International Nuclear Information System (INIS)
Radu, F.; Ignatovich, V.K.
1999-01-01
A generalized matrix method (GMM) for reflection and transmission of polarized and nonpolarized neutrons for multilayer systems with non-colinear magnetization of neighboring layers is developed. Several methods exist for calculation of the reflection and transmission coefficients of the multilayer systems (MS). We consider here only two of them. One is the recurrence method (RM), and another one is the matrix method. Previously these methods were used for scalar particles and for spinor particles. In the last case a limitation was imposed on the directions of the magnetization of different layers: they were required to lie in the plane parallel to the layers. In 1995 Fermon has described a different approach of the neutrons in MS. Here, the behaviour of the wave inside the layers depends on the position within the plane. The RM, as shown by us earlier, permits to treat multilayer systems with arbitrary directions of the magnetization. We show how to treat these systems with the updated matrix method, which we call the generalized matrix method. In the GMM method the transmission and reflection of a layered system are obtained by finding a 4 x 4 matrix, which is a product of elementary 4 x 4 matrices related to the different layers, and in the RM the solution is found by recurrent application of the same procedure of finding the reflection and transmission matrices for a continuously increasing number of layers. The RM method permits to use a simple algorithm to write analytical formulas for the reflection and transmission. However, for more or less complicated systems these formulas become useless and one needs to do numerical calculations. The GMM does not give a simple analytical algorithm, but it gives a very simple numerical algorithm. We have developed two computer codes for computing the coefficients of reflection and transmission of a layered system using the GMM and RM methods. The calculated reflectivities R ++ and R +- for a polarized beam which fall on
Thompson, James H.; Apel, Thomas R.
1990-07-01
A technique for modeling microstrip discontinuities is presented which is derived from the transmission line matrix method of solving three-dimensional electromagnetic problems. In this technique the microstrip patch under investigation is divided into an integer number of square and half-square (triangle) subsections. An equivalent lumped-element model is calculated for each subsection. These individual models are then interconnected as dictated by the geometry of the patch. The matrix of lumped elements is then solved using either of two microwave CAD software interfaces with each port properly defined. Closed-form expressions for the lumped-element representation of the individual subsections is presented and experimentally verified through the X-band frequency range. A model demonstrating the use of symmetry and block construction of a circuit element is discussed, along with computer program development and CAD software interface.
Pollutant Dispersion Modeling in Natural Streams Using the Transmission Line Matrix Method
Directory of Open Access Journals (Sweden)
Safia Meddah
2015-09-01
Full Text Available Numerical modeling has become an indispensable tool for solving various physical problems. In this context, we present a model of pollutant dispersion in natural streams for the far field case where dispersion is considered longitudinal and one-dimensional in the flow direction. The Transmission Line Matrix (TLM, which has earned a reputation as powerful and efficient numerical method, is used. The presented one-dimensional TLM model requires a minimum input data and provides a significant gain in computing time. To validate our model, the results are compared with observations and experimental data from the river Severn (UK. The results show a good agreement with experimental data. The model can be used to predict the spatiotemporal evolution of a pollutant in natural streams for effective and rapid decision-making in a case of emergency, such as accidental discharges in a stream with a dynamic similar to that of the river Severn (UK.
Field analysis of TE and TM modes in photonic crystal Bragg fibers by transmission matrix method
Directory of Open Access Journals (Sweden)
M Hosseini Farzad
2010-03-01
Full Text Available In this article, we considered the field analysis in photonic crystal Bragg fibers. We apply the method of transmission matrix to calculater the dispersion curves, the longitudinal wave number over wave number versus incident wavelength, and the field distributions of TE and TM modes in the Bragg fiber. Our analysis shows that the field of guided modes is confined in the core and can exist only in particular wavelength bands corresponding to the band-gap of the periodic structure of the clad. From another point of view, light confinement is due to Bragg reflection from high-and low-refractive index layers of the clad. Also, the diagram of average angular frequency with respect to average longitudinal wave number is plotted so that the band gap regions of the clad are clearly observed.
Analysis method of beam pointing stability based on optical transmission matrix
Wang, Chuanchuan; Huang, PingXian; Li, Xiaotong; Cen, Zhaofen
2016-10-01
Quite a lot of factors will make effects on beam pointing stability of an optical system, Among them, the element tolerance is one of the most important and common factors. In some large laser systems, it will make final micro beams spot on the image plane deviate obviously. So it is essential for us to achieve effective and accurate analysis theoretically on element tolerance. In order to make the analysis of beam pointing stability convenient and theoretical, we consider transmission of a single chief ray rather than beams approximately to stand for the whole spot deviation. According to optical matrix, we also simplify this complex process of light transmission to multiplication of many matrices. So that we can set up element tolerance model, namely having mathematical expression to illustrate spot deviation in an optical system with element tolerance. In this way, we can realize quantitative analysis of beam pointing stability theoretically. In second half of the paper, we design an experiment to get the spot deviation in a multipass optical system caused by element tolerance, then we adjust the tolerance step by step and compare the results with the datum got from tolerance model, finally prove the correction of tolerance model successfully.
Matrix of transmission in structural dynamics
International Nuclear Information System (INIS)
Mukherjee, S.
1975-01-01
The problem of close-coupled systems and cantilever type buildings can be treated efficiently by means of the very general and versatile method of transmission matrix. The expression 'matrix of transmission' is used to point out the fact that the method to be described differs fundamentally from another method related to matrix calculus, and also successfully used in vibration problem. In this method, forces and displacements are introduced as the 'unknowns' of the problem. The 'matrix of transmission' relates these quantities at one point of the structure to those at the neighbouring point. The natural frequencies of a freely vibrating elastic system can be found by applying proper end conditions. The end conditions will yield the frequency determinate to zero. By using suitable numerical method, the natural frequencies and mode shapes are determined, by making a frequency sweep within the range of interest. Results of analysis of a typical nuclear building by this method show very close agreement with the results obtained by using ASKA and SAP IV Program
Matrix of transmission in structural dynamics
International Nuclear Information System (INIS)
Mukherjee, S.
1975-01-01
Within the last few years numerous papers have been published on the subject of matrix method in elasto-mechanics. 'Matrix of Transmission' is one of the methods in this field which has gained considerable attention in recent years. The basic philosophy adopted in this method is based on the idea of breaking up a complicated system into component parts with simple elastic and dynamic properties which can be readily expressed in matrix form. These component matrices are considered as building blocks, which are fitted together according to a set of predetermined rules which then provide the static and dynamic properties of the entire system. A common type of system occuring in engineering practice consists of a number of elements linked together end to end in the form of a chain. The 'Transfer Matrix' is ideally suited for such a system, because only successive multiplication is necessary to connect these elements together. The number of degrees of freedom and intermediate conditions present no difficulty. Although the 'Transfer Matrix' method is suitable for the treatment of branched and coupled systems its application to systems which do not have predominant chain topology is not effective. Apart from the requirement that the system be linearely elastic, no other restrictions are made. In this paper, it is intended to give a general outline and theoretical formulation of 'Transfer Matrix' and then its application to actual problems in structural dynamics related to seismic analysis. The natural frequencies of a freely vibrating elastic system can be found by applying proper end conditions. The end conditions will yield the frequency determinate to zero. By using a suitable numerical method, the natural frequencies and mode shapes are determined by making a frequency sweep within the range of interest. Results of an analysis of a typical nuclear building by this method show very close agreement with the results obtained by using ASKA and SAP IV program. Therefore
Seti, Julia; Tkach, Mykola; Voitsekhivska, Oxana
2018-03-01
The exact solutions of the Schrödinger equation for a double-barrier open semiconductor plane nanostructure are obtained by using two different approaches, within the model of the rectangular potential profile and the continuous position-dependent effective mass of the electron. The transmission coefficient and scattering matrix are calculated for the double-barrier nanostructure. The resonance energies and resonance widths of the electron quasi-stationary states are analyzed as a function of the size of the near-interface region between wells and barriers, where the effective mass linearly depends on the coordinate. It is established that, in both methods, the increasing size affects in a qualitatively similar way the spectral characteristics of the states, shifting the resonance energies into the low- or high-energy region and increasing the resonance widths. It is shown that the relative difference of resonance energies and widths of a certain state, obtained in the model of position-dependent effective mass and in the widespread abrupt model in physically correct range of near-interface sizes, does not exceed 0.5% and 5%, respectively, independently of the other geometrical characteristics of the structure.
Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging.
Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui
2018-01-01
We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).
A unified transmission loss allocation method
International Nuclear Information System (INIS)
Ding, Qifeng; Abur, Ali
2007-01-01
A new unified method which allocates transmission losses either to buses in a pool market or to individual transactions in a bilateral contract market is presented in this paper. A detailed derivation of the method is given. A bus-loss matrix and a transaction-loss matrix are developed to show the interactions between bus injections and transactions. It is further demonstrated that the ''Physical-power-flow-based'' method can be obtained as an approximation of this unified approach under certain simplifying assumptions. Test systems are used to illustrate how the proposed method behaves under different possible scenarios. (author)
Numerical methods in matrix computations
Björck, Åke
2015-01-01
Matrix algorithms are at the core of scientific computing and are indispensable tools in most applications in engineering. This book offers a comprehensive and up-to-date treatment of modern methods in matrix computation. It uses a unified approach to direct and iterative methods for linear systems, least squares and eigenvalue problems. A thorough analysis of the stability, accuracy, and complexity of the treated methods is given. Numerical Methods in Matrix Computations is suitable for use in courses on scientific computing and applied technical areas at advanced undergraduate and graduate level. A large bibliography is provided, which includes both historical and review papers as well as recent research papers. This makes the book useful also as a reference and guide to further study and research work. Åke Björck is a professor emeritus at the Department of Mathematics, Linköping University. He is a Fellow of the Society of Industrial and Applied Mathematics.
METHODS OF POLYMODAL INFORMATION TRANSMISSION
Directory of Open Access Journals (Sweden)
O. O. Basov
2015-03-01
Full Text Available The research results upon the application of the existing information transmission methods in polymodal info communication systems are presented herein. The analysis of the existing commutation ways and multiplexing schemes has revealed that modern means of telecommunication are capable of providing polymodal information delivery with the required quality to the customer correspondent terminal. Under these conditions substantial capacity resource consumption in the data transmission networks with a simultaneous static time multiplexing is required, however, it is easier to achieve the modality synchronization within that kind of an infrastructure. The data networks with a static time multiplexing demand employing more sophisticated supporting algorithms of the guaranteed data blocks delivery quality. However, due to the stochastic data blocks delays modality synchronizing during the off-line processing is more difficult to provide. Nowadays there are objective preconditions for a data networking realization which is invariable to the applied transmission technology. This capability is defined by a wide (person-to-person application of the optical technologies in the transport infrastructure of the polymodal info communication systems. In case of the availability of the customer terminal and networking functioning matching mode it becomes possible to organize channels in the latter which can adaptively select the most effective networking technology according to the current volume allocation and modality types in the messages.
Measuring methods of matrix diffusion
International Nuclear Information System (INIS)
Muurinen, A.; Valkiainen, M.
1988-03-01
In Finland the spent nuclear fuel is planned to be disposed of at large depths in crystalline bedrock. The radionuclides which are dissolved in the groundwater may be able to diffuse into the micropores of the porous rock matrix and thus be withdrawn from the flowing water in the fractures. This phenomenon is called matrix diffusion. A review over matrix diffusion is presented in the study. The main interest is directed to the diffusion of non-sorbing species. The review covers diffusion experiments and measurements of porosity, pore size, specific surface area and water permeability
Response matrix method for large LMFBR analysis
International Nuclear Information System (INIS)
King, M.J.
1977-06-01
The feasibility of using response matrix techniques for computational models of large LMFBRs is examined. Since finite-difference methods based on diffusion theory have generally found a place in fast-reactor codes, a brief review of their general matrix foundation is given first in order to contrast it to the general strategy of response matrix methods. Then, in order to present the general method of response matrix technique, two illustrative examples are given. Matrix algorithms arising in the application to large LMFBRs are discussed, and the potential of the response matrix method is explored for a variety of computational problems. Principal properties of the matrices involved are derived with a view to application of numerical methods of solution. The Jacobi iterative method as applied to the current-balance eigenvalue problem is discussed
Comparison of Transmission Line Methods for Surface Acoustic Wave Modeling
Wilson, William; Atkinson, Gary
2009-01-01
Surface Acoustic Wave (SAW) technology is low cost, rugged, lightweight, extremely low power and can be used to develop passive wireless sensors. For these reasons, NASA is investigating the use of SAW technology for Integrated Vehicle Health Monitoring (IVHM) of aerospace structures. To facilitate rapid prototyping of passive SAW sensors for aerospace applications, SAW models have been developed. This paper reports on the comparison of three methods of modeling SAWs. The three models are the Impulse Response Method (a first order model), and two second order matrix methods; the conventional matrix approach, and a modified matrix approach that is extended to include internal finger reflections. The second order models are based upon matrices that were originally developed for analyzing microwave circuits using transmission line theory. Results from the models are presented with measured data from devices. Keywords: Surface Acoustic Wave, SAW, transmission line models, Impulse Response Method.
Matrix Krylov subspace methods for image restoration
Directory of Open Access Journals (Sweden)
khalide jbilou
2015-09-01
Full Text Available In the present paper, we consider some matrix Krylov subspace methods for solving ill-posed linear matrix equations and in those problems coming from the restoration of blurred and noisy images. Applying the well known Tikhonov regularization procedure leads to a Sylvester matrix equation depending the Tikhonov regularized parameter. We apply the matrix versions of the well known Krylov subspace methods, namely the Least Squared (LSQR and the conjugate gradient (CG methods to get approximate solutions representing the restored images. Some numerical tests are presented to show the effectiveness of the proposed methods.
Hybrid transfer-matrix FDTD method for layered periodic structures.
Deinega, Alexei; Belousov, Sergei; Valuev, Ilya
2009-03-15
A hybrid transfer-matrix finite-difference time-domain (FDTD) method is proposed for modeling the optical properties of finite-width planar periodic structures. This method can also be applied for calculation of the photonic bands in infinite photonic crystals. We describe the procedure of evaluating the transfer-matrix elements by a special numerical FDTD simulation. The accuracy of the new method is tested by comparing computed transmission spectra of a 32-layered photonic crystal composed of spherical or ellipsoidal scatterers with the results of direct FDTD and layer-multiple-scattering calculations.
Matrix method for acoustic levitation simulation.
Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C
2011-08-01
A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort.
Transfer matrix method for four-flux radiative transfer.
Slovick, Brian; Flom, Zachary; Zipp, Lucas; Krishnamurthy, Srini
2017-07-20
We develop a transfer matrix method for four-flux radiative transfer, which is ideally suited for studying transport through multiple scattering layers. The model predicts the specular and diffuse reflection and transmission of multilayer composite films, including interface reflections, for diffuse or collimated incidence. For spherical particles in the diffusion approximation, we derive closed-form expressions for the matrix coefficients and show remarkable agreement with numerical Monte Carlo simulations for a range of absorption values and film thicknesses, and for an example multilayer slab.
Interface matrix method in AFEN framework
Energy Technology Data Exchange (ETDEWEB)
Pogosbekyan, Leonid; Cho, Jin Young; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1997-12-31
In this study, we extend the application of the interface-matrix(IM) method for reflector modeling to Analytic Flux Expansion Nodal (AFEN) method. This include the modifications of the surface-averaged net current continuity and the net leakage balance conditions for IM method in accordance with AFEN formula. AFEN-interface matrix (AFEN-IM) method has been tested against ZION-1 benchmark problem. The numerical result of AFEN-IM method shows 1.24% of maximum error and 0.42% of root-mean square error in assembly power distribution, and 0.006% {Delta} k of neutron multiplication factor. This result proves that the interface-matrix method for reflector modeling can be useful in AFEN method. 3 refs., 4 figs. (Author)
Interface matrix method in AFEN framework
Energy Technology Data Exchange (ETDEWEB)
Pogosbekyan, Leonid; Cho, Jin Young; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1998-12-31
In this study, we extend the application of the interface-matrix(IM) method for reflector modeling to Analytic Flux Expansion Nodal (AFEN) method. This include the modifications of the surface-averaged net current continuity and the net leakage balance conditions for IM method in accordance with AFEN formula. AFEN-interface matrix (AFEN-IM) method has been tested against ZION-1 benchmark problem. The numerical result of AFEN-IM method shows 1.24% of maximum error and 0.42% of root-mean square error in assembly power distribution, and 0.006% {Delta} k of neutron multiplication factor. This result proves that the interface-matrix method for reflector modeling can be useful in AFEN method. 3 refs., 4 figs. (Author)
The finite element response matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
1983-02-01
A new technique is developed with an alternative formulation of the response matrix method implemented with the finite element scheme. Two types of response matrices are generated from the Galerkin solution to the weak form of the diffusion equation subject to an arbitrary current and source. The piecewise polynomials are defined in two levels, the first for the local (assembly) calculations and the second for the global (core) response matrix calculations. This finite element response matrix technique was tested in two 2-dimensional test problems, 2D-IAEA benchmark problem and Biblis benchmark problem, with satisfatory results. The computational time, whereas the current code is not extensively optimized, is of the same order of the well estabilished coarse mesh codes. Furthermore, the application of the finite element technique in an alternative formulation of response matrix method permits the method to easily incorporate additional capabilities such as treatment of spatially dependent cross-sections, arbitrary geometrical configurations, and high heterogeneous assemblies. (Author) [pt
Definition of a matrix of the generalized parameters asymmetrical multiphase transmission lines
Directory of Open Access Journals (Sweden)
Suslov V.M.
2005-12-01
Full Text Available Idle time, without introduction of wave characteristics, algorithm of definition of a matrix of the generalized parameters asymmetrical multiphase transmission lines is offered. Definition of a matrix of parameters is based on a matrix primary specific of parameters of line and simple iterative procedure. The amount of iterations of iterative procedure is determined by a set error of performance of the resulted matrix ratio between separate blocks of a determined matrix. The given error is connected by close image of with a margin error determined matrix.
The role of extracellular matrix in lateral transmission of force in skeletal muscle
Gao, Yingxin
This dissertation describes the role of extracellular matrix (ECM) in the lateral transmission of force. It consists of an experimental studies of the ECM and mathematical modeling of lateral transmission of force. The effect of aging on the structural and mechanical properties of the epimysium of muscle of the rats were examined. No statistically significant differences were found in the ultrastructure, or the thickness of the epimysium. However, from the tensile stress-strain tests, it was found that the epimysium of muscles from old rats was much stiffer than that of the young rats. Based on these observations. It was concluded that the differences in the mechanical properties of the epimysium of the muscles from the old compared with young rats were not associated with the arrangement and size of collagen fibers in the epimysium. Consequently, other methods will be required to identify the structural bases of the mechanical differences. The stress-strain relationships for the epimysiums of the skeletal muscles from both the young and old rats were found to be nonlinear. A mathematical model was developed that showed that the nonlinear behavior results from the waviness and the reorientation of the collagen fibers in the epimysium. The ECM plays an important role in lateral transmission of force in skeletal muscle by providing shear stress between the muscle fibers or fascicles. A mathematical model was developed to investigate the mechanisms of lateral transmission. It was a modification of the shear lag theory for chopped fiber composite materials used in engineering applications. The modified shear lag theory includes an activation strain to account for muscle contraction and a myofibrils-endomysium interfaces that accounts for the molecular lateral linkages. The model was used to simulate the classic experiments of Street. It was demonstrated that lateral transmission of force in the skeletal muscle is affected by the mechanical and structural properties of
The block Gauss-Seidel method in sound transmission problems
Poblet-Puig, Jordi; Rodríguez Ferran, Antonio
2009-01-01
Sound transmission through partitions can be modelled as an acoustic fluid-elastic structure interaction problem. The block Gauss-Seidel iterative method is used in order to solve the finite element linear system of equations. The blocks are defined in a natural way, respecting the fluid and structural domains. The convergence criterion (spectral radius of iteration matrix smaller than one) is analysed and interpreted in physical terms by means of simple one-dimensional problems. This anal...
A nodal method based on matrix-response method
International Nuclear Information System (INIS)
Rocamora Junior, F.D.; Menezes, A.
1982-01-01
A nodal method based in the matrix-response method, is presented, and its application to spatial gradient problems, such as those that exist in fast reactors, near the core - blanket interface, is investigated. (E.G.) [pt
The finite element response Matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
1983-01-01
A new method for global reactor core calculations is described. This method is based on a unique formulation of the response matrix method, implemented with a higher order finite element method. The unique aspects of this approach are twofold. First, there are two levels to the overall calculational scheme: the local or assembly level and the global or core level. Second, the response matrix scheme, which is formulated at both levels, consists of two separate response matrices rather than one response matrix as is generally the case. These separate response matrices are seen to be quite beneficial for the criticality eigenvalue calculation, because they are independent of k /SUB eff/. The response matrices are generated from a Galerkin finite element solution to the weak form of the diffusion equation, subject to an arbitrary incoming current and an arbitrary distributed source. Calculational results are reported for two test problems, the two-dimensional International Atomic Energy Agency benchmark problem and a two-dimensional pressurized water reactor test problem (Biblis reactor), and they compare well with standard coarse mesh methods with respect to accuracy and efficiency. Moreover, the accuracy (and capability) is comparable to fine mesh for a fraction of the computational cost. Extension of the method to treat heterogeneous assemblies and spatial depletion effects is discussed
Nonlinear response matrix methods for radiative transfer
International Nuclear Information System (INIS)
Miller, W.F. Jr.; Lewis, E.E.
1987-01-01
A nonlinear response matrix formalism is presented for the solution of time-dependent radiative transfer problems. The essential feature of the method is that within each computational cell the temperature is calculated in response to the incoming photons from all frequency groups. Thus the updating of the temperature distribution is placed within the iterative solution of the spaceangle transport problem, instead of being placed outside of it. The method is formulated for both grey and multifrequency problems and applied in slab geometry. The method is compared to the more conventional source iteration technique. 7 refs., 1 fig., 4 tabs
Matrix method for two-dimensional waveguide mode solution
Sun, Baoguang; Cai, Congzhong; Venkatesh, Balajee Seshasayee
2018-05-01
In this paper, we show that the transfer matrix theory of multilayer optics can be used to solve the modes of any two-dimensional (2D) waveguide for their effective indices and field distributions. A 2D waveguide, even composed of numerous layers, is essentially a multilayer stack and the transmission through the stack can be analysed using the transfer matrix theory. The result is a transfer matrix with four complex value elements, namely A, B, C and D. The effective index of a guided mode satisfies two conditions: (1) evanescent waves exist simultaneously in the first (cladding) layer and last (substrate) layer, and (2) the complex element D vanishes. For a given mode, the field distribution in the waveguide is the result of a 'folded' plane wave. In each layer, there is only propagation and absorption; at each boundary, only reflection and refraction occur, which can be calculated according to the Fresnel equations. As examples, we show that this method can be used to solve modes supported by the multilayer step-index dielectric waveguide, slot waveguide, gradient-index waveguide and various plasmonic waveguides. The results indicate the transfer matrix method is effective for 2D waveguide mode solution in general.
ABCD Matrix Method a Case Study
Seidov, Zakir F; Yahalom, Asher
2004-01-01
In the Israeli Electrostatic Accelerator FEL, the distance between the accelerator's end and the wiggler's entrance is about 2.1 m, and 1.4 MeV electron beam is transported through this space using four similar quadrupoles (FODO-channel). The transfer matrix method (ABCD matrix method) was used for simulating the beam transport, a set of programs is written in the several programming languages (MATHEMATICA, MATLAB, MATCAD, MAPLE) and reasonable agreement is demonstrated between experimental results and simulations. Comparison of ABCD matrix method with the direct "numerical experiments" using EGUN, ELOP, and GPT programs with and without taking into account the space-charge effects showed the agreement to be good enough as well. Also the inverse problem of finding emittance of the electron beam at the S1 screen position (before FODO-channel), by using the spot image at S2 screen position (after FODO-channel) as function of quad currents, is considered. Spot and beam at both screens are described as tilted eel...
Efficient computation method of Jacobian matrix
International Nuclear Information System (INIS)
Sasaki, Shinobu
1995-05-01
As well known, the elements of the Jacobian matrix are complex trigonometric functions of the joint angles, resulting in a matrix of staggering complexity when we write it all out in one place. This article addresses that difficulties to this subject are overcome by using velocity representation. The main point is that its recursive algorithm and computer algebra technologies allow us to derive analytical formulation with no human intervention. Particularly, it is to be noted that as compared to previous results the elements are extremely simplified throughout the effective use of frame transformations. Furthermore, in case of a spherical wrist, it is shown that the present approach is computationally most efficient. Due to such advantages, the proposed method is useful in studying kinematically peculiar properties such as singularity problems. (author)
Analytical techniques for instrument design - matrix methods
International Nuclear Information System (INIS)
Robinson, R.A.
1997-01-01
We take the traditional Cooper-Nathans approach, as has been applied for many years for steady-state triple-axis spectrometers, and consider its generalisation to other inelastic scattering spectrometers. This involves a number of simple manipulations of exponentials of quadratic forms. In particular, we discuss a toolbox of matrix manipulations that can be performed on the 6- dimensional Cooper-Nathans matrix: diagonalisation (Moller-Nielsen method), coordinate changes e.g. from (Δk I ,Δk F to ΔE, ΔQ ampersand 2 dummy variables), integration of one or more variables (e.g. over such dummy variables), integration subject to linear constraints (e.g. Bragg's Law for analysers), inversion to give the variance-covariance matrix, and so on. We show how these tools can be combined to solve a number of important problems, within the narrow-band limit and the gaussian approximation. We will argue that a generalised program that can handle multiple different spectrometers could (and should) be written in parallel to the Monte-Carlo packages that are becoming available. We will also discuss the complementarity between detailed Monte-Carlo calculations and the approach presented here. In particular, Monte-Carlo methods traditionally simulate the real experiment as performed in practice, given a model scattering law, while the Cooper-Nathans method asks the inverse question: given that a neutron turns up in a particular spectrometer configuration (e.g. angle and time of flight), what is the probability distribution of possible scattering events at the sample? The Monte-Carlo approach could be applied in the same spirit to this question
Analytical techniques for instrument design - Matrix methods
International Nuclear Information System (INIS)
Robinson, R.A.
1997-01-01
The authors take the traditional Cooper-Nathans approach, as has been applied for many years for steady-state triple-axis spectrometers, and consider its generalization to other inelastic scattering spectrometers. This involves a number of simple manipulations of exponentials of quadratic forms. In particular, they discuss a toolbox of matrix manipulations that can be performed on the 6-dimensional Cooper-Nathans matrix. They show how these tools can be combined to solve a number of important problems, within the narrow-band limit and the gaussian approximation. They will argue that a generalized program that can handle multiple different spectrometers could (and should) be written in parallel to the Monte-Carlo packages that are becoming available. They also discuss the complementarity between detailed Monte-Carlo calculations and the approach presented here. In particular, Monte-Carlo methods traditionally simulate the real experiment as performed in practice, given a model scattering law, while the Cooper-Nathans method asks the inverse question: given that a neutron turns up in a particular spectrometer configuration (e.g. angle and time of flight), what is the probability distribution of possible scattering events at the sample? The Monte-Carlo approach could be applied in the same spirit to this question
A nodal method based on the response-matrix method
International Nuclear Information System (INIS)
Cunha Menezes Filho, A. da; Rocamora Junior, F.D.
1983-02-01
A nodal approach based on the Response-Matrix method is presented with the purpose of investigating the possibility of mixing two different allocations in the same problem. It is found that the use of allocation of albedo combined with allocation of direct reflection produces good results for homogeneous fast reactor configurations. (Author) [pt
A wave propagation matrix method in semiclassical theory
International Nuclear Information System (INIS)
Lee, S.Y.; Takigawa, N.
1977-05-01
A wave propagation matrix method is used to derive the semiclassical formulae of the multiturning point problem. A phase shift matrix and a barrier transformation matrix are introduced to describe the processes of a particle travelling through a potential well and crossing a potential barrier respectively. The wave propagation matrix is given by the products of phase shift matrices and barrier transformation matrices. The method to study scattering by surface transparent potentials and the Bloch wave in solids is then applied
Spectral analysis of the UFBG-based acousto—optical modulator in V-I transmission matrix formalism
Wu, Liang-Ying; Pei, Li; Liu, Chao; Wang, Yi-Qun; Weng, Si-Jun; Wang, Jian-Shuai
2014-11-01
In this study, the V-I transmission matrix formalism (V-I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating (FBG)-based acousto—optic modulators (UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave (AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V-I method is 4 × (2M-1) in addition/subtraction, 8 × (2M - 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix (TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix (TM) method, the V-I method is faster and less complex.
Spectral analysis of the UFBG-based acousto—optical modulator in V–I transmission matrix formalism
International Nuclear Information System (INIS)
Wu Liang-Ying; Pei Li; Liu Chao; Wang Yi-Qun; Weng Si-Jun; Wang Jian-Shuai
2014-01-01
In this study, the V–I transmission matrix formalism (V–I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating (FBG)-based acousto—optic modulators (UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave (AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V–I method is 4 × (2M–1) in addition/subtraction, 8 × (2M – 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix (TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix (TM) method, the V–I method is faster and less complex. (general)
NLTE steady-state response matrix method.
Faussurier, G.; More, R. M.
2000-05-01
A connection between atomic kinetics and non-equilibrium thermodynamics has been recently established by using a collisional-radiative model modified to include line absorption. The calculated net emission can be expressed as a non-local thermodynamic equilibrium (NLTE) symmetric response matrix. In the paper, this connection is extended to both cases of the average-atom model and the Busquet's model (RAdiative-Dependent IOnization Model, RADIOM). The main properties of the response matrix still remain valid. The RADIOM source function found in the literature leads to a diagonal response matrix, stressing the absence of any frequency redistribution among the frequency groups at this order of calculation.
Method of forming a ceramic matrix composite and a ceramic matrix component
de Diego, Peter; Zhang, James
2017-05-30
A method of forming a ceramic matrix composite component includes providing a formed ceramic member having a cavity, filling at least a portion of the cavity with a ceramic foam. The ceramic foam is deposited on a barrier layer covering at least one internal passage of the cavity. The method includes processing the formed ceramic member and ceramic foam to obtain a ceramic matrix composite component. Also provided is a method of forming a ceramic matrix composite blade and a ceramic matrix composite component.
Transmission Index Research of Parallel Manipulators Based on Matrix Orthogonal Degree
Shao, Zhu-Feng; Mo, Jiao; Tang, Xiao-Qiang; Wang, Li-Ping
2017-11-01
Performance index is the standard of performance evaluation, and is the foundation of both performance analysis and optimal design for the parallel manipulator. Seeking the suitable kinematic indices is always an important and challenging issue for the parallel manipulator. So far, there are extensive studies in this field, but few existing indices can meet all the requirements, such as simple, intuitive, and universal. To solve this problem, the matrix orthogonal degree is adopted, and generalized transmission indices that can evaluate motion/force transmissibility of fully parallel manipulators are proposed. Transmission performance analysis of typical branches, end effectors, and parallel manipulators is given to illustrate proposed indices and analysis methodology. Simulation and analysis results reveal that proposed transmission indices possess significant advantages, such as normalized finite (ranging from 0 to 1), dimensionally homogeneous, frame-free, intuitive and easy to calculate. Besides, proposed indices well indicate the good transmission region and relativity to the singularity with better resolution than the traditional local conditioning index, and provide a novel tool for kinematic analysis and optimal design of fully parallel manipulators.
A Golub-Kahan-type reduction method for matrix pairs
Hochstenbach, M.E.; Reichel, L.; Yu, X.
2015-01-01
We describe a novel method for reducing a pair of large matrices {A;B} to a pair of small matrices {H;K}. The method is an extension of Golub-Kahan bidiagonalization to matrix pairs, and simplifies to the latter method when B is the identity matrix. Applications to Tikhonov regularization of large
A Golub-Kahan-type reduction method for matrix pairs
Hochstenbach, M.E.; Reichel, L.; Yu, X.
2015-01-01
We describe a novel method for reducing a pair of large matrices {A,B} to a pair of small matrices {H,K}. The method is an extension of Golub–Kahan bidiagonalization to matrix pairs, and simplifies to the latter method when B is the identity matrix. Applications to Tikhonov regularization of large
Research on Matrix-type Packet Loss Compensation Scheme for Wireless Video Transmission on Subway
Directory of Open Access Journals (Sweden)
Fan Qing-Wu
2017-01-01
Full Text Available As the mainstream wireless LAN technology, Wi-Fi can achieve fast data transfer. With the subway moving in a high speed, video data transmission between the metro and the ground is achieved through Wi-Fi technology. This paper aims at solving the Caton problem caused by switching packet loss in the process of playing real-time video on the train terminal, and proposes matrix-type packet loss compensation scheme. Finally, the feasibility of the scheme is verified by experiments.
An improved 4-step commutation method application for matrix converter
DEFF Research Database (Denmark)
Guo, Yu; Guo, Yougui; Deng, Wenlang
2014-01-01
A novel four-step commutation method is proposed for matrix converter cell, 3 phase inputs to 1 phase output in this paper, which is obtained on the analysis of published commutation methods for matrix converter. The first and fourth step can be shorter than the second or third one. The discussed...... method here is implemented by programming in VHDL language. Finally, the novel method in this paper is verified by experiments....
A Matrix Splitting Method for Composite Function Minimization
Yuan, Ganzhao
2016-12-07
Composite function minimization captures a wide spectrum of applications in both computer vision and machine learning. It includes bound constrained optimization and cardinality regularized optimization as special cases. This paper proposes and analyzes a new Matrix Splitting Method (MSM) for minimizing composite functions. It can be viewed as a generalization of the classical Gauss-Seidel method and the Successive Over-Relaxation method for solving linear systems in the literature. Incorporating a new Gaussian elimination procedure, the matrix splitting method achieves state-of-the-art performance. For convex problems, we establish the global convergence, convergence rate, and iteration complexity of MSM, while for non-convex problems, we prove its global convergence. Finally, we validate the performance of our matrix splitting method on two particular applications: nonnegative matrix factorization and cardinality regularized sparse coding. Extensive experiments show that our method outperforms existing composite function minimization techniques in term of both efficiency and efficacy.
A Matrix Splitting Method for Composite Function Minimization
Yuan, Ganzhao; Zheng, Wei-Shi; Ghanem, Bernard
2016-01-01
Composite function minimization captures a wide spectrum of applications in both computer vision and machine learning. It includes bound constrained optimization and cardinality regularized optimization as special cases. This paper proposes and analyzes a new Matrix Splitting Method (MSM) for minimizing composite functions. It can be viewed as a generalization of the classical Gauss-Seidel method and the Successive Over-Relaxation method for solving linear systems in the literature. Incorporating a new Gaussian elimination procedure, the matrix splitting method achieves state-of-the-art performance. For convex problems, we establish the global convergence, convergence rate, and iteration complexity of MSM, while for non-convex problems, we prove its global convergence. Finally, we validate the performance of our matrix splitting method on two particular applications: nonnegative matrix factorization and cardinality regularized sparse coding. Extensive experiments show that our method outperforms existing composite function minimization techniques in term of both efficiency and efficacy.
An analysis on mode selection by V-I transmission matrix in DBR laser with asymmetric fiber gratings
Li, Zhuoxuan; Pei, Li; Li, Qi; Ning, Tigang; Liu, Chao; Gao, Song
2013-02-01
The V-I Transmission Matrix Method (VITMM) which is well known in the microwave engineering field was firstly applied to analyze the output spectra of the Distributed Bragg Reflector (DBR) laser, formed by asymmetric fiber gratings as resonator mirrors. One mirror is the uniform Bragg grating and the other is chirped grating. A theoretical model of grating was established, and then a numerical simulation of the mode selection in DBR laser with asymmetric fiber gratings was presented. Simulation results show that VITMM, with calculation error less than 0.1%, could save the calculation time compared to the Rouard method. In the experiment, the setup design of the single-longitudinal-mode laser output at 1544.7 nm was carried out, and the result, which lasted about 10 min, observed on an optical spectrum analyzer, demonstrates the feasibility of VITMM to address the mode output issues of DBR fiber laser.
Energy Technology Data Exchange (ETDEWEB)
Ecklebe, Andreas
2009-05-22
The publication discusses a three- to two-phase matrix converter for contactless power transmission systems. Based on relevant publications, possible resonance setups for contactless power transmission systems are investigated to begin with. An analysis of relevant parameters shows the differences between the various setups, but it also shows that for an investigation focusing on the feeding converter, simple modelling of the three investigated resonance setups is possible with the aid of a serial oscillating circuit. In consequence, it should be possible to apply the results also to the matrix converter with other serially resonant loads. The second part of the investigation focuses on the matrix converter. After a theoretical description, a combination von high-frequency control - e.g. bulk pulsing - and low-frequency pulsing patterns for setting the harmonics level of the grid currents is presented. The similarity to a conventional H bridge circuit enables an assessment of commutation and the identification of the necessary inverter states. These are characterized in that a bidirectional connection between the input system and each output phase is available at any time. The functioning of the commutation and of the inverter as a whole is proved by simulation in a first step, in which also the dynamic switching characteristics of the power semiconductors is taken into account. Finally, the results of laboratory measurements are presented and compared with the theoretical results. The laboratory setup consists of the power section of the matrix converter with input filters and modular gate drivers, a DSP/FPGA control system, and a contactless power transmission system with a current inverter and load on the secondary side. The investigation thus provides information on the use of the three-to-two phase matrix converter as an interesting alternative for feeding of contactless power transmission systems and other serially resonant loads. (orig.) [German] Diese
Methods, apparatus, and systems for monitoring transmission systems
Polk, Robert E [Idaho Falls, ID; Svoboda, John M [Idaho Falls, ID; West, Phillip B [Idaho Falls, ID; Heath, Gail L [Iona, ID; Scott, Clark L [Idaho Falls, ID
2010-08-31
A sensing platform for monitoring a transmission system, and method therefor, may include a sensor that senses one or more conditions relating to a condition of the transmission system and/or the condition of an environment around the transmission system. A control system operatively associated with the sensor produces output data based on an output signal produced by the sensor. A transmitter operatively associated with the control system transmits the output data from the control system.
An iterative method to invert the LTSn matrix
Energy Technology Data Exchange (ETDEWEB)
Cardona, A.V.; Vilhena, M.T. de [UFRGS, Porto Alegre (Brazil)
1996-12-31
Recently Vilhena and Barichello proposed the LTSn method to solve, analytically, the Discrete Ordinates Problem (Sn problem) in transport theory. The main feature of this method consist in the application of the Laplace transform to the set of Sn equations and solve the resulting algebraic system for the transport flux. Barichello solve the linear system containing the parameter s applying the definition of matrix invertion exploiting the structure of the LTSn matrix. In this work, it is proposed a new scheme to invert the LTSn matrix, decomposing it in blocks and recursively inverting this blocks.
Modeling cometary photopolarimetric characteristics with Sh-matrix method
Kolokolova, L.; Petrov, D.
2017-12-01
Cometary dust is dominated by particles of complex shape and structure, which are often considered as fractal aggregates. Rigorous modeling of light scattering by such particles, even using parallelized codes and NASA supercomputer resources, is very computer time and memory consuming. We are presenting a new approach to modeling cometary dust that is based on the Sh-matrix technique (e.g., Petrov et al., JQSRT, 112, 2012). This method is based on the T-matrix technique (e.g., Mishchenko et al., JQSRT, 55, 1996) and was developed after it had been found that the shape-dependent factors could be separated from the size- and refractive-index-dependent factors and presented as a shape matrix, or Sh-matrix. Size and refractive index dependences are incorporated through analytical operations on the Sh-matrix to produce the elements of T-matrix. Sh-matrix method keeps all advantages of the T-matrix method, including analytical averaging over particle orientation. Moreover, the surface integrals describing the Sh-matrix elements themselves can be solvable analytically for particles of any shape. This makes Sh-matrix approach an effective technique to simulate light scattering by particles of complex shape and surface structure. In this paper, we present cometary dust as an ensemble of Gaussian random particles. The shape of these particles is described by a log-normal distribution of their radius length and direction (Muinonen, EMP, 72, 1996). Changing one of the parameters of this distribution, the correlation angle, from 0 to 90 deg., we can model a variety of particles from spheres to particles of a random complex shape. We survey the angular and spectral dependencies of intensity and polarization resulted from light scattering by such particles, studying how they depend on the particle shape, size, and composition (including porous particles to simulate aggregates) to find the best fit to the cometary observations.
Refractive index inversion based on Mueller matrix method
Fan, Huaxi; Wu, Wenyuan; Huang, Yanhua; Li, Zhaozhao
2016-03-01
Based on Stokes vector and Jones vector, the correlation between Mueller matrix elements and refractive index was studied with the result simplified, and through Mueller matrix way, the expression of refractive index inversion was deduced. The Mueller matrix elements, under different incident angle, are simulated through the expression of specular reflection so as to analyze the influence of the angle of incidence and refractive index on it, which is verified through the measure of the Mueller matrix elements of polished metal surface. Research shows that, under the condition of specular reflection, the result of Mueller matrix inversion is consistent with the experiment and can be used as an index of refraction of inversion method, and it provides a new way for target detection and recognition technology.
Successive Over Relaxation Method Which Uses Matrix Norms for ...
African Journals Online (AJOL)
An algorithm for S.O.R functional iteration which uses matrix norms for the Jacobi iteration matrices rather than the usual Power method, feasible in Newton Operator for the solution of nonlinear system of equations is proposed. We modified the S.O.R. iterative method known as Multiphase S.O.R. method for Newton ...
An integrating factor matrix method to find first integrals
International Nuclear Information System (INIS)
Saputra, K V I; Quispel, G R W; Van Veen, L
2010-01-01
In this paper we develop an integrating factor matrix method to derive conditions for the existence of first integrals. We use this novel method to obtain first integrals, along with the conditions for their existence, for two- and three-dimensional Lotka-Volterra systems with constant terms. The results are compared to previous results obtained by other methods.
Response Matrix Method Development Program at Savannah River Laboratory
International Nuclear Information System (INIS)
Sicilian, J.M.
1976-01-01
The Response Matrix Method Development Program at Savannah River Laboratory (SRL) has concentrated on the development of an effective system of computer codes for the analysis of Savannah River Plant (SRP) reactors. The most significant contribution of this program to date has been the verification of the accuracy of diffusion theory codes as used for routine analysis of SRP reactor operation. This paper documents the two steps carried out in achieving this verification: confirmation of the accuracy of the response matrix technique through comparison with experiment and Monte Carlo calculations; and establishment of agreement between diffusion theory and response matrix codes in situations which realistically approximate actual operating conditions
The Matrix Element Method at Next-to-Leading Order
Campbell, John M.; Giele, Walter T.; Williams, Ciaran
2012-01-01
This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory. To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis. This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order. A welcome by-product of the method is the straightforward and efficient generation of...
Convergence Improvement of Response Matrix Method with Large Discontinuity Factors
International Nuclear Information System (INIS)
Yamamoto, Akio
2003-01-01
In the response matrix method, a numerical divergence problem has been reported when extremely small or large discontinuity factors are utilized in the calculations. In this paper, an alternative response matrix formulation to solve the divergence problem is discussed, and properties of iteration matrixes are investigated through eigenvalue analyses. In the conventional response matrix formulation, partial currents between adjacent nodes are assumed to be discontinuous, and outgoing partial currents are converted into incoming partial currents by the discontinuity factor matrix. Namely, the partial currents of the homogeneous system (i.e., homogeneous partial currents) are treated in the conventional response matrix formulation. In this approach, the spectral radius of an iteration matrix for the partial currents may exceed unity when an extremely small or large discontinuity factor is used. Contrary to this, an alternative response matrix formulation using heterogeneous partial currents is discussed in this paper. In the latter approach, partial currents are assumed to be continuous between adjacent nodes, and discontinuity factors are directly considered in the coefficients of a response matrix. From the eigenvalue analysis of the iteration matrix for the one-group, one-dimensional problem, the spectral radius for the heterogeneous partial current formulation does not exceed unity even if an extremely small or large discontinuity factor is used in the calculation; numerical stability of the alternative formulation is superior to the conventional one. The numerical stability of the heterogeneous partial current formulation is also confirmed by the two-dimensional light water reactor core analysis. Since the heterogeneous partial current formulation does not require any approximation, the converged solution exactly reproduces the reference solution when the discontinuity factors are directly derived from the reference calculation
Comparison of matrix methods for elastic wave scattering problems
International Nuclear Information System (INIS)
Tsao, S.J.; Varadan, V.K.; Varadan, V.V.
1983-01-01
This article briefly describes the T-matrix method and the MOOT (method of optimal truncation) of elastic wave scattering as they apply to A-D, SH- wave problems as well as 3-D elastic wave problems. Two methods are compared for scattering by elliptical cylinders as well as oblate spheroids of various eccentricity as a function of frequency. Convergence, and symmetry of the scattering cross section are also compared for ellipses and spheroidal cavities of different aspect ratios. Both the T-matrix approach and the MOOT were programmed on an AMDHL 470 computer using double precision arithmetic. Although the T-matrix method and MOOT are not always in agreement, it is in no way implied that any of the published results using MOOT are in error
The J-Matrix Method Developments and Applications
Alhaidari, Abdulaziz D; Heller, Eric J; Abdelmonem, Mohamed S
2008-01-01
This volume aims to provide the fundamental knowledge to appreciate the advantages of the J-matrix method and to encourage its use and further development. The J-matrix method is an algebraic method of quantum scattering with substantial success in atomic and nuclear physics. The accuracy and convergence property of the method compares favourably with other successful scattering calculation methods. Despite its thirty-year long history new applications are being found for the J-matrix method. This book gives a brief account of the recent developments and some selected applications of the method in atomic and nuclear physics. New findings are reported in which experimental results are compared to theoretical calculations. Modifications, improvements and extensions of the method are discussed using the language of the J-matrix. The volume starts with a Foreword by the two co-founders of the method, E.J. Heller and H.A. Yamani and it contains contributions from 24 prominent international researchers.
Nucleon matrix elements using the variational method in lattice QCD
International Nuclear Information System (INIS)
Dragos, J.; Kamleh, W.; Leinweber, D.B.; Zanotti, J.M.; Rakow, P.E.L.; Young, R.D.; Adelaide Univ., SA
2016-06-01
The extraction of hadron matrix elements in lattice QCD using the standard two- and threepoint correlator functions demands careful attention to systematic uncertainties. One of the most commonly studied sources of systematic error is contamination from excited states. We apply the variational method to calculate the axial vector current g_A, the scalar current g_S and the quark momentum fraction left angle x right angle of the nucleon and we compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.
Czech Academy of Sciences Publication Activity Database
Vargová, Lýdia; Syková, Eva
2011-01-01
Roč. 59, S1 (2011), S38 ISSN 0894-1491. [European meeting on Glia l Cells in Health and Disease /10./. 13.09.2011-17.09.2011, Prague] Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50390703 Keywords : diffusion * extracellular matrix * extrasynaptic transmission Subject RIV: FH - Neurology
Matrix-based image reconstruction methods for tomography
International Nuclear Information System (INIS)
Llacer, J.; Meng, J.D.
1984-10-01
Matrix methods of image reconstruction have not been used, in general, because of the large size of practical matrices, ill condition upon inversion and the success of Fourier-based techniques. An exception is the work that has been done at the Lawrence Berkeley Laboratory for imaging with accelerated radioactive ions. An extension of that work into more general imaging problems shows that, with a correct formulation of the problem, positron tomography with ring geometries results in well behaved matrices which can be used for image reconstruction with no distortion of the point response in the field of view and flexibility in the design of the instrument. Maximum Likelihood Estimator methods of reconstruction, which use the system matrices tailored to specific instruments and do not need matrix inversion, are shown to result in good preliminary images. A parallel processing computer structure based on multiple inexpensive microprocessors is proposed as a system to implement the matrix-MLE methods. 14 references, 7 figures
Analysis of Nonlinear Dynamics by Square Matrix Method
Energy Technology Data Exchange (ETDEWEB)
Yu, Li Hua [Brookhaven National Lab. (BNL), Upton, NY (United States). Energy and Photon Sciences Directorate. National Synchrotron Light Source II
2016-07-25
The nonlinear dynamics of a system with periodic structure can be analyzed using a square matrix. In this paper, we show that because the special property of the square matrix constructed for nonlinear dynamics, we can reduce the dimension of the matrix from the original large number for high order calculation to low dimension in the first step of the analysis. Then a stable Jordan decomposition is obtained with much lower dimension. The transformation to Jordan form provides an excellent action-angle approximation to the solution of the nonlinear dynamics, in good agreement with trajectories and tune obtained from tracking. And more importantly, the deviation from constancy of the new action-angle variable provides a measure of the stability of the phase space trajectories and their tunes. Thus the square matrix provides a novel method to optimize the nonlinear dynamic system. The method is illustrated by many examples of comparison between theory and numerical simulation. Finally, in particular, we show that the square matrix method can be used for optimization to reduce the nonlinearity of a system.
A transaction assessment method for allocation of transmission services
Banunarayanan, Venkatasubramaniam
The purpose of this research is to develop transaction assessment methods for allocating transmission services that are provided by an area/utility to power transactions. Transmission services are the services needed to deliver, or provide the capacity to deliver, real and reactive power from one or more supply points to one or more delivery points. As the number of transactions increase rapidly in the emerging deregulated environment, accurate quantification of the transmission services an area/utility provides to accommodate a transaction is becoming important, because then appropriate pricing schemes can be developed to compensate for the parties that provide these services. The Allocation methods developed are based on the "Fair Resource Allocation Principle" and they determine for each transaction the following: the flowpath of the transaction (both real and reactive power components), generator reactive power support from each area/utility, real power loss support from each area/utility. Further, allocation methods for distributing the cost of relieving congestion on transmission lines caused by transactions are also developed. The main feature of the proposed methods is representation of actual usage of the transmission services by the transactions. The proposed method is tested extensively on a variety of systems. The allocation methods developed in this thesis for allocation of transmission services to transactions is not only useful in studying the impact of transactions on a transmission system in a multi-transaction case, but they are indeed necessary to meet the criteria set forth by FERC with regard to pricing based on actual usage. The "consistency" of the proposed allocation methods has also been investigated and tested.
