes augmented with an analytical correction. Although such corrections are accurate for homogeneous systems with a long cutoff, they should not be used in inherently inhomogeneous systems such as biomolecular and interface systems. For such cases, a variant of the particle mesh Ewald algorithm (Lennard-Jones PME) was already proposed 20 years ago (Essmann et al. J. Chem. Phys. 1995, 103, 8577-8593), but it was implemented only recently (Wennberg et al. J. Chem. Theory Comput. 2013, 9, 3527-3537) in a major simulation code (GROMACS). The availability of this method allows surface tensions of liquids as well as bulk properties to be established, such as density and enthalpy of vaporization, without approximations due to truncation. Here, we report on simulations of ≈150 liquids (taken from a force field benchmark: Caleman et al. J. Chem. Theory Comput. 2012, 8, 61-74) using three different force fields and compare simulations with and without explicit long-range van der Waals interactions. We find that the density and enthalpy of vaporization increase for most liquids using the generalized Amber force field (GAFF, Wang et al. J. Comput. Chem. 2004, 25, 1157-1174) and the Charmm generalized force field (CGenFF, Vanommeslaeghe et al. J. Comput. Chem. 2010, 31, 671-690) but less so for OPLS/AA (Jorgensen and Tirado-Rives, Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 6665-6670), which was parametrized with an analytical correction to the van der Waals potential. The surface tension increases by ≈10(-2) N/m for all force fields. These results suggest that van der Waals attractions in force fields are too strong, in particular for the GAFF and CGenFF. In addition to the simulation results, we introduce a new version of a web server, http
Liquid-liquid interfacial properties of a symmetrical Lennard-Jones binary mixture
Energy Technology Data Exchange (ETDEWEB)
Martínez-Ruiz, F. J.; Blas, F. J., E-mail: felipe@uhu.es [Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Física Aplicada, Universidad de Huelva, 21007 Huelva (Spain); Moreno-Ventas Bravo, A. I. [Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Geología, Universidad de Huelva, 21007 Huelva (Spain)
2015-09-14
We determine the interfacial properties of a symmetrical binary mixture of equal-sized spherical Lennard-Jones molecules, σ{sub 11} = σ{sub 22}, with the same dispersive energy between like species, ϵ{sub 11} = ϵ{sub 22}, but different dispersive energies between unlike species low enough to induce phase separation. We use the extensions of the improved version of the inhomogeneous long-range corrections of Janecek [J. Phys. Chem. B 110, 6264 (2006)], presented recently by MacDowell and Blas [J. Chem. Phys. 131, 074705 (2009)] and Martínez-Ruiz et al. [J. Chem. Phys. 141, 184701 (2014)], to deal with the interaction energy and microscopic components of the pressure tensor. We perform Monte Carlo simulations in the canonical ensemble to obtain the interfacial properties of the symmetrical mixture with different cut-off distances r{sub c} and in combination with the inhomogeneous long-range corrections. The pressure tensor is obtained using the mechanical (virial) and thermodynamic route. The liquid-liquid interfacial tension is also evaluated using three different procedures, the Irving-Kirkwood method, the difference between the macroscopic components of the pressure tensor, and the test-area methodology. This allows to check the validity of the recent extensions presented to deal with the contributions due to long-range corrections for intermolecular energy and pressure tensor in the case of binary mixtures that exhibit liquid-liquid immiscibility. In addition to the pressure tensor and the surface tension, we also obtain density profiles and coexistence densities and compositions as functions of pressure, at a given temperature. According to our results, the main effect of increasing the cut-off distance r{sub c} is to sharpen the liquid-liquid interface and to increase the width of the biphasic coexistence region. Particularly interesting is the presence of a relative minimum in the total density profiles of the symmetrical mixture. This minimum is related
Liquid-liquid interfacial properties of a symmetrical Lennard-Jones binary mixture
International Nuclear Information System (INIS)
Martínez-Ruiz, F. J.; Blas, F. J.; Moreno-Ventas Bravo, A. I.