International Nuclear Information System (INIS)
Shahid, M.; Thomson, G.E.
1997-01-01
Along with improved mechanical properties, metal matrix composites (MMC) have a disadvantage of enhanced corrosion susceptibility in aggressive environments. Recent studies on corrosion behaviour of an Al-alloy 8090/SiC MMC, revealed considerably high corrosion rates of the MMC in near neutral solutions containing chloride ions. Anodizing is one of the potential surface treatment for the MMC to provide protective coating against corrosion. The surface and cross section of the anodized MMC can easily be observed using scanning electron microscope. The anodizing behaviour of the MMC can be understood further if the anodized cross section in examined under transmission electron microscope (TEM). However, it is relatively difficult to prepare small (3 mm diameter) electron transparent specimens of the MMC supporting an anodic film. In the present study a technique has been developed for preparing thin electron transparent specimens of the anodized MMC. This technique employed conventional ion beam thinning process but the preparation of small discs was a problem. A MMMC consisting of Al-alloy 8090 with 20 % (by weight) SiC particulate with an average size of 5 Mu m, was anodized and observed in TEM after preparing the samples using the above mentioned techniques. (author)
A nonlinearity compensation method for a matrix converter drive
DEFF Research Database (Denmark)
Lee, Kyo-Beum; Blaabjerg, Frede
2005-01-01
converter model using the direction of current. The proposed method does not need any additional hardware or complicated software and it is easy to realize by applying the algorithm to the conventional vector control. The proposed compensation method is applied for high-performance induction motor drives...... using a 3-kW matrix converter system without a speed sensor. Experimental results show the proposed method provides good compensating characteristics....
A stochastic method for computing hadronic matrix elements
Energy Technology Data Exchange (ETDEWEB)
Alexandrou, Constantia [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; The Cyprus Institute, Nicosia (Cyprus). Computational-based Science and Technology Research Center; Dinter, Simon; Drach, Vincent [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Jansen, Karl [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Hadjiyiannakou, Kyriakos [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Renner, Dru B. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Collaboration: European Twisted Mass Collaboration
2013-02-15
We present a stochastic method for the calculation of baryon three-point functions that is more versatile compared to the typically used sequential method. We analyze the scaling of the error of the stochastically evaluated three-point function with the lattice volume and find a favorable signal-to-noise ratio suggesting that our stochastic method can be used efficiently at large volumes to compute hadronic matrix elements.
Calculating the albedo characteristics by the method of transmission probabilities
International Nuclear Information System (INIS)
Lukhvich, A.A.; Rakhno, I.L.; Rubin, I.E.
1983-01-01
The possibility to use the method of transmission probabilities for calculating the albedo characteristics of homogeneous and heterogeneous zones is studied. The transmission probabilities method is a numerical method for solving the transport equation in the integrated form. All calculations have been conducted as a one-group approximation for the planes and rods with different optical thicknesses and capture-to-scattering ratios. Above calculations for plane and cylindrical geometries have shown the possibility to use the numerical method of transmission probabilities for calculating the albedo characteristics of homogeneous and heterogeneous zones with high accuracy. In this case the computer time consumptions are minimum even with the cylindrical geometry, if the interpolation calculation of characteristics is used for the neutrons of the first path
Monaghan, Philip Harold; Delvaux, John McConnell; Taxacher, Glenn Curtis
2015-06-09
A pre-form CMC cavity and method of forming pre-form CMC cavity for a ceramic matrix component includes providing a mandrel, applying a base ply to the mandrel, laying-up at least one CMC ply on the base ply, removing the mandrel, and densifying the base ply and the at least one CMC ply. The remaining densified base ply and at least one CMC ply form a ceramic matrix component having a desired geometry and a cavity formed therein. Also provided is a method of forming a CMC component.
Decomposition of spectra in EPR dosimetry using the matrix method
International Nuclear Information System (INIS)
Sholom, S.V.; Chumak, V.V.
2003-01-01
The matrix method of EPR spectra decomposition is developed and adapted for routine application in retrospective EPR dosimetry with teeth. According to this method, the initial EPR spectra are decomposed (using methods of matrix algebra) into several reference components (reference matrices) that are specific for each material. Proposed procedure has been tested on the example of tooth enamel. Reference spectra were a spectrum of an empty sample tube and three standard signals of enamel (two at g=2.0045, both for the native signal and one at g perpendicular =2.0018, g parallel =1.9973 for the dosimetric signal). Values of dosimetric signals obtained using the given method have been compared with data obtained by manual manipulation of spectra, and good coincidence was observed. This allows considering the proposed method as potent for application in routine EPR dosimetry
Proper comparison among methods using a confusion matrix
CSIR Research Space (South Africa)
Salmon
2015-07-01
Full Text Available -1 IGARSS 2015, Milan, Italy, 26-31 July 2015 Proper comparison among methods using a confusion matrix 1,2 B.P. Salmon, 2,3 W. Kleynhans, 2,3 C.P. Schwegmann and 1J.C. Olivier 1School of Engineering and ICT, University of Tasmania, Australia 2...
Comparative Study of Inference Methods for Bayesian Nonnegative Matrix Factorisation
DEFF Research Database (Denmark)
Brouwer, Thomas; Frellsen, Jes; Liò, Pietro
2017-01-01
In this paper, we study the trade-offs of different inference approaches for Bayesian matrix factorisation methods, which are commonly used for predicting missing values, and for finding patterns in the data. In particular, we consider Bayesian nonnegative variants of matrix factorisation and tri......-factorisation, and compare non-probabilistic inference, Gibbs sampling, variational Bayesian inference, and a maximum-a-posteriori approach. The variational approach is new for the Bayesian nonnegative models. We compare their convergence, and robustness to noise and sparsity of the data, on both synthetic and real...
Computation of nonuniform transmission lines using the FDTD method
Energy Technology Data Exchange (ETDEWEB)
Miranda, G.C.; Paulino, J.O.S. [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). School of Engineering
1997-12-31
Calculation of lightning overvoltages on transmission lines has been described. Lightning induced overvoltages are of great significance under certain conditions because of the main characteristics of the phenomena. The lightning channel model is one of the most important parameters essential to obtaining the generated electromagnetic fields. In this study, nonuniform transmission line equations were solved using the finite difference method and the leap-frog scheme, the Finite Difference Time Domain (FDTD) method. The subroutine was interfaced with the Electromagnetic Transients Program (EMTP). Two models were used to represent the characteristic impedance of the nonuniform lines used to model the transmission line towers and the lightning main channel. The advantages of the FDTD method was the much smaller code and faster processing time. 35 refs., 5 figs.
Widening the Scope of R-matrix Methods
Energy Technology Data Exchange (ETDEWEB)
Thompson, Ian J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dimitriou, Paraskevi [IAEA, Vienna (Austria); DeBoer, Richard J. [Nieuwland Science Hall, Notre Dame, IN (United States); Kunieda, Satoshi [Nuclear Data Center (JAEA), Tokai (Japan); Paris, Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, Ian [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Trkov, Andrej [IAEA, Vienna (Austria)
2016-03-01
A Consultant’s Meeting was held at the IAEA Headquarters, from 7 to 9 December 2015, to discuss the status of R-matrix codes currently used in calculations of charged-particle induced reaction cross sections at low energies. The ultimate goal was to initiate an international effort, coordinated by the IAEA, to evaluate charged-particle induced reactions in the resolved-resonance region. Participants reviewed the capabilities of the codes, the different implementations of R-matrix theory and translatability of the R-matrix parameters, the evaluation methods and suitable data formats for broader dissemination. The details of the presentations and technical discussions, as well as the actions that were proposed to achieve the goal of the meeting are summarized in this report.
Fujino, Kan; Yamamoto, Yusuke; Daito, Takuji; Makino, Akiko; Honda, Tomoyuki; Tomonaga, Keizo
2017-09-01
Borna disease virus (BoDV), a prototype of mammalian bornavirus, is a non-segmented, negative strand RNA virus that often causes severe neurological disorders in infected animals, including horses and sheep. Unique among animal RNA viruses, BoDV transcribes and replicates non-cytopathically in the cell nucleus, leading to establishment of long-lasting persistent infection. This striking feature of BoDV indicates its potential as an RNA virus vector system. It has previously been demonstrated by our team that recombinant BoDV (rBoDV) lacking an envelope glycoprotein (G) gene develops persistent infections in transduced cells without loss of the viral genome. In this study, a novel non-transmissive rBoDV, rBoDV ΔMG, which lacks both matrix (M) and G genes in the genome, is reported. rBoDV-ΔMG expressing green fluorescence protein (GFP), rBoDV ΔMG-GFP, was efficiently generated in Vero/MG cells stably expressing both BoDV M and G proteins. Infection with rBoDV ΔMG-GFP was persistently maintained in the parent Vero cells without propagation within cell culture. The optimal ratio of M and G for efficient viral particle production by transient transfection of M and G expression plasmids into cells persistently infected with rBoDV ΔMG-GFP was also demonstrated. These findings indicate that the rBoDV ΔMG-based BoDV vector may provide an extremely safe virus vector system and could be a novel strategy for investigating the function of M and G proteins and the host range of bornaviruses. © 2017 The Societies and John Wiley & Sons Australia, Ltd.
Comparison of three retail data communication and transmission methods
Directory of Open Access Journals (Sweden)
MA Yue
2016-04-01
Full Text Available With the rapid development of retail trade,the type and complexity of data keep increasing,and single data file size has a great difference between each other.How to realize an accurate,real-time and efficient data transmission based on a fixed cost is an important problem.Regarding the problem of effective transmission for business data files,this article implements analysis and comparison on 3 existing data transmission methods,considering the requirements on aspects like function in enterprise data communication system,we get a conclusion that which method can both meet the enterprise daily business development requirement better and have good extension ability.
A discrete ordinate response matrix method for massively parallel computers
International Nuclear Information System (INIS)
Hanebutte, U.R.; Lewis, E.E.
1991-01-01
A discrete ordinate response matrix method is formulated for the solution of neutron transport problems on massively parallel computers. The response matrix formulation eliminates iteration on the scattering source. The nodal matrices which result from the diamond-differenced equations are utilized in a factored form which minimizes memory requirements and significantly reduces the required number of algorithm utilizes massive parallelism by assigning each spatial node to a processor. The algorithm is accelerated effectively by a synthetic method in which the low-order diffusion equations are also solved by massively parallel red/black iterations. The method has been implemented on a 16k Connection Machine-2, and S 8 and S 16 solutions have been obtained for fixed-source benchmark problems in X--Y geometry
An interlaboratory comparison of methods for measuring rock matrix porosity
International Nuclear Information System (INIS)
Rasilainen, K.; Hellmuth, K.H.; Kivekaes, L.; Ruskeeniemi, T.; Melamed, A.; Siitari-Kauppi, M.
1996-09-01
An interlaboratory comparison study was conducted for the available Finnish methods of rock matrix porosity measurements. The aim was first to compare different experimental methods for future applications, and second to obtain quality assured data for the needs of matrix diffusion modelling. Three different versions of water immersion techniques, a tracer elution method, a helium gas through-diffusion method, and a C-14-PMMA method were tested. All methods selected for this study were established experimental tools in the respective laboratories, and they had already been individually tested. Rock samples for the study were obtained from a homogeneous granitic drill core section from the natural analogue site at Palmottu. The drill core section was cut into slabs that were expected to be practically identical. The subsamples were then circulated between the different laboratories using a round robin approach. The circulation was possible because all methods were non-destructive, except the C-14-PMMA method, which was always the last method to be applied. The possible effect of drying temperature on the measured porosity was also preliminarily tested. These measurements were done in the order of increasing drying temperature. Based on the study, it can be concluded that all methods are comparable in their accuracy. The selection of methods for future applications can therefore be based on practical considerations. Drying temperature seemed to have very little effect on the measured porosity, but a more detailed study is needed for definite conclusions. (author) (4 refs.)
The transmission probability method in one-dimensional cylindrical geometry
International Nuclear Information System (INIS)
Rubin, I.E.
1983-01-01
The collision probability method widely used in solving the problems of neutron transpopt in a reactor cell is reliable for simple cells with small number of zones. The increase of the number of zones and also taking into account the anisotropy of scattering greatly increase the scope of calculations. In order to reduce the time of calculation the transmission probability method is suggested to be used for flux calculation in one-dimensional cylindrical geometry taking into account the scattering anisotropy. The efficiency of the suggested method is verified using the one-group calculations for cylindrical cells. The use of the transmission probability method allows to present completely angular and spatial dependences is neutrons distributions without the increase in the scope of calculations. The method is especially effective in solving the multi-group problems
Mass spectrometer and method with improved ion transmission
International Nuclear Information System (INIS)
Douglas, D.J.; French, J.B.
1992-01-01
This invention relates to a mass analyzer, and to a method of operating a mass analyzer, of the kind in which ions are transmitted through a first rod set for focussing and separation from an accompanying gas, before passing through a mass filter rod set which which permits transmission only of ions of a selected mass to charge ratio. (author). 19 figs
A numerical method to compute interior transmission eigenvalues
International Nuclear Information System (INIS)
Kleefeld, Andreas
2013-01-01
In this paper the numerical calculation of eigenvalues of the interior transmission problem arising in acoustic scattering for constant contrast in three dimensions is considered. From the computational point of view existing methods are very expensive, and are only able to show the existence of such transmission eigenvalues. Furthermore, they have trouble finding them if two or more eigenvalues are situated closely together. We present a new method based on complex-valued contour integrals and the boundary integral equation method which is able to calculate highly accurate transmission eigenvalues. So far, this is the first paper providing such accurate values for various surfaces different from a sphere in three dimensions. Additionally, the computational cost is even lower than those of existing methods. Furthermore, the algorithm is capable of finding complex-valued eigenvalues for which no numerical results have been reported yet. Until now, the proof of existence of such eigenvalues is still open. Finally, highly accurate eigenvalues of the interior Dirichlet problem are provided and might serve as test cases to check newly derived Faber–Krahn type inequalities for larger transmission eigenvalues that are not yet available. (paper)
Optimization of MIMO Systems Capacity Using Large Random Matrix Methods
Directory of Open Access Journals (Sweden)
Philippe Loubaton
2012-11-01
Full Text Available This paper provides a comprehensive introduction of large random matrix methods for input covariance matrix optimization of mutual information of MIMO systems. It is first recalled informally how large system approximations of mutual information can be derived. Then, the optimization of the approximations is discussed, and important methodological points that are not necessarily covered by the existing literature are addressed, including the strict concavity of the approximation, the structure of the argument of its maximum, the accuracy of the large system approach with regard to the number of antennas, or the justification of iterative water-filling optimization algorithms. While the existing papers have developed methods adapted to a specific model, this contribution tries to provide a unified view of the large system approximation approach.
On a novel matrix method for three-dimensional photoelasticity
International Nuclear Information System (INIS)
Theocaris, P.S.; Gdoutos, E.E.
1978-01-01
A non-destructive method for the photoelastic determination of three-dimensional stress distributions, based on the Mueller and Jones calculi, is developed. The differential equations satisfied by the Stokes and Jones vectors, when a polarized light beam passes through a photoelastic model, presenting rotation of the secondary principal stress directions, are established in matrix form. The Peano-Baker method is used for the solution of these differential equations in a matrix series form, establishing the elements of the Mueller and Jones matrices of the photoelastic model. These matrices are experimentally determined by using different wavelengths in conjunction with Jones' 'equivalence theorem'. The Neumann equations are immediately deduced from the above-mentioned differential equations. (orig.) [de
A collocation finite element method with prior matrix condensation
International Nuclear Information System (INIS)
Sutcliffe, W.J.
1977-01-01
For thin shells with general loading, sixteen degrees of freedom have been used for a previous finite element solution procedure using a Collocation method instead of the usual variational based procedures. Although the number of elements required was relatively small, nevertheless the final matrix for the simultaneous solution of all unknowns could become large for a complex compound structure. The purpose of the present paper is to demonstrate a method of reducing the final matrix size, so allowing solution for large structures with comparatively small computer storage requirements while retaining the accuracy given by high order displacement functions. Collocation points, a number are equilibrium conditions which must be satisfied independently of the overall compatibility of forces and deflections for a complete structure. (Auth.)
Improved determination of hadron matrix elements using the variational method
International Nuclear Information System (INIS)
Dragos, J.; Kamleh, W.; Leinweber, D.B.; Zanotti, J.M.; Rakow, P.E.L.; Young, R.D.; Adelaide Univ.
2015-11-01
The extraction of hadron form factors in lattice QCD using the standard two- and three-point correlator functions has its limitations. One of the most commonly studied sources of systematic error is excited state contamination, which occurs when correlators are contaminated with results from higher energy excitations. We apply the variational method to calculate the axial vector current g A and compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.
Energy-dependent applications of the transfer matrix method
International Nuclear Information System (INIS)
Oeztunali, O.I.; Aronson, R.
1975-01-01
The transfer matrix method is applied to energy-dependent neutron transport problems for multiplying and nonmultiplying media in one-dimensional plane geometry. Experimental cross sections are used for total, elastic, and inelastic scattering and fission. Numerical solutions are presented for the problem of a unit point isotropic source in an infinite medium of water and for the problem of the critical 235 U slab with finite water reflectors. No iterations were necessary in this method. Numerical results obtained are consistent with physical considerations and compare favorably with the moments method results for the problem of the unit point isotropic source in an infinite water medium. (U.S.)
The time-dependent density matrix renormalisation group method
Ma, Haibo; Luo, Zhen; Yao, Yao
2018-04-01
Substantial progress of the time-dependent density matrix renormalisation group (t-DMRG) method in the recent 15 years is reviewed in this paper. By integrating the time evolution with the sweep procedures in density matrix renormalisation group (DMRG), t-DMRG provides an efficient tool for real-time simulations of the quantum dynamics for one-dimensional (1D) or quasi-1D strongly correlated systems with a large number of degrees of freedom. In the illustrative applications, the t-DMRG approach is applied to investigate the nonadiabatic processes in realistic chemical systems, including exciton dissociation and triplet fission in polymers and molecular aggregates as well as internal conversion in pyrazine molecule.
Modelling of packet traffic with matrix analytic methods
DEFF Research Database (Denmark)
Andersen, Allan T.
1995-01-01
BISDN network. The heuristic formula did not seem to yield substantially better results than already available approximations. Finally, some results for the finite capacity BMAP/G/1 queue have been obtained. The steady state probability vector of the embedded chain is found by a direct method where...... process. A heuristic formula for the tail behaviour of a single server queue fed by a superposition of renewal processes has been evaluated. The evaluation was performed by applying Matrix Analytic methods. The heuristic formula has applications in the Call Admission Control (CAC) procedure of the future...
A transfer-matrix method for spatially modulated structures
International Nuclear Information System (INIS)
Surda, A.
1991-03-01
A cluster transfer-matrix method convenient for calculation of spatially modulated structures of a wide class of lattice-gas models is developed. The method formulates the problem of calculation of the partition function in terms of non-linear mapping of effective multi-site fields. It is applied to a lattice-gas model qualitatively describing the system of oxygen atoms in the basal planes of high-temperature superconductors. The properties of an incommensurate structure occurring at intermediate temperatures are discussed in detail. (author). 21 refs, 15 figs
Exact solution of some linear matrix equations using algebraic methods
Djaferis, T. E.; Mitter, S. K.
1977-01-01
A study is done of solution methods for Linear Matrix Equations including Lyapunov's equation, using methods of modern algebra. The emphasis is on the use of finite algebraic procedures which are easily implemented on a digital computer and which lead to an explicit solution to the problem. The action f sub BA is introduced a Basic Lemma is proven. The equation PA + BP = -C as well as the Lyapunov equation are analyzed. Algorithms are given for the solution of the Lyapunov and comment is given on its arithmetic complexity. The equation P - A'PA = Q is studied and numerical examples are given.
Stoykov, S.; Atanassov, E.; Margenov, S.
2016-10-01
Many of the scientific applications involve sparse or dense matrix operations, such as solving linear systems, matrix-matrix products, eigensolvers, etc. In what concerns structural nonlinear dynamics, the computations of periodic responses and the determination of stability of the solution are of primary interest. Shooting method iswidely used for obtaining periodic responses of nonlinear systems. The method involves simultaneously operations with sparse and dense matrices. One of the computationally expensive operations in the method is multiplication of sparse by dense matrices. In the current work, a new algorithm for sparse matrix by dense matrix products is presented. The algorithm takes into account the structure of the sparse matrix, which is obtained by space discretization of the nonlinear Mindlin's plate equation of motion by the finite element method. The algorithm is developed to use the vector engine of Intel Xeon Phi coprocessors. It is compared with the standard sparse matrix by dense matrix algorithm and the one developed by Intel MKL and it is shown that by considering the properties of the sparse matrix better algorithms can be developed.
On the use of transition matrix methods with extended ensembles.
Escobedo, Fernando A; Abreu, Charlles R A
2006-03-14
Different extended ensemble schemes for non-Boltzmann sampling (NBS) of a selected reaction coordinate lambda were formulated so that they employ (i) "variable" sampling window schemes (that include the "successive umbrella sampling" method) to comprehensibly explore the lambda domain and (ii) transition matrix methods to iteratively obtain the underlying free-energy eta landscape (or "importance" weights) associated with lambda. The connection between "acceptance ratio" and transition matrix methods was first established to form the basis of the approach for estimating eta(lambda). The validity and performance of the different NBS schemes were then assessed using as lambda coordinate the configurational energy of the Lennard-Jones fluid. For the cases studied, it was found that the convergence rate in the estimation of eta is little affected by the use of data from high-order transitions, while it is noticeably improved by the use of a broader window of sampling in the variable window methods. Finally, it is shown how an "elastic" window of sampling can be used to effectively enact (nonuniform) preferential sampling over the lambda domain, and how to stitch the weights from separate one-dimensional NBS runs to produce a eta surface over a two-dimensional domain.
Research on Quality Detection Methods for Automotive Transmission
Directory of Open Access Journals (Sweden)
Sheng FU
2014-04-01
Full Text Available Given the problems in intelligent diagnosis methods for automotive transmission, it is difficult to obtain the fault signal features and a large enough sample size to study. To solve these problems, a method integrating order tracking, cepstrum, support vector machine (SVM and extremal curve is proposed in this paper. Order tracking and cepstrum are combined for processing the non- stationary vibration signal emitted by automotive transmission. As conventional intelligent methods cannot produce true results for insufficient samples, a method that combines SVM and extremal curve is presented. Input the vector acquired from the feature signals into the SVM model for the first detection, and then do the second detection by means of extremal curve which in turn can enrich the training samples in SVM model thus making the SVM model be more perfect. Analytical description and experimental studies are presented for the methods of signal processing and quality detection. The experimental results demonstrate the effectiveness and practicability of the proposed method.
DANTE, Activation Analysis Neutron Spectra Unfolding by Covariance Matrix Method
International Nuclear Information System (INIS)
Petilli, M.
1981-01-01
1 - Description of problem or function: The program evaluates activation measurements of reactor neutron spectra and unfolds the results for dosimetry purposes. Different evaluation options are foreseen: absolute or relative fluxes and different iteration algorithms. 2 - Method of solution: A least-square fit method is used. A correlation between available data and their uncertainties has been introduced by means of flux and activity variance-covariance matrices. Cross sections are assumed to be constant, i.e. with variance-covariance matrix equal to zero. The Lagrange multipliers method has been used for calculating the solution. 3 - Restrictions on the complexity of the problem: 9 activation experiments can be analyzed. 75 energy groups are accepted
DEFF Research Database (Denmark)
Kirkeby, Carsten Thure; Hisham Beshara Halasa, Tariq; Gussmann, Maya Katrin
2017-01-01
the transmission rate. We use data from the two simulation models and vary the sampling intervals and the size of the population sampled. We devise two new methods to determine transmission rate, and compare these to the frequently used Poisson regression method in both epidemic and endemic situations. For most...... tested scenarios these new methods perform similar or better than Poisson regression, especially in the case of long sampling intervals. We conclude that transmission rate estimates are easily biased, which is important to take into account when using these rates in simulation models....
Brenner, Konstantin; Hennicker, Julian; Masson, Roland; Samier, Pierre
2018-03-01
In this work, we extend, to two-phase flow, the single-phase Darcy flow model proposed in [26], [12] in which the (d - 1)-dimensional flow in the fractures is coupled with the d-dimensional flow in the matrix. Three types of so called hybrid-dimensional two-phase Darcy flow models are proposed. They all account for fractures acting either as drains or as barriers, since they allow pressure jumps at the matrix-fracture interfaces. The models also permit to treat gravity dominated flow as well as discontinuous capillary pressure at the material interfaces. The three models differ by their transmission conditions at matrix fracture interfaces: while the first model accounts for the nonlinear two-phase Darcy flux conservations, the second and third ones are based on the linear single phase Darcy flux conservations combined with different approximations of the mobilities. We adapt the Vertex Approximate Gradient (VAG) scheme to this problem, in order to account for anisotropy and heterogeneity aspects as well as for applicability on general meshes. Several test cases are presented to compare our hybrid-dimensional models to the generic equi-dimensional model, in which fractures have the same dimension as the matrix, leading to deep insight about the quality of the proposed reduced models.
Character expansion methods for matrix models of dually weighted graphs
International Nuclear Information System (INIS)
Kazakov, V.A.; Staudacher, M.; Wynter, T.
1996-01-01
We consider generalized one-matrix models in which external fields allow control over the coordination numbers on both the original and dual lattices. We rederive in a simple fashion a character expansion formula for these models originally due to Itzykson and Di Francesco, and then demonstrate how to take the large N limit of this expansion. The relationship to the usual matrix model resolvent is elucidated. Our methods give as a by-product an extremely simple derivation of the Migdal integral equation describing the large N limit of the Itzykson-Zuber formula. We illustrate and check our methods by analysing a number of models solvable by traditional means. We then proceed to solve a new model: a sum over planar graphs possessing even coordination numbers on both the original and the dual lattice. We conclude by formulating equations for the case of arbitrary sets of even, self-dual coupling constants. This opens the way for studying the deep problem of phase transitions from random to flat lattices. (orig.). With 4 figs
The current matrix elements from HAL QCD method
Watanabe, Kai; Ishii, Noriyoshi
2018-03-01
HAL QCD method is a method to construct a potential (HAL QCD potential) that reproduces the NN scattering phase shift faithful to the QCD. The HAL QCD potential is obtained from QCD by eliminating the degrees of freedom of quarks and gluons and leaving only two particular hadrons. Therefor, in the effective quantum mechanics of two nucleons defined by HAL QCD potential, the conserved current consists not only of the nucleon current but also an extra current originating from the potential (two-body current). Though the form of the two-body current is closely related to the potential, it is not straight forward to extract the former from the latter. In this work, we derive the the current matrix element formula in the quantum mechanics defined by the HAL QCD potential. As a first step, we focus on the non-relativistic case. To give an explicit example, we consider a second quantized non-relativistic two-channel coupling model which we refer to as the original model. From the original model, the HAL QCD potential for the open channel is constructed by eliminating the closed channel in the elastic two-particle scattering region. The current matrix element formula is derived by demanding the effective quantum mechanics defined by the HAL QCD potential to respond to the external field in the same way as the original two-channel coupling model.
Matrix mineralogy of the Lance CO3 carbonaceous chondrite - A transmission electron microscope study
Keller, Lindsay P.; Buseck, Peter R.
1990-01-01
Results are presented on electron microprobe analyses of three CO chondrites, all of which are falls: Lance, Kainsaz, and Warrenton. The TEM mineralogy results of Lance chondrite show that Fe-rich matrix olivines have been altered to Fe-bearing serpentine and Fe(3+) oxide; matrix metal was also altered to produce Fe(3+) oxides, leaving the residual metal enriched in Ni. Olivine grains in Lance's matrix contain channels along their 100-line and 001-line directions; the formation and convergence of such channels resulted in a grain-size reduction of the olivine. A study of Kainsaz and Warrenton showed that these meteorites do not contain phyllosilicates in their matrices, although both contain Fe(3+) oxide between olivine grains. It is suggested that, prior to its alteration, Lance probably resembled Kainsaz, an unaltered CO3 chondrite.
POLLA-NESC, Resonance Parameter R-Matrix to S-Matrix Conversion by Reich-Moore Method
International Nuclear Information System (INIS)
Saussure, G. de; Perez, R.B.
1975-01-01
1 - Description of problem or function: The program transforms a set of r-matrix nuclear resonance parameters into a set of equivalent s-matrix (or Kapur-Peierls) resonance parameters. 2 - Method of solution: The program utilizes the multilevel formalism of Reich and Moore and avoids diagonalization of the level matrix. The parameters are obtained by a direct partial fraction expansion of the Reich-Moore expression of the collision matrix. This approach appears simpler and faster when the number of fission channels is known and small. The method is particularly useful when a large number of levels must be considered because it does not require diagonalization of a large level matrix. 3 - Restrictions on the complexity of the problem: By DIMENSION statements, the program is limited to maxima of 100 levels and 5 channels
Improved parallel solution techniques for the integral transport matrix method
Energy Technology Data Exchange (ETDEWEB)
Zerr, R. Joseph, E-mail: rjz116@psu.edu [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA (United States); Azmy, Yousry Y., E-mail: yyazmy@ncsu.edu [Department of Nuclear Engineering, North Carolina State University, Burlington Engineering Laboratories, Raleigh, NC (United States)
2011-07-01
Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution time by up to 10´ when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing cases are optically thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block pre conditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient pre conditioner. (author)
Improved parallel solution techniques for the integral transport matrix method
International Nuclear Information System (INIS)
Zerr, R. Joseph; Azmy, Yousry Y.
2011-01-01
Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution time by up to 10´ when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing cases are optically thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block pre conditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient pre conditioner. (author)
Empirical method for matrix effects correction in liquid samples
International Nuclear Information System (INIS)
Vigoda de Leyt, Dora; Vazquez, Cristina
1987-01-01
A simple method for the determination of Cr, Ni and Mo in stainless steels is presented. In order to minimize the matrix effects, the conditions of liquid system to dissolve stainless steels chips has been developed. Pure element solutions were used as standards. Preparation of synthetic solutions with all the elements of steel and also mathematic corrections are avoided. It results in a simple chemical operation which simplifies the method of analysis. The variance analysis of the results obtained with steel samples show that the three elements may be determined from the comparison with the analytical curves obtained with the pure elements if the same parameters in the calibration curves are used. The accuracy and the precision were checked against other techniques using the British Chemical Standards of the Bureau of Anlysed Samples Ltd. (England). (M.E.L.) [es
A multi-stage stochastic transmission expansion planning method
International Nuclear Information System (INIS)
Akbari, Tohid; Rahimikian, Ashkan; Kazemi, Ahad
2011-01-01
Highlights: → We model a multi-stage stochastic transmission expansion planning problem. → We include available transfer capability (ATC) in our model. → Involving this criterion will increase the ATC between source and sink points. → Power system reliability will be increased and more money can be saved. - Abstract: This paper presents a multi-stage stochastic model for short-term transmission expansion planning considering the available transfer capability (ATC). The ATC can have a huge impact on the power market outcomes and the power system reliability. The transmission expansion planning (TEP) studies deal with many uncertainties, such as system load uncertainties that are considered in this paper. The Monte Carlo simulation method has been applied for generating different scenarios. A scenario reduction technique is used for reducing the number of scenarios. The objective is to minimize the sum of investment costs (IC) and the expected operation costs (OC). The solution technique is based on the benders decomposition algorithm. The N-1 contingency analysis is also done for the TEP problem. The proposed model is applied to the IEEE 24 bus reliability test system and the results are efficient and promising.
Aspects of fabrication aluminium matrix heterophase composites by suspension method
Dolata, A. J.; Dyzia, M.
2012-05-01
Composites with an aluminium alloy matrix (AlMMC) exhibit several advantageous properties such as good strength, stiffness, low density, resistance and dimensional stability to elevated temperatures, good thermal expansion coefficient and particularly high resistance to friction wear. Therefore such composites are more and more used in modern engineering constructions. Composites reinforced with hard ceramic particles (Al2O3, SiC) are gradually being implemented into production in automotive or aircraft industries. Another application of AlMMC is in the electronics industry, where the dimensional stability and capacity to absorb and remove heat is used in radiators. However the main problems are still: a reduction of production costs, developing methods of composite material tests and final product quality assessment, standardisation, development of recycling and mechanical processing methods. AlMMC production technologies, based on liquid-phase methods, and the shaping of products by casting methods, belong to the cheapest production methods. Application of a suspension method for the production of composites with heterophase reinforcement may turn out to be a new material and technological solution. The article presents the material and technological aspects of the transfer procedures for the production of composite suspensions from laboratory scale to a semi-industrial scale.
Aspects of fabrication aluminium matrix heterophase composites by suspension method
International Nuclear Information System (INIS)
Dolata, A J; Dyzia, M
2012-01-01
Composites with an aluminium alloy matrix (AlMMC) exhibit several advantageous properties such as good strength, stiffness, low density, resistance and dimensional stability to elevated temperatures, good thermal expansion coefficient and particularly high resistance to friction wear. Therefore such composites are more and more used in modern engineering constructions. Composites reinforced with hard ceramic particles (Al 2 O 3 , SiC) are gradually being implemented into production in automotive or aircraft industries. Another application of AlMMC is in the electronics industry, where the dimensional stability and capacity to absorb and remove heat is used in radiators. However the main problems are still: a reduction of production costs, developing methods of composite material tests and final product quality assessment, standardisation, development of recycling and mechanical processing methods. AlMMC production technologies, based on liquid-phase methods, and the shaping of products by casting methods, belong to the cheapest production methods. Application of a suspension method for the production of composites with heterophase reinforcement may turn out to be a new material and technological solution. The article presents the material and technological aspects of the transfer procedures for the production of composite suspensions from laboratory scale to a semi-industrial scale.
Teaching Improvement Model Designed with DEA Method and Management Matrix
Montoneri, Bernard
2014-01-01
This study uses student evaluation of teachers to design a teaching improvement matrix based on teaching efficiency and performance by combining management matrix and data envelopment analysis. This matrix is designed to formulate suggestions to improve teaching. The research sample consists of 42 classes of freshmen following a course of English…
Vibration analysis of pipes conveying fluid by transfer matrix method
International Nuclear Information System (INIS)
Li, Shuai-jun; Liu, Gong-min; Kong, Wei-tao
2014-01-01
Highlights: • A theoretical study on vibration analysis of pipes with FSI is presented. • Pipelines with high fluid pressure and velocity can be solved by developed method. • Several pipeline schemes are discussed to illustrate the application of the method. • The proposed method is easier to apply compared to most existing procedures. • Influence laws of structural and fluid parameters on FSI of pipe are analyzed. -- Abstract: Considering the effects of pipe wall thickness, fluid pressure and velocity, a developed 14-equation model is presented, which describes the fluid–structure interaction behavior of pipelines. The transfer matrix method has been used for numerical modeling of both hydraulic and structural equations. Based on these models and algorithms, several pipeline schemes are presented to illustrate the application of the proposed method. Furthermore, the influence laws of supports, structural properties and fluid parameters on the dynamic response and natural frequencies of pipeline are analyzed, which shows using the optimal supports and structural properties is beneficial to reduce vibration of pipelines
Comparison of matrix exponential methods for fuel burnup calculations
International Nuclear Information System (INIS)
Oh, Hyung Suk; Yang, Won Sik
1999-01-01
Series expansion methods to compute the exponential of a matrix have been compared by applying them to fuel depletion calculations. Specifically, Taylor, Pade, Chebyshev, and rational Chebyshev approximations have been investigated by approximating the exponentials of bum matrices by truncated series of each method with the scaling and squaring algorithm. The accuracy and efficiency of these methods have been tested by performing various numerical tests using one thermal reactor and two fast reactor depletion problems. The results indicate that all the four series methods are accurate enough to be used for fuel depletion calculations although the rational Chebyshev approximation is relatively less accurate. They also show that the rational approximations are more efficient than the polynomial approximations. Considering the computational accuracy and efficiency, the Pade approximation appears to be better than the other methods. Its accuracy is better than the rational Chebyshev approximation, while being comparable to the polynomial approximations. On the other hand, its efficiency is better than the polynomial approximations and is similar to the rational Chebyshev approximation. In particular, for fast reactor depletion calculations, it is faster than the polynomial approximations by a factor of ∼ 1.7. (author). 11 refs., 4 figs., 2 tabs
Matrix mineralogy of the Lance CO3 carbonaceous chondrite: A transmission electron microscope study
International Nuclear Information System (INIS)
Keller, L.P.; Buseck, P.R.
1990-01-01
The Lance CO3 carbonaceous chondrite (CC) is less altered than the CI and CM chondrites and so provides a view of the mineralogy and textures resulting from the earliest stages of aqueous alteration of CCs. Matrix olivine in Lance has been partly altered to fine-grained, Fe-bearing serpentine and poorly crystalline Fe 3+ oxide, a process that required both hydration and oxidation. Serpentine occurs as discrete packets separated from the olivine surfaces by the Fe 3+ oxide. The Fe released during the dissolution of olivine was partly incorporated into the serpentine; the remainder was oxidized to form Fe 3+ oxide. Matrix metal was also altered to produce Fe oxides, leaving the residual metal enriched in Ni. Olivine grains in Lance matrix contain channels along their [100] and [001] directions. The formation and convergence of such channels resulted in a grain-size reduction of the olivine. The alteration was pervasive but incomplete, suggesting a limited availability of fluid. A brief study of two other CO chondrites, Kainsaz and Warrenton, shows that these meteorites do not contain phyllosilicates in their matrices, although both contain Fe 3+ oxide between olivine grains. Prior to its alteration, Lance probably resembled Kainsaz, an unaltered CO3 chondrite. The alteration assemblage in Lance is only slightly different from that in Mokoia and essentially the same as that in C3 xenoliths from Murchison. Alteration products in Lance show greater similarities to CI than to CM chondrites
Methods for converging correlation energies within the dielectric matrix formalism
Dixit, Anant; Claudot, Julien; Gould, Tim; Lebègue, Sébastien; Rocca, Dario
2018-03-01
Within the dielectric matrix formalism, the random-phase approximation (RPA) and analogous methods that include exchange effects are promising approaches to overcome some of the limitations of traditional density functional theory approximations. The RPA-type methods however have a significantly higher computational cost, and, similarly to correlated quantum-chemical methods, are characterized by a slow basis set convergence. In this work we analyzed two different schemes to converge the correlation energy, one based on a more traditional complete basis set extrapolation and one that converges energy differences by accounting for the size-consistency property. These two approaches have been systematically tested on the A24 test set, for six points on the potential-energy surface of the methane-formaldehyde complex, and for reaction energies involving the breaking and formation of covalent bonds. While both methods converge to similar results at similar rates, the computation of size-consistent energy differences has the advantage of not relying on the choice of a specific extrapolation model.
A new version of transfer matrix method for multibody systems
Energy Technology Data Exchange (ETDEWEB)
Rui, Xiaoting, E-mail: ruixt@163.net [Nanjing University of Science and Technology, Institute of Launch Dynamics (China); Bestle, Dieter, E-mail: bestle@b-tu.de [Brandenburg University of Technology, Engineering Mechanics and Vehicle Dynamics (Germany); Zhang, Jianshu, E-mail: zhangdracpa@sina.com; Zhou, Qinbo, E-mail: zqb912-new@163.com [Nanjing University of Science and Technology, Institute of Launch Dynamics (China)
2016-10-15
In order to avoid the global dynamics equations and increase the computational efficiency for multibody system dynamics (MSD), the transfer matrix method of multibody system (MSTMM) has been developed and applied very widely in research and engineering in recent 20 years. It differs from ordinary methods in multibody system dynamics with respect to the feature that there is no need for a global dynamics equation, and it uses low-order matrices for high computational efficiency. For linear systems, MSTMM is exact even if continuous elements like beams are involved. The discrete time MSTMM, however, has to use local linearization. In order to release the method from such approximations, a new version of MSTMM is presented in this paper where translational and angular accelerations, on the one hand, and internal forces and moments, on the other hand, are used as state variables. Already linear relationships among these quantities are utilized, which results in new element transfer matrices and algorithms making the study of multibody systems as simple as the study of single bodies. The proposed approach also allows combining MSTMM with any general numerical integration procedure. Some numerical examples of MSD are given to demonstrate the proposed method.
Protocol independent transmission method in software defined optical network
Liu, Yuze; Li, Hui; Hou, Yanfang; Qiu, Yajun; Ji, Yuefeng
2016-10-01
With the development of big data and cloud computing technology, the traditional software-defined network is facing new challenges (e.i., ubiquitous accessibility, higher bandwidth, more flexible management and greater security). Using a proprietary protocol or encoding format is a way to improve information security. However, the flow, which carried by proprietary protocol or code, cannot go through the traditional IP network. In addition, ultra- high-definition video transmission service once again become a hot spot. Traditionally, in the IP network, the Serial Digital Interface (SDI) signal must be compressed. This approach offers additional advantages but also bring some disadvantages such as signal degradation and high latency. To some extent, HD-SDI can also be regard as a proprietary protocol, which need transparent transmission such as optical channel. However, traditional optical networks cannot support flexible traffics . In response to aforementioned challenges for future network, one immediate solution would be to use NFV technology to abstract the network infrastructure and provide an all-optical switching topology graph for the SDN control plane. This paper proposes a new service-based software defined optical network architecture, including an infrastructure layer, a virtualization layer, a service abstract layer and an application layer. We then dwell on the corresponding service providing method in order to implement the protocol-independent transport. Finally, we experimentally evaluate that proposed service providing method can be applied to transmit the HD-SDI signal in the software-defined optical network.
Analytical methods for study of transmission line lightning protection
International Nuclear Information System (INIS)
Pettersson, Per.
1993-04-01
Transmission line lightning performance is studied by analytical methods. The elements of shielding failure flashovers and back-flashovers are analysed as functions of incidence, response and insulation. Closed-form approximate expressions are sought to enhance understanding of the phenomena. Probabilistic and wave propagation aspects are particularly studied. The electrogeometric model of lightning attraction to structures is used in combination with the log-normal probability distribution of lightning to ground currents. The log-normality is found to be retained for the currents collected by mast-type as well as line-type structures, but with a change of scale. For both types, exceedingly simple formulas for the number of hits are derived. Simple closed-form expressions for the line outage rates from back- flashovers and shielding failure flashovers are derived in a uniform way as functions of the critical currents. The expressions involve the standardized normal distribution function. System response is analysed by use of Laplace transforms in combination with text-book transmission-line theory. Inversion into time domain is accomplished by an approximate asymptotic method producing closed-form results. The back-flashover problem is analysed in particular. Approximate, image type expressions are derived for shunt admittance of wires above, on and under ground for analyses of fast transients. The derivation parallels that for series impedance, now well-known. 3 refs, 5 figs
Huajiao Li; Haizhong An; Xiangyun Gao; Wei Fang
2015-01-01
The co-fluctuation of two time series has often been studied by analysing the correlation coefficient over a selected period. However, in both domestic and global financial markets, there are more than two active time series that fluctuate constantly as a result of various factors, including geographic locations, information communications and so on. In addition to correlation relationships over longer periods, daily co-fluctuation relationships and their transmission features are also import...
Pigarev, Aleksey V.; Bazarov, Timur O.; Fedorov, Vladimir V.; Ryabushkin, Oleg A.
2018-02-01
Most modern systems of the optical image registration are based on the matrices of photosensitive semiconductor heterostructures. However, measurement of radiation intensities up to several MW/cm2 -level using such detectors is a great challenge because semiconductor elements have low optical damage threshold. Reflecting or absorbing filters that can be used for attenuation of radiation intensity, as a rule, distort beam profile. Furthermore, semiconductor based devices have relatively narrow measurement wavelength bandwidth. We introduce a novel matrix method of optical image registration. This approach doesn't require any attenuation when measuring high radiation intensities. A sensitive element is the matrix made of thin transparent piezoelectric crystals that absorb just a small part of incident optical power. Each crystal element has its own set of intrinsic (acoustic) vibration modes. These modes can be exited due to the inverse piezoelectric effect when the external electric field is applied to the crystal sample providing that the field frequency corresponds to one of the vibration mode frequencies. Such piezoelectric resonances (PR) can be observed by measuring the radiofrequency response spectrum of the crystal placed between the capacitor plates. PR frequencies strongly depend on the crystal temperature. Temperature calibration of PR frequencies is conducted in the uniform heating conditions. In the case a crystal matrix is exposed to the laser radiation the incident power can be obtained separately for each crystal element by measuring its PR frequency kinetics providing that the optical absorption coefficient is known. The operating wavelength range of such sensor is restricted by the transmission bandwidth of the applied crystals. A plane matrix constituting of LiNbO3 crystals was assembled in order to demonstrate the possibility of application of the proposed approach. The crystal elements were placed between two electrodes forming a capacitor which
On matrix diffusion: formulations, solution methods and qualitative effects
Carrera, Jesús; Sánchez-Vila, Xavier; Benet, Inmaculada; Medina, Agustín; Galarza, Germán; Guimerà, Jordi
Matrix diffusion has become widely recognized as an important transport mechanism. Unfortunately, accounting for matrix diffusion complicates solute-transport simulations. This problem has led to simplified formulations, partly motivated by the solution method. As a result, some confusion has been generated about how to properly pose the problem. One of the objectives of this work is to find some unity among existing formulations and solution methods. In doing so, some asymptotic properties of matrix diffusion are derived. Specifically, early-time behavior (short tests) depends only on φm2RmDm / Lm2, whereas late-time behavior (long tracer tests) depends only on φmRm, and not on matrix diffusion coefficient or block size and shape. The latter is always true for mean arrival time. These properties help in: (a) analyzing the qualitative behavior of matrix diffusion; (b) explaining one paradox of solute transport through fractured rocks (the apparent dependence of porosity on travel time); (c) discriminating between matrix diffusion and other problems (such as kinetic sorption or heterogeneity); and (d) describing identifiability problems and ways to overcome them. RésuméLa diffusion matricielle est un phénomène reconnu maintenant comme un mécanisme de transport important. Malheureusement, la prise en compte de la diffusion matricielle complique la simulation du transport de soluté. Ce problème a conduit à des formulations simplifiées, en partie à cause de la méthode de résolution. Il s'en est suivi une certaine confusion sur la façon de poser correctement le problème. L'un des objectifs de ce travail est de trouver une certaine unité parmi les formulations et les méthodes de résolution. C'est ainsi que certaines propriétés asymptotiques de la diffusion matricielle ont été dérivées. En particulier, le comportement à l'origine (expériences de traçage courtes) dépend uniquement du terme φm2RmDm / Lm2, alors que le comportement à long terme
Reactor calculation in coarse mesh by finite element method applied to matrix response method
International Nuclear Information System (INIS)
Nakata, H.
1982-01-01
The finite element method is applied to the solution of the modified formulation of the matrix-response method aiming to do reactor calculations in coarse mesh. Good results are obtained with a short running time. The method is applicable to problems where the heterogeneity is predominant and to problems of evolution in coarse meshes where the burnup is variable in one same coarse mesh, making the cross section vary spatially with the evolution. (E.G.) [pt
Description of elastic scattering in U-matrix method
International Nuclear Information System (INIS)
Edneral, V.F.; Troshin, S.M.; Tyurin, N.E.; Khrustalev, O.A.
1975-01-01
The elastic pp-scattering has been analyzed using a generalized reaction matrix (the U-matrix). A good agreement has been reached with the experimental total cross sections for the (pp) reaction beginning with an energy of 30 GeV and for the dsub(t)(dt)(pp) for four ISR energies [ru
Direct determination of scattering time delays using the R-matrix propagation method
International Nuclear Information System (INIS)
Walker, R.B.; Hayes, E.F.
1989-01-01
A direct method for determining time delays for scattering processes is developed using the R-matrix propagation method. The procedure involves the simultaneous generation of the global R matrix and its energy derivative. The necessary expressions to obtain the energy derivative of the S matrix are relatively simple and involve many of the same matrix elements required for the R-matrix propagation method. This method is applied to a simple model for a chemical reaction that displays sharp resonance features. The test results of the direct method are shown to be in excellent agreement with the traditional numerical differentiation method for scattering energies near the resonance energy. However, for sharp resonances the numerical differentiation method requires calculation of the S-matrix elements at many closely spaced energies. Since the direct method presented here involves calculations at only a single energy, one is able to generate accurate energy derivatives and time delays much more efficiently and reliably
Application of the Method Risk Matrix to Radiotherapy. Main Principles
International Nuclear Information System (INIS)
2012-08-01
The published fundamental principles of security, and basic international standards of security for ionizing radiation safety, contain requirements of protection for patients undergoing medical exposure. In accordance with these requirements and fulfilling its responsibility to provide for the application of these rules, the IAEA has been working intensively in the prevention of accidental exposures in radiotherapy, and this has resulted in a series of technical reports on the lessons learned from the research done in very serious events, and also in teaching materials shared for regional courses and accessible on the website for the protection of patients. The lessons learned are necessary but not sufficient, as we continue receiving information about new types of accidental exposures and not all may have been published. We need a more proactive approach, with a systematic, comprehensive and structured manner, to try to find out in advance what other errors may happen, to prevent or detect them early. Among these approaches are the method of the 'risk matrix', which by its relative simplicity can be applied to all radiotherapy service.
Santmyire, B R
2001-05-01
The impact of the human immunodeficiency virus (HIV) epidemic in sub-Saharan Africa on future mortality rates of infants, children, and mothers, life expectancy, and economic growth is profound. Vertical transmission of HIV, transmission from mother to child, is a major factor in the increasing rates of HIV infection in sub-Saharan Africa. Vertical transmission of HIV occurs in utero, intrapartum during labor and delivery, and postpartum during breast-feeding. Because of the large numbers of HIV-infected mothers in developing countries, the majority trials regarding prevention of vertical transmission of HIV have been conducted in sub-Saharan Africa. Thus, sub-Saharan Africa has become a human laboratory, which demonstrates both the successes and failures of preventative methods to reduce vertical transmission of HIV. This review summarizes the body of research dedicated to understanding the pathophysiology of vertical transmission of HIV and pharmacology of inhibition of vertical transmission of HIV. While many debate the ethics of conducting trials in developing countries where effective prevention modalities have been slow to be implemented for economic, social and political reasons, studies continue and researchers continue to discover therapies and preventative methods, which may reduce the future devastation of HIV both in sub-Saharan Africa and throughout the world.
Modern Nondestructive Test Methods for Army Ceramic Matrix Composites
National Research Council Canada - National Science Library
Strand, Douglas J
2008-01-01
.... Ceramic matrix composites (CMC) are potentially good high-temperature structural materials because of their low density, high elastic moduli, high strength, and for those with weak interfaces, surprisingly good damage tolerance...
Wang, An; Cao, Yang; Shi, Quan
2018-01-01
In this paper, we demonstrate a complete version of the convergence theory of the modulus-based matrix splitting iteration methods for solving a class of implicit complementarity problems proposed by Hong and Li (Numer. Linear Algebra Appl. 23:629-641, 2016). New convergence conditions are presented when the system matrix is a positive-definite matrix and an [Formula: see text]-matrix, respectively.
A Concise Method for Storing and Communicating the Data Covariance Matrix
Energy Technology Data Exchange (ETDEWEB)
Larson, Nancy M [ORNL
2008-10-01
The covariance matrix associated with experimental cross section or transmission data consists of several components. Statistical uncertainties on the measured quantity (counts) provide a diagonal contribution. Off-diagonal components arise from uncertainties on the parameters (such as normalization or background) that figure into the data reduction process; these are denoted systematic or common uncertainties, since they affect all data points. The full off-diagonal data covariance matrix (DCM) can be extremely large, since the size is the square of the number of data points. Fortunately, it is not necessary to explicitly calculate, store, or invert the DCM. Likewise, it is not necessary to explicitly calculate, store, or use the inverse of the DCM. Instead, it is more efficient to accomplish the same results using only the various component matrices that appear in the definition of the DCM. Those component matrices are either diagonal or small (the number of data points times the number of data-reduction parameters); hence, this implicit data covariance method requires far less array storage and far fewer computations while producing more accurate results.
Czech Academy of Sciences Publication Activity Database
Axelsson, Owe
2010-01-01
Roč. 5910, - (2010), s. 76-83 ISSN 0302-9743. [International Conference on Large-Scale Scientific Computations, LSSC 2009 /7./. Sozopol, 04.06.2009-08.06.2009] R&D Projects: GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z30860518 Keywords : additive matrix * condition number * domain decomposition Subject RIV: BA - General Mathematics www.springerlink.com
Briones-Torres, J. A.; Pernas-Salomón, R.; Pérez-Álvarez, R.; Rodríguez-Vargas, I.
2016-05-01
Gapless bilayer graphene (GBG), like monolayer graphene, is a material system with unique properties, such as anti-Klein tunneling and intrinsic Fano resonances. These properties rely on the gapless parabolic dispersion relation and the chiral nature of bilayer graphene electrons. In addition, propagating and evanescent electron states coexist inherently in this material, giving rise to these exotic properties. In this sense, bilayer graphene is unique, since in most material systems in which Fano resonance phenomena are manifested an external source that provides extended states is required. However, from a numerical standpoint, the presence of evanescent-divergent states in the eigenfunctions linear superposition representing the Dirac spinors, leads to a numerical degradation (the so called Ωd problem) in the practical applications of the standard Coefficient Transfer Matrix (K) method used to study charge transport properties in Bilayer Graphene based multi-barrier systems. We present here a straightforward procedure based in the hybrid compliance-stiffness matrix method (H) that can overcome this numerical degradation. Our results show that in contrast to standard matrix method, the proposed H method is suitable to study the transmission and transport properties of electrons in GBG superlattice since it remains numerically stable regardless the size of the superlattice and the range of values taken by the input parameters: the energy and angle of the incident electrons, the barrier height and the thickness and number of barriers. We show that the matrix determinant can be used as a test of the numerical accuracy in real calculations.
Yah, Clarence S
2017-11-01
Despite the shift in antiretroviral therapy (ARVs) eligibility cascade from CD4 ≤ 200 to CD4 ≤ 350 to CD4 ≤ 500 mm 3 , HIV related morbidity and mortality continue to escalate annually, as do HIV infections. The new paradigm of treatment for all HIV positives individual irrespective of CD4 count may significantly reduce HIV and related illnesses. The author assumes that all HIV infected partners should be eligible for HIV treatment and care, irrespective of CD4 count. A second assumption is that high risk HIV negative partners have free access to continuum of HIV pre-exposure prophylaxis (PrEP), post exposure prophylaxis (PEP) and other prevention packages. A literature review search was used to extract evidence-based ARVs-HIV treatment and prevention interventions among HIV positives and high risk partners respectively. Only articles published in English and indexed in journal nuclei were used for the study. The information was used to nurture understanding of HIV treatment and prevention approaches as well as HIV incidence multiplier effect among HIV serodiscordant partners. The imputed HIV incident reference was assumed at 1.2 per 100 person-years (2). This was based on the imputation that retention in care, adherence and other predetermined factors are functions of an effective health care delivery system. The model showed a reduced HIV transmission from 1.2 per 100 person-years to 1.032 per 100 person-years in 6 months. The average threshold period of HIV suppressed partners on ARVs to an undetectable level. The combined multiplier protective-effect probability of transmitting HIV from HIV positive partners on ARVs-suppressed viremic load to HIV negative partners on PrEP/PEP-prevention was detected at 86. The model showed a significant reduction in HIV incidence. Placing serodiscordant sexual partners in HIV treatment and prevention plays a significant role in reducing and controlling HIV infection. Therefore, the policy of enrolling all HIV positives
Theoretical treatment of molecular photoionization based on the R-matrix method
International Nuclear Information System (INIS)
Tashiro, Motomichi
2012-01-01
The R-matrix method was implemented to treat molecular photoionization problem based on the UK R-matrix codes. This method was formulated to treat photoionization process long before, however, its application has been mostly limited to photoionization of atoms. Application of the method to valence photoionization as well as inner-shell photoionization process will be presented.
Transformation Matrix for Time Discretization Based on Tustin’s Method
Directory of Open Access Journals (Sweden)
Yiming Jiang
2014-01-01
Full Text Available This paper studies rules in transformation of transfer function through time discretization. A method of using transformation matrix to realize bilinear transform (also known as Tustin’s method is presented. This method can be described as the conversion between the coefficients of transfer functions, which are expressed as transform by certain matrix. For a polynomial of degree n, the corresponding transformation matrix of order n exists and is unique. Furthermore, the transformation matrix can be decomposed into an upper triangular matrix multiplied with another lower triangular matrix. And both have obvious regularity. The proposed method can achieve rapid bilinear transform used in automatic design of digital filter. The result of numerical simulation verifies the correctness of the theoretical results. Moreover, it also can be extended to other similar problems. Example in the last throws light on this point.
Electromagnetic analysis using transmission line variables
Weiner, Maurice
2010-01-01
This book employs a relatively new method for solving electromagnetic problems, one which makes use of a transmission line matrix (TLM). The propagation space is imagined to be filled with this matrix. The propagating fields and physical properties are then mapped onto the matrix. Mathematically, the procedures are identical with the traditional numerical methods; however, the interpretation and physical appeal of the transmission line matrix are far superior. Any change in the matrix has an immediate physical significance. What is also very important is that the matrix becomes a launching pad
Transverse impedance measurement using response matrix fit method at APS
International Nuclear Information System (INIS)
Sajaev, V.
2007-01-01
of an accelerator. The orbit bump method was done at BINP, APS, and ESRF. All these methods have one common feature: they employ the fact that the beam sees the impedance as an additional defocusing quadrupole whose strength depends on the beam current. At APS we use an orbit response matrix fit to determine the distribution of focusing errors around the machine, and then use these errors to calculate beta functions. Since the beam sees the impedance as a quadrupole whose strength depends on the beam current, the measurement of the beta functions with different currents could be used to determine the impedance distribution around the machine. This approach was first used at APS and reported in.
Matrix methods applied to engineering rigid body mechanics
Crouch, T.
The purpose of this book is to present the solution of a range of rigorous body mechanics problems using a matrix formulation of vector algebra. Essential theory concerning kinematics and dynamics is formulated in terms of matrix algebra. The solution of kinematics and dynamics problems is discussed, taking into account the velocity and acceleration of a point moving in a circular path, the velocity and acceleration determination for a linkage, the angular velocity and angular acceleration of a roller in a taper-roller thrust race, Euler's theroem on the motion of rigid bodies, an automotive differential, a rotating epicyclic, the motion of a high speed rotor mounted in gimbals, and the vibration of a spinning projectile. Attention is given to the activity of a force, the work done by a conservative force, the work and potential in a conservative system, the equilibrium of a mechanism, bearing forces due to rotor misalignment, and the frequency of vibrations of a constrained rod.
Inverse mass matrix via the method of localized lagrange multipliers
Czech Academy of Sciences Publication Activity Database
González, José A.; Kolman, Radek; Cho, S.S.; Felippa, C.A.; Park, K.C.
2018-01-01
Roč. 113, č. 2 (2018), s. 277-295 ISSN 0029-5981 R&D Projects: GA MŠk(CZ) EF15_003/0000493; GA ČR GA17-22615S Institutional support: RVO:61388998 Keywords : explicit time integration * inverse mass matrix * localized Lagrange multipliers * partitioned analysis Subject RIV: BI - Acoustics OBOR OECD: Applied mechanics Impact factor: 2.162, year: 2016 https://onlinelibrary.wiley.com/doi/10.1002/nme.5613
Jang, Hwanchol; Yoon, Changhyeong; Choi, Wonshik; Eom, Tae Joong; Lee, Heung-No
2016-03-01
We provide an approach to improve the quality of image reconstruction in wide-field imaging through turbid media (WITM). In WITM, a calibration stage which measures the transmission matrix (TM), the set of responses of turbid medium to a set of plane waves with different incident angles, is preceded to the image recovery. Then, the TM is used for estimation of object image in image recovery stage. In this work, we aim to estimate highly resolved angular spectrum and use it for high quality image reconstruction. To this end, we propose to perform a dense sampling for TM measurement in calibration stage with finer incident angle spacing. In conventional approaches, incident angle spacing is made to be large enough so that the columns in TM are out of memory effect of turbid media. Otherwise, the columns in TM are correlated and the inversion becomes difficult. We employ compressed sensing (CS) for a successful high resolution angular spectrum recovery with dense sampled TM. CS is a relatively new information acquisition and reconstruction framework and has shown to provide superb performance in ill-conditioned inverse problems. We observe that the image quality metrics such as contrast-to-noise ratio and mean squared error are improved and the perceptual image quality is improved with reduced speckle noise in the reconstructed image. This results shows that the WITM performance can be improved only by executing dense sampling in the calibration stage and with an efficient signal reconstruction framework without elaborating the overall optical imaging systems.
A New Method of Creating Technology/Function Matrix for Systematic Innovation without Expert
Directory of Open Access Journals (Sweden)
Tien-Yuan Cheng
2012-02-01
Full Text Available The technology/function matrix is comprised by specific technologies and functions, and through the technology/function matrix we can known what the technologies with functions have opportunities for innovation of product or technology. However, the technology/function matrix is very difficult to create, because the patents need to be read, analyzed and categorized into the technology/function matrix always more than hundreds or thousands. In this research, I propose a method to create a technology/function matrix just need to execute patent search without reading and analyzing patents. Through the proposed method anyone can create a technology/function matrix in a short time without experts’ help even if there are thousands of thousands of patents need to be read and analyzed.
Comparing methods to quantify experimental transmission of infectious agents
Velthuis, A.G.J.; Jong, de M.C.M.; Bree, de J.
2007-01-01
Transmission of an infectious agent can be quantified from experimental data using the transient-state (TS) algorithm. The TS algorithm is based on the stochastic SIR model and provides a time-dependent probability distribution over the number of infected individuals during an epidemic, with no need
Authentication method for safeguards instruments securing data transmission
International Nuclear Information System (INIS)
Richter, B.; Stein, G.; Neumann, G.; Gartner, K.J.
1986-01-01
Because of the worldwide increase in nuclear fuel cycle activities, the need arises to reduce inspection effort by increasing the inspection efficiency per facility. Therefore, more and more advanced safeguards instruments will be designed for automatic operation. In addition, sensoring and recording devices may be well separated from each other within the facility, while the data transmission medium is a cable. The basic problem is the authenticity of the transmitted information. It has to be ensured that no potential adversary is able to falsify the transmitted safeguards data, i.e. the data transmission is secured. At present, predominantly C/S-devices are designed for automatic and remote interrogation. Also in other areas of safeguards instrumentation authentication will become a major issue, in particular, where the facility operator may offer his process instrumentation to be used also for safeguards purposes. In this paper possibilities to solve the problem of authentication are analysed
Experimental Comparison of Probabilistic Shaping Methods for Unrepeated Fiber Transmission
DEFF Research Database (Denmark)
Renner, Julian; Fehenberger, Tobias; Yankov, Metodi Plamenov
2017-01-01
This paper studies the impact of probabilistic shaping on effective signal-to-noise ratios (SNRs) and achievable information rates (AIRs) in a back-to-back configuration and in unrepeated nonlinear fiber transmissions. For back-to-back, various shaped quadrature amplitude modulation (QAM......) distributions are found to have the same implementation penalty as uniform input. By demonstrating in transmission experiments that shaped QAM input leads to lower effective SNR than uniform input at a fixed average launch power, we experimentally confirm that shaping enhances the fiber nonlinearities. However......, shaping is ultimately found to increase the AIR, which is the most relevant figure of merit as it is directly related to spectral efficiency. In a detailed study of these shaping gains for the nonlinear fiber channel, four strategies for optimizing QAM input distributions are evaluated and experimentally...
Method of modeling transmissions for real-time simulation
Hebbale, Kumaraswamy V.
2012-09-25
A transmission modeling system includes an in-gear module that determines an in-gear acceleration when a vehicle is in gear. A shift module determines a shift acceleration based on a clutch torque when the vehicle is shifting between gears. A shaft acceleration determination module determines a shaft acceleration based on at least one of the in-gear acceleration and the shift acceleration.
Another method for a global fit of the Cabibbo-Kobayashi-Maskawa matrix
International Nuclear Information System (INIS)
Dita, Petre
2005-01-01
Recently we proposed a novel method for doing global fits on the entries of the Cabibbo-Kobayashi-Maskawa matrix. The new used ingredients were a clear relationship between the entries of the CKM matrix and the experimental data, as well as the use of the necessary and sufficient condition the data have to satisfy in order to find a unitary matrix compatible with them. This condition writes as -1 ≤ cosδ ≤1 where δ is the phase that accounts for CP violation. Numerical results are provided for the CKM matrix entries, the mixing angles between generations and all the angles of the standard unitarity triangle. (author)
Statistical image reconstruction methods for simultaneous emission/transmission PET scans
International Nuclear Information System (INIS)
Erdogan, H.; Fessler, J.A.
1996-01-01
Transmission scans are necessary for estimating the attenuation correction factors (ACFs) to yield quantitatively accurate PET emission images. To reduce the total scan time, post-injection transmission scans have been proposed in which one can simultaneously acquire emission and transmission data using rod sources and sinogram windowing. However, since the post-injection transmission scans are corrupted by emission coincidences, accurate correction for attenuation becomes more challenging. Conventional methods (emission subtraction) for ACF computation from post-injection scans are suboptimal and require relatively long scan times. We introduce statistical methods based on penalized-likelihood objectives to compute ACFs and then use them to reconstruct lower noise PET emission images from simultaneous transmission/emission scans. Simulations show the efficacy of the proposed methods. These methods improve image quality and SNR of the estimates as compared to conventional methods
Combined backscatter and transmission method for nuclear density gauge
Directory of Open Access Journals (Sweden)
Golgoun Seyed Mohammad
2015-01-01
Full Text Available Nowadays, the use of nuclear density gauges, due to the ability to work in harsh industrial environments, is very common. In this study, to reduce error related to the ρ of continuous measuring density, the combination of backscatter and transmission are used simultaneously. For this reason, a 137Cs source for Compton scattering dominance and two detectors are simulated by MCNP4C code for measuring the density of 3 materials. Important advantages of this combined radiometric gauge are diminished influence of μ and therefore improving linear regression.
Yucel, Abdulkadir C.; Bagci, Hakan; Michielssen, Eric
2015-01-01
An efficient method for statistically characterizing multiconductor transmission line (MTL) networks subject to a large number of manufacturing uncertainties is presented. The proposed method achieves its efficiency by leveraging a high
Directory of Open Access Journals (Sweden)
Sergiu Ciprian Catinas
2015-07-01
Full Text Available A detailed theoretical and practical investigation of the reinforced concrete elements is due to recent techniques and method that are implemented in the construction market. More over a theoretical study is a demand for a better and faster approach nowadays due to rapid development of the calculus technique. The paper above will present a study for implementing in a static calculus the direct stiffness matrix method in order capable to address phenomena related to different stages of loading, rapid change of cross section area and physical properties. The method is a demand due to the fact that in our days the FEM (Finite Element Method is the only alternative to such a calculus and FEM are considered as expensive methods from the time and calculus resources point of view. The main goal in such a method is to create the moment-curvature diagram in the cross section that is analyzed. The paper above will express some of the most important techniques and new ideas as well in order to create the moment curvature graphic in the cross sections considered.
A low delay transmission method of multi-channel video based on FPGA
Fu, Weijian; Wei, Baozhi; Li, Xiaobin; Wang, Quan; Hu, Xiaofei
2018-03-01
In order to guarantee the fluency of multi-channel video transmission in video monitoring scenarios, we designed a kind of video format conversion method based on FPGA and its DMA scheduling for video data, reduces the overall video transmission delay.In order to sace the time in the conversion process, the parallel ability of FPGA is used to video format conversion. In order to improve the direct memory access (DMA) writing transmission rate of PCIe bus, a DMA scheduling method based on asynchronous command buffer is proposed. The experimental results show that this paper designs a low delay transmission method based on FPGA, which increases the DMA writing transmission rate by 34% compared with the existing method, and then the video overall delay is reduced to 23.6ms.
Risk Evaluation on UHV Power Transmission Construction Project Based on AHP and FCE Method
Huiru Zhao; Sen Guo
2014-01-01
Ultra high voltage (UHV) power transmission construction project is a high-tech power grid construction project which faces many risks and uncertainty. Identifying the risk of UHV power transmission construction project can help mitigate the risk loss and promote the smooth construction. The risk evaluation on “Zhejiang-Fuzhou” UHV power transmission construction project was performed based on analytic hierarchy process (AHP) and fuzzy comprehensive evaluation (FCE) method in this paper. Afte...
Method for analysis of averages over transmission energy of resonance neutrons
International Nuclear Information System (INIS)
Komarov, A.V.; Luk'yanov, A.A.
1981-01-01
Experimental data on transmissions on iron specimens in different energy groups have been analyzed on the basis of an earlier developed theoretical model for the description of resonance neutron averages in transmission energy, as the functions of specimen thickness and mean resonance parameters. The parameter values obtained agree with the corresponding data evaluated in the theory of mean neutron cross sections. The method suggested for the transmission description permits to reproduce experimental results for any thicknesses of specimens [ru
A cluster approximation for the transfer-matrix method
International Nuclear Information System (INIS)
Surda, A.
1990-08-01
A cluster approximation for the transfer-method is formulated. The calculation of the partition function of lattice models is transformed to a nonlinear mapping problem. The method yields the free energy, correlation functions and the phase diagrams for a large class of lattice models. The high accuracy of the method is exemplified by the calculation of the critical temperature of the Ising model. (author). 14 refs, 2 figs, 1 tab
Novel image analysis methods for quantification of in situ 3-D tendon cell and matrix strain.
Fung, Ashley K; Paredes, J J; Andarawis-Puri, Nelly
2018-01-23
Macroscopic tendon loads modulate the cellular microenvironment leading to biological outcomes such as degeneration or repair. Previous studies have shown that damage accumulation and the phases of tendon healing are marked by significant changes in the extracellular matrix, but it remains unknown how mechanical forces of the extracellular matrix are translated to mechanotransduction pathways that ultimately drive the biological response. Our overarching hypothesis is that the unique relationship between extracellular matrix strain and cell deformation will dictate biological outcomes, prompting the need for quantitative methods to characterize the local strain environment. While 2-D methods have successfully calculated matrix strain and cell deformation, 3-D methods are necessary to capture the increased complexity that can arise due to high levels of anisotropy and out-of-plane motion, particularly in the disorganized, highly cellular, injured state. In this study, we validated the use of digital volume correlation methods to quantify 3-D matrix strain using images of naïve tendon cells, the collagen fiber matrix, and injured tendon cells. Additionally, naïve tendon cell images were used to develop novel methods for 3-D cell deformation and 3-D cell-matrix strain, which is defined as a quantitative measure of the relationship between matrix strain and cell deformation. The results support that these methods can be used to detect strains with high accuracy and can be further extended to an in vivo setting for observing temporal changes in cell and matrix mechanics during degeneration and healing. Copyright © 2017. Published by Elsevier Ltd.
Discrete-ordinate method with matrix exponential for a pseudo-spherical atmosphere: Scalar case
International Nuclear Information System (INIS)
Doicu, A.; Trautmann, T.
2009-01-01
We present a discrete-ordinate algorithm using the matrix-exponential solution for pseudo-spherical radiative transfer. Following the finite-element technique we introduce the concept of layer equation and formulate the discrete radiative transfer problem in terms of the level values of the radiance. The layer quantities are expressed by means of matrix exponentials, which are computed by using the matrix eigenvalue method and the Pade approximation. These solution methods lead to a compact and versatile formulation of the radiative transfer. Simulated nadir and limb radiances for an aerosol-loaded atmosphere and a cloudy atmosphere are presented along with a discussion of the model intercomparisons and timings
A pedagogical derivation of the matrix element method in particle physics data analysis
Sumowidagdo, Suharyo
2018-03-01
The matrix element method provides a direct connection between the underlying theory of particle physics processes and detector-level physical observables. I am presenting a pedagogically-oriented derivation of the matrix element method, drawing from elementary concepts in probability theory, statistics, and the process of experimental measurements. The level of treatment should be suitable for beginning research student in phenomenology and experimental high energy physics.
The Visual Matrix Method: Imagery and Affect in a Group-Based Research Setting
Directory of Open Access Journals (Sweden)
Lynn Froggett
2015-07-01
Full Text Available The visual matrix is a method for researching shared experience, stimulated by sensory material relevant to a research question. It is led by imagery, visualization and affect, which in the matrix take precedence over discourse. The method enables the symbolization of imaginative and emotional material, which might not otherwise be articulated and allows "unthought" dimensions of experience to emerge into consciousness in a participatory setting. We describe the process of the matrix with reference to the study "Public Art and Civic Engagement" (FROGGETT, MANLEY, ROY, PRIOR & DOHERTY, 2014 in which it was developed and tested. Subsequently, examples of its use in other contexts are provided. Both the matrix and post-matrix discussions are described, as is the interpretive process that follows. Theoretical sources are highlighted: its origins in social dreaming; the atemporal, associative nature of the thinking during and after the matrix which we describe through the Deleuzian idea of the rhizome; and the hermeneutic analysis which draws from object relations theory and the Lorenzerian tradition of scenic understanding. The matrix has been conceptualized as a "scenic rhizome" to account for its distinctive quality and hybrid origins in research practice. The scenic rhizome operates as a "third" between participants and the "objects" of contemplation. We suggest that some of the drawbacks of other group-based methods are avoided in the visual matrix—namely the tendency for inter-personal dynamics to dominate the event. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs150369
International Nuclear Information System (INIS)
Miranda S, Anabel; Landauro S, Carlos
2008-01-01
In the present work the transfer matrix method is employed to study the electronic properties of the Kronig-Penney model including disorder in the periodic system. The results show that although the electronic properties are very similar to the corresponding periodic case, disorder in the system produces a decrease of the transmission in the whole range of energies which indicates clearly a reduction of the electronic transport (conductivity) due to the disorder in the system. (author)
American Society for Testing and Materials. Philadelphia
2004-01-01
1.1 This test method covers the determination of translaminar fracture toughness, KTL, for laminated and pultruded polymer matrix composite materials of various ply orientations using test results from monotonically loaded notched specimens. 1.2 This test method is applicable to room temperature laboratory air environments. 1.3 Composite materials that can be tested by this test method are not limited by thickness or by type of polymer matrix or fiber, provided that the specimen sizes and the test results meet the requirements of this test method. This test method was developed primarily from test results of various carbon fiber – epoxy matrix laminates and from additional results of glass fiber – epoxy matrix, glass fiber-polyester matrix pultrusions and carbon fiber – bismaleimide matrix laminates (1-4, 6, 7). 1.4 A range of eccentrically loaded, single-edge-notch tension, ESE(T), specimen sizes with proportional planar dimensions is provided, but planar size may be variable and adjusted, with asso...
Emergy Algebra: Improving Matrix Methods for Calculating Tranformities
Transformity is one of the core concepts in Energy Systems Theory and it is fundamental to the calculation of emergy. Accurate evaluation of transformities and other emergy per unit values is essential for the broad acceptance, application and further development of emergy method...
Telfeyan, Katherine; Ware, S. Doug; Reimus, Paul W.; Birdsell, Kay H.
2018-02-01
Diffusion cell and diffusion wafer experiments were conducted to compare methods for estimating effective matrix diffusion coefficients in rock core samples from Pahute Mesa at the Nevada Nuclear Security Site (NNSS). A diffusion wafer method, in which a solute diffuses out of a rock matrix that is pre-saturated with water containing the solute, is presented as a simpler alternative to the traditional through-diffusion (diffusion cell) method. Both methods yielded estimates of effective matrix diffusion coefficients that were within the range of values previously reported for NNSS volcanic rocks. The difference between the estimates of the two methods ranged from 14 to 30%, and there was no systematic high or low bias of one method relative to the other. From a transport modeling perspective, these differences are relatively minor when one considers that other variables (e.g., fracture apertures, fracture spacings) influence matrix diffusion to a greater degree and tend to have greater uncertainty than effective matrix diffusion coefficients. For the same relative random errors in concentration measurements, the diffusion cell method yields effective matrix diffusion coefficient estimates that have less uncertainty than the wafer method. However, the wafer method is easier and less costly to implement and yields estimates more quickly, thus allowing a greater number of samples to be analyzed for the same cost and time. Given the relatively good agreement between the methods, and the lack of any apparent bias between the methods, the diffusion wafer method appears to offer advantages over the diffusion cell method if better statistical representation of a given set of rock samples is desired.
Risk Analysis Method Based on FMEA for Transmission Line in Lightning Hazards
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You-Yuan WANG
2014-05-01
Full Text Available Failure rate of transmission line and reliability of power system are significantly affected by Lightning meteorological factor. In view of the complexity and variability of Lightning meteorological factors, this paper presents lightning trip-out rate model of transmission line in considering distribution of ground flash density and lightning day hours. Meanwhile, presents a failure rate model of transmission line in different condition, and a risk analysis method for transmission line considering multiple risk factors based on risk quantification. This method takes Lightning meteorological factor as the main evaluation standard, and establishes risk degree evaluation system for transmission line including another five evaluation standard. Put forward the risk indicators by quantify the risk factors based on experience date of transmission line in service. Based on the risk indexes comprehensive evaluation is conducted, and the evaluation result closer to practice is achieved, providing basis for transmission line risk warning and maintenance strategy. Through the risk analysis for 220 kV transmission line in a certain power supply bureau, the effectiveness of the proposed method is validated.
Chosen interval methods for solving linear interval systems with special type of matrix
Szyszka, Barbara
2013-10-01
The paper is devoted to chosen direct interval methods for solving linear interval systems with special type of matrix. This kind of matrix: band matrix with a parameter, from finite difference problem is obtained. Such linear systems occur while solving one dimensional wave equation (Partial Differential Equations of hyperbolic type) by using the central difference interval method of the second order. Interval methods are constructed so as the errors of method are enclosed in obtained results, therefore presented linear interval systems contain elements that determining the errors of difference method. The chosen direct algorithms have been applied for solving linear systems because they have no errors of method. All calculations were performed in floating-point interval arithmetic.
Sharpening methods for images captured through Bayer matrix
Kalevo, Ossi; Rantanen, Henry, Jr.
2003-05-01
Image resolution and sharpness are essential criteria for a human observer when estimating the image quality. Typically cheap small-sized, low-resolution CMOS-camera sensors do not provide sharp enough images, at least when comparing to high-end digital cameras. Sharpening function can be used to increase the subjective sharpness seen by the observer. In this paper, few methods to apply sharpening for images captured by CMOS imaging sensors through color filter array (CFA) are compared. The sharpening easily adds also the visibility of noise, pixel-cross talk and interpolation artifacts. Necessary arrangements to avoid the amplification of these unwanted phenomenon are discussed. By applying the sharpening only to the green component the processing power requirements can be clearly reduced. By adjusting the red and blue component sharpness, according to the green component sharpening, creation of false colors are reduced highly. Direction search sharpening method can be used to reduce the amplification of the artifacts caused by the CFA interpolation (CFAI). The comparison of the presented methods is based mainly on subjective image quality. Also the processing power and memory requirements are considered.
A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix
Hu, Zongliang
2017-09-27
The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.
A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix.
Hu, Zongliang; Dong, Kai; Dai, Wenlin; Tong, Tiejun
2017-09-21
The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.
A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix
Hu, Zongliang; Dong, Kai; Dai, Wenlin; Tong, Tiejun
2017-01-01
The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.
NewIn-situ synthesis method of magnesium matrix composites reinforced with TiC particulates
Directory of Open Access Journals (Sweden)
Zhang Xiuqing
2006-12-01
Full Text Available Magnesium matrix composites reinforced with TiC particulates was prepared using a new in-situ synthesis method of remelting and dilution technique. And measurements were performed on the composites. The results of x ray diffraction (XRD analysis confirmed that TiC particulates were synthesized during the sintering process, and they retained in magnesium matrix composites after the remelting and dilution processing. From the microstructure characterization and electron probe microanalysis (EPMA, we could see that fine TiC particulates distributed uniformly in the matrix material.
Discrete-ordinate method with matrix exponential for a pseudo-spherical atmosphere: Vector case
International Nuclear Information System (INIS)
Doicu, A.; Trautmann, T.
2009-01-01
The paper is devoted to the extension of the matrix-exponential formalism for the scalar radiative transfer to the vector case. Using basic results of the theory of matrix-exponential functions we provide a compact and versatile formulation of the vector radiative transfer. As in the scalar case, we operate with the concept of the layer equation incorporating the level values of the Stokes vector. The matrix exponentials which enter in the expression of the layer equation are computed by using the matrix eigenvalue method and the Pade approximation. A discussion of the computational efficiency of the proposed method for both an aerosol-loaded atmosphere as well as a cloudy atmosphere is also provided
Application of the R-matrix method to photoionization of molecules.
Tashiro, Motomichi
2010-04-07
The R-matrix method has been used for theoretical calculation of electron collision with atoms and molecules for long years. The method was also formulated to treat photoionization process, however, its application has been mostly limited to photoionization of atoms. In this work, we implement the R-matrix method to treat molecular photoionization problem based on the UK R-matrix codes. This method can be used for diatomic as well as polyatomic molecules, with multiconfigurational description for electronic states of both target neutral molecule and product molecular ion. Test calculations were performed for valence electron photoionization of nitrogen (N(2)) as well as nitric oxide (NO) molecules. Calculated photoionization cross sections and asymmetry parameters agree reasonably well with the available experimental results, suggesting usefulness of the method for molecular photoionization.
Imagining transitions in old age through the Visual Matrix method
DEFF Research Database (Denmark)
Liveng, Anne; Ramvi, Ellen; Froggett, Lynn
2017-01-01
Dominant discourses of ageing are often confined to what is less painful to think about and therefore idealise or denigrate ageing and later life. We present findings from an exploratory psychosocial study, in a Nordic context, into three later-life transitions: from working life to retirement, f......-generational continuity, which together link life and death, hope and despair, separation and connectedness.......Dominant discourses of ageing are often confined to what is less painful to think about and therefore idealise or denigrate ageing and later life. We present findings from an exploratory psychosocial study, in a Nordic context, into three later-life transitions: from working life to retirement......, from mental health to dementia and from life to death. Because, for some, these topics are hard to bear and therefore defended against and routinely excluded from everyday awareness, we used a method led by imagery and affect–the Visual Matrix–to elicit participant s’ free associative personal...
The matrix method for radiological characterization of radioactive waste
Magistris, M
2007-01-01
Beam losses are responsible for material activation in some of the components of particle accelerators. The activation is caused by several nuclear processes and varies with the irradiation history and the characteristics of the material (namely chemical composition and size). Once at the end of their operational lifetime, these materials require radiological characterization. The radionuclide inventory depends on the particle spectrum, the irradiation history and the chemical composition of the material. As long as these factors are known and the material cross-sections are available, the induced radioactivity can be calculated analytically. However, these factors vary widely among different items of waste and sometimes they are only partially known. The European Laboratory for Particle Physics (CERN, Geneva) has been operating accelerators for high-energy physics for 50 years. Different methods for the evaluation of the radionuclide inventory are currently under investigation at CERN, including the so-calle...
Pascual Pañach, Josep
2010-01-01
Leaks are present in all water distribution systems. In this paper a method for leakage detection and localisation is presented. It uses pressure measurements and simulation models. Leakage localisation methodology is based on pressure sensitivity matrix. Sensitivity is normalised and binarised using a common threshold for all nodes, so a signatures matrix is obtained. A pressure sensor optimal distribution methodology is developed too, but it is not used in the real test. To validate this...
Three-body forces for electrons by the S-matrix method
International Nuclear Information System (INIS)
Margaritelli, R.
1989-01-01
A electromagnetic three-body potential between eletrons is derived by the S-matrix method. This potential can be compared up to a certain point with other electromagnetic potentials (obtained by other methods) encountered in the literature. However, since the potential derived here is far more complete than others, this turns direct comparison with the potentials found in the literature somewhat difficult. These calculations allow a better understanding of the S-matrix method as applied to problems which involve the calculations of three-body nuclear forces (these calculations are performed in order to understand the 3 He form factor). Furthermore, these results enable us to decide between two discrepant works which derive the two-pion exchange three-body potential, both by the S-matrix method. (author) [pt
A New Pseudoinverse Matrix Method For Balancing Chemical Equations And Their Stability
International Nuclear Information System (INIS)
Risteski, Ice B.
2008-01-01
In this work is given a new pseudoniverse matrix method for balancing chemical equations. Here offered method is founded on virtue of the solution of a Diophantine matrix equation by using of a Moore-Penrose pseudoinverse matrix. The method has been tested on several typical chemical equations and found to be very successful for the all equations in our extensive balancing research. This method, which works successfully without any limitations, also has the capability to determine the feasibility of a new chemical reaction, and if it is feasible, then it will balance the equation. Chemical equations treated here possess atoms with fractional oxidation numbers. Also, in the present work are introduced necessary and sufficient criteria for stability of chemical equations over stability of their extended matrices
Novel Direction Of Arrival Estimation Method Based on Coherent Accumulation Matrix Reconstruction
Directory of Open Access Journals (Sweden)
Li Lei
2015-04-01
Full Text Available Based on coherent accumulation matrix reconstruction, a novel Direction Of Arrival (DOA estimation decorrelation method of coherent signals is proposed using a small sample. First, the Signal to Noise Ratio (SNR is improved by performing coherent accumulation operation on an array of observed data. Then, according to the structure characteristics of the accumulated snapshot vector, the equivalent covariance matrix, whose rank is the same as the number of array elements, is constructed. The rank of this matrix is proved to be determined just by the number of incident signals, which realize the decorrelation of coherent signals. Compared with spatial smoothing method, the proposed method performs better by effectively avoiding aperture loss with high-resolution characteristics and low computational complexity. Simulation results demonstrate the efficiency of the proposed method.
The Evaluation Method of the Lightning Strike on Transmission Lines Aiming at Power Grid Reliability
Wen, Jianfeng; Wu, Jianwei; Huang, Liandong; Geng, Yinan; Yu, zhanqing
2018-01-01
Lightning protection of power system focuses on reducing the flashover rate, only distinguishing by the voltage level, without considering the functional differences between the transmission lines, and being lack of analysis the effect on the reliability of power grid. This will lead lightning protection design of general transmission lines is surplus but insufficient for key lines. In order to solve this problem, the analysis method of lightning striking on transmission lines for power grid reliability is given. Full wave process theory is used to analyze the lightning back striking; the leader propagation model is used to describe the process of shielding failure of transmission lines. The index of power grid reliability is introduced and the effect of transmission line fault on the reliability of power system is discussed in detail.
Directory of Open Access Journals (Sweden)
Andrews Nick
2006-07-01
Full Text Available Abstract Background Noroviruses are highly infectious pathogens that cause gastroenteritis in the community and in semi-closed institutions such as hospitals. During outbreaks, multiple units within a hospital are often affected, and a major question for control programs is: are the affected units part of the same outbreak or are they unrelated transmission events? In practice, investigators often assume a transmission link based on epidemiological observations, rather than a systematic approach to tracing transmission. Here, we present a combined molecular and statistical method for assessing: 1 whether observed clusters provide evidence of local transmission and 2 the probability that anecdotally|linked outbreaks truly shared a transmission event. Methods 76 healthcare associated outbreaks were observed in an active and prospective surveillance scheme of 15 hospitals in the county of Avon, England from April 2002 to March 2003. Viral RNA from 64 out of 76 specimens from distinct outbreaks was amplified by reverse transcription-PCR and was sequenced in the polymerase (ORF 1 and capsid (ORF 2 regions. The genetic diversity, at the nucleotide level, was analysed in relation to the epidemiological patterns. Results Two out of four genetic and epidemiological clusters of outbreaks were unlikely to have occurred by chance alone, thus suggesting local transmission. There was anecdotal epidemiological evidence of a transmission link among 5 outbreaks pairs. By combining this epidemiological observation with viral sequence data, the evidence of a link remained convincing in 3 of these pairs. These results are sensitive to prior beliefs of the strength of epidemiological evidence especially when the outbreak strains are common in the background population. Conclusion The evidence suggests that transmission between hospitals units does occur. Using the proposed criteria, certain hypothesized transmission links between outbreaks were supported while
A high-speed transmission method for large-scale marine seismic prospecting systems
International Nuclear Information System (INIS)
KeZhu, Song; Ping, Cao; JunFeng, Yang; FuMing, Ruan
2012-01-01
A marine seismic prospecting system is a kind of data acquisition and transmission system with large-scale coverage and synchronous multi-node acquisition. In this kind of system, data transmission is a fundamental and difficult technique. In this paper, a high-speed data-transmission method is proposed, its implications and limitations are discussed, and conclusions are drawn. The method we propose has obvious advantages over traditional techniques with respect to long-distance operation, high speed, and real-time transmission. A marine seismic system with four streamers, each 6000 m long and capable of supporting up to 1920 channels, was designed and built based on this method. The effective transmission baud rate of this system was found to reach up to 240 Mbps, while the minimum sampling interval time was as short as 0.25 ms. This system was found to achieve a good synchronization: 83 ns. Laboratory and in situ experiments showed that this marine-prospecting system could work correctly and robustly, which verifies the feasibility and validity of the method proposed in this paper. In addition to the marine seismic applications, this method can also be used in land seismic applications and certain other transmission applications such as environmental or engineering monitoring systems. (paper)
A high-speed transmission method for large-scale marine seismic prospecting systems
KeZhu, Song; Ping, Cao; JunFeng, Yang; FuMing, Ruan
2012-12-01
A marine seismic prospecting system is a kind of data acquisition and transmission system with large-scale coverage and synchronous multi-node acquisition. In this kind of system, data transmission is a fundamental and difficult technique. In this paper, a high-speed data-transmission method is proposed, its implications and limitations are discussed, and conclusions are drawn. The method we propose has obvious advantages over traditional techniques with respect to long-distance operation, high speed, and real-time transmission. A marine seismic system with four streamers, each 6000 m long and capable of supporting up to 1920 channels, was designed and built based on this method. The effective transmission baud rate of this system was found to reach up to 240 Mbps, while the minimum sampling interval time was as short as 0.25 ms. This system was found to achieve a good synchronization: 83 ns. Laboratory and in situ experiments showed that this marine-prospecting system could work correctly and robustly, which verifies the feasibility and validity of the method proposed in this paper. In addition to the marine seismic applications, this method can also be used in land seismic applications and certain other transmission applications such as environmental or engineering monitoring systems.
On the generalized eigenvalue method for energies and matrix elements in lattice field theory
Energy Technology Data Exchange (ETDEWEB)
Blossier, Benoit [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Paris-XI Univ., 91 - Orsay (France). Lab. de Physique Theorique; Morte, Michele della [CERN, Geneva (Switzerland). Physics Dept.]|[Mainz Univ. (Germany). Inst. fuer Kernphysik; Hippel, Georg von; Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Mendes, Tereza [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Sao Paulo Univ. (Brazil). IFSC
2009-02-15
We discuss the generalized eigenvalue problem for computing energies and matrix elements in lattice gauge theory, including effective theories such as HQET. It is analyzed how the extracted effective energies and matrix elements converge when the time separations are made large. This suggests a particularly efficient application of the method for which we can prove that corrections vanish asymptotically as exp(-(E{sub N+1}-E{sub n}) t). The gap E{sub N+1}-E{sub n} can be made large by increasing the number N of interpolating fields in the correlation matrix. We also show how excited state matrix elements can be extracted such that contaminations from all other states disappear exponentially in time. As a demonstration we present numerical results for the extraction of ground state and excited B-meson masses and decay constants in static approximation and to order 1/m{sub b} in HQET. (orig.)
A Lexicographic Method for Matrix Games with Payoffs of Triangular Intuitionistic Fuzzy Numbers
Directory of Open Access Journals (Sweden)
Jiang-Xia Nan
2010-09-01
Full Text Available The intuitionistic fuzzy set (IF-set has not been applied to matrix game problems yet since it was introduced by K.T.Atanassov. The aim of this paper is to develop a methodology for solving matrix games with payoffs of triangular intuitionistic fuzzy numbers (TIFNs. Firstly the concept of TIFNs and their arithmetic operations and cut sets are introduced as well as the ranking order relations. Secondly the concept of solutions for matrix games with payoffs of TIFNs is defined. A lexicographic methodology is developed to determine the solutions of matrix games with payoffs of TIFNs for both Players through solving a pair of bi-objective linear programming models derived from two new auxiliary intuitionistic fuzzy programming models. The proposed method is illustrated with a numerical example.
On the generalized eigenvalue method for energies and matrix elements in lattice field theory
International Nuclear Information System (INIS)
Blossier, Benoit; Mendes, Tereza; Sao Paulo Univ.
2009-02-01
We discuss the generalized eigenvalue problem for computing energies and matrix elements in lattice gauge theory, including effective theories such as HQET. It is analyzed how the extracted effective energies and matrix elements converge when the time separations are made large. This suggests a particularly efficient application of the method for which we can prove that corrections vanish asymptotically as exp(-(E N+1 -E n ) t). The gap E N+1 -E n can be made large by increasing the number N of interpolating fields in the correlation matrix. We also show how excited state matrix elements can be extracted such that contaminations from all other states disappear exponentially in time. As a demonstration we present numerical results for the extraction of ground state and excited B-meson masses and decay constants in static approximation and to order 1/m b in HQET. (orig.)
A Synthetic Approach to the Transfer Matrix Method in Classical and Quantum Physics
Pujol, O.; Perez, J. P.
2007-01-01
The aim of this paper is to propose a synthetic approach to the transfer matrix method in classical and quantum physics. This method is an efficient tool to deal with complicated physical systems of practical importance in geometrical light or charged particle optics, classical electronics, mechanics, electromagnetics and quantum physics. Teaching…
Roundtrip matrix method for calculating the leaky resonant modes of open nanophotonic structures
DEFF Research Database (Denmark)
de Lasson, Jakob Rosenkrantz; Kristensen, Philip Trøst; Mørk, Jesper
2014-01-01
We present a numerical method for calculating quasi-normal modes of open nanophotonic structures. The method is based on scattering matrices and a unity eigenvalue of the roundtrip matrix of an internal cavity, and we develop it in detail with electromagnetic fields expanded on Bloch modes...
Evaluation of the streaming-matrix method for discrete-ordinates duct-streaming calculations
International Nuclear Information System (INIS)
Clark, B.A.; Urban, W.T.; Dudziak, D.J.
1983-01-01
A new deterministic streaming technique called the Streaming Matrix Hybrid Method (SMHM) is applied to two realistic duct-shielding problems. The results are compared to standard discrete-ordinates and Monte Carlo calculations. The SMHM shows promise as an alternative deterministic streaming method to standard discrete-ordinates
Method of computer algebraic calculation of the matrix elements in the second quantization language
International Nuclear Information System (INIS)
Gotoh, Masashi; Mori, Kazuhide; Itoh, Reikichi
1995-01-01
An automated method by the algebraic programming language REDUCE3 for specifying the matrix elements expressed in second quantization language is presented and then applied to the case of the matrix elements in the TDHF theory. This program works in a very straightforward way by commuting the electron creation and annihilation operator (a † and a) until these operators have completely vanished from the expression of the matrix element under the appropriate elimination conditions. An improved method using singlet generators of unitary transformations in the place of the electron creation and annihilation operators is also presented. This improvement reduces the time and memory required for the calculation. These methods will make programming in the field of quantum chemistry much easier. 11 refs., 1 tab
Directory of Open Access Journals (Sweden)
Ayşe Betül Koç
2014-01-01
Full Text Available A pseudospectral method based on the Fibonacci operational matrix is proposed to solve generalized pantograph equations with linear functional arguments. By using this method, approximate solutions of the problems are easily obtained in form of the truncated Fibonacci series. Some illustrative examples are given to verify the efficiency and effectiveness of the proposed method. Then, the numerical results are compared with other methods.
Improvement of the Convergence of the Invariant Imbedding T-Matrix Method
Zhai, S.; Panetta, R. L.; Yang, P.
2017-12-01
The invariant imbedding T-matrix method (IITM) is based on an electromagnetic volume integral equation to compute the T-matrix of an arbitrary scattering particle. A free-space Green's function is chosen as the integral kernel and thus each source point is placed in an imaginary vacuum spherical shell extending from the center to that source point. The final T-matrix (of the largest circumscribing sphere) is obtained through an iterative relation that, layer by layer, computes the T-matrix from the particle center to the outermost shell. On each spherical shell surface, an integration of the product of the refractive index 𝜀(𝜃, 𝜑) and vector spherical harmonics must be performed, resulting in the so-called U-matrix, which directly leads to the T-matrix on the spherical surface. Our observations indicate that the matrix size and sparseness are determined by the particular refractive index function 𝜀(𝜃, 𝜑). If 𝜀(𝜃, 𝜑) is an analytic function on the surface, then the matrix elements resulting from the integration decay rapidly, leading to sparse matrix; if 𝜀(𝜃, 𝜑) is not (for example, contains jump discontinuities), then the matrix elements decay slowly, leading to a large dense matrix. The intersection between an irregular scatterer and each spherical shell can leave jump discontinuities in 𝜀(𝜃, 𝜑) distributed over the shell surface. The aforementioned feature is analogous to the Gibbs phenomenon appearing in the orthogonal expansion of non-smooth functions with Hermitian eigenfunctions (complex exponential, Legendre, Bessel,...) where poor convergence speed is a direct consequence of the slow decay rate of the expansion coefficients. Various methods have been developed to deal with this slow convergence in the presence of discontinuities. Among the different approaches the most practical one may be a spectral filter: a filter is applied on the
A Globally Convergent Matrix-Free Method for Constrained Equations and Its Linear Convergence Rate
Directory of Open Access Journals (Sweden)
Min Sun
2014-01-01
Full Text Available A matrix-free method for constrained equations is proposed, which is a combination of the well-known PRP (Polak-Ribière-Polyak conjugate gradient method and the famous hyperplane projection method. The new method is not only derivative-free, but also completely matrix-free, and consequently, it can be applied to solve large-scale constrained equations. We obtain global convergence of the new method without any differentiability requirement on the constrained equations. Compared with the existing gradient methods for solving such problem, the new method possesses linear convergence rate under standard conditions, and a relax factor γ is attached in the update step to accelerate convergence. Preliminary numerical results show that it is promising in practice.
A Predictive-Control-Based Over-Modulation Method for Conventional Matrix Converters
DEFF Research Database (Denmark)
Zhang, Guanguan; Yang, Jian; Sun, Yao
2018-01-01
To increase the voltage transfer ratio of the matrix converter and improve the input/output current performance simultaneously, an over-modulation method based on predictive control is proposed in this paper, where the weighting factor is selected by an automatic adjusting mechanism, which is able...... to further enhance the system performance promptly. This method has advantages like the maximum voltage transfer ratio can reach 0.987 in the experiments; the total harmonic distortion of the input and output current are reduced, and the losses in the matrix converter are decreased. Moreover, the specific...