2015-01-01
We determine the interfacial properties of a symmetrical binary mixture of equal-sized spherical Lennard-Jones molecules, σ 11 = σ 22 , with the same dispersive energy between like species, ϵ 11 = ϵ 22 , but different dispersive energies between unlike species low enough to induce phase separation. We use the extensions of the improved version of the inhomogeneous long-range corrections of Janecek [J. Phys. Chem. B 110, 6264 (2006)], presented recently by MacDowell and Blas [J. Chem. Phys. 131, 074705 (2009)] and Martínez-Ruiz et al. [J. Chem. Phys. 141, 184701 (2014)], to deal with the interaction energy and microscopic components of the pressure tensor. We perform Monte Carlo simulations in the canonical ensemble to obtain the interfacial properties of the symmetrical mixture with different cut-off distances r c and in combination with the inhomogeneous long-range corrections. The pressure tensor is obtained using the mechanical (virial) and thermodynamic route. The liquid-liquid interfacial tension is also evaluated using three different procedures, the Irving-Kirkwood method, the difference between the macroscopic components of the pressure tensor, and the test-area methodology. This allows to check the validity of the recent extensions presented to deal with the contributions due to long-range corrections for intermolecular energy and pressure tensor in the case of binary mixtures that exhibit liquid-liquid immiscibility. In addition to the pressure tensor and the surface tension, we also obtain density profiles and coexistence densities and compositions as functions of pressure, at a given temperature. According to our results, the main effect of increasing the cut-off distance r c is to sharpen the liquid-liquid interface and to increase the width of the biphasic coexistence region. Particularly interesting is the presence of a relative minimum in the total density profiles of the symmetrical mixture. This minimum is related with a desorption of the
Porta, Tiffany; Grivet, Chantal; Knochenmuss, Richard; Varesio, Emmanuel; Hopfgartner, Gérard
2011-02-01
Analysis of low molecular weight compounds (LMWC) in complex matrices by vacuum matrix-assisted laser desorption/ionization (MALDI) often suffers from matrix interferences, which can severely degrade limits of quantitation. It is, therefore, useful to have available a range of suitable matrices, which exhibit complementary regions of interference. Two newly synthesized α-cyanocinnamic acid derivatives are reported here; (E)-2-cyano-3-(naphthalen-2-yl)acrylic acid (NpCCA) and (2E)-3-(anthracen-9-yl)-2-cyanoprop-2enoic acid (AnCCA). Along with the commonly used α-cyano-4-hydroxycinnamic acid (CHCA), and the recently developed 4-chloro-α-cyanocinnamic acid (Cl-CCA) matrices, these constitute a chemically similar series of matrices covering a range of molecular weights, and with correspondingly differing ranges of spectral interference. Their performance was compared by measuring the signal-to-noise ratios (S/N) of 47 analytes, mostly pharmaceuticals, with the different matrices using the selected reaction monitoring (SRM) mode on a triple quadrupole instrument equipped with a vacuum MALDI source. AnCCA, NpCCA and Cl-CCA were found to offer better signal-to-noise ratios in SRM mode than CHCA, but Cl-CCA yielded the best results for 60% of the compounds tested. To better understand the relative performance of this matrix series, the proton affinities (PAs) were measured using the kinetic method. Their relative values were: AnCCA > CHCA > NpCCA > Cl-CCA. This ordering is consistent with the performance data. The synthesis of the new matrices is straightforward and they provide (1) tunability of matrix background interfering ions and (2) enhanced analyte response for certain classes of compounds. Copyright © 2011 John Wiley & Sons, Ltd.
Theoretical Properties for Neural Networks with Weight Matrices of Low Displacement Rank
Zhao, Liang; Liao, Siyu; Wang, Yanzhi; Li, Zhe; Tang, Jian; Pan, Victor; Yuan, Bo
2017-01-01
Recently low displacement rank (LDR) matrices, or so-called structured matrices, have been proposed to compress large-scale neural networks. Empirical results have shown that neural networks with weight matrices of LDR matrices, referred as LDR neural networks, can achieve significant reduction in space and computational complexity while retaining high accuracy. We formally study LDR matrices in deep learning. First, we prove the universal approximation property of LDR neural networks with a ...