Directory of Open Access Journals (Sweden)
Tamer Ahmed El-Sayed
2017-01-01
Full Text Available The exact solution for multistepped Timoshenko beam is derived using a set of fundamental solutions. This set of solutions is derived to normalize the solution at the origin of the coordinates. The start, end, and intermediate boundary conditions involve concentrated masses and linear and rotational elastic supports. The beam start, end, and intermediate equations are assembled using the present normalized transfer matrix (NTM. The advantage of this method is that it is quicker than the standard method because the size of the complete system coefficient matrix is 4 × 4. In addition, during the assembly of this matrix, there are no inverse matrix steps required. The validity of this method is tested by comparing the results of the current method with the literature. Then the validity of the exact stepped analysis is checked using experimental and FE(3D methods. The experimental results for stepped beams with single step and two steps, for sixteen different test samples, are in excellent agreement with those of the three-dimensional finite element FE(3D. The comparison between the NTM method and the finite element method results shows that the modal percentage deviation is increased when a beam step location coincides with a peak point in the mode shape. Meanwhile, the deviation decreases when a beam step location coincides with a straight portion in the mode shape.
Matrix-based system reliability method and applications to bridge networks
International Nuclear Information System (INIS)
Kang, W.-H.; Song Junho; Gardoni, Paolo
2008-01-01
Using a matrix-based system reliability (MSR) method, one can estimate the probabilities of complex system events by simple matrix calculations. Unlike existing system reliability methods whose complexity depends highly on that of the system event, the MSR method describes any general system event in a simple matrix form and therefore provides a more convenient way of handling the system event and estimating its probability. Even in the case where one has incomplete information on the component probabilities and/or the statistical dependence thereof, the matrix-based framework enables us to estimate the narrowest bounds on the system failure probability by linear programming. This paper presents the MSR method and applies it to a transportation network consisting of bridge structures. The seismic failure probabilities of bridges are estimated by use of the predictive fragility curves developed by a Bayesian methodology based on experimental data and existing deterministic models of the seismic capacity and demand. Using the MSR method, the probability of disconnection between each city/county and a critical facility is estimated. The probability mass function of the number of failed bridges is computed as well. In order to quantify the relative importance of bridges, the MSR method is used to compute the conditional probabilities of bridge failures given that there is at least one city disconnected from the critical facility. The bounds on the probability of disconnection are also obtained for cases with incomplete information
Research on Condition Assessment Method of Transmission Tower Under the Action of Strong Wind
Huang, Ren-mou; An, Li-qiang; Zhang, Rong-lun; Wu, Jiong; Liang, Ya-feng
2018-03-01
Transmission towers are often subjected to the external damage of severe weather like strong wind and so on, which may cause the collapse due to the yield and fracture of the tower material. Aiming this issue, an assessment method was proposed in this paper to assess the operation condition of transmission towers under strong wind. With a reasonable assess index system established firstly, then the internal force of the tower material was solved and its stability was determined through the mechanical analysis of the transmission tower finite element model. Meanwhile, the condition risk level of the tower was finally determined by considering the difference among the influences of other factors like corrosion and loose of members, slope on the transmission tower through the analytic hierarchy process. The assessment method was applied to assess the wind-induced collapse of towers in 110kV Bao Yi II line in Wenchang City, Hainan Province, of which the result proves the method can assess the condition of transmission tower under strong wind and of guiding significance for improving the windproof capability of transmission towers.
Energy Technology Data Exchange (ETDEWEB)
Telfeyan, Katherine Christina [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ware, Stuart Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Birdsell, Kay Hanson [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-11-06
Diffusion cell and diffusion wafer experiments were conducted to compare methods for estimating matrix diffusion coefficients in rock core samples from Pahute Mesa at the Nevada Nuclear Security Site (NNSS). A diffusion wafer method, in which a solute diffuses out of a rock matrix that is pre-saturated with water containing the solute, is presented as a simpler alternative to the traditional through-diffusion (diffusion cell) method. Both methods yielded estimates of matrix diffusion coefficients that were within the range of values previously reported for NNSS volcanic rocks. The difference between the estimates of the two methods ranged from 14 to 30%, and there was no systematic high or low bias of one method relative to the other. From a transport modeling perspective, these differences are relatively minor when one considers that other variables (e.g., fracture apertures, fracture spacings) influence matrix diffusion to a greater degree and tend to have greater uncertainty than diffusion coefficients. For the same relative random errors in concentration measurements, the diffusion cell method yields diffusion coefficient estimates that have less uncertainty than the wafer method. However, the wafer method is easier and less costly to implement and yields estimates more quickly, thus allowing a greater number of samples to be analyzed for the same cost and time. Given the relatively good agreement between the methods, and the lack of any apparent bias between the methods, the diffusion wafer method appears to offer advantages over the diffusion cell method if better statistical representation of a given set of rock samples is desired.
The Split Coefficient Matrix method for hyperbolic systems of gasdynamic equations
Chakravarthy, S. R.; Anderson, D. A.; Salas, M. D.
1980-01-01
The Split Coefficient Matrix (SCM) finite difference method for solving hyperbolic systems of equations is presented. This new method is based on the mathematical theory of characteristics. The development of the method from characteristic theory is presented. Boundary point calculation procedures consistent with the SCM method used at interior points are explained. The split coefficient matrices that define the method for steady supersonic and unsteady inviscid flows are given for several examples. The SCM method is used to compute several flow fields to demonstrate its accuracy and versatility. The similarities and differences between the SCM method and the lambda-scheme are discussed.
Linear programming models and methods of matrix games with payoffs of triangular fuzzy numbers
Li, Deng-Feng
2016-01-01
This book addresses two-person zero-sum finite games in which the payoffs in any situation are expressed with fuzzy numbers. The purpose of this book is to develop a suite of effective and efficient linear programming models and methods for solving matrix games with payoffs in fuzzy numbers. Divided into six chapters, it discusses the concepts of solutions of matrix games with payoffs of intervals, along with their linear programming models and methods. Furthermore, it is directly relevant to the research field of matrix games under uncertain economic management. The book offers a valuable resource for readers involved in theoretical research and practical applications from a range of different fields including game theory, operational research, management science, fuzzy mathematical programming, fuzzy mathematics, industrial engineering, business and social economics. .
Graphene-Reinforced Aluminum Matrix Composites: A Review of Synthesis Methods and Properties
Chen, Fei; Gupta, Nikhil; Behera, Rakesh K.; Rohatgi, Pradeep K.
2018-06-01
Graphene-reinforced aluminum (Gr-Al) matrix nanocomposites (NCs) have attracted strong interest from both research and industry in high-performance weight-sensitive applications. Due to the vastly different bonding characteristics of the Al matrix (metallic) and graphene (in-plane covalent + inter-plane van der Waals), the graphene phase has a general tendency to agglomerate and phase separate in the metal matrix, which is detrimental for the mechanical and chemical properties of the composite. Thus, synthesis of Gr-Al NCs is extremely challenging. This review summarizes the different methods available to synthesize Gr-Al NCs and the resulting properties achieved in these NCs. Understanding the effect of processing parameters on the realized properties opens up the possibility of tailoring the synthesis methods to achieve the desired properties for a given application.
Graphene-Reinforced Aluminum Matrix Composites: A Review of Synthesis Methods and Properties
Chen, Fei; Gupta, Nikhil; Behera, Rakesh K.; Rohatgi, Pradeep K.
2018-03-01
Graphene-reinforced aluminum (Gr-Al) matrix nanocomposites (NCs) have attracted strong interest from both research and industry in high-performance weight-sensitive applications. Due to the vastly different bonding characteristics of the Al matrix (metallic) and graphene (in-plane covalent + inter-plane van der Waals), the graphene phase has a general tendency to agglomerate and phase separate in the metal matrix, which is detrimental for the mechanical and chemical properties of the composite. Thus, synthesis of Gr-Al NCs is extremely challenging. This review summarizes the different methods available to synthesize Gr-Al NCs and the resulting properties achieved in these NCs. Understanding the effect of processing parameters on the realized properties opens up the possibility of tailoring the synthesis methods to achieve the desired properties for a given application.
J-matrix method of scattering in one dimension: The nonrelativistic theory
International Nuclear Information System (INIS)
Alhaidari, A.D.; Bahlouli, H.; Abdelmonem, M.S.
2009-01-01
We formulate a theory of nonrelativistic scattering in one dimension based on the J-matrix method. The scattering potential is assumed to have a finite range such that it is well represented by its matrix elements in a finite subset of a basis that supports a tridiagonal matrix representation for the reference wave operator. Contrary to our expectation, the 1D formulation reveals a rich and highly nontrivial structure compared to the 3D formulation. Examples are given to demonstrate the utility and accuracy of the method. It is hoped that this formulation constitutes a viable alternative to the classical treatment of 1D scattering problem and that it will help unveil new and interesting applications.
Solution of the Multigroup-Diffusion equation by the response matrix method
International Nuclear Information System (INIS)
Oliveira, C.R.E.
1980-10-01
A preliminary analysis of the response matrix method is made, considering its application to the solution of the multigroup diffusion equations. The one-dimensional formulation is presented and used to test some flux expansions, seeking the application of the method to the two-dimensional problem. This formulation also solves the equations that arise from the integro-differential synthesis algorithm. The slow convergence of the power method, used to solve the eigenvalue problem, and its acceleration by means of the Chebyshev polynomial method, are also studied. An algorithm for the estimation of the dominance ratio is presented, based on the residues of two successive iteration vectors. This ratio, which is not known a priori, is fundamental for the efficiency of the method. Some numerical problems are solved, testing the 1D formulation of the response matrix method, its application to the synthesis algorithm and also, at the same time, the algorithm to accelerate the source problem. (Author) [pt
Liang, Sai; Qu, Shen; Xu, Ming
2016-02-02
To develop industry-specific policies for mitigating environmental pressures, previous studies primarily focus on identifying sectors that directly generate large amounts of environmental pressures (a.k.a. production-based method) or indirectly drive large amounts of environmental pressures through supply chains (e.g., consumption-based method). In addition to those sectors as important environmental pressure producers or drivers, there exist sectors that are also important to environmental pressure mitigation as transmission centers. Economy-wide environmental pressure mitigation might be achieved by improving production efficiency of these key transmission sectors, that is, using less upstream inputs to produce unitary output. We develop a betweenness-based method to measure the importance of transmission sectors, borrowing the betweenness concept from network analysis. We quantify the betweenness of sectors by examining supply chain paths extracted from structural path analysis that pass through a particular sector. We take China as an example and find that those critical transmission sectors identified by betweenness-based method are not always identifiable by existing methods. This indicates that betweenness-based method can provide additional insights that cannot be obtained with existing methods on the roles individual sectors play in generating economy-wide environmental pressures. Betweenness-based method proposed here can therefore complement existing methods for guiding sector-level environmental pressure mitigation strategies.
International Nuclear Information System (INIS)
Sarma, J.; Robson, P.N.
1979-01-01
The two dimensional transmission line matrix (TLM) numerical method has been adapted to compute electromagnetic field distributions in cylindrical co-ordinates and it is applied to evaluate the radiation loss from a charge bunch passing through a 'pill-box' resonator. The computer program has been developed to calculate not only the total energy loss to the resonator but also that component of it which exists in the TM 010 mode. The numerically computed results are shown to agree very well with the analytically derived values as found in the literature which, therefore, established the degree of accuracy that is obtained with the TLM method. The particular features of computational simplicity, numerical stability and the inherently time-domain solutions produced by the TLM method are cited as additional, attractive reasons for using this numerical procedure in solving such problems. (Auth.)
A matrix structured LED backlight system with 2D-DHT local dimming method
Liu, Jia; Li, Yang; Du, Sidan
To reduce the number of the drivers in the conventional local dimming method for LCDs, a novel LED backlight local dimming system is proposed in this paper. The backlight of this system is generated by 2D discrete Hadamard transform and its matrix structured LED modules. Compared with the conventional 2D local dimming method, the proposed method costs much fewer drivers but with little degradation.
Adaptation of chemical methods of analysis to the matrix of pyrite-acidified mining lakes
International Nuclear Information System (INIS)
Herzsprung, P.; Friese, K.
2000-01-01
Owing to the unusual matrix of pyrite-acidified mining lakes, the analysis of chemical parameters may be difficult. A number of methodological improvements have been developed so far, and a comprehensive validation of methods is envisaged. The adaptation of the available methods to small-volume samples of sediment pore waters and the adaptation of sensitivity to the expected concentration ranges is an important element of the methods applied in analyses of biogeochemical processes in mining lakes [de
The response-matrix based AFEN method for the hexagonal geometry
International Nuclear Information System (INIS)
Noh, Jae Man; Kim, Keung Koo; Zee, Sung Quun; Joo, Hyung Kook; Cho, Byng Oh; Jeong, Hyung Guk; Cho, Jin Young
1998-03-01
The analytic function expansion nodal (AFEN) method, developed to overcome the limitations caused by the transverse integration, has been successfully to predict the neutron behavior in the hexagonal core as well as rectangular core. In the hexagonal node, the transverse leakage resulted from the transverse integration has some singular terms such as delta-function and step-functions near the node center line. In most nodal methods using the transverse integration, the accuracy of nodal method is degraded because the transverse leakage is approximated as a smooth function across the node center line by ignoring singular terms. However, the AFEN method in which there is no transverse leakage term in deriving nodal coupling equations keeps good accuracy for hexagonal node. In this study, the AFEN method which shows excellent accuracy in the hexagonal core analyses is reformulated as a response matrix form. This form of the AFEN method can be implemented easily to nodal codes based on the response matrix method. Therefore, the Coarse Mesh Rebalance (CMR) acceleration technique which is one of main advantages of the response matrix method can be utilized for the AFEN method. The response matrix based AFEN method has been successfully implemented into the MASTER code and its accuracy and computational efficiency were examined by analyzing the two- and three- dimensional benchmark problem of VVER-440. Based on the results, it can be concluded that the newly formulated AFEN method predicts accurately the assembly powers (within 0.2% average error) as well as the effective multiplication factor (within 0.2% average error) as well as the effective multiplication factor (within 20 pcm error). In addition, the CMR acceleration technique is quite efficient in reducing the computation time of the AFEN method by 8 to 10 times. (author). 22 refs., 1 tab., 4 figs
Jarlebring, E.; Hochstenbach, M.E.
2009-01-01
Several recent methods used to analyze asymptotic stability of delay-differential equations (DDEs) involve determining the eigenvalues of a matrix, a matrix pencil or a matrix polynomial constructed by Kronecker products. Despite some similarities between the different types of these so-called
Butler, Brandon M.; Suh, Yonghee; Scott, Wendy
2015-01-01
In this article, the authors investigate the extent to which 9 elementary social studies methods textbooks present the purpose of teaching and learning social studies. Using Stanley's three perspectives of teaching social studies for knowledge transmission, method of intelligence, and social transformation; we analyze how these texts prepare…
International Nuclear Information System (INIS)
Wasastjerna, F.; Lux, I.
1980-03-01
A transmission probability method implemented in the program TPHEX is described. This program was developed for the calculation of neutron flux distributions in hexagonal light water reactor fuel assemblies. The accuracy appears to be superior to diffusion theory, and the computation time is shorter than that of the collision probability method. (author)
A Control Method of Current Type Matrix Converter for Plasma Control Coil Power Supply
International Nuclear Information System (INIS)
Shimada, K.; Matsukawa, M.; Kurihara, K.; Jun-ichi Itoh
2006-01-01
In exploration to a tokamak fusion reactor, the control of plasma instabilities of high β plasma such as neoclassical tearing mode (NTM), resistive wall mode (RWM) etc., is the key issue for steady-state sustainment. One of the proposed methods to avoid suppressing RWM is that AC current having a phase to work for reduction the RWM growth is generated in a coil (sector coil) equipped spirally on the plasma vacuum vessel. To stabilize RWM, precise and fast real-time feedback control of magnetic field with proper amplitude and frequency is necessary. This implies that an appropriate power supply dedicated for such an application is expected to be developed. A matrix converter as one of power supply candidates for this purpose could provide a solution The matrix converter, categorized in an AC/AC direct converter composed of nine bi-directional current switches, has a great feature that a large energy storage element is unnecessary in comparison with a standard existing AC/AC indirect converter, which is composed of an AC/DC converter and a DC/AC inverter. It is also advantageous in cost and size of its applications. Fortunately, a voltage type matrix converter has come to be available at the market recently, while a current type matrix converter, which is advantageous for fast control of the large-inductance coil current, has been unavailable. On the background above mentioned, we proposed a new current type matrix converter and its control method applicable to a power supply with fast response for suppressing plasma instabilities. Since this converter is required with high accuracy control, the gate control method is adopted to three-phase switching method using middle phase to reduce voltage and current waveforms distortion. The control system is composed of VME-bus board with DSP (Digital Signal Processor) and FPGA (Field Programmable Gate Array) for high speed calculation and control. This paper describes the control method of a current type matrix converter
The Dirac operator on a finite domain and the R-matrix method
International Nuclear Information System (INIS)
Grant, I P
2008-01-01
Relativistic effects in electron-atom collisions and photo-excitation and -ionization processes increase in importance as the atomic number of the target atom grows and spin-dependent effects increase. A relativistic treatment in which electron motion is described using the Dirac Hamiltonian is then desirable. A version of the popular nonrelativistic R-matrix package incorporating terms from the Breit-Pauli Hamiltonian has been used for modelling such processes for some years. The fully relativistic Dirac R-matrix method has been less popular, but is becoming increasingly relevant for applications to heavy ion targets, where the need to use relativistic wavefunctions is more obvious. The Dirac R-matrix method has been controversial ever since it was first proposed by Goertzel (1948 Phys. Rev. 73 1463-6), and it is therefore important to confirm that recent elaborate and costly applications of the method, such as, Badnell et al (2004 J. Phys. B: At. Mol. Phys. 37 4589) and Ballance and Griffin (2007 J. Phys. B: At. Mol. Opt. Phys. 40 247-58), rest on secure foundations. The first part of this paper analyses the structure of the two-point boundary-value problem for the Dirac operator on a finite domain, from which we construct a unified derivation of the Schroedinger (nonrelativistic) and Dirac (relativistic) R-matrix methods. Suggestions that the usual relativistic theory is not well founded are shown to be without foundation
Algebraic method for analysis of nonlinear systems with a normal matrix
International Nuclear Information System (INIS)
Konyaev, Yu.A.; Salimova, A.F.
2014-01-01
A promising method has been proposed for analyzing a class of quasilinear nonautonomous systems of differential equations whose matrix can be represented as a sum of nonlinear normal matrices, which makes it possible to analyze stability without using the Lyapunov functions [ru
A Simple DTC-SVM method for Matrix Converter Drives Using a Deadbeat Scheme
DEFF Research Database (Denmark)
Lee, Kyo-Beum; Blaabjerg, Frede; Lee, Kwang-Won
2005-01-01
In this paper, a simple direct torque control (DTC) method for sensorless matrix converter drives is proposed, which is characterized by a simple structure, minimal torque ripple and unity input power factor. Also a good sensorless speed-control performance in the low speed operation is obtained,...
On the Numerical Behavior of Matrix Splitting Iteration Methods for Solving Linear Systems
Czech Academy of Sciences Publication Activity Database
Bai, Z.-Z.; Rozložník, Miroslav
2015-01-01
Roč. 53, č. 4 (2015), s. 1716-1737 ISSN 0036-1429 R&D Projects: GA ČR GA13-06684S Institutional support: RVO:67985807 Keywords : matrix splitting * stationary iteration method * backward error * rounding error analysis Subject RIV: BA - General Mathematics Impact factor: 1.899, year: 2015
A matrix-inversion method for gamma-source mapping from gamma-count data - 59082
International Nuclear Information System (INIS)
Bull, Richard K.; Adsley, Ian; Burgess, Claire
2012-01-01
Gamma ray counting is often used to survey the distribution of active waste material in various locations. Ideally the output from such surveys would be a map of the activity of the waste. In this paper a simple matrix-inversion method is presented. This allows an array of gamma-count data to be converted to an array of source activities. For each survey area the response matrix is computed using the gamma-shielding code Microshield [1]. This matrix links the activity array to the count array. The activity array is then obtained via matrix inversion. The method was tested on artificially-created arrays of count-data onto which statistical noise had been added. The method was able to reproduce, quite faithfully, the original activity distribution used to generate the dataset. The method has been applied to a number of practical cases, including the distribution of activated objects in a hot cell and to activated Nimonic springs amongst fuel-element debris in vaults at a nuclear plant. (authors)
Large-N limit of the two-Hermitian-matrix model by the hidden BRST method
International Nuclear Information System (INIS)
Alfaro, J.
1993-01-01
This paper discusses the large-N limit of the two-Hermitian-matrix model in zero dimensions, using the hidden Becchi-Rouet-Stora-Tyutin method. A system of integral equations previously found is solved, showing that it contained the exact solution of the model in leading order of large N
Application of differential transformation method for solving dengue transmission mathematical model
Ndii, Meksianis Z.; Anggriani, Nursanti; Supriatna, Asep K.
2018-03-01
The differential transformation method (DTM) is a semi-analytical numerical technique which depends on Taylor series and has application in many areas including Biomathematics. The aim of this paper is to employ the differential transformation method (DTM) to solve system of non-linear differential equations for dengue transmission mathematical model. Analytical and numerical solutions are determined and the results are compared to that of Runge-Kutta method. We found a good agreement between DTM and Runge-Kutta method.
Jensen, Kevin L.; Finkenstadt, Daniel; Shabaev, Andrew; Lambrakos, Samuel G.; Moody, Nathan A.; Petillo, John J.; Yamaguchi, Hisato; Liu, Fangze
2018-01-01
Recent experimental measurements of a bulk material covered with a small number of graphene layers reported by Yamaguchi et al. [NPJ 2D Mater. Appl. 1, 12 (2017)] (on bialkali) and Liu et al. [Appl. Phys. Lett. 110, 041607 (2017)] (on copper) and the needs of emission models in beam optics codes have lead to substantial changes in a Moments model of photoemission. The changes account for (i) a barrier profile and density of states factor based on density functional theory (DFT) evaluations, (ii) a Drude-Lorentz model of the optical constants and laser penetration depth, and (iii) a transmission probability evaluated by an Airy Transfer Matrix Approach. Importantly, the DFT results lead to a surface barrier profile of a shape similar to both resonant barriers and reflectionless wells: the associated quantum mechanical transmission probabilities are shown to be comparable to those recently required to enable the Moments (and Three Step) model to match experimental data but for reasons very different than the assumption by conventional wisdom that a barrier is responsible. The substantial modifications of the Moments model components, motivated by computational materials methods, are developed. The results prepare the Moments model for use in treating heterostructures and discrete energy level systems (e.g., quantum dots) proposed for decoupling the opposing metrics of performance that undermine the performance of advanced light sources like the x-ray Free Electron Laser. The consequences of the modified components on quantum yield, emittance, and emission models needed by beam optics codes are discussed.
Calculating Relativistic Transition Matrix Elements for Hydrogenic Atoms Using Monte Carlo Methods
Alexander, Steven; Coldwell, R. L.
2015-03-01
The nonrelativistic transition matrix elements for hydrogen atoms can be computed exactly and these expressions are given in a number of classic textbooks. The relativistic counterparts of these equations can also be computed exactly but these expressions have been described in only a few places in the literature. In part, this is because the relativistic equations lack the elegant simplicity of the nonrelativistic equations. In this poster I will describe how variational Monte Carlo methods can be used to calculate the energy and properties of relativistic hydrogen atoms and how the wavefunctions for these systems can be used to calculate transition matrix elements.
Legendre Wavelet Operational Matrix Method for Solution of Riccati Differential Equation
Directory of Open Access Journals (Sweden)
S. Balaji
2014-01-01
Full Text Available A Legendre wavelet operational matrix method (LWM is presented for the solution of nonlinear fractional-order Riccati differential equations, having variety of applications in quantum chemistry and quantum mechanics. The fractional-order Riccati differential equations converted into a system of algebraic equations using Legendre wavelet operational matrix. Solutions given by the proposed scheme are more accurate and reliable and they are compared with recently developed numerical, analytical, and stochastic approaches. Comparison shows that the proposed LWM approach has a greater performance and less computational effort for getting accurate solutions. Further existence and uniqueness of the proposed problem are given and moreover the condition of convergence is verified.
International Nuclear Information System (INIS)
Constantinescu, V.; Orban, R.; Colan, H.
1993-01-01
Starting from the observation that Sintering by Infiltration of Loose Mixture of Powders confers large possibilities for both complex shaped and of large dimensions Particulate Reinforced Metal Matrix Composite components elaboration, its mechanism comparative with those of the classical melt infiltration was investigated. Appropriate measures in order to prevent an excessive hydrostatic flow of the melt and, consequently, reinforcement particle dispersion, as well as to promote wetting in both infiltration and liquid phase sintering stages of the process were established as necessary. Some experimental results in the method application to the fusion tungsten carbide and diamond reinforced metal matrix composite elaboration are, also, presented. (orig.)
Directory of Open Access Journals (Sweden)
Thomas Gomez
2018-04-01
Full Text Available Atomic structure of N-electron atoms is often determined by solving the Hartree-Fock equations, which are a set of integro-differential equations. The integral part of the Hartree-Fock equations treats electron exchange, but the Hartree-Fock equations are not often treated as an integro-differential equation. The exchange term is often approximated as an inhomogeneous or an effective potential so that the Hartree-Fock equations become a set of ordinary differential equations (which can be solved using the usual shooting methods. Because the Hartree-Fock equations are an iterative-refinement method, the inhomogeneous term relies on the previous guess of the wavefunction. In addition, there are numerical complications associated with solving inhomogeneous differential equations. This work uses matrix methods to solve the Hartree-Fock equations as an integro-differential equation. It is well known that a derivative operator can be expressed as a matrix made of finite-difference coefficients; energy eigenvalues and eigenvectors can be obtained by using linear-algebra packages. The integral (exchange part of the Hartree-Fock equation can be approximated as a sum and written as a matrix. The Hartree-Fock equations can be solved as a matrix that is the sum of the differential and integral matrices. We compare calculations using this method against experiment and standard atomic structure calculations. This matrix method can also be used to solve for free-electron wavefunctions, thus improving how the atoms and free electrons interact. This technique is important for spectral line broadening in two ways: it improves the atomic structure calculations, and it improves the motion of the plasma electrons that collide with the atom.
Synthesizing (ZrAl3 + AlN)/Mg-Al composites by a 'matrix exchange' method
Gao, Tong; Li, Zengqiang; Hu, Kaiqi; Han, Mengxia; Liu, Xiangfa
2018-06-01
A method named 'matrix exchange' to synthesize ZrAl3 and AlN reinforced Mg-Al composite was developed in this paper. By inserting Al-10ZrN master alloy into Mg matrix and reheating the cooled ingot to 550 °C, Al and Mg atoms diffuse to the opposite side. As a result, liquid melt occurs once the interface areas reach to proper compositions. Then dissolved Al atoms react with ZrN, leading to the in-situ formation of ZrAl3 and AlN particles, while the Al matrix is finally replaced by Mg. This study provides a new insight for preparing Mg composites.
Directory of Open Access Journals (Sweden)
Shujing Su
2015-01-01
Full Text Available For the characteristics of parameters dispersion in large factories, storehouses, and other applications, a distributed parameter measurement system is designed that is based on the ring network. The structure of the system and the circuit design of the master-slave node are described briefly. The basic protocol architecture about transmission communication is introduced, and then this paper comes up with two kinds of distributed transmission control methods. Finally, the reliability, extendibility, and control characteristic of these two methods are tested through a series of experiments. Moreover, the measurement results are compared and discussed.
A Practical Radiosity Method for Predicting Transmission Loss in Urban Environments
Directory of Open Access Journals (Sweden)
Liang Ming
2004-01-01
Full Text Available The ability to predict transmission loss or field strength distribution is crucial for determining coverage in planning personal communication systems. This paper presents a practical method to accurately predict entire average transmission loss distribution in complicated urban environments. The method uses a 3D propagation model based on radiosity and a simplified city information database including surfaces of roads and building groups. Narrowband validation measurements with line-of-sight (LOS and non-line-of-sight (NLOS cases at 1800 MHz give excellent agreement in urban environments.
Directory of Open Access Journals (Sweden)
Novita Astin
2016-12-01
Full Text Available This paper presents about the transmission of Digital Video Broadcasting system with streaming video resolution 640x480 on different IQ rate and modulation. In the video transmission, distortion often occurs, so the received video has bad quality. Key frames selection algorithm is flexibel on a change of video, but on these methods, the temporal information of a video sequence is omitted. To minimize distortion between the original video and received video, we aimed at adding methodology using sequential distortion minimization algorithm. Its aim was to create a new video, better than original video without significant loss of content between the original video and received video, fixed sequentially. The reliability of video transmission was observed based on a constellation diagram, with the best result on IQ rate 2 Mhz and modulation 8 QAM. The best video transmission was also investigated using SEDIM (Sequential Distortion Minimization Method and without SEDIM. The experimental result showed that the PSNR (Peak Signal to Noise Ratio average of video transmission using SEDIM was an increase from 19,855 dB to 48,386 dB and SSIM (Structural Similarity average increase 10,49%. The experimental results and comparison of proposed method obtained a good performance. USRP board was used as RF front-end on 2,2 GHz.
International Nuclear Information System (INIS)
Ishikawa, H.; Nakano, S.; Yuuki, R.; Chung, N.Y.
1991-01-01
In the virtual crack extension method, the stress intensity factor, K, is obtained from the converged value of the energy release rate by the difference of the finite element stiffness matrix when some crack extension are taken. Instead of the numerical difference of the finite element stiffness, a new method to use a direct dirivative of the finite element stiffness matrix with respect to crack length is proposed. By the present method, the results of some example problems, such as uniform tension problems of a square plate with a center crack and a rectangular plate with an internal slant crack, are obtained with high accuracy and good efficiency. Comparing with analytical results, the present values of the stress intensity factors of the problems are obtained with the error that is less than 0.6%. This shows the numerical assurance of the usefulness of the present method. A personal computer program for the analysis is developed
Determination of Dispersion Curves for Composite Materials with the Use of Stiffness Matrix Method
Directory of Open Access Journals (Sweden)
Barski Marek
2017-06-01
Full Text Available Elastic waves used in Structural Health Monitoring systems have strongly dispersive character. Therefore it is necessary to determine the appropriate dispersion curves in order to proper interpretation of a received dynamic response of an analyzed structure. The shape of dispersion curves as well as number of wave modes depends on mechanical properties of layers and frequency of an excited signal. In the current work, the relatively new approach is utilized, namely stiffness matrix method. In contrast to transfer matrix method or global matrix method, this algorithm is considered as numerically unconditionally stable and as effective as transfer matrix approach. However, it will be demonstrated that in the case of hybrid composites, where mechanical properties of particular layers differ significantly, obtaining results could be difficult. The theoretical relationships are presented for the composite plate of arbitrary stacking sequence and arbitrary direction of elastic waves propagation. As a numerical example, the dispersion curves are estimated for the lamina, which is made of carbon fibers and epoxy resin. It is assumed that elastic waves travel in the parallel, perpendicular and arbitrary direction to the fibers in lamina. Next, the dispersion curves are determined for the following laminate [0°, 90°, 0°, 90°, 0°, 90°, 0°, 90°] and hybrid [Al, 90°, 0°, 90°, 0°, 90°, 0°], where Al is the aluminum alloy PA38 and the rest of layers are made of carbon fibers and epoxy resin.
A self-consistent nodal method in response matrix formalism for the multigroup diffusion equations
International Nuclear Information System (INIS)
Malambu, E.M.; Mund, E.H.
1996-01-01
We develop a nodal method for the multigroup diffusion equations, based on the transverse integration procedure (TIP). The efficiency of the method rests upon the convergence properties of a high-order multidimensional nodal expansion and upon numerical implementation aspects. The discrete 1D equations are cast in response matrix formalism. The derivation of the transverse leakage moments is self-consistent i.e. does not require additional assumptions. An outstanding feature of the method lies in the linear spatial shape of the local transverse leakage for the first-order scheme. The method is described in the two-dimensional case. The method is validated on some classical benchmark problems. (author)
Alternating optimization method based on nonnegative matrix factorizations for deep neural networks
Sakurai, Tetsuya; Imakura, Akira; Inoue, Yuto; Futamura, Yasunori
2016-01-01
The backpropagation algorithm for calculating gradients has been widely used in computation of weights for deep neural networks (DNNs). This method requires derivatives of objective functions and has some difficulties finding appropriate parameters such as learning rate. In this paper, we propose a novel approach for computing weight matrices of fully-connected DNNs by using two types of semi-nonnegative matrix factorizations (semi-NMFs). In this method, optimization processes are performed b...
Efficient Tridiagonal Preconditioner for the Matrix-Free Truncated Newton Method
Czech Academy of Sciences Publication Activity Database
Lukšan, Ladislav; Vlček, Jan
2014-01-01
Roč. 235, 25 May (2014), s. 394-407 ISSN 0096-3003 R&D Projects: GA ČR GA13-06684S Institutional support: RVO:67985807 Keywords : unconstrained optimization * large scale optimization * matrix-free truncated Newton method * preconditioned conjugate gradient method * preconditioners obtained by the directional differentiation * numerical algorithms Subject RIV: BA - General Mathematics Impact factor: 1.551, year: 2014
International Nuclear Information System (INIS)
Arshad, M.; Shakoor, A.; Ahmad, M.
2013-01-01
An important aquifer characteristic, transmissivity significantly contributes to the development of local and regional groundwater resources and solute transport management. Estimation of this property allows quantitative prediction of the hydraulic response and solute transport of the aquifer to recharge and pumping. This study presents the three techniques, used to compare transmissivity determination by Vertical Electric Sounding (VES) over the traditional techniques. The validation of VES was compared with the old widely used methods such as grain size distribution and pumping test techniques. Grain size distribution analysis was carried out to determine transmissivity. Pumping test was performed to determine transmissivity using the type curves solution for unconfined aquifer and taking into account the delayed yield. In resistivity imaging survey, the soil layers were detected through interpretation of resistivity data. Formation factor for each layer was determined with the relation of aquifer soil resistivity and ground water resistivity. The estimated transmissivities though grain size distribution, pumping test and resistivity survey were 0.588, 0.578 and 0.756m/sup 2//min, respectively. The results emphasized the potential of the resistivity survey for aquifer transmissivity determination. (author)
Research on atmospheric transmission distortion of Gauss laser using multiple phase screen method
Zhang, Yizhuo; Wang, Qiushi; Gu, Haidong
2018-02-01
The laser beam is attenuated, broadened, defocused and may even be deflected from its initial propagation direction as it propagates through the atmosphere. It leads to the decrease of the laser intensity of the receiving surface. Gauss beam is the fundamental components of all possible laser waveforms. Therefore, research on the transmission of the Gauss laser has far-reaching consequences in optical communication, weaponry, target designation, ranging, remote sensing and other applications that require transmission of laser beams through the atmosphere. In this paper, we propose a laboratory simulation method using multi-phase screen to calculate the effects of atmospheric turbulence. Theoretical analysis of Gauss laser transmission in the atmosphere is given. By calculating the propagation of the Gauss beam TEM00, the far field intensity and phase distribution is shown. By the given method, the optical setup is presented and used for optimizing the adaptive optics algorithm.
Quantum propagation and confinement in 1D systems using the transfer-matrix method
International Nuclear Information System (INIS)
Pujol, Olivier; Carles, Robert; Pérez, José-Philippe
2014-01-01
The aim of this article is to provide some Matlab scripts to the teaching community in quantum physics. The scripts are based on the transfer-matrix formalism and offer a very efficient and versatile tool to solve problems of a physical object (electron, proton, neutron, etc) with one-dimensional (1D) stationary potential energy. Resonant tunnelling through a multiple-barrier or confinement in wells of various shapes is particularly analysed. The results are quantitatively discussed with semiconductor heterostructures, harmonic and anharmonic molecular vibrations, or neutrons in a gravity field. Scripts and other examples (hydrogen-like ions and transmission by a smooth variation of potential energy) are available freely at http://www-loa.univ-lille1.fr/~pujol in three languages: English, French and Spanish. (paper)
Directory of Open Access Journals (Sweden)
Rosemary M McCloskey
2017-11-01
Full Text Available Clustering infections by genetic similarity is a popular technique for identifying potential outbreaks of infectious disease, in part because sequences are now routinely collected for clinical management of many infections. A diverse number of nonparametric clustering methods have been developed for this purpose. These methods are generally intuitive, rapid to compute, and readily scale with large data sets. However, we have found that nonparametric clustering methods can be biased towards identifying clusters of diagnosis-where individuals are sampled sooner post-infection-rather than the clusters of rapid transmission that are meant to be potential foci for public health efforts. We develop a fundamentally new approach to genetic clustering based on fitting a Markov-modulated Poisson process (MMPP, which represents the evolution of transmission rates along the tree relating different infections. We evaluated this model-based method alongside five nonparametric clustering methods using both simulated and actual HIV sequence data sets. For simulated clusters of rapid transmission, the MMPP clustering method obtained higher mean sensitivity (85% and specificity (91% than the nonparametric methods. When we applied these clustering methods to published sequences from a study of HIV-1 genetic clusters in Seattle, USA, we found that the MMPP method categorized about half (46% as many individuals to clusters compared to the other methods. Furthermore, the mean internal branch lengths that approximate transmission rates were significantly shorter in clusters extracted using MMPP, but not by other methods. We determined that the computing time for the MMPP method scaled linearly with the size of trees, requiring about 30 seconds for a tree of 1,000 tips and about 20 minutes for 50,000 tips on a single computer. This new approach to genetic clustering has significant implications for the application of pathogen sequence analysis to public health, where
Investigation of noise in gear transmissions by the method of mathematical smoothing of experiments
Sheftel, B. T.; Lipskiy, G. K.; Ananov, P. P.; Chernenko, I. K.
1973-01-01
A rotatable central component smoothing method is used to analyze rotating gear noise spectra. A matrix is formulated in which the randomized rows correspond to various tests and the columns to factor values. Canonical analysis of the obtained regression equation permits the calculation of optimal speed and load at a previous assigned noise level.
Multiple resonance compensation for betatron coupling and its equivalence with matrix method
De Ninno, G
1999-01-01
Analyses of betatron coupling can be broadly divided into two categories: the matrix approach that decouples the single-turn matrix to reveal the normal modes and the hamiltonian approach that evaluates the coupling in terms of the action of resonances in perturbation theory. The latter is often regarded as being less exact but good for physical insight. The common opinion is that the correction of the two closest sum and difference resonances to the working point is sufficient to reduce the off-axis terms in the 4X4 single-turn matrix, but this is only partially true. The reason for this is explained, and a method is developed that sums to infinity all coupling resonances and, in this way, obtains results equivalent to the matrix approach. The two approaches is discussed with reference to the dynamic aperture. Finally, the extension of the summation method to resonances of all orders is outlined and the relative importance of a single resonance compared to all resonances of a given order is analytically desc...
Energy Technology Data Exchange (ETDEWEB)
Simmons, Daniel, E-mail: daniel.simmons@nottingham.ac.uk; Cools, Kristof; Sewell, Phillip
2016-11-01
Time domain electromagnetic simulation tools have the ability to model transient, wide-band applications, and non-linear problems. The Boundary Element Method (BEM) and the Transmission Line Modeling (TLM) method are both well established numerical techniques for simulating time-varying electromagnetic fields. The former surface based method can accurately describe outwardly radiating fields from piecewise uniform objects and efficiently deals with large domains filled with homogeneous media. The latter volume based method can describe inhomogeneous and non-linear media and has been proven to be unconditionally stable. Furthermore, the Unstructured TLM (UTLM) enables modelling of geometrically complex objects by using triangular meshes which removes staircasing and unnecessary extensions of the simulation domain. The hybridization of BEM and UTLM which is described in this paper is named the Boundary Element Unstructured Transmission-line (BEUT) method. It incorporates the advantages of both methods. The theory and derivation of the 2D BEUT method is described in this paper, along with any relevant implementation details. The method is corroborated by studying its correctness and efficiency compared to the traditional UTLM method when applied to complex problems such as the transmission through a system of Luneburg lenses and the modelling of antenna radomes for use in wireless communications. - Graphical abstract:.
A massively parallel discrete ordinates response matrix method for neutron transport
International Nuclear Information System (INIS)
Hanebutte, U.R.; Lewis, E.E.
1992-01-01
In this paper a discrete ordinates response matrix method is formulated with anisotropic scattering for the solution of neutron transport problems on massively parallel computers. The response matrix formulation eliminates iteration on the scattering source. The nodal matrices that result from the diamond-differenced equations are utilized in a factored form that minimizes memory requirements and significantly reduces the number of arithmetic operations required per node. The red-black solution algorithm utilizes massive parallelism by assigning each spatial node to one or more processors. The algorithm is accelerated by a synthetic method in which the low-order diffusion equations are also solved by massively parallel red-black iterations. The method is implemented on a 16K Connection Machine-2, and S 8 and S 16 solutions are obtained for fixed-source benchmark problems in x-y geometry
Invariant Imbedding T-Matrix Method for Axial Symmetric Hydrometeors with Extreme Aspect Ratios
Pelissier, C.; Clune, T.; Kuo, K. S.; Munchak, S. J.; Adams, I. S.
2017-12-01
The single-scattering properties (SSPs) of hydrometeors are the fundamental quantities for physics-based precipitation retrievals. Thus, efficient computation of their electromagnetic scattering is of great value. Whereas the semi-analytical T-Matrix methods are likely the most efficient for nonspherical hydrometeors with axial symmetry, they are not suitable for arbitrarily shaped hydrometeors absent of any significant symmetry, for which volume integral methods such as those based on Discrete Dipole Approximation (DDA) are required. Currently the two leading T-matrix methods are the Extended Boundary Condition Method (EBCM) and the Invariant Imbedding T-matrix Method incorporating Lorentz-Mie Separation of Variables (IITM+SOV). EBCM is known to outperform IITM+SOV for hydrometeors with modest aspect ratios. However, in cases when aspect ratios become extreme, such as needle-like particles with large height to diameter values, EBCM fails to converge. Such hydrometeors with extreme aspect ratios are known to be present in solid precipitation and their SSPs are required to model the radiative responses accurately. In these cases, IITM+SOV is shown to converge. An efficient, parallelized C++ implementation for both EBCM and IITM+SOV has been developed to conduct a performance comparison between EBCM, IITM+SOV, and DDSCAT (a popular implementation of DDA). We present the comparison results and discuss details. Our intent is to release the combined ECBM & IITM+SOV software to the community under an open source license.
Workshop report on large-scale matrix diagonalization methods in chemistry theory institute
Energy Technology Data Exchange (ETDEWEB)
Bischof, C.H.; Shepard, R.L.; Huss-Lederman, S. [eds.
1996-10-01
The Large-Scale Matrix Diagonalization Methods in Chemistry theory institute brought together 41 computational chemists and numerical analysts. The goal was to understand the needs of the computational chemistry community in problems that utilize matrix diagonalization techniques. This was accomplished by reviewing the current state of the art and looking toward future directions in matrix diagonalization techniques. This institute occurred about 20 years after a related meeting of similar size. During those 20 years the Davidson method continued to dominate the problem of finding a few extremal eigenvalues for many computational chemistry problems. Work on non-diagonally dominant and non-Hermitian problems as well as parallel computing has also brought new methods to bear. The changes and similarities in problems and methods over the past two decades offered an interesting viewpoint for the success in this area. One important area covered by the talks was overviews of the source and nature of the chemistry problems. The numerical analysts were uniformly grateful for the efforts to convey a better understanding of the problems and issues faced in computational chemistry. An important outcome was an understanding of the wide range of eigenproblems encountered in computational chemistry. The workshop covered problems involving self- consistent-field (SCF), configuration interaction (CI), intramolecular vibrational relaxation (IVR), and scattering problems. In atomic structure calculations using the Hartree-Fock method (SCF), the symmetric matrices can range from order hundreds to thousands. These matrices often include large clusters of eigenvalues which can be as much as 25% of the spectrum. However, if Cl methods are also used, the matrix size can be between 10{sup 4} and 10{sup 9} where only one or a few extremal eigenvalues and eigenvectors are needed. Working with very large matrices has lead to the development of
Tuladhar, E.
2014-01-01
Intervention methods to control the transmission of noroviruses and other enteric and respiratory viruses
Era Tuladhar
Abstract
Human noroviruses are the leading cause of acute and outbreak associated gastroenteritis worldwide. The outbreaks
A hybrid Planning Method for Transmission Network in a Deregulated Enviroment
DEFF Research Database (Denmark)
Xu, Zhao; Dong, Zhaoyang; Poulsen, Kit
2006-01-01
The reconstruction of power industries has brought fundamental changes to both power system operation and planning. This paper presents a new planning method using a multi-objective optimization (MOOP) technique, as well as human knowledge, to expand the transmission network in open-access scheme...
Simplified method to solve sound transmission through structures lined with elastic porous material.
Lee, J H; Kim, J
2001-11-01
An approximate analysis method is developed to calculate sound transmission through structures lined with porous material. Because the porous material has both the solid phase and fluid phase, three wave components exist in the material, which makes the related analysis very complicated. The main idea in developing the approximate method is very simple: modeling the porous material using only the strongest of the three waves, which in effect idealizes the material as an equivalent fluid. The analysis procedure has to be conducted in two steps. In the first step, sound transmission through a flat double panel with a porous liner of infinite extents, which has the same cross sectional construction as the actual structure, is solved based on the full theory and the strongest wave component is identified. In the second step sound transmission through the actual structure is solved modeling the porous material as an equivalent fluid while using the actual geometry of the structure. The development and validation of the method are discussed in detail. As an application example, the transmission loss through double walled cylindrical shells with a porous core is calculated utilizing the simplified method.
A method to compute the inverse of a complex n-block tridiagonal quasi-hermitian matrix
International Nuclear Information System (INIS)
Godfrin, Elena
1990-01-01
This paper presents a method to compute the inverse of a complex n-block tridiagonal quasi-hermitian matrix using adequate partitions of the complete matrix. This type of matrix is very usual in quantum mechanics and, more specifically, in solid state physics (e.g., interfaces and superlattices), when the tight-binding approximation is used. The efficiency of the method is analyzed comparing the required CPU time and work-area for different usual techniques. (Author)
Analysis of Crystallographic Structure of a Japanese Sword by the Pulsed Neutron Transmission Method
Kino, K.; Ayukawa, N.; Kiyanagi, Y.; Uchida, T.; Uno, S.; Grazzi, F.; Scherillo, A.
We measured two-dimensional transmission spectra of pulsed neutron beams for a Japanese sword sample. Atom density, crystalline size, and preferred orientation of crystals were obtained using the RITS code. The position dependence of the atomic density is consistent with the shape of the sample. The crystalline size is very small and shows position dependence, which is understood by the unique structure of Japanese swords. The preferred orientation has strong position dependence. Our study shows the usefulness of the pulsed neutron transmission method for cultural metal artifacts.
Frank, Andrew A.
1984-01-01
A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine.
A comparison of companion matrix methods to find roots of a trigonometric polynomial
Boyd, John P.
2013-08-01
A trigonometric polynomial is a truncated Fourier series of the form fN(t)≡∑j=0Naj cos(jt)+∑j=1N bj sin(jt). It has been previously shown by the author that zeros of such a polynomial can be computed as the eigenvalues of a companion matrix with elements which are complex valued combinations of the Fourier coefficients, the "CCM" method. However, previous work provided no examples, so one goal of this new work is to experimentally test the CCM method. A second goal is introduce a new alternative, the elimination/Chebyshev algorithm, and experimentally compare it with the CCM scheme. The elimination/Chebyshev matrix (ECM) algorithm yields a companion matrix with real-valued elements, albeit at the price of usefulness only for real roots. The new elimination scheme first converts the trigonometric rootfinding problem to a pair of polynomial equations in the variables (c,s) where c≡cos(t) and s≡sin(t). The elimination method next reduces the system to a single univariate polynomial P(c). We show that this same polynomial is the resultant of the system and is also a generator of the Groebner basis with lexicographic ordering for the system. Both methods give very high numerical accuracy for real-valued roots, typically at least 11 decimal places in Matlab/IEEE 754 16 digit floating point arithmetic. The CCM algorithm is typically one or two decimal places more accurate, though these differences disappear if the roots are "Newton-polished" by a single Newton's iteration. The complex-valued matrix is accurate for complex-valued roots, too, though accuracy decreases with the magnitude of the imaginary part of the root. The cost of both methods scales as O(N3) floating point operations. In spite of intimate connections of the elimination/Chebyshev scheme to two well-established technologies for solving systems of equations, resultants and Groebner bases, and the advantages of using only real-valued arithmetic to obtain a companion matrix with real-valued elements
IMPACT OF MATRIX INVERSION ON THE COMPLEXITY OF THE FINITE ELEMENT METHOD
Directory of Open Access Journals (Sweden)
M. Sybis
2016-04-01
Full Text Available Purpose. The development of a wide construction market and a desire to design innovative architectural building constructions has resulted in the need to create complex numerical models of objects having increasingly higher computational complexity. The purpose of this work is to show that choosing a proper method for solving the set of equations can improve the calculation time (reduce the complexity by a few levels of magnitude. Methodology. The article presents an analysis of the impact of matrix inversion algorithm on the deflection calculation in the beam, using the finite element method (FEM. Based on the literature analysis, common methods of calculating set of equations were determined. From the found solutions the Gaussian elimination, LU and Cholesky decomposition methods have been implemented to determine the effect of the matrix inversion algorithm used for solving the equations set on the number of computational operations performed. In addition, each of the implemented method has been further optimized thereby reducing the number of necessary arithmetic operations. Findings. These optimizations have been performed on the use of certain properties of the matrix, such as symmetry or significant number of zero elements in the matrix. The results of the analysis are presented for the division of the beam to 5, 50, 100 and 200 nodes, for which the deflection has been calculated. Originality. The main achievement of this work is that it shows the impact of the used methodology on the complexity of solving the problem (or equivalently, time needed to obtain results. Practical value. The difference between the best (the less complex and the worst (the most complex is in the row of few orders of magnitude. This result shows that choosing wrong methodology may enlarge time needed to perform calculation significantly.
International Nuclear Information System (INIS)
Tyas-Djuhariningrum
2004-01-01
The gold sample analysis can be deviated more than >10% to those thrue value caused by the matrix element. So that the matrix element character need to be study in order to reduce the deviation. In rock samples, the matrix elements can cause self quenching, self absorption and ionization process, so there is a result analysis error. In the rock geochemical process, the elements of the same group at the periodic system have the tendency to be together because of their same characteristic. In absorption Atomic Spectroscopy analysis, the elements associate can absorb primer energy with similar wave length so that it can cause deviation in the result interpretation. The aim of study is to predict matrix element influences from rock sample with application standard method for reducing deviation. In quantitative way, assessment of primer light intensity that will be absorbed is proportional to the concentration atom in the sample that relationship between photon intensity with concentration in part per million is linier (ppm). These methods for eliminating matrix elements influence consist of three methods : external standard method, internal standard method, and addition standard method. External standard method for all matrix element, internal standard method for elimination matrix element that have similar characteristics, addition standard methods for elimination matrix elements in Au, Pt samples. The third of standard posess here accuracy are about 95-97%. (author)
Method and apparatus for executing an asynchronous clutch-to-clutch shift in a hybrid transmission
Demirovic, Besim; Gupta, Pinaki; Kaminsky, Lawrence A.; Naqvi, Ali K.; Heap, Anthony H.; Sah, Jy-Jen F.
2014-08-12
A hybrid transmission includes first and second electric machines. A method for operating the hybrid transmission in response to a command to execute a shift from an initial continuously variable mode to a target continuously variable mode includes increasing torque of an oncoming clutch associated with operating in the target continuously variable mode and correspondingly decreasing a torque of an off-going clutch associated with operating in the initial continuously variable mode. Upon deactivation of the off-going clutch, torque outputs of the first and second electric machines and the torque of the oncoming clutch are controlled to synchronize the oncoming clutch. Upon synchronization of the oncoming clutch, the torque for the oncoming clutch is increased and the transmission is operated in the target continuously variable mode.
Analysis of a wavelength selectable cascaded DFB laser based on the transfer matrix method
International Nuclear Information System (INIS)
Xie Hongyun; Chen Liang; Shen Pei; Sun Botao; Wang Renqing; Xiao Ying; You Yunxia; Zhang Wanrong
2010-01-01
A novel cascaded DFB laser, which consists of two serial gratings to provide selectable wavelengths, is presented and analyzed by the transfer matrix method. In this method, efficient facet reflectivity is derived from the transfer matrix built for each serial section and is then used to simulate the performance of the novel cascaded DFB laser through self-consistently solving the gain equation, the coupled wave equation and the current continuity equations. The simulations prove the feasibility of this kind of wavelength selectable laser and a corresponding designed device with two selectable wavelengths of 1.51 μm and 1.53 μm is realized by experiments on InP-based multiple quantum well structure. (semiconductor devices)
Newton's method for solving a quadratic matrix equation with special coefficient matrices
International Nuclear Information System (INIS)
Seo, Sang-Hyup; Seo, Jong Hyun; Kim, Hyun-Min
2014-01-01
We consider the iterative method for solving a quadratic matrix equation with special coefficient matrices which arises in the quasi-birth-death problem. In this paper, we show that the elementwise minimal positive solvents to quadratic matrix equations can be obtained using Newton's method. We also prove that the convergence rate of the Newton iteration is quadratic if the Fréchet derivative at the elementwise minimal positive solvent is nonsingular. However, if the Fréchet derivative is singular, the convergence rate is at least linear. Numerical experiments of the convergence rate are given.(This is summarized a paper which is to appear in Honam Mathematical Journal.)
A Novel Method to Implement the Matrix Pencil Super Resolution Algorithm for Indoor Positioning
Directory of Open Access Journals (Sweden)
Tariq Jamil Saifullah Khanzada
2011-10-01
Full Text Available This article highlights the estimation of the results for the algorithms implemented in order to estimate the delays and distances for the indoor positioning system. The data sets for the transmitted and received signals are captured at a typical outdoor and indoor area. The estimation super resolution algorithms are applied. Different state of art and super resolution techniques based algorithms are applied to avail the optimal estimates of the delays and distances between the transmitted and received signals and a novel method for matrix pencil algorithm is devised. The algorithms perform variably at different scenarios of transmitted and received positions. Two scenarios are experienced, for the single antenna scenario the super resolution techniques like ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique and theMatrix Pencil algorithms give optimal performance compared to the conventional techniques. In two antenna scenario RootMUSIC and Matrix Pencil algorithm performed better than other algorithms for the distance estimation, however, the accuracy of all the algorithms is worst than the single antenna scenario. In all cases our devised Matrix Pencil algorithm achieved the best estimation results.
Analysis of Off Gas From Disintegration Process of Graphite Matrix by Electrochemical Method
International Nuclear Information System (INIS)
Tian Lifang; Wen Mingfen; Chen Jing
2010-01-01
Using electrochemical method with salt solutions as electrolyte, some gaseous substances (off gas) would be generated during the disintegration of graphite from high-temperature gas-cooled reactor fuel elements. The off gas is determined to be composed of H 2 , O 2 , N 2 , CO 2 and NO x by gas chromatography. Only about 1.5% graphite matrix is oxidized to CO 2 . Compared to the direct burning-graphite method, less off gas,especially CO 2 , is generated in the disintegration process of graphite by electrochemical method and the treatment of off gas becomes much easier. (authors)
A spot-matching method using cumulative frequency matrix in 2D gel images
Han, Chan-Myeong; Park, Joon-Ho; Chang, Chu-Seok; Ryoo, Myung-Chun
2014-01-01
A new method for spot matching in two-dimensional gel electrophoresis images using a cumulative frequency matrix is proposed. The method improves on the weak points of the previous method called ‘spot matching by topological patterns of neighbour spots’. It accumulates the frequencies of neighbour spot pairs produced through the entire matching process and determines spot pairs one by one in order of higher frequency. Spot matching by frequencies of neighbour spot pairs shows a fairly better performance. However, it can give researchers a hint for whether the matching results can be trustworthy or not, which can save researchers a lot of effort for verification of the results. PMID:26019609
Finding all real roots of a polynomial by matrix algebra and the Adomian decomposition method
Directory of Open Access Journals (Sweden)
Hooman Fatoorehchi
2014-10-01
Full Text Available In this paper, we put forth a combined method for calculation of all real zeroes of a polynomial equation through the Adomian decomposition method equipped with a number of developed theorems from matrix algebra. These auxiliary theorems are associated with eigenvalues of matrices and enable convergence of the Adomian decomposition method toward different real roots of the target polynomial equation. To further improve the computational speed of our technique, a nonlinear convergence accelerator known as the Shanks transform has optionally been employed. For the sake of illustration, a number of numerical examples are given.
Solving Eigenvalue response matrix equations with Jacobian-Free Newton-Krylov methods
International Nuclear Information System (INIS)
Roberts, Jeremy A.; Forget, Benoit
2011-01-01
The response matrix method for reactor eigenvalue problems is motivated as a technique for solving coarse mesh transport equations, and the classical approach of power iteration (PI) for solution is described. The method is then reformulated as a nonlinear system of equations, and the associated Jacobian is derived. A Jacobian-Free Newton-Krylov (JFNK) method is employed to solve the system, using an approximate Jacobian coupled with incomplete factorization as a preconditioner. The unpreconditioned JFNK slightly outperforms PI, and preconditioned JFNK outperforms both PI and Steffensen-accelerated PI significantly. (author)
Efficient propagation of the hierarchical equations of motion using the matrix product state method
Shi, Qiang; Xu, Yang; Yan, Yaming; Xu, Meng
2018-05-01
We apply the matrix product state (MPS) method to propagate the hierarchical equations of motion (HEOM). It is shown that the MPS approximation works well in different type of problems, including boson and fermion baths. The MPS method based on the time-dependent variational principle is also found to be applicable to HEOM with over one thousand effective modes. Combining the flexibility of the HEOM in defining the effective modes and the efficiency of the MPS method thus may provide a promising tool in simulating quantum dynamics in condensed phases.
A Numerical Matrix-Based method in Harmonic Studies in Wind Power Plants
DEFF Research Database (Denmark)
Dowlatabadi, Mohammadkazem Bakhshizadeh; Hjerrild, Jesper; Kocewiak, Łukasz Hubert
2016-01-01
In the low frequency range, there are some couplings between the positive- and negative-sequence small-signal impedances of the power converter due to the nonlinear and low bandwidth control loops such as the synchronization loop. In this paper, a new numerical method which also considers...... these couplings will be presented. The numerical data are advantageous to the parametric differential equations, because analysing the high order and complex transfer functions is very difficult, and finally one uses the numerical evaluation methods. This paper proposes a numerical matrix-based method, which...
Method of selecting optimum cross arm lengths for a 750 kV transmission line
Energy Technology Data Exchange (ETDEWEB)
Aleksandrov, G N; Olorokov, V P
1965-01-01
A method is presented, based on both technical and economic considerations, for selecting cross arm lengths for intermediate poles of power transmission lines according to the effects of internal overvoltage, methods from probability theory and mathematical statistics employed. The problem of optimum pole size is considered in terms of the effect of internal overvoltages for a prescribed maximum level of 2.1 PU currently used in the USSR for the design of 750 kV lines.
A transfer matrix method for the analysis of fractal quantum potentials
International Nuclear Information System (INIS)
Monsoriu, Juan A; Villatoro, Francisco R; Marin, Maria J; UrchueguIa, Javier F; Cordoba, Pedro Fernandez de
2005-01-01
The scattering properties of quantum particles on a sequence of potentials converging towards a fractal one are obtained by means of the transfer matrix method. The reflection coefficients for both the fractal potential and finite periodic potential are calculated and compared. It is shown that the reflection coefficient for the fractal potential has a self-similar structure associated with the fractal distribution of the potential whose degree of self-similarity has been quantified by means of the correlation function
Radiation safety assessment of cobalt 60 external beam radiotherapy using the risk-matrix method
International Nuclear Information System (INIS)
Dumenigo, C; Vilaragut, J.J.; Ferro, R.; Guillen, A.; Ramirez, M.L.; Ortiz Lopez, P.; Rodriguez, M.; McDonnell, J.D.; Papadopulos, S.; Pereira, P.P.; Goncalvez, M.; Morales, J.; Larrinaga, E.; Lopez Morones, R.; Sanchez, R.; Delgado, J.M.; Sanchez, C.; Somoano, F.
2008-01-01
External beam radiotherapy is the only practice in which humans are placed directly in a radiation beam with the intention to deliver a very high dose. This is why safety in radiotherapy is very critical, and is a matter of interest to both radiotherapy departments and regulatory bodies. Accidental exposures have occurred throughout the world, thus showing the need for systematic safety assessments, capable to identify preventive measures and to minimize consequences of accidental exposure. Risk-matrix is a systematic approach which combines the relevant event features to assess the overall risk of each particular event. Once an event sequence is identified, questions such as how frequent the event, how severe the potential consequences and how reliable the existing safety measures are answered in a risk-matrix table. The ultimate goal is to achieve that the overall risk for events with severe consequences should always be low o very low. In the present study, the risk-matrix method has been applied to an hypothetical radiotherapy department, which could be equivalent to an upper level hospital of the Ibero American region, in terms of safety checks and preventive measures. The application of the method has identified 76 event sequences and revealed that the hypothetical radiotherapy department is sufficiently protected (low risk) against them, including 23 event sequences with severe consequences. The method has revealed that the risk of these sequences could grow to high level if certain specific preventive measures were degraded with time. This study has identified these preventive measures, thus facilitating a rational allocation of resources in regular controls to detect any loss of reliability. The method has proven to have an important practical value and is affordable at hospital level. The elaborated risk-matrix can be easily adapted to local circumstances, in terms of existing controls and safety measures. This approach can help hospitals to identify
A transfer matrix method for the analysis of fractal quantum potentials
Energy Technology Data Exchange (ETDEWEB)
Monsoriu, Juan A [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Villatoro, Francisco R [Departamento de Lenguajes y Ciencias de la Computacion, Universidad de Malaga, E-29071 Malaga (Spain); Marin, Maria J [Departamento de Termodinamica, Universitat de Valencia, E-46100 Burjassot (Spain); UrchueguIa, Javier F [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Cordoba, Pedro Fernandez de [Departamento de Matematica Aplicada, Universidad Politecnica de Valencia, E-46022 Valencia (Spain)
2005-07-01
The scattering properties of quantum particles on a sequence of potentials converging towards a fractal one are obtained by means of the transfer matrix method. The reflection coefficients for both the fractal potential and finite periodic potential are calculated and compared. It is shown that the reflection coefficient for the fractal potential has a self-similar structure associated with the fractal distribution of the potential whose degree of self-similarity has been quantified by means of the correlation function.
Directory of Open Access Journals (Sweden)
Mateja Šnajdar Musa
2013-06-01
Full Text Available Aluminium based metal matrix composites are rapidly developing group of materials due to their unique combination of properties that include low weight, elevated strength, improved wear and corrosion resistance and relatively good ductility. This combination of properties is a result of mixing two groups of materials with rather different properties with aluminium as ductile matrix and different oxides and carbides added as reinforcement. Al2O3, SiC and ZrO2 are the most popular choices of reinforcement material. One of the most common methods for producing this type of metal matrix composites is powder metallurgy since it has many variations and also is relatively low-cost method. Many different techniques of compacting aluminium and ceramic powders have been previously investigated. Among those techniques equal channel angular pressing (ECAP stands out due to its beneficial influence on the main problem that arises during powder compaction and that is a non-uniform distribution of reinforcement particles. This paper gives an overview on ECAP method principles, advantages and produced powder composite properties.
Iterative approach as alternative to S-matrix in modal methods
Semenikhin, Igor; Zanuccoli, Mauro
2014-12-01
The continuously increasing complexity of opto-electronic devices and the rising demands of simulation accuracy lead to the need of solving very large systems of linear equations making iterative methods promising and attractive from the computational point of view with respect to direct methods. In particular, iterative approach potentially enables the reduction of required computational time to solve Maxwell's equations by Eigenmode Expansion algorithms. Regardless of the particular eigenmodes finding method used, the expansion coefficients are computed as a rule by scattering matrix (S-matrix) approach or similar techniques requiring order of M3 operations. In this work we consider alternatives to the S-matrix technique which are based on pure iterative or mixed direct-iterative approaches. The possibility to diminish the impact of M3 -order calculations to overall time and in some cases even to reduce the number of arithmetic operations to M2 by applying iterative techniques are discussed. Numerical results are illustrated to discuss validity and potentiality of the proposed approaches.
A 2D/1D coupling neutron transport method based on the matrix MOC and NEM methods
Energy Technology Data Exchange (ETDEWEB)
Zhang, H.; Zheng, Y.; Wu, H.; Cao, L. [School of Nuclear Science and Technology, Xi' an Jiaotong University, No. 28, Xianning West Road, Xi' an, Shaanxi 710049 (China)
2013-07-01
A new 2D/1D coupling method based on the matrix MOC method (MMOC) and nodal expansion method (NEM) is proposed for solving the three-dimensional heterogeneous neutron transport problem. The MMOC method, used for radial two-dimensional calculation, constructs a response matrix between source and flux with only one sweep and then solves the linear system by using the restarted GMRES algorithm instead of the traditional trajectory sweeping process during within-group iteration for angular flux update. Long characteristics are generated by using the customization of commercial software AutoCAD. A one-dimensional diffusion calculation is carried out in the axial direction by employing the NEM method. The 2D and ID solutions are coupled through the transverse leakage items. The 3D CMFD method is used to ensure the global neutron balance and adjust the different convergence properties of the radial and axial solvers. A computational code is developed based on these theories. Two benchmarks are calculated to verify the coupling method and the code. It is observed that the corresponding numerical results agree well with references, which indicates that the new method is capable of solving the 3D heterogeneous neutron transport problem directly. (authors)
A 2D/1D coupling neutron transport method based on the matrix MOC and NEM methods
International Nuclear Information System (INIS)
Zhang, H.; Zheng, Y.; Wu, H.; Cao, L.
2013-01-01
A new 2D/1D coupling method based on the matrix MOC method (MMOC) and nodal expansion method (NEM) is proposed for solving the three-dimensional heterogeneous neutron transport problem. The MMOC method, used for radial two-dimensional calculation, constructs a response matrix between source and flux with only one sweep and then solves the linear system by using the restarted GMRES algorithm instead of the traditional trajectory sweeping process during within-group iteration for angular flux update. Long characteristics are generated by using the customization of commercial software AutoCAD. A one-dimensional diffusion calculation is carried out in the axial direction by employing the NEM method. The 2D and ID solutions are coupled through the transverse leakage items. The 3D CMFD method is used to ensure the global neutron balance and adjust the different convergence properties of the radial and axial solvers. A computational code is developed based on these theories. Two benchmarks are calculated to verify the coupling method and the code. It is observed that the corresponding numerical results agree well with references, which indicates that the new method is capable of solving the 3D heterogeneous neutron transport problem directly. (authors)
R-matrix analysis of 235U neutron transmission and cross sections in the energy range 0 to 2.25 keV
International Nuclear Information System (INIS)
Leal, L.C.; Derrien, H.; Larson, N.M.; Wright, R.Q.
1997-11-01
This document describes a new R-matrix analysis of 235 U cross section data in the energy range from 0 to 2,250 eV. The analysis was performed with the computer code SAMMY, that has recently been updated to permit, for the first time, inclusion of both differential and integral data within the analysis process. Fourteen differential data sets and six integral quantities were used in this evaluation: two measurements of fission plus capture, one of fission plus absorption, six of fission alone, two of transmission, and one of eta, plus standard values of thermal cross sections for fission, capture, and scattering, and of K1 and the Westcott g-factors for both fission and absorption. An excellent representation was obtained for the high-resolution transmission, fission, and capture cross-section data as well as for the integral quantities. The result is a single set of resonance parameters spanning the entire range up to 2,250 eV, a decided improvement over the present ENDF/VI evaluation, in which eleven discrete resonance parameter sets are required to cover that same energy range. This new evaluation is expected to greatly improve predictability of the criticality safety margins for nuclear systems in which 235 U is present
Optimized Signaling Method for High-Speed Transmission Channels with Higher Order Transfer Function
Ševčík, Břetislav; Brančík, Lubomír; Kubíček, Michal
2017-08-01
In this paper, the selected results from testing of optimized CMOS friendly signaling method for high-speed communications over cables and printed circuit boards (PCBs) are presented and discussed. The proposed signaling scheme uses modified concept of pulse width modulated (PWM) signal which enables to better equalize significant channel losses during data high-speed transmission. Thus, the very effective signaling method to overcome losses in transmission channels with higher order transfer function, typical for long cables and multilayer PCBs, is clearly analyzed in the time and frequency domain. Experimental results of the measurements include the performance comparison of conventional PWM scheme and clearly show the great potential of the modified signaling method for use in low power CMOS friendly equalization circuits, commonly considered in modern communication standards as PCI-Express, SATA or in Multi-gigabit SerDes interconnects.
Matrix pencil method-based reference current generation for shunt active power filters
DEFF Research Database (Denmark)
Terriche, Yacine; Golestan, Saeed; Guerrero, Josep M.
2018-01-01
response and works well under distorted and unbalanced voltage. Moreover, the proposed method can estimate the voltage phase accurately; this property enables the algorithm to compensate for both power factor and current unbalance. The effectiveness of the proposed method is verified using simulation...... are using the discrete Fourier transform (DFT) in the frequency domain or the instantaneous p–q theory and the synchronous reference frame in the time domain. The DFT, however, suffers from the picket-fence effect and spectral leakage. On the other hand, the DFT takes at least one cycle of the nominal...... frequency. The time-domain methods show a weakness under voltage distortion, which requires prior filtering techniques. The aim of this study is to present a fast yet effective method for generating the RCC for SAPFs. The proposed method, which is based on the matrix pencil method, has a fast dynamic...
Response matrix method and its application to SCWR single channel stability analysis
International Nuclear Information System (INIS)
Zhao, Jiyun; Tseng, K.J.; Tso, C.P.
2011-01-01
To simulate the reactor system dynamic features during density wave oscillations (DWO), both the non-linear method and the linear method can be used. Although some transient information is lost through model linearization, the high computational efficiency and relatively accurate results make the linear analysis methodology attractive, especially for prediction of the onset of instability. In the linear stability analysis, the system models are simplified through linearization of the complex non-linear differential equations, and then, the linear differential equations are generally solved in the frequency domain through Laplace transformation. In this paper, a system response matrix method was introduced by directly solving the differential equations in the time domain. By using a system response matrix method, the complicated transfer function derivation, which must be done in the frequency domain method, can be avoided. Using the response matrix method, a model was developed and applied to the single channel or parallel channel type instability analyses of the typical proposed SCWR design. The sensitivity of the decay ratio (DR) to the axial mesh size was analyzed and it was found that the DR is not sensitive to mesh size once sufficient number of axial nodes is applied. To demonstrate the effects of the inlet orificing to the stability feature for the supercritical condition, the sensitivity of the stability to inlet orifice coefficient was conducted for hot channel. It is clearly shown that a higher inlet orifice coefficient will make the system more stable. The susceptibility of stability to operating parameters such as mass flow rate, power and system pressure was also performed. And the measure to improve the SCWR stability sensitivity to operating parameters was investigated. It was found that the SCWR stability sensitivity feature can be improved by carefully managing the inlet orifices and choosing proper operating parameters. (author)
International Nuclear Information System (INIS)
Albou, A.; Galceran, M.; Renard, K.; Godet, S.; Jacques, P.J.
2013-01-01
The evolution of the orientation relationship between mechanical twins and the surrounding matrix with the degree of plastic deformation has been characterized at the nanoscale in twinning-induced plasticity steel. The recently developed automated crystal orientation mapping in transmission electron microscopy revealed that the ideal twin relationship is retained up to large levels of strain, while large orientation gradients are built up within the matrix. This particular evolution undoubtedly plays a role in the large work hardening rate of these steels.
Leonard, Annemarie K; Loughran, Elizabeth A; Klymenko, Yuliya; Liu, Yueying; Kim, Oleg; Asem, Marwa; McAbee, Kevin; Ravosa, Matthew J; Stack, M Sharon
2018-01-01
This chapter highlights methods for visualization and analysis of extracellular matrix (ECM) proteins, with particular emphasis on collagen type I, the most abundant protein in mammals. Protocols described range from advanced imaging of complex in vivo matrices to simple biochemical analysis of individual ECM proteins. The first section of this chapter describes common methods to image ECM components and includes protocols for second harmonic generation, scanning electron microscopy, and several histological methods of ECM localization and degradation analysis, including immunohistochemistry, Trichrome staining, and in situ zymography. The second section of this chapter details both a common transwell invasion assay and a novel live imaging method to investigate cellular behavior with respect to collagen and other ECM proteins of interest. The final section consists of common electrophoresis-based biochemical methods that are used in analysis of ECM proteins. Use of the methods described herein will enable researchers to gain a greater understanding of the role of ECM structure and degradation in development and matrix-related diseases such as cancer and connective tissue disorders. © 2018 Elsevier Inc. All rights reserved.
Le Vu, Stéphane; Ratmann, Oliver; Delpech, Valerie; Brown, Alison E; Gill, O Noel; Tostevin, Anna; Fraser, Christophe; Volz, Erik M
2018-06-01
Phylogenetic clustering of HIV sequences from a random sample of patients can reveal epidemiological transmission patterns, but interpretation is hampered by limited theoretical support and statistical properties of clustering analysis remain poorly understood. Alternatively, source attribution methods allow fitting of HIV transmission models and thereby quantify aspects of disease transmission. A simulation study was conducted to assess error rates of clustering methods for detecting transmission risk factors. We modeled HIV epidemics among men having sex with men and generated phylogenies comparable to those that can be obtained from HIV surveillance data in the UK. Clustering and source attribution approaches were applied to evaluate their ability to identify patient attributes as transmission risk factors. We find that commonly used methods show a misleading association between cluster size or odds of clustering and covariates that are correlated with time since infection, regardless of their influence on transmission. Clustering methods usually have higher error rates and lower sensitivity than source attribution method for identifying transmission risk factors. But neither methods provide robust estimates of transmission risk ratios. Source attribution method can alleviate drawbacks from phylogenetic clustering but formal population genetic modeling may be required to estimate quantitative transmission risk factors. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Matrix-variational method: an efficient approach to bound state eigenproblems
International Nuclear Information System (INIS)
Gerck, E.; d'Oliveira, A.B.
1978-11-01
A new matrix-variational method for solving the radial Schroedinger equation is described. It consists in obtaining an adjustable matrix formulation for the boundary value differential equation, using a set of three functions that obey the boundary conditions. These functions are linearly combined at every three adjacents points to fit the true unknown eigenfunction by a variational technique. With the use of a new class of central differences, the exponential differences, tridiagonal or bidiagonal matrices are obtained. In the bidiagonal case, closed form expressions for the eigenvalues are given for the Coulomb, harmonic, linear, square-root and logarithmic potentials. The values obtained are within 0.1% of the true numerical value. The eigenfunction can be calculated using the eigenvectors to reconstruct the linear combination of the set functions [pt
Matrix-operator method for calculation of dynamics of intense beams of charged particles
International Nuclear Information System (INIS)
Kapchinskij, M.I.; Korenev, I.L.; Rinskij, L.A.
1989-01-01
Calculation algorithm for particle dynamics in high-current cyclic and linear accelerators is suggested. Particle movement in six-dimensional phase space is divided into coherent and incoherent components. Incoherent movement is described by envelope method; particle cluster is considered to be even-charged by tri-axial ellipsoid. Coherent movement is described in para-axial approximation; each structure element of the accelerator transport channel is characterized by six-dimensional matrix of phase coordinate transformation of cluster centre and by shift vector resulting from deviation of focusing element parameters from calculated values. Effect of space charge reflected forces is taken into account in the element matrix. Algorithm software is realized using well-known TRANSPORT program
Current matrix element in HAL QCD's wavefunction-equivalent potential method
Watanabe, Kai; Ishii, Noriyoshi
2018-04-01
We give a formula to calculate a matrix element of a conserved current in the effective quantum mechanics defined by the wavefunction-equivalent potentials proposed by the HAL QCD collaboration. As a first step, a non-relativistic field theory with two-channel coupling is considered as the original theory, with which a wavefunction-equivalent HAL QCD potential is obtained in a closed analytic form. The external field method is used to derive the formula by demanding that the result should agree with the original theory. With this formula, the matrix element is obtained by sandwiching the effective current operator between the left and right eigenfunctions of the effective Hamiltonian associated with the HAL QCD potential. In addition to the naive one-body current, the effective current operator contains an additional two-body term emerging from the degrees of freedom which has been integrated out.
Charge-constrained auxiliary-density-matrix methods for the Hartree–Fock exchange contribution
DEFF Research Database (Denmark)
Merlot, Patrick; Izsak, Robert; Borgoo, Alex
2014-01-01
Three new variants of the auxiliary-density-matrix method (ADMM) of Guidon, Hutter, and VandeVondele [J. Chem. Theory Comput. 6, 2348 (2010)] are presented with the common feature thatthey have a simplified constraint compared with the full orthonormality requirement of the earlier ADMM1 method. ....... All ADMM variants are tested for accuracy and performance in all-electron B3LYP calculations with several commonly used basis sets. The effect of the choice of the exchange functional for the ADMM exchange–correction term is also investigated....
Stratoudaki, Theodosia; Clark, Matt; Wilcox, Paul D
2016-09-19
Laser ultrasonics is a technique where lasers are employed to generate and detect ultrasound. A data collection method (full matrix capture) and a post processing imaging algorithm, the total focusing method, both developed for ultrasonic arrays, are modified and used in order to enhance the capabilities of laser ultrasonics for nondestructive testing by improving defect detectability and increasing spatial resolution. In this way, a laser induced ultrasonic phased array is synthesized. A model is developed and compared with experimental results from aluminum samples with side drilled holes and slots at depths of 5 - 20 mm from the surface.
International Nuclear Information System (INIS)
Mitsuyasu, T.; Ishii, K.; Hino, T.; Aoyama, M.
2009-01-01
Spectral history methods for pin-by-pin core analysis method using the three-dimensional direct response matrix have been developed. The direct response matrix is formalized by four sub-response matrices in order to respond to a core eigenvalue k and thus can be recomposed at each outer iteration in the core analysis. For core analysis, it is necessary to take into account the burn-up effect related to spectral history. One of the methods is to evaluate the nodal burn-up spectrum obtained using the out-going neutron current. The other is to correct the fuel rod neutron production rates obtained the pin-by-pin correction. These spectral history methods were tested in a heterogeneous system. The test results show that the neutron multiplication factor error can be reduced by half during burn-up, the nodal neutron production rates errors can be reduced by 30% or more. The root-mean-square differences between the relative fuel rod neutron production rate distributions can be reduced within 1.1% error. This means that these methods can accurately reflect the effects of intra- and inter-assembly heterogeneities during burn-up and can be used for core analysis. Core analysis with the DRM method was carried out for an ABWR quarter core and it was found that both thermal power and coolant-flow distributions were smoothly converged. (authors)
International Nuclear Information System (INIS)
Grinman, Ana; Giustina, Daniel; Mondini, Julia; Diodat, Jorge
2008-01-01
Full text: This paper describes the steps which should be followed by a laboratory in order to validate the fluorimetric method for natural uranium in water matrix. The validation of an analytical method is a necessary requirement prior accreditation under Standard norm ISO/IEC 17025, of a non normalized method. Different analytical techniques differ in a sort of variables to be validated. Depending on the chemical process, measurement technique, matrix type, data fitting and measurement efficiency, a laboratory must set up experiments to verify reliability of data, through the application of several statistical tests and by participating in Quality Programs (QP) organized by reference laboratories such as the National Institute of Standards and Technology (NIST), National Physics Laboratory (NPL), or Environmental Measurements Laboratory (EML). However, the participation in QP not only involves international reference laboratories, but also, the national ones which are able to prove proficiency to the Argentinean Accreditation Board. The parameters that the ARN laboratory had to validate in the fluorimetric method to fit in accordance with Eurachem guide and IUPAC definitions, are: Detection Limit, Quantification Limit, Precision, Intra laboratory Precision, Reproducibility Limit, Repeatability Limit, Linear Range and Robustness. Assays to fit the above parameters were designed on the bases of statistics requirements, and a detailed data treatment is presented together with the respective tests in order to show the parameters validated. As a final conclusion, the uranium determination by fluorimetry is a reliable method for direct measurement to meet radioprotection requirements in water matrix, within its linear range which is fixed every time a calibration is carried out at the beginning of the analysis. The detection limit ( depending on blank standard deviation and slope) varies between 3 ug U and 5 ug U which yields minimum detectable concentrations (MDC) of
Producing accurate wave propagation time histories using the global matrix method
International Nuclear Information System (INIS)
Obenchain, Matthew B; Cesnik, Carlos E S
2013-01-01
This paper presents a reliable method for producing accurate displacement time histories for wave propagation in laminated plates using the global matrix method. The existence of inward and outward propagating waves in the general solution is highlighted while examining the axisymmetric case of a circular actuator on an aluminum plate. Problems with previous attempts to isolate the outward wave for anisotropic laminates are shown. The updated method develops a correction signal that can be added to the original time history solution to cancel the inward wave and leave only the outward propagating wave. The paper demonstrates the effectiveness of the new method for circular and square actuators bonded to the surface of isotropic laminates, and these results are compared with exact solutions. Results for circular actuators on cross-ply laminates are also presented and compared with experimental results, showing the ability of the new method to successfully capture the displacement time histories for composite laminates. (paper)
A projection-adapted cross entropy (PACE) method for transmission network planning
Energy Technology Data Exchange (ETDEWEB)
Eshragh, Ali; Filar, Jerzy [University of South Australia, School of Mathematics and Statistics, Mawson Lakes, SA (Australia); Nazar, Asef [University of South Australia, Institute for Sustainable Systems Technologies, School of Mathematics and Statistics, Mawson Lakes, SA (Australia)
2011-06-15
In this paper, we propose an adaptation of the cross entropy (CE) method called projection-adapted CE (PACE) to solve a transmission expansion problem that arises in management of national and provincial electricity grids. The aim of the problem is to find an expansion policy that is both economical and operational from the technical perspective. Often, the transmission network expansion problem is mathematically formulated as a mixed integer nonlinear program that is very challenging algorithmically. The challenge originates from the fact that a global optimum should be found despite the presence, of possibly a huge number, of local optima. The PACE method shows promise in solving global optimization problems regardless of continuity or other assumptions. In our approach, we sample the integer variables using the CE mechanism, and solve LPs to obtain matching continuous variables. Numerical results, on selected test systems, demonstrate the potential of this approach. (orig.)
The method of fundamental solutions for computing acoustic interior transmission eigenvalues
Kleefeld, Andreas; Pieronek, Lukas
2018-03-01
We analyze the method of fundamental solutions (MFS) in two different versions with focus on the computation of approximate acoustic interior transmission eigenvalues in 2D for homogeneous media. Our approach is mesh- and integration free, but suffers in general from the ill-conditioning effects of the discretized eigenoperator, which we could then successfully balance using an approved stabilization scheme. Our numerical examples cover many of the common scattering objects and prove to be very competitive in accuracy with the standard methods for PDE-related eigenvalue problems. We finally give an approximation analysis for our framework and provide error estimates, which bound interior transmission eigenvalue deviations in terms of some generalized MFS output.
A prestorage method to measure neutron transmission of ultracold neutron guides
International Nuclear Information System (INIS)
Blau, B.; Daum, M.; Fertl, M.; Geltenbort, P.; Göltl, L.; Henneck, R.; Kirch, K.; Knecht, A.; Lauss, B.; Schmidt-Wellenburg, P.; Zsigmond, G.
2016-01-01
There are worldwide efforts to search for physics beyond the Standard Model of particle physics. Precision experiments using ultracold neutrons (UCN) require very high intensities of UCN. Efficient transport of UCN from the production volume to the experiment is therefore of great importance. We have developed a method using prestored UCN in order to quantify UCN transmission in tubular guides. This method simulates the final installation at the Paul Scherrer Institute's UCN source where neutrons are stored in an intermediate storage vessel serving three experimental ports. This method allowed us to qualify UCN guides for their intended use and compare their properties.
Low-complexity video encoding method for wireless image transmission in capsule endoscope.
Takizawa, Kenichi; Hamaguchi, Kiyoshi
2010-01-01
This paper presents a low-complexity video encoding method applicable for wireless image transmission in capsule endoscopes. This encoding method is based on Wyner-Ziv theory, in which side information available at a transmitter is treated as side information at its receiver. Therefore complex processes in video encoding, such as estimation of the motion vector, are moved to the receiver side, which has a larger-capacity battery. As a result, the encoding process is only to decimate coded original data through channel coding. We provide a performance evaluation for a low-density parity check (LDPC) coding method in the AWGN channel.
A method of mobile video transmission based on J2ee
Guo, Jian-xin; Zhao, Ji-chun; Gong, Jing; Chun, Yang
2013-03-01
As 3G (3rd-generation) networks evolve worldwide, the rising demand for mobile video services and the enormous growth of video on the internet is creating major new revenue opportunities for mobile network operators and application developers. The text introduced a method of mobile video transmission based on J2ME, giving the method of video compressing, then describing the video compressing standard, and then describing the software design. The proposed mobile video method based on J2EE is a typical mobile multimedia application, which has a higher availability and a wide range of applications. The users can get the video through terminal devices such as phone.
A generalized transmission method for gamma-efficiency determinations in soil samples
International Nuclear Information System (INIS)
Bolivar, J.P.; Garcia-Tenorio, R.; Garcia-Leon, M.
1994-01-01
In this paper, a generalization of the γ-ray transmission method which is useful for measurements on soil samples, for example, is presented. The correction factor, f, is given, which is a function of the apparent density of the soil and the γ-ray energy. With this method, the need for individual determinations of f, for each energy and apparent soil density is avoided. Although the method has been developed for soils, the general philosophy can be applied to other sample matrices, such as water or vegetables for example. (author)
A method of applying two-pump system in automatic transmissions for energy conservation
Directory of Open Access Journals (Sweden)
Peng Dong
2015-06-01
Full Text Available In order to improve the hydraulic efficiency, modern automatic transmissions tend to apply electric oil pump in their hydraulic system. The electric oil pump can support the mechanical oil pump for cooling, lubrication, and maintaining the line pressure at low engine speeds. In addition, the start–stop function can be realized by means of the electric oil pump; thus, the fuel consumption can be further reduced. This article proposes a method of applying two-pump system (one electric oil pump and one mechanical oil pump in automatic transmissions based on the forward driving simulation. A mathematical model for calculating the transmission power loss is developed. The power loss transfers to heat which requires oil flow for cooling and lubrication. A leakage model is developed to calculate the leakage of the hydraulic system. In order to satisfy the flow requirement, a flow-based control strategy for the electric oil pump is developed. Simulation results of different driving cycles show that there is a best combination of the size of electric oil pump and the size of mechanical oil pump with respect to the optimal energy conservation. Besides, the two-pump system can also satisfy the requirement of the start–stop function. This research is extremely valuable for the forward design of a two-pump system in automatic transmissions with respect to energy conservation and start–stop function.
Han, Miaomiao; Guo, Zhirong; Liu, Haifeng; Li, Qinghua
2018-05-01
Tomographic Gamma Scanning (TGS) is a method used for the nondestructive assay of radioactive wastes. In TGS, the actual irregular edge voxels are regarded as regular cubic voxels in the traditional treatment method. In this study, in order to improve the performance of TGS, a novel edge treatment method is proposed that considers the actual shapes of these voxels. The two different edge voxel treatment methods were compared by computing the pixel-level relative errors and normalized mean square errors (NMSEs) between the reconstructed transmission images and the ideal images. Both methods were coupled with two different interative algorithms comprising Algebraic Reconstruction Technique (ART) with a non-negativity constraint and Maximum Likelihood Expectation Maximization (MLEM). The results demonstrated that the traditional method for edge voxel treatment can introduce significant error and that the real irregular edge voxel treatment method can improve the performance of TGS by obtaining better transmission reconstruction images. With the real irregular edge voxel treatment method, MLEM algorithm and ART algorithm can be comparable when assaying homogenous matrices, but MLEM algorithm is superior to ART algorithm when assaying heterogeneous matrices. Copyright © 2018 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Zhang Zhiping; Liu Shengkang; Zhang Yongjie
2001-01-01
The theoretical calculation and experimental study on the moisture disturbance in the boron content measurement of wet glass fibre materials using the thermal neutron transmission method were reported. The relevant formula of the moisture disturbance was derived. For samples with a mass of 16 g, it was found that a moisture variation of 1% (mass percent) would result in a deviation of 0.28% (mass percent) in the measurement of boron contents
PREDICTION OF RESERVOIR FLOW RATE OF DEZ DAM BY THE PROBABILITY MATRIX METHOD
Directory of Open Access Journals (Sweden)
Mohammad Hashem Kanani
2012-12-01
Full Text Available The data collected from the operation of existing storage reservoirs, could offer valuable information for the better allocation and management of fresh water rates for future use to mitigation droughts effect. In this paper the long-term Dez reservoir (IRAN water rate prediction is presented using probability matrix method. Data is analyzed to find the probability matrix of water rates in Dez reservoir based on the previous history of annual water entrance during the past and present years(40 years. The algorithm developed covers both, the overflow and non-overflow conditions in the reservoir. Result of this study shows that in non-overflow conditions the most exigency case is equal to 75%. This means that, if the reservoir is empty (the stored water is less than 100 MCM this year, it would be also empty by 75% next year. The stored water in the reservoir would be less than 300 MCM by 85% next year if the reservoir is empty this year. This percentage decreases to 70% next year if the water of reservoir is less than 300 MCM this year. The percentage also decreases to 5% next year if the reservoir is full this year. In overflow conditions the most exigency case is equal to 75% again. The reservoir volume would be less than 150 MCM by 90% next year, if it is empty this year. This percentage decreases to 70% if its water volume is less than 300 MCM and 55% if the water volume is less than 500 MCM this year. Result shows that too, if the probability matrix of water rates to a reservoir is multiplied by itself repeatedly; it converges to a constant probability matrix, which could be used to predict the long-term water rate of the reservoir. In other words, the probability matrix of series of water rates is changed to a steady probability matrix in the course of time, which could reflect the hydrological behavior of the watershed and could be easily used for the long-term prediction of water storage in the down stream reservoirs.
International Nuclear Information System (INIS)
Kussmann, Jörg; Luenser, Arne; Beer, Matthias; Ochsenfeld, Christian
2015-01-01
An analytical method to calculate the molecular vibrational Hessian matrix at the self-consistent field level is presented. By analysis of the multipole expansions of the relevant derivatives of Coulomb-type two-electron integral contractions, we show that the effect of the perturbation on the electronic structure due to the displacement of nuclei decays at least as r −2 instead of r −1 . The perturbation is asymptotically local, and the computation of the Hessian matrix can, in principle, be performed with O(N) complexity. Our implementation exhibits linear scaling in all time-determining steps, with some rapid but quadratic-complexity steps remaining. Sample calculations illustrate linear or near-linear scaling in the construction of the complete nuclear Hessian matrix for sparse systems. For more demanding systems, scaling is still considerably sub-quadratic to quadratic, depending on the density of the underlying electronic structure
Simplified LCA and matrix methods in identifying the environmental aspects of a product system.
Hur, Tak; Lee, Jiyong; Ryu, Jiyeon; Kwon, Eunsun
2005-05-01
In order to effectively integrate environmental attributes into the product design and development processes, it is crucial to identify the significant environmental aspects related to a product system within a relatively short period of time. In this study, the usefulness of life cycle assessment (LCA) and a matrix method as tools for identifying the key environmental issues of a product system were examined. For this, a simplified LCA (SLCA) method that can be applied to Electrical and Electronic Equipment (EEE) was developed to efficiently identify their significant environmental aspects for eco-design, since a full scale LCA study is usually very detailed, expensive and time-consuming. The environmentally responsible product assessment (ERPA) method, which is one of the matrix methods, was also analyzed. Then, the usefulness of each method in eco-design processes was evaluated and compared using the case studies of the cellular phone and vacuum cleaner systems. It was found that the SLCA and the ERPA methods provided different information but they complemented each other to some extent. The SLCA method generated more information on the inherent environmental characteristics of a product system so that it might be useful for new design/eco-innovation when developing a completely new product or method where environmental considerations play a major role from the beginning. On the other hand, the ERPA method gave more information on the potential for improving a product so that it could be effectively used in eco-redesign which intends to alleviate environmental impacts of an existing product or process.
Matrix elements and few-body calculations within the unitary correlation operator method
International Nuclear Information System (INIS)
Roth, R.; Hergert, H.; Papakonstantinou, P.
2005-01-01
We employ the unitary correlation operator method (UCOM) to construct correlated, low-momentum matrix elements of realistic nucleon-nucleon interactions. The dominant short-range central and tensor correlations induced by the interaction are included explicitly by an unitary transformation. Using correlated momentum-space matrix elements of the Argonne V18 potential, we show that the unitary transformation eliminates the strong off-diagonal contributions caused by the short-range repulsion and the tensor interaction and leaves a correlated interaction dominated by low-momentum contributions. We use correlated harmonic oscillator matrix elements as input for no-core shell model calculations for few-nucleon systems. Compared to the bare interaction, the convergence properties are dramatically improved. The bulk of the binding energy can already be obtained in very small model spaces or even with a single Slater determinant. Residual long-range correlations, not treated explicitly by the unitary transformation, can easily be described in model spaces of moderate size allowing for fast convergence. By varying the range of the tensor correlator we are able to map out the Tjon line and can in turn constrain the optimal correlator ranges. (orig.)
Matrix elements and few-body calculations within the unitary correlation operator method
International Nuclear Information System (INIS)
Roth, R.; Hergert, H.; Papakonstantinou, P.; Neff, T.; Feldmeier, H.
2005-01-01
We employ the unitary correlation operator method (UCOM) to construct correlated, low-momentum matrix elements of realistic nucleon-nucleon interactions. The dominant short-range central and tensor correlations induced by the interaction are included explicitly by an unitary transformation. Using correlated momentum-space matrix elements of the Argonne V18 potential, we show that the unitary transformation eliminates the strong off-diagonal contributions caused by the short-range repulsion and the tensor interaction and leaves a correlated interaction dominated by low-momentum contributions. We use correlated harmonic oscillator matrix elements as input for no-core shell model calculations for few-nucleon systems. Compared to the bare interaction, the convergence properties are dramatically improved. The bulk of the binding energy can already be obtained in very small model spaces or even with a single Slater determinant. Residual long-range correlations, not treated explicitly by the unitary transformation, can easily be described in model spaces of moderate size allowing for fast convergence. By varying the range of the tensor correlator we are able to map out the Tjon line and can in turn constrain the optimal correlator ranges
International Nuclear Information System (INIS)
Fano, G.; Ortolani, F.; Ziosi, L.
1997-10-01
The density matrix renormalization group (DMRG) method introduced by White for the study of strongly interacting electron systems is reviewed; the method is variational and considers a system of localized electrons as the union of two adjacent fragments A,B. A density matrix ρ is introduced, whose eigenvectors corresponding to the largest eigenvalues are the most significant, the most probable states of A in the presence of B; these states are retained, while states corresponding to small eigenvalues of ρ are neglected. It is conjectured that the decreasing behaviour of the eigenvalues is gaussian. The DMRG method is tested on the Pariser-Parr-Pople Hamiltonian of a cyclic polyene (CH) N up to N = 34. A Hilbert space of dimension 5. x 10 18 is explored. The ground state energy is 10 -3 eV within the full Cl value in the case N = 18. The DMRG method compares favourably also with coupled cluster approximations. The unrestricted Hartree-Fock solution (which presents spin density waves) is briefly reviewed, and a comparison is made with the DMRG energy values. Finally, the spin-spin and density-density correlation functions are computed; the results suggest that the antiferromagnetic order of the exact solution does not extend up to large distances but exists locally. No charge density waves are present. (author)
A pseudospectral matrix method for time-dependent tensor fields on a spherical shell
International Nuclear Information System (INIS)
Brügmann, Bernd
2013-01-01
We construct a pseudospectral method for the solution of time-dependent, non-linear partial differential equations on a three-dimensional spherical shell. The problem we address is the treatment of tensor fields on the sphere. As a test case we consider the evolution of a single black hole in numerical general relativity. A natural strategy would be the expansion in tensor spherical harmonics in spherical coordinates. Instead, we consider the simpler and potentially more efficient possibility of a double Fourier expansion on the sphere for tensors in Cartesian coordinates. As usual for the double Fourier method, we employ a filter to address time-step limitations and certain stability issues. We find that a tensor filter based on spin-weighted spherical harmonics is successful, while two simplified, non-spin-weighted filters do not lead to stable evolutions. The derivatives and the filter are implemented by matrix multiplication for efficiency. A key technical point is the construction of a matrix multiplication method for the spin-weighted spherical harmonic filter. As example for the efficient parallelization of the double Fourier, spin-weighted filter method we discuss an implementation on a GPU, which achieves a speed-up of up to a factor of 20 compared to a single core CPU implementation
Leone, Frank A., Jr.
2015-01-01
A method is presented to represent the large-deformation kinematics of intraply matrix cracks and delaminations in continuum damage mechanics (CDM) constitutive material models. The method involves the additive decomposition of the deformation gradient tensor into 'crack' and 'bulk material' components. The response of the intact bulk material is represented by a reduced deformation gradient tensor, and the opening of an embedded cohesive interface is represented by a normalized cohesive displacement-jump vector. The rotation of the embedded interface is tracked as the material deforms and as the crack opens. The distribution of the total local deformation between the bulk material and the cohesive interface components is determined by minimizing the difference between the cohesive stress and the bulk material stress projected onto the cohesive interface. The improvements to the accuracy of CDM models that incorporate the presented method over existing approaches are demonstrated for a single element subjected to simple shear deformation and for a finite element model of a unidirectional open-hole tension specimen. The material model is implemented as a VUMAT user subroutine for the Abaqus/Explicit finite element software. The presented deformation gradient decomposition method reduces the artificial load transfer across matrix cracks subjected to large shearing deformations, and avoids the spurious secondary failure modes that often occur in analyses based on conventional progressive damage models.
Applying the response matrix method for solving coupled neutron diffusion and transport problems
International Nuclear Information System (INIS)
Sibiya, G.S.
1980-01-01
The numerical determination of the flux and power distribution in the design of large power reactors is quite a time-consuming procedure if the space under consideration is to be subdivided into very fine weshes. Many computing methods applied in reactor physics (such as the finite-difference method) require considerable computing time. In this thesis it is shown that the response matrix method can be successfully used as an alternative approach to solving the two-dimension diffusion equation. Furthermore it is shown that sufficient accuracy of the method is achieved by assuming a linear space dependence of the neutron currents on the boundaries of the geometries defined for the given space. (orig.) [de
Concerning an application of the method of least squares with a variable weight matrix
Sukhanov, A. A.
1979-01-01
An estimate of a state vector for a physical system when the weight matrix in the method of least squares is a function of this vector is considered. An iterative procedure is proposed for calculating the desired estimate. Conditions for the existence and uniqueness of the limit of this procedure are obtained, and a domain is found which contains the limit estimate. A second method for calculating the desired estimate which reduces to the solution of a system of algebraic equations is proposed. The question of applying Newton's method of tangents to solving the given system of algebraic equations is considered and conditions for the convergence of the modified Newton's method are obtained. Certain properties of the estimate obtained are presented together with an example.