Hierarchical Matrices Method and Its Application in Electromagnetic Integral Equations
Directory of Open Access Journals (Sweden)
Han Guo
2012-01-01
Full Text Available Hierarchical (H- matrices method is a general mathematical framework providing a highly compact representation and efficient numerical arithmetic. When applied in integral-equation- (IE- based computational electromagnetics, H-matrices can be regarded as a fast algorithm; therefore, both the CPU time and memory requirement are reduced significantly. Its kernel independent feature also makes it suitable for any kind of integral equation. To solve H-matrices system, Krylov iteration methods can be employed with appropriate preconditioners, and direct solvers based on the hierarchical structure of H-matrices are also available along with high efficiency and accuracy, which is a unique advantage compared to other fast algorithms. In this paper, a novel sparse approximate inverse (SAI preconditioner in multilevel fashion is proposed to accelerate the convergence rate of Krylov iterations for solving H-matrices system in electromagnetic applications, and a group of parallel fast direct solvers are developed for dealing with multiple right-hand-side cases. Finally, numerical experiments are given to demonstrate the advantages of the proposed multilevel preconditioner compared to conventional “single level” preconditioners and the practicability of the fast direct solvers for arbitrary complex structures.
MALDI matrices for low molecular weight compounds: an endless story?
Calvano, Cosima Damiana; Monopoli, Antonio; Cataldi, Tommaso R I; Palmisano, Francesco
2018-04-23
Since its introduction in the 1980s, matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has gained a prominent role in the analysis of high molecular weight biomolecules such as proteins, peptides, oligonucleotides, and polysaccharides. Its application to low molecular weight compounds has remained for long time challenging due to the spectral interferences produced by conventional organic matrices in the low m/z window. To overcome this problem, specific sample preparation such as analyte/matrix derivatization, addition of dopants, or sophisticated deposition technique especially useful for imaging experiments, have been proposed. Alternative approaches based on second generation (rationally designed) organic matrices, ionic liquids, and inorganic matrices, including metallic nanoparticles, have been the object of intense and continuous research efforts. Definite evidences are now provided that MALDI MS represents a powerful and invaluable analytical tool also for small molecules, including their quantification, thus opening new, exciting applications in metabolomics and imaging mass spectrometry. This review is intended to offer a concise critical overview of the most recent achievements about MALDI matrices capable of specifically address the challenging issue of small molecules analysis. Graphical abstract An ideal Book of matrices for MALDI MS of small molecules.
Hypersymmetric functions and Pochhammers of 2×2 nonautonomous matrices
Directory of Open Access Journals (Sweden)
A. F. Antippa
2004-01-01
Full Text Available We introduce the hypersymmetric functions of 2×2 nonautonomous matrices and show that they are related, by simple expressions, to the Pochhammers (factorial polynomials of these matrices. The hypersymmetric functions are generalizations of the associated elementary symmetric functions, and for a specific class of 2×2 matrices, having a high degree of symmetry, they reduce to these latter functions. This class of matrices includes rotations, Lorentz boosts, and discrete time generators for the harmonic oscillators. The hypersymmetric functions are defined over four sets of independent indeterminates using a triplet of interrelated binary partitions. We work out the algebra of this triplet of partitions and then make use of the results in order to simplify the expressions for the hypersymmetric functions for a special class of matrices. In addition to their obvious applications in matrix theory, in coupled difference equations, and in the theory of symmetric functions, the results obtained here also have useful applications in problems involving successive rotations, successive Lorentz transformations, discrete harmonic oscillators, and linear two-state systems.
Construction and Validation of a Scale to Measure Maslow's Concept of Self-Actualization
Jones, Kenneth Melvin; Randolph, Daniel Lee
1978-01-01
Designed to measure self-actualization as defined by Abraham Maslow, the Jones Self Actualizing Scale, as assessed in this study, possesses content validity, reliability, and a number of other positive characteristics. (JC)
Neutrino mass priors for cosmology from random matrices
Long, Andrew J.; Raveri, Marco; Hu, Wayne; Dodelson, Scott
2018-02-01
Cosmological measurements of structure are placing increasingly strong constraints on the sum of the neutrino masses, Σ mν, through Bayesian inference. Because these constraints depend on the choice for the prior probability π (Σ mν), we argue that this prior should be motivated by fundamental physical principles rather than the ad hoc choices that are common in the literature. The first step in this direction is to specify the prior directly at the level of the neutrino mass matrix Mν, since this is the parameter appearing in the Lagrangian of the particle physics theory. Thus by specifying a probability distribution over Mν, and by including the known squared mass splittings, we predict a theoretical probability distribution over Σ mν that we interpret as a Bayesian prior probability π (Σ mν). Assuming a basis-invariant probability distribution on Mν, also known as the anarchy hypothesis, we find that π (Σ mν) peaks close to the smallest Σ mν allowed by the measured mass splittings, roughly 0.06 eV (0.1 eV) for normal (inverted) ordering, due to the phenomenon of eigenvalue repulsion in random matrices. We consider three models for neutrino mass generation: Dirac, Majorana, and Majorana via the seesaw mechanism; differences in the predicted priors π (Σ mν) allow for the possibility of having indications about the physical origin of neutrino masses once sufficient experimental sensitivity is achieved. We present fitting functions for π (Σ mν), which provide a simple means for applying these priors to cosmological constraints on the neutrino masses or marginalizing over their impact on other cosmological parameters.