Chen, Meixiong; Yuan, Jie; Long, Xingwu; Kang, Zhenglong; Wang, Zhiguo; Li, Yingying
2013-12-01
A general beam position controlling method for 3D optical systems based on the method of solving ray matrix equations has been proposed in this paper. As a typical 3D optical system, nonplanar ring resonator of Zero-Lock Laser Gyroscopes has been chosen as an example to show its application. The total mismatching error induced by Faraday-wedge in nonplanar ring resonator has been defined and eliminated quite accurately with the error less than 1 μm. Compared with the method proposed in Ref. [14], the precision of the beam position controlling has been improved by two orders of magnitude. The novel method can be used to implement automatic beam position controlling in 3D optical systems with servo circuit. All those results have been confirmed by related alignment experiments. The results in this paper are important for beam controlling, ray tracing, cavity design and alignment in 3D optical systems.
Method and apparatus for evaluating structural weakness in polymer matrix composites
Wachter, Eric A.; Fisher, Walter G.
1996-01-01
A method and apparatus for evaluating structural weaknesses in polymer matrix composites is described. An object to be studied is illuminated with laser radiation and fluorescence emanating therefrom is collected and filtered. The fluorescence is then imaged and the image is studied to determine fluorescence intensity over the surface of the object being studied and the wavelength of maximum fluorescent intensity. Such images provide a map of the structural integrity of the part being studied and weaknesses, particularly weaknesses created by exposure of the object to heat, are readily visible in the image.
DeCarvalho, Nelson V.; Chen, B. Y.; Pinho, Silvestre T.; Baiz, P. M.; Ratcliffe, James G.; Tay, T. E.
2013-01-01
A novel approach is proposed for high-fidelity modeling of progressive damage and failure in composite materials that combines the Floating Node Method (FNM) and the Virtual Crack Closure Technique (VCCT) to represent multiple interacting failure mechanisms in a mesh-independent fashion. In this study, the approach is applied to the modeling of delamination migration in cross-ply tape laminates. Delamination, matrix cracking, and migration are all modeled using fracture mechanics based failure and migration criteria. The methodology proposed shows very good qualitative and quantitative agreement with experiments.
A spectral method to detect community structure based on distance modularity matrix
Yang, Jin-Xuan; Zhang, Xiao-Dong
2017-08-01
There are many community organizations in social and biological networks. How to identify these community structure in complex networks has become a hot issue. In this paper, an algorithm to detect community structure of networks is proposed by using spectra of distance modularity matrix. The proposed algorithm focuses on the distance of vertices within communities, rather than the most weakly connected vertex pairs or number of edges between communities. The experimental results show that our method achieves better effectiveness to identify community structure for a variety of real-world networks and computer generated networks with a little more time-consumption.
A method for the estimation of dual transmissivities from slug tests
Wolny, Filip; Marciniak, Marek; Kaczmarek, Mariusz
2018-03-01
Aquifer homogeneity is usually assumed when interpreting the results of pumping and slug tests, although aquifers are essentially heterogeneous. The aim of this study is to present a method of determining the transmissivities of dual-permeability water-bearing formations based on slug tests such as the pressure-induced permeability test. A bi-exponential rate-of-rise curve is typically observed during many of these tests conducted in heterogeneous formations. The work involved analyzing curves deviating from the exponential rise recorded at the Belchatow Lignite Mine in central Poland, where a significant number of permeability tests have been conducted. In most cases, bi-exponential movement was observed in piezometers with a screen installed in layered sediments, each with a different hydraulic conductivity, or in fissured rock. The possibility to identify the flow properties of these geological formations was analyzed. For each piezometer installed in such formations, a set of two transmissivity values was calculated piecewise based on the interpretation algorithm of the pressure-induced permeability test—one value for the first (steeper) part of the obtained rate-of-rise curve, and a second value for the latter part of the curve. The results of transmissivity estimation for each piezometer are shown. The discussion presents the limitations of the interpretational method and suggests future modeling plans.
Directory of Open Access Journals (Sweden)
Yong Chen
2016-01-01
Full Text Available The Modular Multilevel Converters (MMC have been a spotlight for the high voltage and high power transmission systems. In the VSC-HVDC (High Voltage Direct Current based on Voltage Source Converter transmission system, the energy of DC link is stored in the distributed capacitors, and the difference of capacitors in parameters and charge rates causes capacitor voltage balance which affects the safety and stability of HVDC system. A method of MMC based on the expert system for reducing the frequency of the submodules (SMs of the IGBT switching frequency is proposed. Firstly, MMC with 51 levels for HVDC is designed. Secondly, the nearest level control (NLC for 51-level MMC is introduced. Thirdly, a modified capacitor voltage balancing method based on expert system for MMC-based HVDC transmission system is proposed. Finally, a simulation platform for 51-level Modular Multilevel Converter is constructed by using MATLAB/SIMULINK. The results indicate that the strategy proposed reduces the switching frequency on the premise of keeping submodule voltage basically identical, which greatly reduces the power losses for MMC-HVDC system.
Location of Faults in Power Transmission Lines Using the ARIMA Method
Directory of Open Access Journals (Sweden)
Danilo Pinto Moreira de Souza
2017-10-01
Full Text Available One of the major problems in transmission lines is the occurrence of failures that affect the quality of the electric power supplied, as the exact localization of the fault must be known for correction. In order to streamline the work of maintenance teams and standardize services, this paper proposes a method of locating faults in power transmission lines by analyzing the voltage oscillographic signals extracted at the line monitoring terminals. The developed method relates time series models obtained specifically for each failure pattern. The parameters of the autoregressive integrated moving average (ARIMA model are estimated in order to adjust the voltage curves and calculate the distance from the initial fault localization to the terminals. Simulations of the failures are performed through the ATPDraw ® (5.5 software and the analyses were completed using the RStudio ® (1.0.143 software. The results obtained with respect to the failures, which did not involve earth return, were satisfactory when compared with widely used techniques in the literature, particularly when the fault distance became larger in relation to the beginning of the transmission line.
Efficient Data Gathering Methods in Wireless Sensor Networks Using GBTR Matrix Completion
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Donghao Wang
2016-09-01
Full Text Available To obtain efficient data gathering methods for wireless sensor networks (WSNs, a novel graph based transform regularized (GBTR matrix completion algorithm is proposed. The graph based transform sparsity of the sensed data is explored, which is also considered as a penalty term in the matrix completion problem. The proposed GBTR-ADMM algorithm utilizes the alternating direction method of multipliers (ADMM in an iterative procedure to solve the constrained optimization problem. Since the performance of the ADMM method is sensitive to the number of constraints, the GBTR-A2DM2 algorithm obtained to accelerate the convergence of GBTR-ADMM. GBTR-A2DM2 benefits from merging two constraint conditions into one as well as using a restart rule. The theoretical analysis shows the proposed algorithms obtain satisfactory time complexity. Extensive simulation results verify that our proposed algorithms outperform the state of the art algorithms for data collection problems in WSNs in respect to recovery accuracy, convergence rate, and energy consumption.
Yang, Haixuan; Seoighe, Cathal
2016-01-01
Nonnegative Matrix Factorization (NMF) has proved to be an effective method for unsupervised clustering analysis of gene expression data. By the nonnegativity constraint, NMF provides a decomposition of the data matrix into two matrices that have been used for clustering analysis. However, the decomposition is not unique. This allows different clustering results to be obtained, resulting in different interpretations of the decomposition. To alleviate this problem, some existing methods directly enforce uniqueness to some extent by adding regularization terms in the NMF objective function. Alternatively, various normalization methods have been applied to the factor matrices; however, the effects of the choice of normalization have not been carefully investigated. Here we investigate the performance of NMF for the task of cancer class discovery, under a wide range of normalization choices. After extensive evaluations, we observe that the maximum norm showed the best performance, although the maximum norm has not previously been used for NMF. Matlab codes are freely available from: http://maths.nuigalway.ie/~haixuanyang/pNMF/pNMF.htm.
Directory of Open Access Journals (Sweden)
A.M. Yu
2012-01-01
Full Text Available Free vibration equations for non-cylindrical (conical, barrel, and hyperboloidal types helical springs with noncircular cross-sections, which consist of 14 first-order ordinary differential equations with variable coefficients, are theoretically derived using spatially curved beam theory. In the formulation, the warping effect upon natural frequencies and vibrating mode shapes is first studied in addition to including the rotary inertia, the shear and axial deformation influences. The natural frequencies of the springs are determined by the use of improved Riccati transfer matrix method. The element transfer matrix used in the solution is calculated using the Scaling and Squaring method and Pad'e approximations. Three examples are presented for three types of springs with different cross-sectional shapes under clamped-clamped boundary condition. The accuracy of the proposed method has been compared with the FEM results using three-dimensional solid elements (Solid 45 in ANSYS code. Numerical results reveal that the warping effect is more pronounced in the case of non-cylindrical helical springs than that of cylindrical helical springs, which should be taken into consideration in the free vibration analysis of such springs.
Choi, Du Hyung; Shin, Sangmun; Khoa Viet Truong, Nguyen; Jeong, Seong Hoon
2012-09-01
A robust experimental design method was developed with the well-established response surface methodology and time series modeling to facilitate the formulation development process with magnesium stearate incorporated into hydrophilic matrix tablets. Two directional analyses and a time-oriented model were utilized to optimize the experimental responses. Evaluations of tablet gelation and drug release were conducted with two factors x₁ and x₂: one was a formulation factor (the amount of magnesium stearate) and the other was a processing factor (mixing time), respectively. Moreover, different batch sizes (100 and 500 tablet batches) were also evaluated to investigate an effect of batch size. The selected input control factors were arranged in a mixture simplex lattice design with 13 experimental runs. The obtained optimal settings of magnesium stearate for gelation were 0.46 g, 2.76 min (mixing time) for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The optimal settings for drug release were 0.33 g, 7.99 min for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The exact ratio and mixing time of magnesium stearate could be formulated according to the resulting hydrophilic matrix tablet properties. The newly designed experimental method provided very useful information for characterizing significant factors and hence to obtain optimum formulations allowing for a systematic and reliable experimental design method.
Urena; Gomez De Salazar JM; Gil; Escalera; Baldonedo
1999-11-01
Processing of aluminium matrix composites (AMCs), especially those constituted by a reactive system such as Al-SiC, presents great difficulties which limit their potential applications. The interface reactivity between SiC and molten Al generates an aluminium carbide which degrades the composite properties. Scanning and transmission electron microscopes equipped with energy-dispersive X-ray spectroscopes are essential tools for determining the structure and chemistry of the Al-SiC interfaces in AMCs and changes occurring during casting and arc welding. In the present work, an aluminium-copper alloy (AA2014) reinforced with three different percentages of SiC particles was subjected to controlled remelting tests, at temperatures in the range 750-900 degrees C for 10 and 30 min. Arc welding tests using a tungsten intert gas with power inputs in the range 850-2000 W were also carried out. The results of these studies showed that during remelting there is preferential SiC particle consumption with formation of Al4C3 by interface reaction between the solid SiC particle and the molten aluminium matrix. The formation of Al4C3 by the same mechanism has also been detected in molten pools of arc welded composites. However, in this case there was formation of an almost continuous layer of Al4C3, which protects the particle against further consumption, and formation of aciculate aluminium carbide on the top weld. Both are formed by fusion and dissolution of the SiC in molten aluminium followed by reaction and precipitation of the Al4C3 during cooling.
Power-efficient method for IM-DD optical transmission of multiple OFDM signals.
Effenberger, Frank; Liu, Xiang
2015-05-18
We propose a power-efficient method for transmitting multiple frequency-division multiplexed (FDM) orthogonal frequency-division multiplexing (OFDM) signals in intensity-modulation direct-detection (IM-DD) optical systems. This method is based on quadratic soft clipping in combination with odd-only channel mapping. We show, both analytically and experimentally, that the proposed approach is capable of improving the power efficiency by about 3 dB as compared to conventional FDM OFDM signals under practical bias conditions, making it a viable solution in applications such as optical fiber-wireless integrated systems where both IM-DD optical transmission and OFDM signaling are important.
Calculation of large ion densities under HVdc transmission lines by the finite difference method
International Nuclear Information System (INIS)
Suda, Tomotaka; Sunaga, Yoshitaka
1995-01-01
A calculation method for large ion densities (charged aerosols) under HVdc transmission lines was developed considering both the charging mechanism of aerosols by small ions and the drifting process by wind. Large ion densities calculated by this method agreed well with the ones measured under the Shiobara HVdc test line on the lateral profiles at ground level up to about 70m downwind from the line. Measured values decreased more quickly than calculated ones farther downwind from the line. Considering the effect of point discharge from ground cover (earth corona) improved the agreement in the farther downwind region
The Matrix Method of Representation, Analysis and Classification of Long Genetic Sequences
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Ivan V. Stepanyan
2017-01-01
Full Text Available The article is devoted to a matrix method of comparative analysis of long nucleotide sequences by means of presenting each sequence in the form of three digital binary sequences. This method uses a set of symmetries of biochemical attributes of nucleotides. It also uses the possibility of presentation of every whole set of N-mers as one of the members of a Kronecker family of genetic matrices. With this method, a long nucleotide sequence can be visually represented as an individual fractal-like mosaic or another regular mosaic of binary type. In contrast to natural nucleotide sequences, artificial random sequences give non-regular patterns. Examples of binary mosaics of long nucleotide sequences are shown, including cases of human chromosomes and penicillins. The obtained results are then discussed.
Photonic band structures solved by a plane-wave-based transfer-matrix method.
Li, Zhi-Yuan; Lin, Lan-Lan
2003-04-01
Transfer-matrix methods adopting a plane-wave basis have been routinely used to calculate the scattering of electromagnetic waves by general multilayer gratings and photonic crystal slabs. In this paper we show that this technique, when combined with Bloch's theorem, can be extended to solve the photonic band structure for 2D and 3D photonic crystal structures. Three different eigensolution schemes to solve the traditional band diagrams along high-symmetry lines in the first Brillouin zone of the crystal are discussed. Optimal rules for the Fourier expansion over the dielectric function and electromagnetic fields with discontinuities occurring at the boundary of different material domains have been employed to accelerate the convergence of numerical computation. Application of this method to an important class of 3D layer-by-layer photonic crystals reveals the superior convergency of this different approach over the conventional plane-wave expansion method.
Photonic band structures solved by a plane-wave-based transfer-matrix method
International Nuclear Information System (INIS)
Li Zhiyuan; Lin Lanlan
2003-01-01
Transfer-matrix methods adopting a plane-wave basis have been routinely used to calculate the scattering of electromagnetic waves by general multilayer gratings and photonic crystal slabs. In this paper we show that this technique, when combined with Bloch's theorem, can be extended to solve the photonic band structure for 2D and 3D photonic crystal structures. Three different eigensolution schemes to solve the traditional band diagrams along high-symmetry lines in the first Brillouin zone of the crystal are discussed. Optimal rules for the Fourier expansion over the dielectric function and electromagnetic fields with discontinuities occurring at the boundary of different material domains have been employed to accelerate the convergence of numerical computation. Application of this method to an important class of 3D layer-by-layer photonic crystals reveals the superior convergency of this different approach over the conventional plane-wave expansion method
Improved method for eliminating center-of-mass coordinates from matrix elements in oscillator basis
International Nuclear Information System (INIS)
Richardson, R.H.; Shapiro, J.Y.
1986-01-01
This paper presents a concise, efficient method of reducing potential energy matrix elements to relative coordinates, when one is using an oscillator basis. It is especially suited to computer calculations. One nice feature of the method is its modular form, which allows a wide range of calculations. Separate FORTRAN subroutines have been written which calculate and store tables of the one-dimensional brackets of an equation that is presented and the single particle brackets from the isotropic to the axially symmetric oscillator equations. The tables are used by other subroutines which calculate the modified brackets and the brackets with spin. The methods developed here are a substantial improvement over what has been done heretofore, and open up new possibilities for performing nuclear structure calculations
Evaluation of the thermodynamics of a four level system using canonical density matrix method
Directory of Open Access Journals (Sweden)
Awoga Oladunjoye A.
2013-02-01
Full Text Available We consider a four-level system with two subsystems coupled by weak interaction. The system is in thermal equilibrium. The thermodynamics of the system, namely internal energy, free energy, entropy and heat capacity, are evaluated using the canonical density matrix by two methods. First by Kronecker product method and later by treating the subsystems separately and then adding the evaluated thermodynamic properties of each subsystem. It is discovered that both methods yield the same result, the results obey the laws of thermodynamics and are the same as earlier obtained results. The results also show that each level of the subsystems introduces a new degree of freedom and increases the entropy of the entire system. We also found that the four-level system predicts a linear relationship between heat capacity and temperature at very low temperatures just as in metals. Our numerical results show the same trend.
EDF's new environment-oriented method for planning the Extra High Voltage transmission network
International Nuclear Information System (INIS)
Trogneux, F.; Doquet, M.; Blondel, H.; Mallet, P.
1996-01-01
As EDF is experiencing increasing difficulties to develop its transmission network, the time may have come to reconsider the project selection method. In this paper, we point out that the currently used method essentially relies on a classical discounted balance criterion. We then present a new method taking into account the impact of a project on the environment by considering an environmental risk which may jeopardize the project's success. This method helps to evaluate the probability that each possible route of each project will be carried through. A simple probability computation then allows us to derive a global comparison of the eligible projects on the basis of an expected discounted balance criterion. Experiments now in progress will help to decide upon this method's efficiency in the context of an operational use. (author). 5 figs., 1 tab., 4 refs
Determination of the transmission coefficients for quantum structures using FDTD method.
Peng, Yangyang; Wang, Xiaoying; Sui, Wenquan
2011-12-01
The purpose of this work is to develop a simple method to incorporate quantum effect in traditional finite-difference time-domain (FDTD) simulators. Witch could make it possible to co-simulate systems include quantum structures and traditional components. In this paper, tunneling transmission coefficient is calculated by solving time-domain Schrödinger equation with a developed FDTD technique, called FDTD-S method. To validate the feasibility of the method, a simple resonant tunneling diode (RTD) structure model has been simulated using the proposed method. The good agreement between the numerical and analytical results proves its accuracy. The effectness and accuracy of this approach makes it a potential method for analysis and design of hybrid systems includes quantum structures and traditional components.
Directory of Open Access Journals (Sweden)
Sette Alessandro
2005-05-01
Full Text Available Abstract Background Many processes in molecular biology involve the recognition of short sequences of nucleic-or amino acids, such as the binding of immunogenic peptides to major histocompatibility complex (MHC molecules. From experimental data, a model of the sequence specificity of these processes can be constructed, such as a sequence motif, a scoring matrix or an artificial neural network. The purpose of these models is two-fold. First, they can provide a summary of experimental results, allowing for a deeper understanding of the mechanisms involved in sequence recognition. Second, such models can be used to predict the experimental outcome for yet untested sequences. In the past we reported the development of a method to generate such models called the Stabilized Matrix Method (SMM. This method has been successfully applied to predicting peptide binding to MHC molecules, peptide transport by the transporter associated with antigen presentation (TAP and proteasomal cleavage of protein sequences. Results Herein we report the implementation of the SMM algorithm as a publicly available software package. Specific features determining the type of problems the method is most appropriate for are discussed. Advantageous features of the package are: (1 the output generated is easy to interpret, (2 input and output are both quantitative, (3 specific computational strategies to handle experimental noise are built in, (4 the algorithm is designed to effectively handle bounded experimental data, (5 experimental data from randomized peptide libraries and conventional peptides can easily be combined, and (6 it is possible to incorporate pair interactions between positions of a sequence. Conclusion Making the SMM method publicly available enables bioinformaticians and experimental biologists to easily access it, to compare its performance to other prediction methods, and to extend it to other applications.
International Nuclear Information System (INIS)
Park, Yujin; Kazantzis, Nikolaos; Parlos, Alexander G.; Chong, Kil To
2013-01-01
Highlights: • Numerical solution for stiff differential equations using matrix exponential method. • The approximation is based on First Order Hold assumption. • Various input examples applied to the point kinetics equations. • The method shows superior useful and effective activity. - Abstract: A system of nonlinear differential equations is derived to model the dynamics of neutron density and the delayed neutron precursors within a point kinetics equation modeling framework for a nuclear reactor. The point kinetic equations are mathematically characterized as stiff, occasionally nonlinear, ordinary differential equations, posing significant challenges when numerical solutions are sought and traditionally resulting in the need for smaller time step intervals within various computational schemes. In light of the above realization, the present paper proposes a new discretization method inspired by system-theoretic notions and technically based on a combination of the matrix exponential method (MEM) and the First-Order Hold (FOH) assumption. Under the proposed time discretization structure, the sampled-data representation of the nonlinear point kinetic system of equations is derived. The performance of the proposed time discretization procedure is evaluated using several case studies with sinusoidal reactivity profiles and multiple input examples (reactivity and neutron source function). It is shown, that by applying the proposed method under a First-Order Hold for the neutron density and the precursor concentrations at each time step interval, the stiffness problem associated with the point kinetic equations can be adequately addressed and resolved. Finally, as evidenced by the aforementioned detailed simulation studies, the proposed method retains its validity and accuracy for a wide range of reactor operating conditions, including large sampling periods dictated by physical and/or technical limitations associated with the current state of sensor and
Measurement of the top quark mass in the dilepton final state using the matrix element method
Energy Technology Data Exchange (ETDEWEB)
Grohsjean, Alexander [Ludwig Maximilian Univ., Munich (Germany)
2008-12-15
The top quark, discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron Collider, is the heaviest known fundamental particle. The precise knowledge of its mass yields important constraints on the mass of the yet-unobserved Higgs boson and allows to probe for physics beyond the Standard Model. The first measurement of the top quark mass in the dilepton channel with the Matrix Element method at the D0 experiment is presented. After a short description of the experimental environment and the reconstruction chain from hits in the detector to physical objects, a detailed review of the Matrix Element method is given. The Matrix Element method is based on the likelihood to observe a given event under the assumption of the quantity to be measured, e.g. the mass of the top quark. The method has undergone significant modifications and improvements compared to previous measurements in the lepton+jets channel: the two undetected neutrinos require a new reconstruction scheme for the four-momenta of the final state particles, the small event sample demands the modeling of additional jets in the signal likelihood, and a new likelihood is designed to account for the main source of background containing tauonic Z decay. The Matrix Element method is validated on Monte Carlo simulated events at the generator level. For the measurement, calibration curves are derived from events that are run through the full D0 detector simulation. The analysis makes use of the Run II data set recorded between April 2002 and May 2008 corresponding to an integrated luminosity of 2.8 fb^{-1}. A total of 107 t$\\bar{t}$ candidate events with one electron and one muon in the final state are selected. Applying the Matrix Element method to this data set, the top quark mass is measured to be m_{top}^{Run IIa} = 170.6 ± 6.1(stat.)_{-1.5}^{+2.1}(syst.)GeV; m_{top}^{Run IIb} = 174.1 ± 4.4(stat.)_{-1.8}^{+2.5}(syst.)GeV; m
Zhang, Hongqin; Tian, Xiangjun
2018-04-01
Ensemble-based data assimilation methods often use the so-called localization scheme to improve the representation of the ensemble background error covariance (Be). Extensive research has been undertaken to reduce the computational cost of these methods by using the localized ensemble samples to localize Be by means of a direct decomposition of the local correlation matrix C. However, the computational costs of the direct decomposition of the local correlation matrix C are still extremely high due to its high dimension. In this paper, we propose an efficient local correlation matrix decomposition approach based on the concept of alternating directions. This approach is intended to avoid direct decomposition of the correlation matrix. Instead, we first decompose the correlation matrix into 1-D correlation matrices in the three coordinate directions, then construct their empirical orthogonal function decomposition at low resolution. This procedure is followed by the 1-D spline interpolation process to transform the above decompositions to the high-resolution grid. Finally, an efficient correlation matrix decomposition is achieved by computing the very similar Kronecker product. We conducted a series of comparison experiments to illustrate the validity and accuracy of the proposed local correlation matrix decomposition approach. The effectiveness of the proposed correlation matrix decomposition approach and its efficient localization implementation of the nonlinear least-squares four-dimensional variational assimilation are further demonstrated by several groups of numerical experiments based on the Advanced Research Weather Research and Forecasting model.
Perturbation theory corrections to the two-particle reduced density matrix variational method.
Juhasz, Tamas; Mazziotti, David A
2004-07-15
In the variational 2-particle-reduced-density-matrix (2-RDM) method, the ground-state energy is minimized with respect to the 2-particle reduced density matrix, constrained by N-representability conditions. Consider the N-electron Hamiltonian H(lambda) as a function of the parameter lambda where we recover the Fock Hamiltonian at lambda=0 and we recover the fully correlated Hamiltonian at lambda=1. We explore using the accuracy of perturbation theory at small lambda to correct the 2-RDM variational energies at lambda=1 where the Hamiltonian represents correlated atoms and molecules. A key assumption in the correction is that the 2-RDM method will capture a fairly constant percentage of the correlation energy for lambda in (0,1] because the nonperturbative 2-RDM approach depends more significantly upon the nature rather than the strength of the two-body Hamiltonian interaction. For a variety of molecules we observe that this correction improves the 2-RDM energies in the equilibrium bonding region, while the 2-RDM energies at stretched or nearly dissociated geometries, already highly accurate, are not significantly changed. At equilibrium geometries the corrected 2-RDM energies are similar in accuracy to those from coupled-cluster singles and doubles (CCSD), but at nonequilibrium geometries the 2-RDM energies are often dramatically more accurate as shown in the bond stretching and dissociation data for water and nitrogen. (c) 2004 American Institute of Physics.
Rudzki, Piotr J; Gniazdowska, Elżbieta; Buś-Kwaśnik, Katarzyna
2018-06-05
Liquid chromatography coupled to mass spectrometry (LC-MS) is a powerful tool for studying pharmacokinetics and toxicokinetics. Reliable bioanalysis requires the characterization of the matrix effect, i.e. influence of the endogenous or exogenous compounds on the analyte signal intensity. We have compared two methods for the quantitation of matrix effect. The CVs(%) of internal standard normalized matrix factors recommended by the European Medicines Agency were evaluated against internal standard normalized relative matrix effects derived from Matuszewski et al. (2003). Both methods use post-extraction spiked samples, but matrix factors require also neat solutions. We have tested both approaches using analytes of diverse chemical structures. The study did not reveal relevant differences in the results obtained with both calculation methods. After normalization with the internal standard, the CV(%) of the matrix factor was on average 0.5% higher than the corresponding relative matrix effect. The method adopted by the European Medicines Agency seems to be slightly more conservative in the analyzed datasets. Nine analytes of different structures enabled a general overview of the problem, still, further studies are encouraged to confirm our observations. Copyright © 2018 Elsevier B.V. All rights reserved.
Calculation of the fast multiplication factor by the fission matrix method
International Nuclear Information System (INIS)
Naumov, V.A.; Rozin, S.G.; Ehl'perin, T.I.
1976-01-01
A variation of the Monte Carlo method to calculate an effective breeding factor of a nuclear reactor is described. The evaluation procedure of reactivity perturbations by the Monte Carlo method in the first order perturbation theory is considered. The method consists in reducing an integral neutron transport equation to a set of linear algebraic equations. The coefficients of this set are elements of a fission matrix. The fission matrix being a Grin function of the neutron transport equation, is evaluated by the Monte Carlo method. In the program realizing the suggested algorithm, the game for initial neutron energy of a fission spectrum and then for the region of neutron birth, ΔVsub(f)sup(i)has been played in proportion to the product of Σsub(f)sup(i)ΔVsub(f)sup(i), where Σsub(f)sup(i) is a macroscopic cross section in the region numbered at the birth energy. Further iterations of a space distribution of neutrons in the system are performed by the generation method. In the adopted scheme of simulation of neutron histories the emission of secondary neutrons is controlled by weights; it occurs at every collision and not only in the end on the history. The breeding factor is calculated simultaneously with the space distribution of neutron worth in the system relative to the fission process and neutron flux. Efficiency of the described procedure has been tested on the calculation of the breeding factor for the Godiva assembly, simulating a fast reactor with a hard spectrum. A high accuracy of calculations at moderate number of zones in the core and reasonable statistics has been stated
Vahidi, Vahid; Saberinia, Ebrahim; Regentova, Emma E.
2017-10-01
A channel estimation (CE) method based on compressed sensing (CS) is proposed to estimate the sparse and doubly selective (DS) channel for hyperspectral image transmission from unmanned aircraft vehicles to ground stations. The proposed method contains three steps: (1) the priori estimate of the channel by orthogonal matching pursuit (OMP), (2) calculation of the linear minimum mean square error (LMMSE) estimate of the received pilots given the estimated channel, and (3) estimate of the complex amplitudes and Doppler shifts of the channel using the enhanced received pilot data applying a second round of a CS algorithm. The proposed method is named DS-LMMSE-OMP, and its performance is evaluated by simulating transmission of AVIRIS hyperspectral data via the communication channel and assessing their fidelity for the automated analysis after demodulation. The performance of the DS-LMMSE-OMP approach is compared with that of two other state-of-the-art CE methods. The simulation results exhibit up to 8-dB figure of merit in the bit error rate and 50% improvement in the hyperspectral image classification accuracy.
Method of transmission of dynamic multibit digital images from micro-unmanned aerial vehicles
Petrov, E. P.; Kharina, N. L.
2018-01-01
In connection with successful usage of nanotechnologies in remote sensing great attention is paid to the systems in micro-unmanned aerial vehicles (MUAVs) capable to provide high spatial resolution of dynamic multibit digital images (MDI). Limited energy resources on board the MUAV do not allow transferring a large amount of video information in the shortest possible time. It keeps back the broad development of MUAV. The search for methods to shorten the transmission time of dynamic MDIs from MUAV over the radio channel leads to the methods of MDI compression without computational operations onboard the MUAV. The known compression codecs of video information can not be applied because of the limited energy resources. In this paper we propose a method for reducing the transmission time of dynamic MDIs without computational operations and distortions onboard the MUAV. To develop the method a mathematical apparatus of the theory of conditional Markov processes with discrete arguments was used. On its basis a mathematical model for the transformation of the MDI represented by binary images (BI) in the MDI, consisting of groups of neighboring BIs (GBI) transmitted by multiphase (MP) signals, is constructed. The algorithm for multidimensional nonlinear filtering of MP signals is synthesized, realizing the statistical redundancy of the MDI to compensate for the noise stability losses caused by the use of MP signals.
International Nuclear Information System (INIS)
Kawamura, Kazuo; Ikeda, Kazuto; Terauchi, Masami
2004-01-01
We have developed a new method using conventional transmission electron microscopy (TEM) to obtain two dimensional dopant profiles in silicon and applied it to 40 nm-gate-length N + /p metal oxide semiconductor field effect transistors (MOSFETs). The results are consistent with those of selective-chemically etched samples observed by TEM. This method, using focused ion beam (FIB) sample preparation and conventional TEM, has the great advantage of simple sample preparation and high spatial resolution compared to other characterization methods, such as atomic capacitance microscopy, spreading resistance microscopy, and TEM combined with selective chemical etching. This indicates that this method can be applicable to the analysis of FETs at the 65 nm or smaller node
Energy Technology Data Exchange (ETDEWEB)
Liu Guoming [Department of Nuclear Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)], E-mail: gmliusy@gmail.com; Wu Hongchun; Cao Liangzhi [Department of Nuclear Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)
2008-09-15
This paper presents a transmission probability method (TPM) to solve the neutron transport equation in three-dimensional triangular-z geometry. The source within the mesh is assumed to be spatially uniform and isotropic. At the mesh surface, the constant and the simplified P{sub 1} approximation are invoked for the anisotropic angular flux distribution. Based on this model, a code TPMTDT is encoded. It was verified by three 3D Takeda benchmark problems, in which the first two problems are in XYZ geometry and the last one is in hexagonal-z geometry, and an unstructured geometry problem. The results of the present method agree well with those of Monte-Carlo calculation method and Spherical Harmonics (P{sub N}) method.
DEFF Research Database (Denmark)
Xu, Fengda; Guo, Qinglai; Sun, Hongbin
2015-01-01
For an AC/DC coupled transmission system, the change of transmission power on the DC lines will significantly influence the AC systems’ voltage. This paper describes a method to coordinated control the reactive power of power plants and shunt capacitors at DC converter stations nearby, in order t...
Directory of Open Access Journals (Sweden)
Yan Chen
2017-03-01
Full Text Available Based on the vectorised and cache optimised kernel, a parallel lower upper decomposition with a novel communication avoiding pivoting scheme is developed to solve dense complex matrix equations generated by the method of moments. The fine-grain data rearrangement and assembler instructions are adopted to reduce memory accessing times and improve CPU cache utilisation, which also facilitate vectorisation of the code. Through grouping processes in a binary tree, a parallel pivoting scheme is designed to optimise the communication pattern and thus reduces the solving time of the proposed solver. Two large electromagnetic radiation problems are solved on two supercomputers, respectively, and the numerical results demonstrate that the proposed method outperforms those in open source and commercial libraries.
The Virasoro algebra in integrable hierarchies and the method of matrix models
International Nuclear Information System (INIS)
Semikhatov, A.M.
1992-01-01
The action of the Virasoro algebra on hierarchies of nonlinear integrable equations, and also the structure and consequences of Virasoro constraints on these hierarchies, are studied. It is proposed that a broad class of hierarchies, restricted by Virasoro constraints, can be defined in terms of dressing operators hidden in the structure of integrable systems. The Virasoro-algebra representation constructed on the dressing operators displays a number of analogies with structures in conformal field theory. The formulation of the Virasoro constraints that stems from this representation makes it possible to translate into the language of integrable systems a number of concepts from the method of the 'matrix models' that describe nonperturbative quantum gravity, and, in particular, to realize a 'hierarchical' version of the double scaling limit. From the Virasoro constraints written in terms of the dressing operators generalized loop equations are derived, and this makes it possible to do calculations on a reconstruction of the field-theoretical description. The reduction of the Kadomtsev-Petviashvili (KP) hierarchy, subject to Virasoro constraints, to generalized Korteweg-deVries (KdV) hierarchies is implemented, and the corresponding representation of the Virasoro algebra on these hierarchies is found both in the language of scalar differential operators and in the matrix formalism of Drinfel'd and Sokolov. The string equation in the matrix formalism does not replicate the structure of the scalar string equation. The symmetry algebras of the KP and N-KdV hierarchies restricted by Virasoro constraints are calculated: A relationship is established with algebras from the family W ∞ (J) of infinite W-algebras
Love waves in functionally graded piezoelectric materials by stiffness matrix method.
Ben Salah, Issam; Wali, Yassine; Ben Ghozlen, Mohamed Hédi
2011-04-01
A numerical matrix method relative to the propagation of ultrasonic guided waves in functionally graded piezoelectric heterostructure is given in order to make a comparative study with the respective performances of analytical methods proposed in literature. The preliminary obtained results show a good agreement, however numerical approach has the advantage of conceptual simplicity and flexibility brought about by the stiffness matrix method. The propagation behaviour of Love waves in a functionally graded piezoelectric material (FGPM) is investigated in this article. It involves a thin FGPM layer bonded perfectly to an elastic substrate. The inhomogeneous FGPM heterostructure has been stratified along the depth direction, hence each state can be considered as homogeneous and the ordinary differential equation method is applied. The obtained solutions are used to study the effect of an exponential gradient applied to physical properties. Such numerical approach allows applying different gradient variation for mechanical and electrical properties. For this case, the obtained results reveal opposite effects. The dispersive curves and phase velocities of the Love wave propagation in the layered piezoelectric film are obtained for electrical open and short cases on the free surface, respectively. The effect of gradient coefficients on coupled electromechanical factor, on the stress fields, the electrical potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the well known heterostructure PZT-5H/SiO(2), the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Love wave propagation behaviour. Copyright Â© 2010 Elsevier B.V. All rights reserved.
DEFF Research Database (Denmark)
Zhang, Wei; Kuhn, Luise Theil; Jørgensen, Peter Stanley
2013-01-01
An optimum method is proposed to prepare thin foil transmission electron microscopy (TEM) lamellae of multiphase porous functional ceramics: prefilling the pore space of these materials with an epoxy resin prior to focused ion beam milling. Several advantages of epoxy impregnation are demonstrated...... by successful preparation of TEM specimens that maintain the structural integrity of the entire lamella. Feasibility of the TEM alignment procedure is demonstrated, and ideal TEM analyses are illustrated on solid oxide fuel cell and solid oxide electrolysis cell materials. Some potential drawbacks of the TEM...
Wu, Madeline; Davidson, Norman
1981-01-01
A transmission electron microscope method for gene mapping by in situ hybridization to Drosophila polytene chromosomes has been developed. As electron-opaque labels, we use colloidal gold spheres having a diameter of 25 nm. The spheres are coated with a layer of protein to which Escherichia coli single-stranded DNA is photochemically crosslinked. Poly(dT) tails are added to the 3' OH ends of these DNA strands, and poly(dA) tails are added to the 3' OH ends of a fragmented cloned Drosophila DN...
International Nuclear Information System (INIS)
Ijaes, Asko; Kuitunen, Markku T.; Jalava, Kimmo
2010-01-01
In this paper the applicability of the RIAM method (rapid impact assessment matrix) is evaluated in the context of impact significance assessment. The methodological issues considered in the study are: 1) to test the possibilities of enlarging the scoring system used in the method, and 2) to compare the significance classifications of RIAM and unaided decision-making to estimate the consistency between these methods. The data used consisted of projects for which funding had been applied for via the European Union's Regional Development Trust in the area of Central Finland. Cases were evaluated with respect to their environmental, social and economic impacts using an assessment panel. The results showed the scoring framework used in RIAM could be modified according to the problem situation at hand, which enhances its application potential. However the changes made in criteria B did not significantly affect the final ratings of the method, which indicates the high importance of criteria A1 (importance) and A2 (magnitude) to the overall results. The significance classes obtained by the two methods diverged notably. In general the ratings given by RIAM tended to be smaller compared to intuitive judgement implying that the RIAM method may be somewhat conservative in character.
Mukhamedzhanov, A. M.; Shubhchintak, Bertulani, C. A.
2017-08-01
In this paper we discuss the R -matrix approach to treat the subthreshold resonances for the single-level and one-channel and for the single-level and two-channel cases. In particular, the expression relating the asymptotic normalization coefficient (ANC) with the observable reduced width, when the subthreshold bound state is the only channel or coupled with an open channel, which is a resonance, is formulated. Since the ANC plays a very important role in nuclear astrophysics, these relations significantly enhance the power of the derived equations. We present the relationship between the resonance width and the ANC for the general case and consider two limiting cases: wide and narrow resonances. Different equations for the astrophysical S factors in the R -matrix approach are presented. After that we discuss the Trojan horse method (THM) formalism. The developed equations are obtained using the surface-integral formalism and the generalized R -matrix approach for the three-body resonant reactions. It is shown how the Trojan horse (TH) double-differential cross section can be expressed in terms of the on-the-energy-shell astrophysical S factor for the binary subreaction. Finally, we demonstrate how the THM can be used to calculate the astrophysical S factor for the neutron generator 13C(α ,n )16O in low-mass AGB stars. At astrophysically relevant energies this astrophysical S factor is controlled by the threshold level 1 /2+,Ex=6356 keV. Here, we reanalyzed recent TH data taking into account more accurately the three-body effects and using both assumptions that the threshold level is a subthreshold bound state or it is a resonance state.
New computational method for non-LTE, the linear response matrix
International Nuclear Information System (INIS)
Fournier, K.B.; Grasiani, F.R.; Harte, J.A.; Libby, S.B.; More, R.M.; Zimmerman, G.B.
1998-01-01
My coauthors have done extensive theoretical and computational calculations that lay the ground work for a linear response matrix method to calculate non-LTE (local thermodynamic equilibrium) opacities. I will give briefly review some of their work and list references. Then I will describe what has been done to utilize this theory to create a computational package to rapidly calculate mild non-LTE emission and absorption opacities suitable for use in hydrodynamic calculations. The opacities are obtained by performing table look-ups on data that has been generated with a non-LTE package. This scheme is currently under development. We can see that it offers a significant computational speed advantage. It is suitable for mild non-LTE, quasi-steady conditions. And it offers a new insertion path for high-quality non-LTE data. Currently, the linear response matrix data file is created using XSN. These data files could be generated by more detailed and rigorous calculations without changing any part of the implementation in the hydro code. The scheme is running in Lasnex and is being tested and developed
Energy Technology Data Exchange (ETDEWEB)
Wu Hongchun [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China)]. E-mail: hongchun@mail.xjtu.edu.cn; Liu Pingping [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Zhou Yongqiang [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Cao Liangzhi [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China)
2007-01-15
In the advanced reactor, the fuel assembly or core with unstructured geometry is frequently used and for calculating its fuel assembly, the transmission probability method (TPM) has been used widely. However, the rectangle or hexagon meshes are mainly used in the TPM codes for the normal core structure. The triangle meshes are most useful for expressing the complicated unstructured geometry. Even though finite element method and Monte Carlo method is very good at solving unstructured geometry problem, they are very time consuming. So we developed the TPM code based on the triangle meshes. The TPM code based on the triangle meshes was applied to the hybrid fuel geometry, and compared with the results of the MCNP code and other codes. The results of comparison were consistent with each other. The TPM with triangle meshes would thus be expected to be able to apply to the two-dimensional arbitrary fuel assembly.
Basic matrix algebra and transistor circuits
Zelinger, G
1963-01-01
Basic Matrix Algebra and Transistor Circuits deals with mastering the techniques of matrix algebra for application in transistors. This book attempts to unify fundamental subjects, such as matrix algebra, four-terminal network theory, transistor equivalent circuits, and pertinent design matters. Part I of this book focuses on basic matrix algebra of four-terminal networks, with descriptions of the different systems of matrices. This part also discusses both simple and complex network configurations and their associated transmission. This discussion is followed by the alternative methods of de
Separable expansions of the NN t-matrix via exact half off the energy shell methods
International Nuclear Information System (INIS)
Pisent, G.; Amos, K.; Dortmans, P.J.
1992-01-01
Recently a method was proposed by which one can obtain rank 1 (for uncoupled channels) and rank 2 (for coupled channels), energy dependent t-matrix representations which are exact on- and half off of the energy shell. Fully off shell, this representation, though accurate at low energies, is flawed. For uncoupled channels, if the phase shift passes through zero, the representation has a pathology. Two methods which overcome this are investigated one due to Haberzettl which was extended to coupled channels, and the second which is based upon selective combination of the elements of Sturmian expansions. All methods of separation over a range of energies up to 250 MeV for the 1 S 0 and 3 S 1 channels are compared with the Paris interaction. Special attention is paid to the convergence of the higher order Haberzettl expansion and to the comparison of the extended methods for energies around the zero phase shift pathology for the 1 S 0 channel. The method describes well the fully off-shell properties of the t-matrices up to quite high energies, while keeping the rank of the separation as low as possible in order to be used in three or more body calculations. 39 refs., 10 figs
International Nuclear Information System (INIS)
He, Cenlin; Takano, Yoshi; Liou, Kuo-Nan; Yang, Ping; Li, Qinbin; Mackowski, Daniel W.
2016-01-01
We perform a comprehensive intercomparison of the geometric-optics surface-wave (GOS) approach, the superposition T-matrix method, and laboratory measurements for optical properties of fresh and coated/aged black carbon (BC) particles with complex structures. GOS and T-matrix calculations capture the measured optical (i.e., extinction, absorption, and scattering) cross sections of fresh BC aggregates, with 5–20% differences depending on particle size. We find that the T-matrix results tend to be lower than the measurements, due to uncertainty in theoretical approximations of realistic BC structures, particle property measurements, and numerical computations in the method. On the contrary, the GOS results are higher than the measurements (hence the T-matrix results) for BC radii 100 nm. We find good agreement (differences 100 nm. We find small deviations (≤10%) in asymmetry factors computed from the two methods for most BC coating structures and sizes, but several complex structures have 10–30% differences. This study provides the foundation for downstream application of the GOS approach in radiative transfer and climate studies. - Highlights: • The GOS and T-matrix methods capture laboratory measurements of BC optical properties. • The GOS results are consistent with the T-matrix results for BC optical properties. • BC optical properties vary remarkably with coating structures and sizes during aging.
Directory of Open Access Journals (Sweden)
William Senkondo
2017-12-01
Full Text Available Information on aquifer processes and characteristics across scales has long been a cornerstone for understanding water resources. However, point measurements are often limited in extent and representativeness. Techniques that increase the support scale (footprint of measurements or leverage existing observations in novel ways can thus be useful. In this study, we used a recession-curve-displacement method to estimate regional-scale aquifer transmissivity (T from streamflow records across the Kilombero Valley of Tanzania. We compare these estimates to local-scale estimates made from pumping tests across the Kilombero Valley. The median T from the pumping tests was 0.18 m2/min. This was quite similar to the median T estimated from the recession-curve-displacement method applied during the wet season for the entire basin (0.14 m2/min and for one of the two sub-basins tested (0.16 m2/min. On the basis of our findings, there appears to be reasonable potential to inform water resource management and hydrologic model development through streamflow-derived transmissivity estimates, which is promising for data-limited environments facing rapid development, such as the Kilombero Valley.
Zhang, Xiaoliang; Ugurbil, Kamil; Chen, Wei
2006-04-04
Apparatus and method for MRI imaging using a coil constructed of microstrip transmission line (MTL coil) are disclosed. In one method, a target is positioned to be imaged within the field of a main magnetic field of a magnet resonance imaging (MRI) system, a MTL coil is positioned proximate the target, and a MRI image is obtained using the main magnet and the MTL coil. In another embodiment, the MRI coil is used for spectroscopy. MRI imaging and spectroscopy coils are formed using microstrip transmission line. These MTL coils have the advantageous property of good performance while occupying a relatively small space, thus allowing MTL coils to be used inside restricted areas more easily than some other prior art coils. In addition, the MTL coils are relatively simple to construct of inexpensive components and thus relatively inexpensive compared to other designs. Further, the MTL coils of the present invention can be readily formed in a wide variety of coil configurations, and used in a wide variety of ways. Further, while the MTL coils of the present invention work well at high field strengths and frequencies, they also work at low frequencies and in low field strengths as well.
Hankel Matrix Correlation Function-Based Subspace Identification Method for UAV Servo System
Directory of Open Access Journals (Sweden)
Minghong She
2018-01-01
Full Text Available For the identification problem of closed-loop subspace model, we propose a zero space projection method based on the estimation of correlation function to fill the block Hankel matrix of identification model by combining the linear algebra with geometry. By using the same projection of related data in time offset set and LQ decomposition, the multiplication operation of projection is achieved and dynamics estimation of the unknown equipment system model is obtained. Consequently, we have solved the problem of biased estimation caused when the open-loop subspace identification algorithm is applied to the closed-loop identification. A simulation example is given to show the effectiveness of the proposed approach. In final, the practicability of the identification algorithm is verified by hardware test of UAV servo system in real environment.
Comparison of matrix method and ray tracing in the study of complex optical systems
Anterrieu, Eric; Perez, Jose-Philippe
2000-06-01
In the context of the classical study of optical systems within the geometrical Gauss approximation, the cardinal elements are efficiently obtained with the aid of the transfer matrix between the input and output planes of the system. In order to take into account the geometrical aberrations, a ray tracing approach, using the Snell- Descartes laws, has been implemented in an interactive software. Both methods are applied for measuring the correction to be done to a human eye suffering from ametropia. This software may be used by optometrists and ophthalmologists for solving the problems encountered when considering this pathology. The ray tracing approach gives a significant improvement and could be very helpful for a better understanding of an eventual surgical act.
Response matrix method for neutron transport in reactor lattices using group symmetry properties
International Nuclear Information System (INIS)
Mund, E.H.
1991-01-01
This paper describes a response matrix method for the approximate solution of one-velocity, multi-dimensional transport problems in reactor lattices, with isotropic neutron scattering. The transport equation is solved on a homogeneous cell by using a Petrov-Galerkin technique based on a set of trial and test functions (including polynomials and exponential functions) closely related to transport problems in infinite media. The number of non-zero elements of the response matrices reduces to a minimum when the symmetry properties of the cell are included ab initio in the span of the basis functions. To include these properties, use is made of projection operations which are performed very efficiently on symbolic manipulation programs. Numerical results of model problems in square geometry show a good agreement with reference solutions
A study on measurement on artificial radiation dose rate using the response matrix method
International Nuclear Information System (INIS)
Kidachi, Hiroshi; Ishikawa, Yoichi; Konno, Tatsuya
2004-01-01
We examined accuracy and stability of estimated artificial dose contribution which is distinguished from natural background gamma-ray dose rate using Response Matrix method. Irradiation experiments using artificial gamma-ray sources indicated that there was a linear relationship between observed dose rate and estimated artificial dose contribution, when irradiated artificial gamma-ray dose rate was higher than about 2 nGy/h. Statistical and time-series analyses of long term data made it clear that estimated artificial contribution showed almost constant values under no artificial influence from the nuclear power plants. However, variations of estimated artificial dose contribution were infrequently observed due to of rainfall, detector maintenance operation and occurrence of calibration error. Some considerations on the factors to these variations were made. (author)
Matrix based method for synthesis of main intensified and integrated distillation sequences
International Nuclear Information System (INIS)
Khalili-Garakani, Amirhossein; Kasiri, Norollah; Ivakpour, Javad
2016-01-01
The objective of many studies in this area has involved access to a column-sequencing algorithm enabling designers and researchers alike to generate a wide range of sequences in a broad search space, and be as mathematically and as automated as possible for programing purposes and with good generality. In the present work an algorithm previously developed by the authors, called the matrix method, has been developed much further. The new version of the algorithm includes thermally coupled, thermodynamically equivalent, intensified, simultaneous heat and mass integrated and divided-wall column sequences which are of gross application and provide vast saving potential both on capital investment, operating costs and energy usage in industrial applications. To demonstrate the much wider searchable space now accessible, a three component separation has been thoroughly examined as a case study, always resulting in an integrated sequence being proposed as the optimum.