Lichstein, Paul M; Kleimeyer, John P; Githens, Michael; Vorhies, John S; Gardner, Michael J; Bellino, Michael; Bishop, Julius
2018-04-24
A well-reduced femoral neck fracture is more likely to heal than a poorly reduced one, and increasing the quality of the surgical exposure makes it easier to achieve anatomic fracture reduction. Two open approaches are in common use for femoral neck fractures, the modified Smith-Petersen and Watson-Jones; however, to our knowledge, the quality of exposure of the femoral neck exposure provided by each approach has not been investigated. (1) What is the respective area of exposed femoral neck afforded by the Watson-Jones and modified Smith-Petersen approaches? (2) Is there a difference in the ability to visualize and/or palpate important anatomic landmarks provided by the Watson-Jones and modified Smith-Petersen approaches? Ten fresh-frozen human pelvi underwent both modified Smith-Petersen (utilizing the caudal extent of the standard Smith-Petersen interval distal to the anterosuperior iliac spine and parallel to the palpable interval between the tensor fascia lata and the sartorius) and Watson-Jones approaches. Dissections were performed by three fellowship-trained orthopaedic traumatologists with extensive experience in both approaches. Exposure (in cm) was quantified with calibrated digital photographs and specialized software. Modified Smith-Petersen approaches were analyzed before and after rectus femoris tenotomy. The ability to visualize and palpate seven clinically relevant anatomic structures (the labrum, femoral head, subcapital femoral neck, basicervical femoral neck, greater trochanter, lesser trochanter, and medial femoral neck) was also recorded. The quantified area of the exposed proximal femur was utilized to compare which approach afforded the largest field of view of the femoral neck and articular surface for assessment of femoral neck fracture and associated femoral head injury. The ability to visualize and palpate surrounding structures was assessed so that we could better understand which approach afforded the ability to assess structures that
Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Li, En; Miura, Masahiro; Yasuno, Yoshiaki
2016-03-01
A new optical coherence angiography (OCA) method, called correlation mapping OCA (cmOCA), is presented by using the SNR-corrected complex correlation. An SNR-correction theory for the complex correlation calculation is presented. The method also integrates a motion-artifact-removal method for the sample motion induced decorrelation artifact. The theory is further extended to compute more reliable correlation by using multi- channel OCT systems, such as Jones-matrix OCT. The high contrast vasculature imaging of in vivo human posterior eye has been obtained. Composite imaging of cmOCA and degree of polarization uniformity indicates abnormalities of vasculature and pigmented tissues simultaneously.
Fully constrained Majorana neutrino mass matrices using Σ(72 x 3)
Energy Technology Data Exchange (ETDEWEB)
Krishnan, R.; Harrison, P.F. [Warwick Univ., Coventry (United Kingdom); Scott, W.G. [Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom)
2018-01-15
In 2002, two neutrino mixing ansatze having trimaximally mixed middle (ν{sub 2}) columns, namely tri-chi-maximal mixing (TχM) and tri-phi-maximal mixing (TφM), were proposed. In 2012, it was shown that TχM with χ = ± (π)/(16) as well as TφM with φ = ± (π)/(16) leads to the solution, sin{sup 2} θ{sub 13} = (2)/(3) sin{sup 2} (π)/(16), consistent with the latest measurements of the reactor mixing angle, θ{sub 13}. To obtain TχM{sub (χ=±(π)/(16))} and TφM{sub (φ=±(π)/(16))}, the type I see-saw framework with fully constrained Majorana neutrino mass matrices was utilised. These mass matrices also resulted in the neutrino mass ratios, m{sub 1}: m{sub 2}: m{sub 3} = ((2+√2))/(1+√(2(2+√2))): 1: ((2+√2))/(-1+√(2(2+√2))). In this paper we construct a flavour model based on the discrete group Σ(72 x 3) and obtain the aforementioned results. A Majorana neutrino mass matrix (a symmetric 3 x 3 matrix with six complex degrees of freedom) is conveniently mapped into a flavon field transforming as the complex six-dimensional representation of Σ(72 x 3). Specific vacuum alignments of the flavons are used to arrive at the desired mass matrices. (orig.)