Design of Electronic Medical Record User Interfaces: A Matrix-Based Method for Improving Usability
Directory of Open Access Journals (Sweden)
Kushtrim Kuqi
2013-01-01
Full Text Available This study examines a new approach of using the Design Structure Matrix (DSM modeling technique to improve the design of Electronic Medical Record (EMR user interfaces. The usability of an EMR medication dosage calculator used for placing orders in an academic hospital setting was investigated. The proposed method captures and analyzes the interactions between user interface elements of the EMR system and groups elements based on information exchange, spatial adjacency, and similarity to improve screen density and time-on-task. Medication dose adjustment task time was recorded for the existing and new designs using a cognitive simulation model that predicts user performance. We estimate that the design improvement could reduce time-on-task by saving an average of 21 hours of hospital physicians’ time over the course of a month. The study suggests that the application of DSM can improve the usability of an EMR user interface.
Evaluation of two fast and easy methods for pesticide residue analysis in fatty food matrixes.
Lehotay, Steven J; Mastovská, Katerina; Yun, Seon Jong
2005-01-01
Two rapid methods of sample preparation and analysis of fatty foods (e.g., milk, eggs, and avocado) were evaluated and compared for 32 pesticide residues representing a wide range of physicochemical properties. One method, dubbed the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticide residue analysis, entailed extraction of 15 g sample with 15 mL acetonitrile (MeCN) containing 1% acetic acid followed by addition of 6 g anhydrous magnesium sulfate and 1.5 g sodium acetate. After centrifugation, 1 mL of the buffered MeCN extract underwent a cleanup step (in a technique known as dispersive solid-phase extraction) using 50 mg each of C18 and primary secondary amine sorbents plus 150 mg MgSO4. The second method incorporated a form of matrix solid-phase dispersion (MSPD), in which 0.5 g sample plus 2 g C18 and 2 g anhydrous sodium sulfate was mixed in a mortar and pestle and added above a 2 g Florisil column on a vacuum manifold. Then, 5 x 2 mL MeCN was used to elute the pesticide analytes from the sample into a collection tube, and the extract was concentrated to 0.5 mL by evaporation. Extracts in both methods were analyzed concurrently by gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry. The recoveries of semi-polar and polar pesticides were typically 100% in both methods (except that basic pesticides, such as thiabendazole and imazalil, were not recovered in the MSPD method), but recovery of nonpolar pesticides decreased as fat content of the sample increased. This trend was more pronounced in the QuEChERS method, in which case the most lipophilic analyte tested, hexachlorobenzene, gave 27 +/- 1% recovery (n=6) in avocado (15% fat) with a<10 ng/g limit of quantitation.
International Nuclear Information System (INIS)
Bartle, C.M.
1998-01-01
This research programme is designed to develop industrial measurement systems utilising simultaneous transmission of neutrons and gamma rays (Neugat method). Descriptions of these systems have been given in reports and magazine articles, and industrial site trials have been undertaken. (author)
International Nuclear Information System (INIS)
Attobrah, A. T
2012-01-01
The nuclear method widely used in determining the density and moisture content of soil - aggregates, asphalt concretes, roller compacted concretes and Portland cement concretes, is the radiometry technique. Generally, all radiometry systems consist of a source of radiation, the sample being examined and a radiation detector. In operation, a radioactive source and a detector are placed on the same or opposite sides of a concrete sample. A portion of radiation from the source which passes through the concrete sample and reaches the detector produces a series of electrical pulses which when counted gives a measure of the dimensions or physical characteristics of the concrete sample. In this research work, concrete beams were fabricated using a 500 x 225 x 200mm wooden mould whiles a table vibrator was used to consolidate the concrete after placement in the mould. The mass of the beam was determined and the actual density calculated and inputted in the gauge. Measurements were performed on the unhardened and hardened concrete using the backscatter method and the direct transmission method at depths of 50mm, 100mm and 150mm. The measuring times of 15, 60 and 240 second were use to take the measurements. The study provided information on the variation of density with depth and this was observed to be within the range of 0 kg/m 3 to 1 kg/m 3 and 13 kg/m 3 to 23 kg/m 3 for the unhardened concrete samples in which density increased with depth and those in which density decreased with depth respectively. For the hardened concrete sample, the average change in density with depth was between 4 - 11 kg/m 3 for the samples in which density increased with depth and between 11 - 21 kg/m 3 for the samples in which density decreased with depth. The study also provided information about the degree of consolidation of Portland cement concrete which on the average was between 95% - 97% for the unhardened concrete samples and increased to between 97% - 99% for the hardened concrete
Yucel, Abdulkadir C.
2015-05-05
An efficient method for statistically characterizing multiconductor transmission line (MTL) networks subject to a large number of manufacturing uncertainties is presented. The proposed method achieves its efficiency by leveraging a high-dimensional model representation (HDMR) technique that approximates observables (quantities of interest in MTL networks, such as voltages/currents on mission-critical circuits) in terms of iteratively constructed component functions of only the most significant random variables (parameters that characterize the uncertainties in MTL networks, such as conductor locations and widths, and lumped element values). The efficiency of the proposed scheme is further increased using a multielement probabilistic collocation (ME-PC) method to compute the component functions of the HDMR. The ME-PC method makes use of generalized polynomial chaos (gPC) expansions to approximate the component functions, where the expansion coefficients are expressed in terms of integrals of the observable over the random domain. These integrals are numerically evaluated and the observable values at the quadrature/collocation points are computed using a fast deterministic simulator. The proposed method is capable of producing accurate statistical information pertinent to an observable that is rapidly varying across a high-dimensional random domain at a computational cost that is significantly lower than that of gPC or Monte Carlo methods. The applicability, efficiency, and accuracy of the method are demonstrated via statistical characterization of frequency-domain voltages in parallel wire, interconnect, and antenna corporate feed networks.
International Nuclear Information System (INIS)
Nordin, Jamillah Amer; Prajitno, Djoko Hadi; Saidin, Syafiqah; Nur, Hadi; Hermawan, Hendra
2015-01-01
Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone–implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12 h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12 h milling in the presence of HPO 4 2− ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12 h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis - Highlights: • Improvement of mechanical properties of HAp bioceramics by mechanosynthesis method • Structure–property relationship of iron–hydroxyapatite ceramic matrix nanocomposite • Milling time influenced the properties of iron–hydroxyapatite ceramic matrix nanocomposite
Energy Technology Data Exchange (ETDEWEB)
Nordin, Jamillah Amer [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Prajitno, Djoko Hadi [Nuclear Technology Center for Materials and Radiometry, National Nuclear Energy, Bandung 40132 (Indonesia); Saidin, Syafiqah [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Nur, Hadi, E-mail: hadi@kimia.fs.utm.my [Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Department of Physics, Institut Sains dan Teknologi Nasional, Jl. Moh. Kahfi II, Jagakarsa, Jakarta Selatan 12640 (Indonesia); Hermawan, Hendra, E-mail: hendra.hermawan@gmn.ulaval.ca [Department of Mining, Metallurgical and Materials Engineering & CHU de Québec Research Center, Laval University, Québec City G1V 0A6 (Canada)
2015-06-01
Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone–implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12 h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12 h milling in the presence of HPO{sub 4}{sup 2−} ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12 h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis - Highlights: • Improvement of mechanical properties of HAp bioceramics by mechanosynthesis method • Structure–property relationship of iron–hydroxyapatite ceramic matrix nanocomposite • Milling time influenced the properties of iron–hydroxyapatite ceramic matrix nanocomposite.
A fault diagnosis method based on signed directed graph and matrix for nuclear power plants
International Nuclear Information System (INIS)
Liu, Yong-Kuo; Wu, Guo-Hua; Xie, Chun-Li; Duan, Zhi-Yong; Peng, Min-Jun; Li, Meng-Kun
2016-01-01
Highlights: • “Rules matrix” is proposed for FDD. • “State matrix” is proposed to solve SDG online inference. • SDG inference and search method are combined for FDD. - Abstract: In order to solve SDG online fault diagnosis and inference, matrix diagnosis and inference methods are proposed for fault detection and diagnosis (FDD). Firstly, “rules matrix” based on SDG model is used for FDD. Secondly, “status matrix” is proposed to achieve SDG online inference. According to different diagnosis results, “status matrix” is applied for the depth-first search and the breadth-first search respectively to find the propagation paths of each fault. Finally, the SDG model of the secondary-loop system in pressurized water reactor (PWR) is built to verify the effectiveness of the proposed method. The simulation experiment results indicate that the “status matrix” used for online inference can be used to find the fault propagation paths and to explain the causes for fault. Therefore, it can be concluded that the proposed method is one of the fault diagnosis for nuclear power plants (NPPs), which can be used to facilitate the development of fault diagnostic system.
A fault diagnosis method based on signed directed graph and matrix for nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Liu, Yong-Kuo, E-mail: LYK08@126.com [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China); Wu, Guo-Hua [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China); Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084 (China); Xie, Chun-Li [Traffic College, Northeast Forestry University, Harbin, 150040 (China); Duan, Zhi-Yong; Peng, Min-Jun; Li, Meng-Kun [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China)
2016-02-15
Highlights: • “Rules matrix” is proposed for FDD. • “State matrix” is proposed to solve SDG online inference. • SDG inference and search method are combined for FDD. - Abstract: In order to solve SDG online fault diagnosis and inference, matrix diagnosis and inference methods are proposed for fault detection and diagnosis (FDD). Firstly, “rules matrix” based on SDG model is used for FDD. Secondly, “status matrix” is proposed to achieve SDG online inference. According to different diagnosis results, “status matrix” is applied for the depth-first search and the breadth-first search respectively to find the propagation paths of each fault. Finally, the SDG model of the secondary-loop system in pressurized water reactor (PWR) is built to verify the effectiveness of the proposed method. The simulation experiment results indicate that the “status matrix” used for online inference can be used to find the fault propagation paths and to explain the causes for fault. Therefore, it can be concluded that the proposed method is one of the fault diagnosis for nuclear power plants (NPPs), which can be used to facilitate the development of fault diagnostic system.
Rotation Matrix Method Based on Ambiguity Function for GNSS Attitude Determination.
Yang, Yingdong; Mao, Xuchu; Tian, Weifeng
2016-06-08
Global navigation satellite systems (GNSS) are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM) to search for integer ambiguity, and it is validated in reducing the span of candidates. The noise error is always the key factor to the success rate. It is closely related to the satellite geometry model. In contrast to the AFM, the LAMBDA (Least-squares AMBiguity Decorrelation Adjustment) method gets better results in solving the relationship of the geometric model and the noise error. Although the AFM is more flexible, it is lack of analysis on this aspect. In this study, the influence of the satellite geometry model on the success rate is analyzed in detail. The computation error and the noise error are effectively treated. Not only is the flexibility of the AFM inherited, but the success rate is also increased. An experiment is conducted in a selected campus, and the performance is proved to be effective. Our results are based on simulated and real-time GNSS data and are applied on single-frequency processing, which is known as one of the challenging case of GNSS attitude determination.
Rotation Matrix Method Based on Ambiguity Function for GNSS Attitude Determination
Directory of Open Access Journals (Sweden)
Yingdong Yang
2016-06-01
Full Text Available Global navigation satellite systems (GNSS are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM to search for integer ambiguity, and it is validated in reducing the span of candidates. The noise error is always the key factor to the success rate. It is closely related to the satellite geometry model. In contrast to the AFM, the LAMBDA (Least-squares AMBiguity Decorrelation Adjustment method gets better results in solving the relationship of the geometric model and the noise error. Although the AFM is more flexible, it is lack of analysis on this aspect. In this study, the influence of the satellite geometry model on the success rate is analyzed in detail. The computation error and the noise error are effectively treated. Not only is the flexibility of the AFM inherited, but the success rate is also increased. An experiment is conducted in a selected campus, and the performance is proved to be effective. Our results are based on simulated and real-time GNSS data and are applied on single-frequency processing, which is known as one of the challenging case of GNSS attitude determination.
Directory of Open Access Journals (Sweden)
Fan Meng
Full Text Available This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the l(1-norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image.
Directory of Open Access Journals (Sweden)
Hongzhao Dong
2012-01-01
Full Text Available To analyze the spreading regularity of the initial traffic congestion, the improved cell transmission model (CTM is proposed to describe the evolution mechanism of traffic congestion in regional road grid. Ordinary cells and oriented cells are applied to render the crowd roads and their adjacent roads. Therefore the traffic flow could be simulated by these cells. Resorting to the proposed model, the duration of the initial traffic congestion could be predicted and the subsequent secondary congestion could be located. Accordingly, the spatial diffusion of traffic congestion could be estimated. At last, taking a road network region of Hangzhou city as an example, the simulation experiment is implemented to verify the proposed method by PARAMICS software. The result shows that the method could predict the duration of the initial congestion and estimate its spatial diffusion accurately.
Directory of Open Access Journals (Sweden)
Yuxia Hu
2017-01-01
Full Text Available An analytic method together with the Mie scattering theory and Beer-Lambert law is proposed for the characteristic parameter determination of bacterial cells (Escherichia coli 10389 from multiwavelength transmission spectroscopy measurements. We calculate the structural parameters of E. coli cells, and compared with the microscopy, the relative error of cell volume is 7.90%, the cell number is compared with those obtained by plate counting, the relative error is l.02%, and the nucleic content and protein content of single E. coli cells are consistent with the data reported elsewhere. The proposed method can obtain characteristic parameters of bacteria as an excellent candidate for the rapid detection and identification of bacteria in the water.
Directory of Open Access Journals (Sweden)
Andrew Speakman
Full Text Available Life expectancy for people diagnosed with HIV has improved dramatically however the number of new infections in the UK remains high. Understanding patterns of sexual behaviour among people living with diagnosed HIV, and the factors associated with having condom-less sex, is important for informing HIV prevention strategies and clinical care. In addition, in view of the current interest in a policy of early antiretroviral treatment (ART for all people diagnosed with HIV in the UK, it is of particular importance to assess whether ART use is associated with increased levels of condom-less sex. In this context the ASTRA study was designed to investigate current sexual activity, and attitudes to HIV transmission risk, in a large unselected sample of HIV-infected patients under care in the UK. The study also gathered background information on demographic, socio-economic, lifestyle and disease-related characteristics, and physical and psychological symptoms, in order to identify other key factors impacting on HIV patients and the behaviours which underpin transmission. In this paper we describe the study rationale, design, methods, response rate and the demographic characteristics of the participants. People diagnosed with HIV infection attending 8 UK HIV out-patient clinics in 2011-2012 were invited to participate in the study. Those who agreed to participate completed a confidential, self-administered pen-and-paper questionnaire, and their latest CD4 count and viral load test results were recorded. During the study period, 5112 eligible patients were invited to take part in the study and 3258 completed questionnaires were obtained, representing a response rate of 64% of eligible patients. The study includes 2248 men who have sex with men (MSM, 373 heterosexual men and 637 women. Future results from ASTRA will be a key resource for understanding HIV transmission within the UK, targeting prevention efforts, and informing clinical care of individuals
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
International Nuclear Information System (INIS)
Ablinger, Jakob; Schneider, Carsten; Bluemlein, Johannes; Raab, Clemens; Wissbrock, Fabian
2014-02-01
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version to the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∝30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N element of C. Integrals with a power-like divergence in N-space∝a N , a element of R, a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions.
Matrix-product-state method with local basis optimization for nonequilibrium electron-phonon systems
Heidrich-Meisner, Fabian; Brockt, Christoph; Dorfner, Florian; Vidmar, Lev; Jeckelmann, Eric
We present a method for simulating the time evolution of quasi-one-dimensional correlated systems with strongly fluctuating bosonic degrees of freedom (e.g., phonons) using matrix product states. For this purpose we combine the time-evolving block decimation (TEBD) algorithm with a local basis optimization (LBO) approach. We discuss the performance of our approach in comparison to TEBD with a bare boson basis, exact diagonalization, and diagonalization in a limited functional space. TEBD with LBO can reduce the computational cost by orders of magnitude when boson fluctuations are large and thus it allows one to investigate problems that are out of reach of other approaches. First, we test our method on the non-equilibrium dynamics of a Holstein polaron and show that it allows us to study the regime of strong electron-phonon coupling. Second, the method is applied to the scattering of an electronic wave packet off a region with electron-phonon coupling. Our study reveals a rich physics including transient self-trapping and dissipation. Supported by Deutsche Forschungsgemeinschaft (DFG) via FOR 1807.
Response matrix of regular moderator volumes with 3He detector using Monte Carlo methods
International Nuclear Information System (INIS)
Baltazar R, A.; Vega C, H. R.; Ortiz R, J. M.; Solis S, L. O.; Castaneda M, R.; Soto B, T. G.; Medina C, D.
2017-10-01
In the last three decades the uses of Monte Carlo methods, for the estimation of physical phenomena associated with the interaction of radiation with matter, have increased considerably. The reason is due to the increase in computing capabilities and the reduction of computer prices. Monte Carlo methods allow modeling and simulating real systems before their construction, saving time and costs. The interaction mechanisms between neutrons and matter are diverse and range from elastic dispersion to nuclear fission; to facilitate the neutrons detection, is necessary to moderate them until reaching electronic equilibrium with the medium at standard conditions of pressure and temperature, in this state the total cross section of the 3 He is large. The objective of the present work was to estimate the response matrix of a proportional detector of 3 He using regular volumes of moderator through Monte Carlo methods. Neutron monoenergetic sources with energies of 10 -9 to 20 MeV and polyethylene moderators of different sizes were used. The calculations were made with the MCNP5 code; the number of stories for each detector-moderator combination was large enough to obtain errors less than 1.5%. We found that for small moderators the highest response is obtained for lower energy neutrons, when increasing the moderator dimension we observe that the response decreases for neutrons of lower energy and increases for higher energy neutrons. The total sum of the responses of each moderator allows obtaining a response close to a constant function. (Author)
Directory of Open Access Journals (Sweden)
Chris Cheadle
2007-01-01
Full Text Available Background: Microarray technology has become highly valuable for identifying complex global changes in gene expression patterns. The assignment of functional information to these complex patterns remains a challenging task in effectively interpreting data and correlating results from across experiments, projects and laboratories. Methods which allow the rapid and robust evaluation of multiple functional hypotheses increase the power of individual researchers to data mine gene expression data more efficiently.Results: We have developed (gene set matrix analysis GSMA as a useful method for the rapid testing of group-wise up- or downregulation of gene expression simultaneously for multiple lists of genes (gene sets against entire distributions of gene expression changes (datasets for single or multiple experiments. The utility of GSMA lies in its flexibility to rapidly poll gene sets related by known biological function or as designated solely by the end-user against large numbers of datasets simultaneously.Conclusions: GSMA provides a simple and straightforward method for hypothesis testing in which genes are tested by groups across multiple datasets for patterns of expression enrichment.
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Reserach Inst. for Symbolic Computation (RISC); Bluemlein, Johannes; Raab, Clemens [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Wissbrock, Fabian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Reserach Inst. for Symbolic Computation (RISC)
2014-02-15
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version to the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∝30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N element of C. Integrals with a power-like divergence in N-space∝a{sup N}, a element of R, a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions.
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Blümlein, Johannes; Raab, Clemens [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Schneider, Carsten [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Wißbrock, Fabian [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2014-08-15
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version of the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators, new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∼30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N∈C. Integrals with a power-like divergence in N-space ∝a{sup N},a∈R,a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions.
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
International Nuclear Information System (INIS)
Ablinger, Jakob; Blümlein, Johannes; Raab, Clemens; Schneider, Carsten; Wißbrock, Fabian
2014-01-01
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version of the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators, new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∼30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N∈C. Integrals with a power-like divergence in N-space ∝a N ,a∈R,a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions
Constructing stage-structured matrix population models from life tables: comparison of methods
Directory of Open Access Journals (Sweden)
Masami Fujiwara
2017-10-01
Full Text Available A matrix population model is a convenient tool for summarizing per capita survival and reproduction rates (collectively vital rates of a population and can be used for calculating an asymptotic finite population growth rate (λ and generation time. These two pieces of information can be used for determining the status of a threatened species. The use of stage-structured population models has increased in recent years, and the vital rates in such models are often estimated using a life table analysis. However, potential bias introduced when converting age-structured vital rates estimated from a life table into parameters for a stage-structured population model has not been assessed comprehensively. The objective of this study was to investigate the performance of methods for such conversions using simulated life histories of organisms. The underlying models incorporate various types of life history and true population growth rates of varying levels. The performance was measured by comparing differences in λ and the generation time calculated using the Euler-Lotka equation, age-structured population matrices, and several stage-structured population matrices that were obtained by applying different conversion methods. The results show that the discretization of age introduces only small bias in λ or generation time. Similarly, assuming a fixed age of maturation at the mean age of maturation does not introduce much bias. However, aggregating age-specific survival rates into a stage-specific survival rate and estimating a stage-transition rate can introduce substantial bias depending on the organism’s life history type and the true values of λ. In order to aggregate survival rates, the use of the weighted arithmetic mean was the most robust method for estimating λ. Here, the weights are given by survivorship curve after discounting with λ. To estimate a stage-transition rate, matching the proportion of individuals transitioning, with λ used
A method of signal transmission path analysis for multivariate random processes
International Nuclear Information System (INIS)
Oguma, Ritsuo
1984-04-01
A method for noise analysis called ''STP (signal transmission path) analysis'' is presentd as a tool to identify noise sources and their propagation paths in multivariate random proceses. Basic idea of the analysis is to identify, via time series analysis, effective network for the signal power transmission among variables in the system and to make use of its information to the noise analysis. In the present paper, we accomplish this through two steps of signal processings; first, we estimate, using noise power contribution analysis, variables which have large contribution to the power spectrum of interest, and then evaluate the STPs for each pair of variables to identify STPs which play significant role for the generated noise to transmit to the variable under evaluation. The latter part of the analysis is executed through comparison of partial coherence function and newly introduced partial noise power contribution function. This paper presents the procedure of the STP analysis and demonstrates, using simulation data as well as Borssele PWR noise data, its effectiveness for investigation of noise generation and propagation mechanisms. (author)
Risk of malaria transmission through blood transfusion and its detection by serological method
International Nuclear Information System (INIS)
Rahman, M.; Akhtar, G.N.; Rashid, S.; Lodhi, Y.
2003-01-01
Objective: To assess the risk of transmission of malaria through blood transfusion, and compare efficacy of testing by immuno chromatographic (ICT) devices vis a vis peripheral blood film (PBF). Results: Amongst healthy blood donors we did not find even a single case of malaria and there was no report of persistent post transfusion pyrexia. We are unable to comment on species frequency in blood donors. However, amongst known patients of malaria we found a higher frequency of Plasmodium viax(P.v) as compared to Plasmodium falciparum(P.f). Testing by serological method, helped us to diagnose 5% of our patients who were missed by peripheral blood films. Conclusion: Between properly selected voluntary non-remunerated blood donors the incidence of malaria transmission is zero and the blood is safe for transfusion. Serological testing shows good correlation with peripheral blood film detection. In fact, it can detect the disease even when film detection has been unsuccessful. If proper donor selection criteria are observed there is little risk of transmitting malaria through transfusion. However, as the donor pool in the Service is not necessarily totally the of voluntary non-remunerated donors and substantive numbers of replacement/first time, occasionally uneducated/unaware donors, are being bled, screening for malaria will not be totally unrewarding. (author)
Fast gradient-based methods for Bayesian reconstruction of transmission and emission PET images
International Nuclear Information System (INIS)
Mumcuglu, E.U.; Leahy, R.; Zhou, Z.; Cherry, S.R.
1994-01-01
The authors describe conjugate gradient algorithms for reconstruction of transmission and emission PET images. The reconstructions are based on a Bayesian formulation, where the data are modeled as a collection of independent Poisson random variables and the image is modeled using a Markov random field. A conjugate gradient algorithm is used to compute a maximum a posteriori (MAP) estimate of the image by maximizing over the posterior density. To ensure nonnegativity of the solution, a penalty function is used to convert the problem to one of unconstrained optimization. Preconditioners are used to enhance convergence rates. These methods generally achieve effective convergence in 15--25 iterations. Reconstructions are presented of an 18 FDG whole body scan from data collected using a Siemens/CTI ECAT931 whole body system. These results indicate significant improvements in emission image quality using the Bayesian approach, in comparison to filtered backprojection, particularly when reprojections of the MAP transmission image are used in place of the standard attenuation correction factors
Evaluation of the transport matrix method for simulation of ocean biogeochemical tracers
Kvale, Karin F.; Khatiwala, Samar; Dietze, Heiner; Kriest, Iris; Oschlies, Andreas
2017-06-01
Conventional integration of Earth system and ocean models can accrue considerable computational expenses, particularly for marine biogeochemical applications. Offline numerical schemes in which only the biogeochemical tracers are time stepped and transported using a pre-computed circulation field can substantially reduce the burden and are thus an attractive alternative. One such scheme is the transport matrix method (TMM), which represents tracer transport as a sequence of sparse matrix-vector products that can be performed efficiently on distributed-memory computers. While the TMM has been used for a variety of geochemical and biogeochemical studies, to date the resulting solutions have not been comprehensively assessed against their online counterparts. Here, we present a detailed comparison of the two. It is based on simulations of the state-of-the-art biogeochemical sub-model embedded within the widely used coarse-resolution University of Victoria Earth System Climate Model (UVic ESCM). The default, non-linear advection scheme was first replaced with a linear, third-order upwind-biased advection scheme to satisfy the linearity requirement of the TMM. Transport matrices were extracted from an equilibrium run of the physical model and subsequently used to integrate the biogeochemical model offline to equilibrium. The identical biogeochemical model was also run online. Our simulations show that offline integration introduces some bias to biogeochemical quantities through the omission of the polar filtering used in UVic ESCM and in the offline application of time-dependent forcing fields, with high latitudes showing the largest differences with respect to the online model. Differences in other regions and in the seasonality of nutrients and phytoplankton distributions are found to be relatively minor, giving confidence that the TMM is a reliable tool for offline integration of complex biogeochemical models. Moreover, while UVic ESCM is a serial code, the TMM can
Directory of Open Access Journals (Sweden)
Angelo Fabbri
2017-06-01
Full Text Available Walk behind tractors have some advantages over other agricultural machines, such as the cheapness and the easy to use, however the driver is exposed to high level of vibrations transmitted from handles to hand-arm system and to shoulders. The vibrations induce discomfort and early fatigue to the operator. In order to control the vibration transmissibility, a ballast mass may be added to the handles. Even if the determination of the appropriate ballast mass is a critical point in the handle design. The aim of this research was to study the influence of the handle mass modification, on the dynamic structure behaviour. Modal frequencies and subsequent transmissibility calculated by using an analytical approach and a finite elements model, were compared. A good agreement between the results obtained by the two methods was found (average percentage difference calculated on natural frequencies equal to 5.8±3.8%. Power tillers are made generally by small or medium-small size manufacturers that have difficulties in dealing with finite element codes or modal analysis techniques. As a consequence, the proposed analytical method could be used to find the optimal ballast mass in a simple and economic way, without experimental tests or complex finite element codes. A specific and very simple software or spreadsheet, developed on the base of the analytical method here discussed, could effectively to help the manufacturers in the handlebar design phase. The choice of the correct elastic mount, the dimensioning of the guide members and the ballast mass could be considerably simplified.
International Nuclear Information System (INIS)
Pavlov, R.L.; Pavlov, L.I.; Raychev, P.P.; Garistov, V.P.; Dimitrova-Ivanovich, M.
2002-01-01
The matrix elements and expectation values of the hyperfine interaction operators are presented in a form suitable for numerical implementation in density matrix methods. The electron-nuclear spin-spin (dipolar and contact) interactions are considered, as well as the interaction between nuclear spin and electron-orbital motions. These interactions from the effective Breit-Pauli Hamiltonian determine the hyperfine structure in ESR spectra and contribute to chemical shifts in NMR. Applying the Wigner-Eckart theorem in the irreducible tensor-operator technique and the spin-space separation scheme, the matrix elements and expectation values of these relativistic corrections are expressed in analytical form. The final results are presented as products, or sums of products, of factors determined by the spin and (or) angular momentum symmetry and a spatial part determined by the action of the symmetrized tensor-operators on the normalized matrix or function of the spin or charge distribution.
Razzaq, Alaa Mohammed; Majid, Dayang Laila Abang Abdul; Ishak, M. R.; B, Uday M.
2017-05-01
The development of new methods for addition fine ceramic powders to Al aluminium alloy melts, which would lead to more uniform distribution and effective incorporation of the reinforcement particles into the aluminium matrix alloy. Recently the materials engineering research has moved to composite materials from monolithic, adapting to the global need for lightweight, low cost, quality, and high performance advanced materials. Among the different methods, stir casting is one of the simplest ways of making aluminium matrix composites. However, it suffers from poor distribution and combination of the reinforcement ceramic particles in the metal matrix. These problems become significantly effect to reduce reinforcement size, more agglomeration and tendency with less wettability for the ceramic particles in the melt process. Many researchers have carried out different studies on the wettability between the metal matrix and dispersion phase, which includes added wettability agents, fluxes, preheating the reinforcement particles, coating the reinforcement particles, and use composting techniques. The enhancement of wettability of ceramic particles by the molten matrix alloy and the reinforcement particles distribution improvement in the solidified matrix is the main objective for many studies that will be discussed in this paper.
International Nuclear Information System (INIS)
Zhang, L.
1981-08-01
A method based on the tight-binding approximation is developed to calculate the electron-phonon matrix element for the disordered transition metals. With the method as a basis the experimental Tsub(c) data of the amorphous transition metal superconductors are re-analysed. Some comments on the superconductivity of the disordered materials are given
Groenland, E.A.G.
2014-01-01
This article addresses three issues: 1. It explains the characteristics and the process of the analysis of empirical, qualitative data. 2. It introduces a method for qualitative analysis, as relevant to business research, i.e., the Matrix Method. 3. It presents a coherent approach about structuring
MCDM based evaluation and ranking of commercial off-the-shelf using fuzzy based matrix method
Directory of Open Access Journals (Sweden)
Rakesh Garg
2017-04-01
Full Text Available In today’s scenario, software has become an essential component in all kinds of systems. The size and the complexity of the software increases with a corresponding increase in its functionality, hence leads to the development of the modular software systems. Software developers emphasize on the concept of component based software engineering (CBSE for the development of modular software systems. The CBSE concept consists of dividing the software into a number of modules; selecting Commercial Off-the-Shelf (COTS for each module; and finally integrating the modules to develop the final software system. The selection of COTS for any module plays a vital role in software development. To address the problem of selection of COTS, a framework for ranking and selection of various COTS components for any software system based on expert opinion elicitation and fuzzy-based matrix methodology is proposed in this research paper. The selection problem is modeled as a multi-criteria decision making (MCDM problem. The evaluation criteria are identified through extensive literature study and the COTS components are ranked based on these identified and selected evaluation criteria using the proposed methods according to the value of a permanent function of their criteria matrices. The methodology is explained through an example and is validated by comparing with an existing method.
Research on Improved Control Strategy for STATCOM Based on Virtual Matrix Method
Directory of Open Access Journals (Sweden)
Wang Xudong
2016-01-01
Full Text Available Fast and accurate detection of reactive current is the precondition for the realization of static synchronous compensator (STATCOM reactive power compensation and harmonic suppression. Aiming at deviation and delay of the traditional reactive current detection algorithm with phase-locked loop (PLL and low-pass filter (LPF of STATCOM, a novel improved reactive current detection algorithm without PLL is proposed, in which the virtual matrix (VM is built to replace the original PLL, and improved current average value filter is used to realize the function of LPF, so as to improve the real-time performance and robustness of reactive current detection. The realization process of VM detection method is derived in this paper, and improved control strategy for STATCOM is designed based on the VM detection method. Simulation analysis of the proposed detection algorithm and control strategy is conducted in Matlab platform so as to verify the correctness and effectiveness of the control strategy. The VM detection has the advantages of simple structure, fast response and easy for digital realization, which provides reference for the improvement of reactive power compensation precision for STATCOM.
Use of the Streaming Matrix Hybrid Method for discrete-ordinates fusion reactor calculations
International Nuclear Information System (INIS)
Battat, M.E.; Davidson, J.W.; Dudziak, D.J.; Thayer, G.R.
1984-01-01
The use of the discrete-ordinates method for solving two-dimensional, neutral-particle transport in fusion reactor blankets and shields is often limited by inherent inaccuracies due to the ray-effect. This effect presents a particular problem in the case of neutron streaming in the large internal void regions of a fusion reactor. A deterministic streaming technique called the Streaming Matrix Hybrid Method (SMHM) has been incorporated in the two-dimensional discrete-ordinates code TRIDENT-CTR. Calculations have been performed for an actual inertial-confinement fusion (ICF) reactor design using TRIDENT-CTR both with and without the SMHM. Comparisons of the calculated fluxes indicate that substantial mitigation of the ray effect can be achieved with the SMHM. Calculations were performed for the Los Alamos FIRST STEP hybrid ICF reactor designed for tritium production. Conventional 238 U fuel rod assemblies surround the spherical steel target chamber to form an annular cylindrical blanket. An axial fuel region is included to complete the blanket
International Nuclear Information System (INIS)
Silva, L.M. da; Rocha, M.C. da; Appoloni, C.R.; Portezan Filho, O.; Lopes, F.; Melquiades, F.L.; Santos, E.A. dos; Santos, A.O. dos; Moreira, A.C.; Poetker, W.E.; Almeida, E. de; Tannous, C.Q.; Kuramoto, R.; Cavalcante, F.H. de M.; Barbieri, P.F.
2000-01-01
Samples of concrete for popular habitation (0,1x0,03x0,1 m) and cellular concrete (0,1x0,05x0,1 m) were submitted to water vertical ascending infiltration. The moisture content spatial and temporal evolution of each sample it was monitored in three halfway positions in a same horizontal line, applying the gamma rays transmission method. The data were taken with a 137 Cs (3,7x10 10 Bq, 0662 MeV) source, NaI (Tl) of 2x2' detector coupled to between wetting profiles and concrete strength. The cellular concrete showed a wetting profile compatible to its greater porosity. (author)
Methods to Regulate Unbundled Transmission and Distribution Business on Electricity Markets
International Nuclear Information System (INIS)
Forsberg, Kaj; Fritz, Peter
2003-11-01
The regulation of distribution utilities is evolving from the traditional approach based on a cost of service or rate of return remuneration, to ways of regulation more specifically focused on providing incentives for improving efficiency, known as performance-based regulation or ratemaking. Modern regulation systems are also, to a higher degree than previously, intended to simulate competitive market conditions. The Market Design 2003-conference gathered people from 18 countries to discuss 'Methods to regulate unbundled transmission and distribution business on electricity markets'. Speakers from nine different countries and backgrounds (academics, industry and regulatory) presented their experiences and most recent works on how to make the regulation of unbundled distribution business as accurate as possible. This paper does not claim to be a fully representative summary of everything that was presented or discussed during the conference. Rather, it is a purposely restricted document where we focus on a few central themes and experiences from different countries
Method and apparatus for controlling a powertrain system including a multi-mode transmission
Hessell, Steven M.; Morris, Robert L.; McGrogan, Sean W.; Heap, Anthony H.; Mendoza, Gil J.
2015-09-08
A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.
Nurulain, S.; Manap, H.
2017-09-01
This paper describes about a visible light transmission (VLT) measurement system using an optical method. VLT rate plays an important role in order to determine the visibility of a medium. Current instrument to measure visibility has a gigantic set up, costly and mostly fails to function at low light condition environment. This research focuses on the development of a VLT measurement system using a simple experimental set-up and at a low cost. An open path optical technique is used to measure a few series of known-VLT thin film that act as sample of different visibilities. This measurement system is able to measure the light intensity of these thin films within the visible light region (535-540 nm) and the response time is less than 1s.
Aliabadi, Amir A.; Rogak, Steven N.; Bartlett, Karen H.; Green, Sheldon I.
2011-01-01
Health care facility ventilation design greatly affects disease transmission by aerosols. The desire to control infection in hospitals and at the same time to reduce their carbon footprint motivates the use of unconventional solutions for building design and associated control measures. This paper considers indoor sources and types of infectious aerosols, and pathogen viability and infectivity behaviors in response to environmental conditions. Aerosol dispersion, heat and mass transfer, deposition in the respiratory tract, and infection mechanisms are discussed, with an emphasis on experimental and modeling approaches. Key building design parameters are described that include types of ventilation systems (mixing, displacement, natural and hybrid), air exchange rate, temperature and relative humidity, air flow distribution structure, occupancy, engineered disinfection of air (filtration and UV radiation), and architectural programming (source and activity management) for health care facilities. The paper describes major findings and suggests future research needs in methods for ventilation design of health care facilities to prevent airborne infection risk. PMID:22162813
Methods to Regulate Unbundled Transmission and Distribution Business on Electricity Markets
Energy Technology Data Exchange (ETDEWEB)
Forsberg, Kaj; Fritz, Peter
2003-11-01
The regulation of distribution utilities is evolving from the traditional approach based on a cost of service or rate of return remuneration, to ways of regulation more specifically focused on providing incentives for improving efficiency, known as performance-based regulation or ratemaking. Modern regulation systems are also, to a higher degree than previously, intended to simulate competitive market conditions. The Market Design 2003-conference gathered people from 18 countries to discuss 'Methods to regulate unbundled transmission and distribution business on electricity markets'. Speakers from nine different countries and backgrounds (academics, industry and regulatory) presented their experiences and most recent works on how to make the regulation of unbundled distribution business as accurate as possible. This paper does not claim to be a fully representative summary of everything that was presented or discussed during the conference. Rather, it is a purposely restricted document where we focus on a few central themes and experiences from different countries.
International Nuclear Information System (INIS)
Poblete, V.; Alvarez, M.; Hermosilla, M.
2000-01-01
This is a study of an analysis of trace elements in medium thick solid samples, by the modified transmission emission method, using the energy dispersion X-ray fluorescence technique (EDXRF). The effects of absorption and reinforcement are the main disadvantages of the EDXRF technique for the quantitative analysis of bigger elements and trace elements in solid samples. The implementation of this method and its application to a variety of samples was carried out using an infinitely thick multi-element white sample that calculates the correction factors by absorbing all the analytes in the sample. The discontinuities in the masic absorption coefficients versus energies association for each element, with medium thick and homogenous samples, are analyzed and corrected. A thorough analysis of the different theoretical and test variables are proven by using real samples, including certified material with known concentration. The simplicity of the calculation method and the results obtained show the method's major precision, with possibilities for the non-destructive routine analysis of different solid samples, using the EDXRF technique (author)
A real-time data transmission method based on Linux for physical experimental readout systems
International Nuclear Information System (INIS)
Cao Ping; Song Kezhu; Yang Junfeng
2012-01-01
In a typical physical experimental instrument, such as a fusion or particle physical application, the readout system generally implements an interface between the data acquisition (DAQ) system and the front-end electronics (FEE). The key task of a readout system is to read, pack, and forward the data from the FEE to the back-end data concentration center in real time. To guarantee real-time performance, the VxWorks operating system (OS) is widely used in readout systems. However, VxWorks is not an open-source OS, which gives it has many disadvantages. With the development of multi-core processor and new scheduling algorithm, Linux OS exhibits performance in real-time applications similar to that of VxWorks. It has been successfully used even for some hard real-time systems. Discussions and evaluations of real-time Linux solutions for a possible replacement of VxWorks arise naturally. In this paper, a real-time transmission method based on Linux is introduced. To reduce the number of transfer cycles for large amounts of data, a large block of contiguous memory buffer for DMA transfer is allocated by modifying the Linux Kernel (version 2.6) source code slightly. To increase the throughput for network transmission, the user software is designed into formation of parallelism. To achieve high performance in real-time data transfer from hardware to software, mapping techniques must be used to avoid unnecessary data copying. A simplified readout system is implemented with 4 readout modules in a PXI crate. This system can support up to 48 MB/s data throughput from the front-end hardware to the back-end concentration center through a Gigabit Ethernet connection. There are no restrictions on the use of this method, hardware or software, which means that it can be easily migrated to other interrupt related applications.
The classical r-matrix method for nonlinear sigma-model
Sevostyanov, Alexey
1995-01-01
The canonical Poisson structure of nonlinear sigma-model is presented as a Lie-Poisson r-matrix bracket on coadjoint orbits. It is shown that the Poisson structure of this model is determined by some `hidden singularities' of the Lax matrix.
Energy Technology Data Exchange (ETDEWEB)
Martini, Till; Uwer, Peter [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstraße 15, 12489 Berlin (Germany)
2015-09-14
In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e{sup +}e{sup −} annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.
International Nuclear Information System (INIS)
Martini, Till; Uwer, Peter
2015-01-01
In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e"+e"− annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.
International Nuclear Information System (INIS)
Itagaki, Masafumi; Sahashi, Naoki.
1997-01-01
The multiple reciprocity boundary element method has been applied to three-dimensional two-group neutron diffusion problems. A matrix-type boundary integral equation has been derived to solve the first and the second group neutron diffusion equations simultaneously. The matrix-type fundamental solutions used here satisfy the equation which has a point source term and is adjoint to the neutron diffusion equations. A multiple reciprocity method has been employed to transform the matrix-type domain integral related to the fission source into an equivalent boundary one. The higher order fundamental solutions required for this formulation are composed of a series of two types of analytic functions. The eigenvalue itself is also calculated using only boundary integrals. Three-dimensional test calculations indicate that the present method provides stable and accurate solutions for criticality problems. (author)
Control of Pan-tilt Mechanism Angle using Position Matrix Method
Directory of Open Access Journals (Sweden)
Hendri Maja Saputra
2013-12-01
Full Text Available Control of a Pan-Tilt Mechanism (PTM angle for the bomb disposal robot Morolipi-V2 using inertial sensor measurement unit, x-IMU, has been done. The PTM has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving Morolipi-V2 platform. The x-IMU detects the platform orientation and sends the result in order to automatically control the PTM. The orientation is calculated using the quaternion combined with Madwick and Mahony filter methods. The orientation data that consists of angles of roll (α, pitch (β, and yaw (γ from the x-IMU are then being sent to the camera for controlling the PTM motion (pan & tilt angles after calculating the reverse angle using position matrix method. Experiment results using Madwick and Mahony methods show that the x-IMU can be used to find the robot platform orientation. Acceleration data from accelerometer and flux from magnetometer produce noise with standard deviation of 0.015 g and 0.006 G, respectively. Maximum absolute errors caused by Madgwick and Mahony method with respect to Xaxis are 48.45º and 33.91º, respectively. The x-IMU implementation as inertia sensor to control the Pan-Tilt Mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle..
Removal of round off errors in the matrix exponential method for solving the heavy nuclide chain
International Nuclear Information System (INIS)
Lee, Hyun Chul; Noh, Jae Man; Joo, Hyung Kook
2005-01-01
Many nodal codes for core simulation adopt the micro-depletion procedure for the depletion analysis. Unlike the macro-depletion procedure, the microdepletion procedure uses micro-cross sections and number densities of important nuclides to generate the macro cross section of a spatial calculational node. Therefore, it needs to solve the chain equations of the nuclides of interest to obtain their number densities. There are several methods such as the matrix exponential method (MEM) and the chain linearization method (CLM) for solving the nuclide chain equations. The former solves chain equations exactly even when the cycles that come from the alpha decay exist in the chain while the latter solves the chain approximately when the cycles exist in the chain. The former has another advantage over the latter. Many nodal codes for depletion analysis, such as MASTER, solve only the hard coded nuclide chains with the CLM. Therefore, if we want to extend the chain by adding some more nuclides to the chain, we have to modify the source code. In contrast, we can extend the chain just by modifying the input in the MEM because it is easy to implement the MEM solver for solving an arbitrary nuclide chain. In spite of these advantages of the MEM, many nodal codes adopt the chain linearization because the former has a large round off error when the flux level is very high or short lived or strong absorber nuclides exist in the chain. In this paper, we propose a new technique to remove the round off errors in the MEM and we compared the performance of the two methods
ASTM and VAMAS activities in titanium matrix composites test methods development
Johnson, W. S.; Harmon, D. M.; Bartolotta, P. A.; Russ, S. M.
1994-01-01
Titanium matrix composites (TMC's) are being considered for a number of aerospace applications ranging from high performance engine components to airframe structures in areas that require high stiffness to weight ratios at temperatures up to 400 C. TMC's exhibit unique mechanical behavior due to fiber-matrix interface failures, matrix cracks bridged by fibers, thermo-viscoplastic behavior of the matrix at elevated temperatures, and the development of significant thermal residual stresses in the composite due to fabrication. Standard testing methodology must be developed to reflect the uniqueness of this type of material systems. The purpose of this paper is to review the current activities in ASTM and Versailles Project on Advanced Materials and Standards (VAMAS) that are directed toward the development of standard test methodology for titanium matrix composites.
A method to improve data transmission efficiency of non-cabled seismographs
Zheng, F.; Lin, J.; Huaizhu, Z.; Yang, H.
2012-12-01
having the functions of a regular non-cable seismograph such as collecting, storing and transmitting, and on top of that, the abilities to acquire, record and transmit source triggering time. GPS is built into the non-cable seismograph to ensure accurate clock synchronization for all working non-cable seismographs. The source-triggered station can obtain the source trigger time accurately and store it in a file, send it to the server or portable terminal using wireless technology. The management system in the server checks clock synchronization information of each non-cable seismograph against the trigger time, determines the exact sampling location of the trigger time, extracts the corresponding data according to predetermined triggering length. It then sequences data according to the survey line, and integrate it into the seismic data file in appropriate format, thus completing the extraction of single-shot data. For off-site data recovery, one can extract all trigger time from the triggered station and recover data in the above-mentioned method post-experimental. The method can rapidly extract valid data from recovered data. Many field experiments have shown that the method can effectively improve data transmission efficiency of non-cabled seismographs and save data storage spaces in the servers.
Directory of Open Access Journals (Sweden)
V. Yu. Kleshnin
2016-01-01
Full Text Available The article describes the matrix algebra libraries based on the modern technologies of parallel programming for the Spectrum software, which can use a spectral method (in the spectral form of mathematical description to analyse, synthesise and identify deterministic and stochastic dynamical systems. The developed matrix algebra libraries use the following technologies for the GPUs: OmniThreadLibrary, OpenMP, Intel Threading Building Blocks, Intel Cilk Plus for CPUs nVidia CUDA, OpenCL, and Microsoft Accelerated Massive Parallelism.The developed libraries support matrices with real elements (single and double precision. The matrix dimensions are limited by 32-bit or 64-bit memory model and computer configuration. These libraries are general-purpose and can be used not only for the Spectrum software. They can also find application in the other projects where there is a need to perform operations with large matrices.The article provides a comparative analysis of the libraries developed for various matrix operations (addition, subtraction, scalar multiplication, multiplication, powers of matrices, tensor multiplication, transpose, inverse matrix, finding a solution of the system of linear equations through the numerical experiments using different CPU and GPU. The article contains sample programs and performance test results for matrix multiplication, which requires most of all computational resources in regard to the other operations.
Externbrink, Anna; Eggenreich, Karin; Eder, Simone; Mohr, Stefan; Nickisch, Klaus; Klein, Sandra
2017-01-01
Accelerated drug release testing is a valuable quality control tool for long-acting non-oral extended release formulations. Currently, several intravaginal ring candidates designed for the long-term delivery of steroids or anti-infective drugs are being in the developing pipeline. The present article addresses the demand for accelerated drug release methods for these formulations. We describe the development and evaluation of accelerated release methods for a steroid releasing matrix-type intravaginal ring. The drug release properties of the formulation were evaluated under real-time and accelerated test conditions. Under real-time test conditions drug release from the intravaginal ring was strongly affected by the steroid solubility in the release medium. Under sufficient sink conditions that were provided in release media containing surfactants drug release was Fickian diffusion driven. Both temperature and hydro-organic dissolution media were successfully employed to accelerate drug release from the formulation. Drug release could be further increased by combining the temperature effect with the application of a hydro-organic release medium. The formulation continued to exhibit a diffusion controlled release kinetic under the investigated accelerated conditions. Moreover, the accelerated methods were able to differentiate between different prototypes of the intravaginal ring that exhibited different release profiles under real-time test conditions. Overall, the results of the present study indicate that both temperature and hydro-organic release media are valid parameters for accelerating drug release from the intravaginal ring. Variation of either a single or both parameters yielded release profiles that correlated well with real-time release. Copyright © 2016 Elsevier B.V. All rights reserved.
Dynamic-stiffness matrix of embedded and pile foundations by indirect boundary-element method
International Nuclear Information System (INIS)
Wolf, J.P.; Darbre, G.R.
1984-01-01
The boundary-integral equation method is well suited for the calculation of the dynamic-stiffness matrix of foundations embedded in a layered visco-elastic halfspace (or a transmitting boundary of arbitrary shape), which represents an unbounded domain. It also allows pile groups to be analyzed, taking pile-soil-pile interaction into account. The discretization of this boundary-element method is restricted to the structure-soil interface. All trial functions satisfy exactly the field equations and the radiation condition at infinity. In the indirect boundary-element method distributed source loads of initially unknown intensities act on a source line located in the excavated part of the soil and are determined such that the prescribed boundary conditions on the structure-soil interface are satisfied in an average sense. In the two-dimensional case the variables are expanded in a Fourier integral in the wave number domain, while in three dimensions, Fourier series in the circumferential direction and bessel functions of the wave number domain, while in three dimensions, Fourier series in the circumferential direction and Bessel functions of the wave number in the radial direction are selected. Accurate results arise with a small number of parameters of the loads acting on a source line which should coincide with the structure-soil interface. In a parametric study the dynamic-stiffness matrices of rectangular foundations of various aspect ratios embedded in a halfplane and in a layer built-in at its base are calculated. For the halfplane, the spring coefficients for the translational directions hardly depend on the embedment, while the corresponding damping coefficients increase for larger embedments, this tendency being more pronounced in the horizontal direction. (orig.)