Radiation-induced transformations of isolated organic molecules in solid rare gas matrices
International Nuclear Information System (INIS)
Feldman, V.I.
1998-01-01
Complete text of publication follows. The studies of radiation-chemical behaviour of isolated organic molecules in rigid inert media are of considerable interest for radiation chemistry and general structural chemistry. Previous efforts were limited to the ESR studies of radicals resulting from some small hydrocarbon molecules in frozen rare gas solutions. Recently, we developed an approach to the radiation chemistry of isolated organic molecules using classic matrix isolation procedure for sample preparation and a combination of ESR and IR spectroscopy for characterization of paramagnetic and diamagnetic species resulting form electron irradiation or organic molecules in solid rare gas matrices at 10-15 K. The results obtained reveal high efficiency of energy transfer from rare gas matrix to organic molecules. The total radiation-chemical yields of degradation of organic molecules in argon and xenon matrices were measured directly by IR spectroscopy. The studies of the effect of electron scavengers on the radiolysis of organic molecules in solid rare gases show that the main primary process is positive hole transfer from matrix to additive molecule. ESR spectra of a number of radical cations (alkanes, ethers, arenes) were first characterized in a low-disturbing environment. It was found that the electronic characteristics (IP, polarizability) of the matrix used had crucial effect on trapping and degradation of primary organic radical cations. Using matrices with various IP provides an unique possibility to examine the chemical meaning of excess energy resulting from exothermic positive hole transfer, that is, to follow the fate of excited cations in condensed phase
Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices
Chamis, Christos C.
2009-01-01
Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.
Square matrices of order 2 theory, applications, and problems
Pop, Vasile
2017-01-01
This unique and innovative book presents an exciting and complete detail of all the important topics related to the theory of square matrices of order 2. The readers exploring every detailed aspect of matrix theory are gently led toward understanding advanced topics. They will follow every notion of matrix theory with ease, accumulating a thorough understanding of algebraic and geometric aspects of matrices of order 2. The prime jewel of this book is its offering of an unusual collection of problems, theoretically motivated, most of which are new, original, and seeing the light of publication for the first time in the literature. Nearly all of the exercises are presented with detailed solutions and vary in difficulty from easy to more advanced. Many problems are particularly challenging. These, and not only these, invite the reader to unleash their creativity and research capabilities and to discover their own methods of attacking a problem. Matrices have a vast practical importance to mathematics, science, a...
Two-mode Gaussian density matrices and squeezing of photons
International Nuclear Information System (INIS)
Tucci, R.R.
1992-01-01
In this paper, the authors generalize to 2-mode states the 1-mode state results obtained in a previous paper. The authors study 2-mode Gaussian density matrices. The authors find a linear transformation which maps the two annihilation operators, one for each mode, into two new annihilation operators that are uncorrelated and unsqueezed. This allows the authors to express the density matrix as a product of two 1-mode density matrices. The authors find general conditions under which 2-mode Gaussian density matrices become pure states. Possible pure states include the 2-mode squeezed pure states commonly mentioned in the literature, plus other pure states never mentioned before. The authors discuss the entropy and thermodynamic laws (Second Law, Fundamental Equation, and Gibbs-Duhem Equation) for the 2-mode states being considered
A Workshop on Algebraic Design Theory and Hadamard Matrices
2015-01-01
This volume develops the depth and breadth of the mathematics underlying the construction and analysis of Hadamard matrices and their use in the construction of combinatorial designs. At the same time, it pursues current research in their numerous applications in security and cryptography, quantum information, and communications. Bridges among diverse mathematical threads and extensive applications make this an invaluable source for understanding both the current state of the art and future directions. The existence of Hadamard matrices remains one of the most challenging open questions in combinatorics. Substantial progress on their existence has resulted from advances in algebraic design theory using deep connections with linear algebra, abstract algebra, finite geometry, number theory, and combinatorics. Hadamard matrices arise in a very diverse set of applications. Starting with applications in experimental design theory and the theory of error-correcting codes, they have found unexpected and important ap...