Directory of Open Access Journals (Sweden)
Qiangliang Guo
2018-02-01
Full Text Available Power transmission line icing (PTLI problems, which cause tremendous damage to the power grids, has drawn much attention. Existing three-dimensional measurement methods based on binocular stereo vision was recently introduced to measure the ice thickness in PTLI, but failed to meet requirements of practical applications due to inefficient keypoint matching in the complex PTLI scene. In this paper, a new keypoint matching method is proposed based on the local multi-layer convolutional neural network (CNN features, termed Local Convolutional Features (LCFs. LCFs are deployed to extract more discriminative features than the conventional CNNs. Particularly in LCFs, a multi-layer features fusion scheme is exploited to boost the matching performance. Together with a location constraint method, the correspondence of neighboring keypoints is further refined. Our approach achieves 1.5%, 5.3%, 13.1%, 27.3% improvement in the average matching precision compared with SIFT, SURF, ORB and MatchNet on the public Middlebury dataset, and the measurement accuracy of ice thickness can reach 90.9% compared with manual measurement on the collected PTLI dataset.
Method of gamma transmission analysis for controlling the hydraulic transport of raw coal
International Nuclear Information System (INIS)
Pepelnik, R.; Boessow, E.; Fanger, H.U.
1978-01-01
The capacity of the methods for measuring gamma absorption developed at GKSS to be used for the analysis of conweyer flows of water/coal/refuse mixtures has been studied. As only the absorption properties of the refuse are essentially different from those of water the refuce is detected with higher accuracy than the coal. In this way the sensitivity of the gamma transmission analysis method agrees with the fact that in coal mining the critical mining parameters are influenced by refuse. The results of the investigations indicate that for measuring times of about 10 sec, accounting for realisitic variations of the chemism of the refuse, the volume shares can be determined with an accuracy of about +- 4.7 V/O of coal and about +- . 5 V/O of refuse. The measuring arrangement for the drift velocity is capable to record also the size and the number of the refuse lumps. The methods described therefore are well suited for controlling an optimal conveying operation. (orig.) [de
Study on Two-Phase Flow in Heterogeneous Porous Media by Light Transmission Method
Qiao, W.
2015-12-01
The non-aqueous phase liquid (NAPL) released to the subsurface can form residual ganglia and globules occupying pores and also accumulate and form pools, in which multiphase system forms. Determining transient fluid saturations in a multiphase system is essential to understand the flow characteristics of systems and to perform effective remediation strategies. As a non-destructive and non-invasive laboratory technique utilized for the measurement of liquid saturation in porous media, light transmission is of the lowest cost and safe. Utilization of Coupled Charge Device camera in light transmission systems provides a nearly instantaneous high-density array of spatial measurements over a very large dynamic range. The migration of NAPL and air spariging technique applied to remove NAPL in aquifer systems are typically two-phase flow problem. Because of the natural aquifer normally being heterogeneous, two 2-D sandboxes (Length55cm×width1.3cm×hight45cm) are set up to study the migration of gas and DNAPL in heterogeneous porous media based on light transmission method and its application in two-phase flow. Model D for water/gas system developed by Niemet and Selker (2001) and Model NW-A for water/NAPL system developed by Zhang et al. (2014) are applied for the calculation of fluid saturation in the two experiments, respectively. The gas injection experiments show that the gas moves upward in the irregular channels, piling up beneath the low permeability lenses and starting lateral movement. Bypassing the lenses, the gas moves upward and forms continuous distribution in the top of the sandbox. The faster of gas injects, the wider of gas migration will be. The DNAPL infiltration experiment shows that TCE mainly moves downward as the influence of gravity, stopping vertical infiltration when reaching the low permeability lenses because of its failure to overcome the capillary pressure. Then, TCE accumulates on the surface and starts transverse movement. Bypassing the
A new method to determine in situ the transmission of a neutron-guide system at a reactor source
Haan, V O D; Gommers, R M; Labohm, F; Well, A A V; De Leege, P F A; Schebetov, A; Pusenkov, V
2002-01-01
In this paper, a description of a new method to determine the transmission of neutron guides after they are installed in a beam-tube at a reactor source is given. The method is based on activation measurements of gold foils at the entrance of the beam-tube and at the exit of the neutron guides compared to Monte-Carlo calculations. In this method, a quality factor is defined as the ratio between the actual transmission and the theoretical maximum attainable transmission. This method is used to determine the quality of an optimised neutron-guide system developed for beam-tube R2 of the HOR. The HOR is a pool-type nuclear research reactor at the Interfaculty Reactor Institute of the Delft University of Technology. It is shown that the quality factors of the newly installed neutron guides are between 0.49 and 0.63.
A new method to determine in situ the transmission of a neutron-guide system at a reactor source
International Nuclear Information System (INIS)
Haan, V.O. de; Gibcus, H.P.M.; Gommers, R.M.; Labohm, F.; Well, A.A. van; Leege, P.F.A. de; Schebetov, A.; Pusenkov, V.
2002-01-01
In this paper, a description of a new method to determine the transmission of neutron guides after they are installed in a beam-tube at a reactor source is given. The method is based on activation measurements of gold foils at the entrance of the beam-tube and at the exit of the neutron guides compared to Monte-Carlo calculations. In this method, a quality factor is defined as the ratio between the actual transmission and the theoretical maximum attainable transmission. This method is used to determine the quality of an optimised neutron-guide system developed for beam-tube R2 of the HOR. The HOR is a pool-type nuclear research reactor at the Interfaculty Reactor Institute of the Delft University of Technology. It is shown that the quality factors of the newly installed neutron guides are between 0.49 and 0.63
DeQuach, Jessica A; Mezzano, Valeria; Miglani, Amar; Lange, Stephan; Keller, Gordon M; Sheikh, Farah; Christman, Karen L
2010-09-27
The native extracellular matrix (ECM) consists of a highly complex, tissue-specific network of proteins and polysaccharides, which help regulate many cellular functions. Despite the complex nature of the ECM, in vitro cell-based studies traditionally assess cell behavior on single ECM component substrates, which do not adequately mimic the in vivo extracellular milieu. We present a simple approach for developing naturally derived ECM coatings for cell culture that provide important tissue-specific cues unlike traditional cell culture coatings, thereby enabling the maturation of committed C2C12 skeletal myoblast progenitors and human embryonic stem cells differentiated into cardiomyocytes. Here we show that natural muscle-specific coatings can (i) be derived from decellularized, solubilized adult porcine muscle, (ii) contain a complex mixture of ECM components including polysaccharides, (iii) adsorb onto tissue culture plastic and (iv) promote cell maturation of committed muscle progenitor and stem cells. This versatile method can create tissue-specific ECM coatings, which offer a promising platform for cell culture to more closely mimic the mature in vivo ECM microenvironment.
System and method for the adaptive mapping of matrix data to sets of polygons
Burdon, David (Inventor)
2003-01-01
A system and method for converting bitmapped data, for example, weather data or thermal imaging data, to polygons is disclosed. The conversion of the data into polygons creates smaller data files. The invention is adaptive in that it allows for a variable degree of fidelity of the polygons. Matrix data is obtained. A color value is obtained. The color value is a variable used in the creation of the polygons. A list of cells to check is determined based on the color value. The list of cells to check is examined in order to determine a boundary list. The boundary list is then examined to determine vertices. The determination of the vertices is based on a prescribed maximum distance. When drawn, the ordered list of vertices create polygons which depict the cell data. The data files which include the vertices for the polygons are much smaller than the corresponding cell data files. The fidelity of the polygon representation can be adjusted by repeating the logic with varying fidelity values to achieve a given maximum file size or a maximum number of vertices per polygon.
USING MATRIX METHODS OF PORTFOLIO ANALYSIS IN DESIGNING VERTICAL-INTEGRATED BUILDING STRUCTURE
Directory of Open Access Journals (Sweden)
Rakytska S.
2018-01-01
Full Text Available Introduction. Ensuring productive functioning of corporations requires assessment and management decisions in terms of choosing effective areas of its activities. Purpose. Investigation of the possibilities of using matrix methods in the formation of a business portfolio in order to create a vertically-integrated structure in the construction complex. Results. Portfolio analysis is an effective tool, first of all, for functionally flexible, “many grocery” companies, who have the opportunity to quickly make changes to their business portfolio. For the production of the final construction product, you need the entire technological chain – from the supplier of primary raw materials, to the implementation and further maintenance of finished products. The strategy of the integrated structure is designed to: coordinate the objectives of the merged enterprises, determine the degree of their interaction, maximize the effect of the integration of business entities, develop ways to react newly formed corporation to changes taking place in the external environment, determine the most effective way of its development time, to ensure the competitive advantages of an integrated structure. The construction of a complex multi-level corporation in a building complex requires the development of a certain algorithm of action, which will ensure the optimality of the newly created structure and effective functioning.
International Nuclear Information System (INIS)
Ohlsson, Y.; Neretnieks, I.
1998-01-01
Traditional laboratory diffusion experiments in rock material are time consuming, and quite small samples are generally used. Electrical conductivity measurements, on the other hand, provide a fast means for examining transport properties in rock and allow measurements on larger samples as well. Laboratory measurements using electrical conductivity give results that compare well to those from traditional diffusion experiments. The measurement of the electrical resistivity in the rock surrounding a borehole is a standard method for the detection of water conducting fractures. If these data could be correlated to matrix diffusion properties, in-situ diffusion data from large areas could be obtained. This would be valuable because it would make it possible to obtain data very early in future investigations of potentially suitable sites for a repository. This study compares laboratory electrical conductivity measurements with in-situ resistivity measurements from a borehole at Aespoe. The laboratory samples consist mainly of Aespoe diorite and fine-grained granite and the rock surrounding the borehole of Aespoe diorite, Smaaland granite and fine-grained granite. The comparison shows good agreement between laboratory measurements and in-situ data
A study of radiative properties of fractal soot aggregates using the superposition T-matrix method
International Nuclear Information System (INIS)
Li Liu; Mishchenko, Michael I.; Patrick Arnott, W.
2008-01-01
We employ the numerically exact superposition T-matrix method to perform extensive computations of scattering and absorption properties of soot aggregates with varying state of compactness and size. The fractal dimension, D f , is used to quantify the geometrical mass dispersion of the clusters. The optical properties of soot aggregates for a given fractal dimension are complex functions of the refractive index of the material m, the number of monomers N S , and the monomer radius a. It is shown that for smaller values of a, the absorption cross section tends to be relatively constant when D f f >2. However, a systematic reduction in light absorption with D f is observed for clusters with sufficiently large N S , m, and a. The scattering cross section and single-scattering albedo increase monotonically as fractals evolve from chain-like to more densely packed morphologies, which is a strong manifestation of the increasing importance of scattering interaction among spherules. Overall, the results for soot fractals differ profoundly from those calculated for the respective volume-equivalent soot spheres as well as for the respective external mixtures of soot monomers under the assumption that there are no electromagnetic interactions between the monomers. The climate-research implications of our results are discussed
Wu, Xuan Hui
2008-01-01
This book gives a step-by-step presentation of a generalized transmission line method to study the far-zone radiation of antennas under a multilayer structure. Normally, a radiation problem requires a full wave analysis which may be time consuming. The beauty of the generalized transmission line method is that it transforms the radiation problem for a specific type of structure, say the multilayer structure excited by an antenna, into a circuit problem that can be efficiently analyzed. Using the Reciprocity Theorem and far-field approximation, the method computes the far-zone radiation due to
The measurement of the transmission loss of single leaf walls and panels by an impulse method
Balilah, Y. A.; Gibbs, B. M.
1988-06-01
The standard methods of measurement and rating of sound insulation of panels and walls are generally time-consuming and require expensive and often bulky equipment. In addition, the methods establish only that there has been failure to comply with insulation requirements without indicating the mode of failure. An impulse technique is proposed for the measurement of walls and partitions in situ. The method requires the digital capture of a short duration signal generated by a loudspeaker, and the isolation of the direct component from other reflected and scattered components by time-of-flight methods and windowing. The signal, when transferred from the time to frequency domain by means of fast Fourier transforms, can yield the sound insulation of a partition expressed as a transfer function. Experimental problems in the use of this technique, including those resulting from sphericity of the incident wave front and concentric bending excitation of the partition, are identified and methods proposed for their elimination. Most of the results presented are of single leaf panels subjected to sound at normal incidence, although some measurements were undertaken at oblique incidence. The range of surface densities considered was 7-500 kg/m 2, the highest value corresponding to a brick and plaster wall of thickness 285 mm. Measurement is compared with theoretical prediction, at one-third octave intervals in a frequency range of 100-5000 Hz, or as a continuous function of frequency with a typical resolution of 12·5 Hz. The dynamic range of the measurement equipment sets an upper limit to the measurable transmission loss. For the equipment eventually employed this was represented by a random incidence value of 50 dB.
Synthesis of Ag{sub 2}S nanorods by biomimetic method in the lysozyme matrix
Energy Technology Data Exchange (ETDEWEB)
Qin, Dezhi, E-mail: dezhiqin@163.com; Zhang, Li; He, Guoxu; Zhang, Qiuxia
2013-09-01
Graphical abstract: - Highlights: • Firstly, Ag{sub 2}S nanorods were synthesized by biomimetic method in the lysozyme solutions. • The study of the interaction between Ag{sup +} and the lysozyme. • Discussion of possible formation mechanism of Ag{sub 2}S nanorods. • The synthesis process of lyso-conjugated Ag{sub 2}S nanocrystals is facile, effective and environment friendly. - Abstract: Ag{sub 2}S nanorods were successfully synthesized by biomimetic route in the lysozyme solution at physiological temperature and atmospheric pressure. The transmission electron microscopy (TEM) images revealed that the prepared nanorods are uniform and monodisperse with homogeneous size about 50 nm in diameter and 150 nm in length. The optical property of Ag{sub 2}S nanocrystals was studied by the ultraviolet–visible (UV–vis) and photoluminescence (PL) spectroscopy, the results show that the products exhibit well-defined emission at 471 nm and 496 nm excited by 292 nm. The interaction of Ag{sup +}/Ag{sub 2}S with the lysozyme was investigated through Fourier transform infrared (FT-IR) spectroscopy, which shows that the cooperation effect of the lysozyme and Ag{sup +} could be responsible for the formation of as obtained Ag{sub 2}S nanorods.
International Nuclear Information System (INIS)
Conti, C.F.S.; Watson, F.V.
1991-01-01
A computational code to solve a two energy group neutron diffusion problem has been developed base d on the Response Matrix Method. That method solves the global problem of PWR core, without using the cross sections homogenization process, thus it is equivalent to a pontwise core calculation. The present version of the code calculates the response matrices by the first order perturbative method and considers developments on arbitrary order Fourier series for the boundary fluxes and interior fluxes. (author)
Agar/gelatin bilayer gel matrix fabricated by simple thermo-responsive sol-gel transition method.
Wang, Yifeng; Dong, Meng; Guo, Mengmeng; Wang, Xia; Zhou, Jing; Lei, Jian; Guo, Chuanhang; Qin, Chaoran
2017-08-01
We present a simple and environmentally-friendly method to generate an agar/gelatin bilayer gel matrix for further biomedical applications. In this method, the thermally responsive sol-gel transitions of agar and gelatin combined with the different transition temperatures are exquisitely employed to fabricate the agar/gelatin bilayer gel matrix and achieve separate loading for various materials (e.g., drugs, fluorescent materials, and nanoparticles). Importantly, the resulting bilayer gel matrix provides two different biopolymer environments (a polysaccharide environment vs a protein environment) with a well-defined border, which allows the loaded materials in different layers to retain their original properties (e.g., magnetism and fluorescence) and reduce mutual interference. In addition, the loaded materials in the bilayer gel matrix exhibit an interesting release behavior under the control of thermal stimuli. Consequently, the resulting agar/gelatin bilayer gel matrix is a promising candidate for biomedical applications in drug delivery, controlled release, fluorescence labeling, and bio-imaging. Copyright © 2017 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Dumenigo Gonzalez, Cruz; Vilaragut Llanes, Juan J.; Morales Lopez, Jorge L.
2009-01-01
Accidents in the world of radiation, demonstrating the need for deepen security assessments. This study evaluates the safety of the treatment of teletherapy linear accelerator (LINAC) at a hospital in Cuba, based on applying the method Risk Matrix. This method has been used for many years in conventional industry, is simple, easy to apply and is based on the equation General risk R = f * P * C (where: f frequency of occurrence of the initiating event, P probability of failure of all barriers and magnitude of the consequences C expected). We have evaluated 140 accident sequences that were identified during the analysis of the treatment process. It was identified that 5 sequences are associated with the level of risk is very low, 96 low-risk, high risk and 39 with no very high risk. All accident sequences associated with high risk (considered unacceptable), have an impact on patients, and no concerns workers and public, which reaffirms that major security problems are related to radiation protection of patients. 34 sequences accidental high risk are associated with human errors and failures only 5 to equipment (LINAC, TPS, TAC, etc.). demonstrating the importance of human error. It shows that 35 of the 39 high-risk accident sequences leading to serious or very serious consequences for patients, which would mean the death of one or more patients, making specific recommendations to reduce risk in these cases. The findings of this work and regulators allow users to refine their programs quality assurance and inspection and suggest the hospital management, prioritize material resources according to criteria of irrigation management. (author)
Saito, Akira; Numata, Yasushi; Hamada, Takuya; Horisawa, Tomoyoshi; Cosatto, Eric; Graf, Hans-Peter; Kuroda, Masahiko; Yamamoto, Yoichiro
2016-01-01
Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity. In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features. CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image
Bisetti, Fabrizio
2012-01-01
with the computational cost associated with the time integration of stiff, large chemical systems, a novel approach is proposed. The approach combines an exponential integrator and Krylov subspace approximations to the exponential function of the Jacobian matrix
Library designs for generic C++ sparse matrix computations of iterative methods
Energy Technology Data Exchange (ETDEWEB)
Pozo, R.
1996-12-31
A new library design is presented for generic sparse matrix C++ objects for use in iterative algorithms and preconditioners. This design extends previous work on C++ numerical libraries by providing a framework in which efficient algorithms can be written *independent* of the matrix layout or format. That is, rather than supporting different codes for each (element type) / (matrix format) combination, only one version of the algorithm need be maintained. This not only reduces the effort for library developers, but also simplifies the calling interface seen by library users. Furthermore, the underlying matrix library can be naturally extended to support user-defined objects, such as hierarchical block-structured matrices, or application-specific preconditioners. Utilizing optimized kernels whenever possible, the resulting performance of such framework can be shown to be competitive with optimized Fortran programs.
International Nuclear Information System (INIS)
Zhang Xiangsong; He Zuoxiang
2004-01-01
Objective: To establish the method of three dimension volumetric fusion of emission and transmission images for PET imaging. Methods: The volume data of emission and transmission images acquired with Siemens ECAT HR + PET scanner were transferred to PC computer by local area network. The PET volume data were converted into 8 bit byte type, and scaled to the range of 0-255. The data coordinates of emission and transmission images were normalized by three-dimensional coordinate conversion in the same way. The images were fused with the mode of alpha-blending. The accuracy of image fusion was confirmed by its clinical application in 13 cases. Results: The three dimension volumetric fusion of emission and transmission images clearly displayed the silhouette and anatomic configuration in chest, including chest wall, lung, heart, mediastinum, et al. Forty-eight lesions in chest in 13 cases were accurately located by the image fusion. Conclusions: The volume data of emission and transmission images acquired with Siemens ECAT HR + PET scanner have the same data coordinate. The three dimension fusion software can conveniently used for the three dimension volumetric fusion of emission and transmission images, and also can correctly locate the lesions in chest
Rubino, Stefano; Akhtar, Sultan; Leifer, Klaus
2016-02-01
We present a simple, fast method for thickness characterization of suspended graphene/graphite flakes that is based on transmission electron microscopy (TEM). We derive an analytical expression for the intensity of the transmitted electron beam I 0(t), as a function of the specimen thickness t (tgraphite). We show that in thin graphite crystals the transmitted intensity is a linear function of t. Furthermore, high-resolution (HR) TEM simulations are performed to obtain λ for a 001 zone axis orientation, in a two-beam case and in a low symmetry orientation. Subsequently, HR (used to determine t) and bright-field (to measure I 0(0) and I 0(t)) images were acquired to experimentally determine λ. The experimental value measured in low symmetry orientation matches the calculated value (i.e., λ=225±9 nm). The simulations also show that the linear approximation is valid up to a sample thickness of 3-4 nm regardless of the orientation and up to several ten nanometers for a low symmetry orientation. When compared with standard techniques for thickness determination of graphene/graphite, the method we propose has the advantage of being simple and fast, requiring only the acquisition of bright-field images.
A method for describing the doses delivered by transmission x-ray computed tomography
International Nuclear Information System (INIS)
Shope, T.B.; Gagne, R.M.; Johnson, G.C.
1981-01-01
A method for describing the absorbed dose delivered by x-ray transmission computed tomography (CT) is proposed which provides a means to characterize the dose resulting from CT procedures consisting of a series of adjacent scans. The dose descriptor chosen is the average dose at several locations in the imaged volume of the central scan of the series. It is shown that this average dose, as defined, for locations in the central scan of the series can be obtained from the integral of the dose profile perpendicular to the scan plane at these same locations for a single scan. This method for estimating the average dose from a CT procedure has been evaluated as a function of the number of scans in the multiple scan procedure and location in the dosimetry phantom using single scan dose profiles obtained from five different types of CT systems. For the higher dose regions in the phantoms, the multiple scan dose descriptor derived from the single scan dose profiles overestimates the multiple scan average dose by no more than 10%, provided the procedure consists of at least eight scans
Analysis of Service Quality Management in the Materials Industry using the BCG Matrix Method
Adrian Ioana; Vasile Mirea; Cezar Balescu
2009-01-01
For each product or service, the area of the circle represents the value of its sales. The BCG (Boston Consulting Group) matrix thus offers a very useful map of the organization's service strengths and weaknesses, at least in terms of current profitability, as well as the likely cash flows. The criteria function concept consists of transforming the criteria function (CF) in a qualityeconomical matrix MQE. The levels of prescribing the criteria function were obtained by using a composition alg...
NEW METHODS FOR IMPLANT MATRIX FORMATION BASED ON ELECTROSPINNING AND BIOPRINTING TECHNOLOGIES
Directory of Open Access Journals (Sweden)
V. N. Vasilets
2009-01-01
Full Text Available New implant materials for regenerative and replacement surgery based on biodegradable polymers like collagens and polyoxybutirates are developed. Porous structures with controllable morphology were formed from biodegradable polymers using electrospinning and bioprinting technologies. The matrixes were studied by visible and electron scanning microscopy as well as INTEGRA Tomo scanning probe platform making possible the restoration of inner 3D structure of polymer matrix.
On the processes of generation of particles in the extended S-matrix method
International Nuclear Information System (INIS)
Dushutin, N.K.; Mal'tsev, V.M.; Sinegovskij, S.I.
1975-01-01
In order to understand the processes of hadron multiple production very important are integral characteristics, such as the multiplicity distribution function Psub(n)=sigmasub(n)/sigmasub(inel) and correlation parameters of fsub(K). From the shape of distribution and the energy dependence of correlation parameters one may arrive at definite conclusions about the interaction dynamics. In the paper a possibility is studied of obtaining integral characteristics in the S matrix formulation of the quantum field theory. This technique is based on principles of the scattering matrix expanding beyond the energy surface (ES). This follows from the fact that the predetermination of the scattering matrix on the ES does not permit strict to determinate the condition for causality. The expansion of S matrix is performed by introducing some object described by a substantial function rho(x) and interacting with a quantum system, properties of rho(x) being such that the space of asymptotic states remains complete for the expanded matrix also, i.e., the unitarity condition is fulfilled for S(rho) too. The expansion of S-matrix over the function of the interaction insertion g(x) and the transition to the differential equations for the coupling constant allowed investigation of hadron inelastic processes at some simplifying suppositions. Experimental data do not contradict in the main the proposed picture of interactions [ru
DEFF Research Database (Denmark)
Lee, Kyo Beum; Blaabjerg, Frede
2007-01-01
In this paper, an improved direct torque control (DTC) method for sensorless matrix converter drives is proposed, which is characterized by minimal torque ripple, unity input power factor, and good sensorless speed-control performance in the low-speed operation, while maintaining constant switchi...
Energy Technology Data Exchange (ETDEWEB)
Choi, Yong Joon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yoo, Jun Soo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2015-09-01
This INL plan comprehensively describes the Requirements Traceability Matrix (RTM) on main physics and numerical method of the RELAP-7. The plan also describes the testing-based software verification and validation (SV&V) process—a set of specially designed software models used to test RELAP-7.
Force transmissibility versus displacement transmissibility
Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.
2014-10-01
It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this
International Nuclear Information System (INIS)
Lemieux, M.A.; Breton, P.; Tremblay, A.M.S.
1985-01-01
It is shown that the Negative Eigenvalue Theorem and transfer matrix methods may be considered within a unified framework and generalized to compute projected densities of states or, more generally, any linear combination of matrix elements of the inverse of large symmetric random matrices. As examples of applications, extensive simulations for one- and two-mode behaviour in the Raman spectrum of one-dimensional mixed crystals and a finite-size analysis of critical exponents for the central force percolation universality class are presented
International Nuclear Information System (INIS)
Lopez G, A.; Cruz, D.; Truppa, W.; Aravena, M.; Tamayo, B.
2015-09-01
Although the uses of ionizing radiation in industry are subject to procedures that provide a high level of safety, experience has shown that equipment failure, human errors, or the combination of both that can trigger accidental exposures may occur. Traditionally, the radiation safety checks whether these industrial practices (industrial radiography, industrial irradiators, among others) are sufficiently safe to prevent similar accidental exposures already occurred, so that becomes dependent on the published information and not always answers questions like: What other events can occur, or what other risks are present? Taking into account the results achieved by the Foro Iberoamericano de Organismos Reguladores Radiologicos y Nucleares, its leading position in the use of techniques of risk analysis in radioactive facilities and the need to develop a proactive approach to the prevention of accidents arising from the use of ionizing radiations in the industry, it intends to apply the risk analysis technique known as Risk Matrix to a hypothetical reference entity for the region in which industrial radiography is performed. In this paper the results of the first stage of this study are shown, that is the identification of initiating events (IE) and barriers that help mitigate the consequences of such IE, so that can appreciate the applicability of this method to industrial radiography services, to reduce the risk to acceptable levels. The fundamental advantage associated with the application of this methodology is that can be applied by the professionals working in the service and identifies specific weaknesses that from the point of view of safety there, so they can be prioritized resources depending on risk reduction. (Author)
Jiao, C. F.; Engel, J.; Holt, J. D.
2017-11-01
We use the generator-coordinate method (GCM) with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless double-β decay of 48Ca, 76Ge, and 82Se. We work in one major shell for the first isotope, in the f5 /2p g9 /2 space for the second and third, and finally in two major shells for all three. Our coordinates include not only the usual axial deformation parameter β , but also the triaxiality angle γ and neutron-proton pairing amplitudes. In the smaller model spaces our matrix elements agree well with those of full shell-model diagonalization, suggesting that our Hamiltonian-based GCM captures most of the important valence-space correlations. In two major shells, where exact diagonalization is not currently possible, our matrix elements are only slightly different from those in a single shell.
International Nuclear Information System (INIS)
Qiu, Dong; Zhang, Mingxing
2014-01-01
A simple and inclusive method is proposed for accurate determination of the habit plane between bicrystals in transmission electron microscope. Whilst this method can be regarded as a variant of surface trace analysis, the major innovation lies in the improved accuracy and efficiency of foil thickness measurement, which involves a simple tilt of the thin foil about a permanent tilting axis of the specimen holder, rather than cumbersome tilt about the surface trace of the habit plane. Experimental study has been done to validate this proposed method in determining the habit plane between lamellar α 2 plates and γ matrix in a Ti–Al–Nb alloy. Both high accuracy (± 1°) and high precision (± 1°) have been achieved by using the new method. The source of the experimental errors as well as the applicability of this method is discussed. Some tips to minimise the experimental errors are also suggested. - Highlights: • An improved algorithm is formulated to measure the foil thickness. • Habit plane can be determined with a single tilt holder based on the new algorithm. • Better accuracy and precision within ± 1° are achievable using the proposed method. • The data for multi-facet determination can be collected simultaneously
Directory of Open Access Journals (Sweden)
Jianguo Ding
2014-11-01
Full Text Available Portal frame structures are widely used in industrial building design but unfortunately are often damaged during an earthquake. As a result, a study on the seismic response of this type of structure is important to both human safety and future building designs. Traditionally, finite element methods such as the ANSYS and MIDAS have been used as the primary methods of computing the response of such a structure during an earthquake; however, these methods yield low calculation efficiencies. In this paper, the mechanical model of a single-story portal frame structure with two spans is constructed based on the transfer matrix method of multibody system (MS-TMM; both the transfer matrix of the components in the model and the total transfer matrix equation of the structure are derived, and the corresponding MATLAB program is compiled to determine the natural period and seismic response of the structure. The results show that the results based on the MS-TMM are similar to those obtained by ANSYS, but the calculation time of the MS-TMM method is only 1/20 of that of the ANSYS method. Additionally, it is shown that the MS-TMM method greatly increases the calculation efficiency while maintaining accuracy.
Bonitati, Joey; Slimmer, Ben; Li, Weichuan; Potel, Gregory; Nunes, Filomena
2017-09-01
The calculable form of the R-matrix method has been previously shown to be a useful tool in approximately solving the Schrodinger equation in nuclear scattering problems. We use this technique combined with the Gauss quadrature for the Lagrange-mesh method to efficiently solve for the wave functions of projectile nuclei in low energy collisions (1-100 MeV) involving an arbitrary number of channels. We include the local Woods-Saxon potential, the non-local potential of Perey and Buck, a Coulomb potential, and a coupling potential to computationally solve for the wave function of two nuclei at short distances. Object oriented programming is used to increase modularity, and parallel programming techniques are introduced to reduce computation time. We conclude that the R-matrix method is an effective method to predict the wave functions of nuclei in scattering problems involving both multiple channels and non-local potentials. Michigan State University iCER ACRES REU.
Method and apparatus for reducing radiation exposure through the use of infrared data transmission
Austin, Frank S.; Hance, Albert B.
1989-01-01
A method and apparatus is described for transmitting information, for exae, dosimetry data from a hazardous environment such as a radioactive area to a remote relatively safe location. A radiation detector senses the radiation and generates an electrical signal which is fed as a binary coded decimal signal to an infrared transmitter having a microprocessor. The microprocessor formats the detected information into digits of data and modulates a 40 kHz oscillator, the output of which is fed to and intensity modulates one or more infrared emitting diodes. The infrared signal from the diodes is transmitted to a portable hand-held infrared receiver remote from the hazardous environment. The receiver includes an infrared sensitive diode which decodes the data and generates an electrical signal which is coupled to a microcomputer. The microcomputer synchronizes itself to the transmitter, reads the digits of data as they are received, sums the digits and compares the sum with a checksum signal generated and transmitted from the transmitter. If a match of the checksum signals exists, the received data is displayed, otherwise it is described and the receiver conditions itself for the next transmission of data.
Matrix-exponential description of radiative transfer
International Nuclear Information System (INIS)
Waterman, P.C.
1981-01-01
By appling the matrix-exponential operator technique to the radiative-transfer equation in discrete form, new analytical solutions are obtained for the transmission and reflection matrices in the limiting cases x >1, where x is the optical depth of the layer. Orthongonality of the eigenvectors of the matrix exponential apparently yields new conditions for determining. Chandrasekhar's characteristic roots. The exact law of reflection for the discrete eigenfunctions is also obtained. Finally, when used in conjuction with the doubling method, the matrix exponential should result in reduction in both computation time and loss of precision
International Nuclear Information System (INIS)
Geraldo, L.P.; Smith, D.L.
1989-01-01
The methodology of covariance matrix and square methods have been applied in the relative efficiency calibration for a Ge(Li) detector apllied in the relative efficiency calibration for a Ge(Li) detector. Procedures employed to generate, manipulate and test covariance matrices which serve to properly represent uncertainties of experimental data are discussed. Calibration data fitting using least square methods has been performed for a particular experimental data set. (author) [pt
Metal matrix coated fiber composites and the methods of manufacturing such composites
Weeks, J.K. Jr.; Gensse, C.
1993-09-14
A fiber coating which allows ceramic or metal fibers to be wetted by molten metals is disclosed. The coating inhibits degradation of the physical properties caused by chemical reaction between the fiber and the coating itself or between the fiber and the metal matrix. The fiber coating preferably includes at least a wetting layer, and in some applications, a wetting layer and a barrier layer between the fiber and the wetting layer. The wetting layer promotes fiber wetting by the metal matrix. The barrier layer inhibits fiber degradation. The fiber coating permits the fibers to be infiltrated with the metal matrix resulting in composites having unique properties not obtainable in pure materials. 8 figures.
Forssen, B.; Wang, Y. S.; Crocker, M. J.
1981-12-01
Several aspects were studied. The SEA theory was used to develop a theoretical model to predict the transmission loss through an aircraft window. This work mainly consisted of the writing of two computer programs. One program predicts the sound transmission through a plexiglass window (the case of a single partition). The other program applies to the case of a plexiglass window window with a window shade added (the case of a double partition with an air gap). The sound transmission through a structure was measured in experimental studies using several different methods in order that the accuracy and complexity of all the methods could be compared. Also, the measurements were conducted on the simple model of a fuselage (a cylindrical shell), on a real aircraft fuselage, and on stiffened panels.
ORIGEN-2.2, Isotope Generation and Depletion Code Matrix Exponential Method
International Nuclear Information System (INIS)
2002-01-01
1 - Description of problem or function: ORIGEN is a computer code system for calculating the buildup, decay, and processing of radioactive materials. ORIGEN2 is a revised version of ORIGEN and incorporates updates of the reactor models, cross sections, fission product yields, decay data, and decay photon data, as well as the source code. ORIGEN-2.1 replaces ORIGEN and includes additional libraries for standard and extended-burnup PWR and BWR calculations, which are documented in ORNL/TM-11018. ORIGEN2.1 was first released in August 1991 and was replaced with ORIGEN2 Version 2.2 in June 2002. Version 2.2 was the first update to ORIGEN2 in over 10 years and was stimulated by a user discovering a discrepancy in the mass of fission products calculated using ORIGEN2 V2.1. Code modifications, as well as reducing the irradiation time step to no more than 100 days/step reduced the discrepancy from ∼10% to 0.16%. The bug does not noticeably affect the fission product mass in typical ORIGEN2 calculations involving reactor fuels because essentially all of the fissions come from actinides that have explicit fission product yield libraries. Thus, most previous ORIGEN2 calculations that were otherwise set up properly should not be affected. 2 - Method of solution: ORIGEN uses a matrix exponential method to solve a large system of coupled, linear, first-order ordinary differential equations with constant coefficients. ORIGEN2 has been variably dimensioned to allow the user to tailor the size of the executable module to the problem size and/or the available computer space. Dimensioned arrays have been set large enough to handle almost any size problem, using virtual memory capabilities available on most mainframe and 386/486 based PCS. The user is provided with much of the framework necessary to put some of the arrays to several different uses, call for the subroutines that perform the desired operations, and provide a mechanism to execute multiple ORIGEN2 problems with a single
Directory of Open Access Journals (Sweden)
Qu Li
2014-01-01
Full Text Available Online friend recommendation is a fast developing topic in web mining. In this paper, we used SVD matrix factorization to model user and item feature vector and used stochastic gradient descent to amend parameter and improve accuracy. To tackle cold start problem and data sparsity, we used KNN model to influence user feature vector. At the same time, we used graph theory to partition communities with fairly low time and space complexity. What is more, matrix factorization can combine online and offline recommendation. Experiments showed that the hybrid recommendation algorithm is able to recommend online friends with good accuracy.
Directory of Open Access Journals (Sweden)
Akaa Agbaeze Eteng
Full Text Available Q-factor constraints are usually imposed on conductor loops employed as proximity range High Frequency Radio Frequency Identification (HF-RFID reader antennas to ensure adequate data bandwidth. However, pairing such low Q-factor loops in inductive energy transmission links restricts the link transmission performance. The contribution of this paper is to assess the improvement that is reached with a two-stage design method, concerning the transmission performance of a planar square loop relative to an initial design, without compromise to a Q-factor constraint. The first stage of the synthesis flow is analytical in approach, and determines the number and spacing of turns by which coupling between similar paired square loops can be enhanced with low deviation from the Q-factor limit presented by an initial design. The second stage applies full-wave electromagnetic simulations to determine more appropriate turn spacing and widths to match the Q-factor constraint, and achieve improved coupling relative to the initial design. Evaluating the design method in a test scenario yielded a more than 5% increase in link transmission efficiency, as well as an improvement in the link fractional bandwidth by more than 3%, without violating the loop Q-factor limit. These transmission performance enhancements are indicative of a potential for modifying proximity HF-RFID reader antennas for efficient inductive energy transfer and data telemetry links.
Cakoni, Fioralba; Haddar, Houssem
2013-10-01
In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission
Evaluation of Extraction Methods for the Analysis of Carotenoids for Different Vegetable Matrix
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Stancuta Scrob
2013-11-01
Full Text Available In this study, different solvents were used to achieve the maximum extractibility of total carotenoids. The extracted total carotenoids were estimated using UV- visible spectrophotometer. Carotenoids from vegetable matrix can be used as a food colorant, food additive, cosmetics, antioxidants and nutraceuticals.
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Tao Hu
2018-04-01
Full Text Available Because the traditional transmission line method treats electromagnetic waves as excitation sources and the cavity as a rectangular waveguide whose terminal is shorted, the transmission line method can only calculate shielding effectiveness in the center line of the cavity with apertures on one side. In this paper, the aperture coupling effect of different sides was analyzed based on vector analysis. According to the field intensity distribution of different transport modes in the rectangular waveguide, the calculation model of cavity shielding effectiveness in any position is proposed, which can solve the question of the calculation model of shielding effectiveness in any position in the traditional method of equivalent transmission methods. Further expansion of the equivalent transmission lines model is adopted to study the shielding effectiveness of different aperture cavities, and the coupling effect rule of the incident angle, the number of apertures, and the size of the cavity is obtained, which can provide the technical support for the design of electromagnetic shielding cavities for electronic equipment.
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POSTOLATI V.M.
2010-08-01
Full Text Available The Transmission Power Lines of new generation are described in the article (single- compact, double-circuit compact, double-circuit Controlled Self-compensating High Voltage Transmission Power Lines (CSHVL. Basic principles of creation, design elements and comparative characteristics of the transmission lines of the new generation are described, the advantages of its are showed. Methodical approaches to the choosing of a new generation of transmission lines and facilities management FACTS are formulated. Methodical approaches to the choice of options for transmission lines 220 kV and facilities management are shown.
Wang, C C; Tan, J Y; Ma, Y Q; Liu, L H
2017-06-20
The optical constants of vegetable oils and biodiesels are the basic input parameters in the study of the thermal radiation transfer and monitoring the productivity of vegetable oils converting to biodiesels. In this work, a combined ellipsometry-transmission method is presented to obtain the optical constants of palm oil and palm oil biodiesel between 20°C and 150°C in the spectral range 600-4100 cm -1 and to study the temperature effect on the optical constants. In the combined method, a modified ellipsometry method is used to measure the optical constants of palm oil and palm oil biodiesel for the whole researched wave bands. For the weak absorption regions in which the ellipsometry method cannot give precise absorption indices, the transmission method is conducted to get the absorption indices using the refractive indices obtained by the proposed ellipsometry method. Deionized water and methanol are taken as examples to verify the combined ellipsometry-transmission method. It is shown that the combined method can overcome the deficiencies of the traditional ellipsometry and transmission method, which can be used for the measurements of both strong and weak absorption wave bands. The experimental analyses indicate that temperature exerts a noticeable influence on the infrared optical constants of palm oil and palm oil biodiesel. With the increase of temperature, the refractive indices at certain wavenumbers decrease nearly linearly, and the amplitudes of dominant absorption peaks show a decreasing trend. The absorption peaks located around 3550 cm -1 show blueshift trends as temperature increases. Comparing these two kinds of oils, palm oil presents larger values in refractive indices and dominant absorption peaks.
Ruuska, Salla; Hämäläinen, Wilhelmiina; Kajava, Sari; Mughal, Mikaela; Matilainen, Pekka; Mononen, Jaakko
2018-03-01
The aim of the present study was to evaluate empirically confusion matrices in device validation. We compared the confusion matrix method to linear regression and error indices in the validation of a device measuring feeding behaviour of dairy cattle. In addition, we studied how to extract additional information on classification errors with confusion probabilities. The data consisted of 12 h behaviour measurements from five dairy cows; feeding and other behaviour were detected simultaneously with a device and from video recordings. The resulting 216 000 pairs of classifications were used to construct confusion matrices and calculate performance measures. In addition, hourly durations of each behaviour were calculated and the accuracy of measurements was evaluated with linear regression and error indices. All three validation methods agreed when the behaviour was detected very accurately or inaccurately. Otherwise, in the intermediate cases, the confusion matrix method and error indices produced relatively concordant results, but the linear regression method often disagreed with them. Our study supports the use of confusion matrix analysis in validation since it is robust to any data distribution and type of relationship, it makes a stringent evaluation of validity, and it offers extra information on the type and sources of errors. Copyright © 2018 Elsevier B.V. All rights reserved.
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Juhásová L.
2017-06-01
Full Text Available The combination of multicriteria analysis (MCA, particularly analytic hierarchy process (AHP and geographic information system (GIS were applied for transmission risk assessment of Fascioloides magna (Trematoda; Fasciolidae in south-western Slovakia. Based on the details on F. magna life cycle, the following risk factors (RF of parasite transmission were determined: intermediate (RFIH and final hosts (RFFH (biological factors, annual precipitation (RFAP, land use (RFLU, flooded area (RFFA, and annual mean air temperature (RFAT (environmental factors. Two types of risk analyses were modelled: (1 potential risk analysis was focused on the determination of the potential risk of parasite transmission into novel territories (data on F. magna occurrence were excluded; (2 actual risk analysis considered also the summary data on F. magna occurrence in the model region (risk factor parasite occurrence RFPO included in the analysis. The results of the potential risk analysis provided novel distribution pattern and revealed new geographical area as the potential risk zone of F. magna occurrence. Although the actual risk analysis revealed all four risk zones of F. magna transmission (acceptable, moderate, undesirable and unacceptable, its outputs were significantly affected by the data on parasite occurrence what reduced the informative value of the actual transmission risk assessment.
Jung, C. C.; Stumpe, J.
2005-02-01
The new method of immersion transmission ellipsometry (ITE) [1] has been developed. It allows the highly accurate determination of the absolute three-dimensional (3D) refractive indices of anisotropic thin films. The method is combined with conventional ellipsometry in transmission and reflection, and the thickness determination of anisotropic films solely by optical methods also becomes more accurate. The method is applied to the determination of the 3D refractive indices of thin spin-coated films of an azobenzene-containing liquid-crystalline copolymer. The development of the anisotropy in these films by photo-orientation and subsequent annealing is demonstrated. Depending on the annealing temperature, oblate or prolate orders are generated.
Directory of Open Access Journals (Sweden)
Xinyan Qin
2018-02-01
Full Text Available With the growth of the national economy, there is increasing demand for electricity, which forces transmission line corridors to become structurally complicated and extend to complex environments (e.g., mountains, forests. It is a great challenge to inspect transmission line in these regions. To address these difficulties, a novel method of autonomous inspection for transmission line is proposed based on cable inspection robot (CIR LiDAR data, which mainly includes two steps: preliminary inspection and autonomous inspection. In preliminary inspection, the position and orientation system (POS data is used for original point cloud dividing, ground point filtering, and structured partition. A hierarchical classification strategy is established to identify the classes and positions of the abnormal points. In autonomous inspection, CIR can autonomously reach the specified points through inspection planning. These inspection targets are imaged with PTZ (pan, tilt, zoom cameras by coordinate transformation. The feasibility and effectiveness of the proposed method are verified by test site experiments and actual line experiments, respectively. The proposed method greatly reduces manpower and improves inspection accuracy, providing a theoretical basis for intelligent inspection of transmission lines in the future.
Wang, Lei; Fan, Youping; Zhang, Dai; Ge, Mengxin; Zou, Xianbin; Li, Jingjiao
2017-09-01
This paper proposes a method to simulate a back-to-back modular multilevel converter (MMC) HVDC transmission system. In this paper we utilize an equivalent networks to simulate the dynamic power system. Moreover, to account for the performance of converter station, core components of model of the converter station gives a basic model of simulation. The proposed method is applied to an equivalent real power system.
International Nuclear Information System (INIS)
Tian Lifang; Wen Mingfen; Li Linyan; Chen Jing
2009-01-01
Electrochemical method with salt as electrolyte has been studied to disintegrate the graphite matrix from the simulative high temperature gas-cooled reactor fuel elements. Ammonium nitrate was experimentally chosen as the appropriate electrolyte. The volume average diameter of disintegrated graphite fragments is about 100 μm and the maximal value is less than 900 μm. After disintegration, the weight of graphite is found to increase by about 20% without the release of a large amount of CO 2 probably owing to the partial oxidation to graphite in electrochemical process. The present work indicates that the improved electrochemical method has the potential to reduce the secondary nuclear waste and is a promising option to disintegrate graphite matrix from high temperature gas-cooled reactor spent fuel elements in the head-end of reprocessing.
Banker, J.G.; Anderson, R.C.
1975-10-21
A method and apparatus are provided for preparing a composite structure consisting of filamentary material within a metal matrix. The method is practiced by the steps of confining the metal for forming the matrix in a first chamber, heating the confined metal to a temperature adequate to effect melting thereof, introducing a stream of inert gas into the chamber for pressurizing the atmosphere in the chamber to a pressure greater than atmospheric pressure, confining the filamentary material in a second chamber, heating the confined filamentary material to a temperature less than the melting temperature of the metal, evacuating the second chamber to provide an atmosphere therein at a pressure, placing the second chamber in registry with the first chamber to provide for the forced flow of the molten metal into the second chamber to effect infiltration of the filamentary material with the molten metal, and thereafter cooling the metal infiltrated-filamentary material to form said composite structure.
Energy Technology Data Exchange (ETDEWEB)
Park, M.G.; Kim, Y.H.; Cha, K.H.; Kim, M.K. [Korea Electric Power Research Institute, Taejon (Korea)
1999-07-01
A method is described to develop and H{infinity} filtering method for the dynamic compensation of self-powered neutron detectors normally used for fixed incore instruments. An H{infinity} norm of the filter transfer matrix is used as the optimization criteria in the worst-case estimation error sense. Filter modeling is performed for both continuous- and discrete-time models. The filter gains are optimized in the sense of noise attenuation level of H{infinity} setting. By introducing Bounded Real Lemma, the conventional algebraic Riccati inequalities are converted into Linear Matrix Inequalities (LMIs). Finally, the filter design problem is solved via the convex optimization framework using LMIs. The simulation results show that remarkable improvements are achieved in view of the filter response time and the filter design efficiency. (author). 15 refs., 4 figs., 3 tabs.
International Nuclear Information System (INIS)
Banker, J.G.; Anderson, R.C.
1975-01-01
A method and apparatus are provided for preparing a composite structure consisting of filamentary material within a metal matrix. The method is practiced by the steps of confining the metal for forming the matrix in a first chamber, heating the confined metal to a temperature adequate to effect melting thereof, introducing a stream of inert gas into the chamber for pressurizing the atmosphere in the chamber to a pressure greater than atmospheric pressure, confining the filamentary material in a second chamber, heating the confined filamentary material to a temperature less than the melting temperature of the metal, evacuating the second chamber to provide an atmosphere therein at a pressure, placing the second chamber in registry with the first chamber to provide for the forced flow of the molten metal into the second chamber to effect infiltration of the filamentary material with the molten metal, and thereafter cooling the metal infiltrated-filamentary material to form said composite structure
Use of risk-matrix methods in the radiation safety analysis of PET/CT facilities
International Nuclear Information System (INIS)
Calderón Marín, Carlos F.; González González, Joaquín J.; Quesada Cepero, Waldo; Sinconegui Gómez, Belkys; Solá Rodríguez, Yeline; Duménigo Ámbar, Cruz; Guerrero Cancio, Mayka
2016-01-01
Introduction. Radiological safety is essential during clinical applications of ionizing radiations. Cuban legislation considers it mandatory to carry out risk analysis during safety assessments of facilities where Nuclear Medicine practices are performed. The Risk Matrix (R-M) method has been used in risk assessments in Radiotherapy and some experiences in Nuclear Medicine have been reported. In the present work the results of the safety evaluation, using the M-R method, of the first PET / CT center constructed at the Institute of Oncology and Radiobiology in Havana, are shown. The facilities will work as a satellite center and the production of radioactive drugs of 68 Ga will be conceived. The images will be acquired with a Philips Gemini TF64 scanner. Several stages and sub-stages were considered, including the design of the facility, quality control programs, review of the relevance of study requests, radiopharmaceutical reception and fractionation, 68 Ga radiopharmaceuticals production, management of Patient during the administration of radiopharmaceuticals and patient positioning. Initiating events (IEs), available barriers, as well as measures for the reduction of frequency (RFMs) of IEs and consequences (RCMs) were identified. In addition, IEs sequences are considered for CT scans. The incidence of risk reduction was assessed by the ratio of the number of times they were used and the total number of IEs. The calculation of the R-M was made by modeling the practice with the SEVRRA code R iskAssessmentSystem . Results. As a result, 76 IEs were identified with a distribution of 72% affecting patients, 7.9% in the Public and 19.7% on Occupationally Exposed Workers (TOEs). 89.5% of IEs are caused by human errors. Barriers and consequences and frequency reducers produced a risk distribution of 2.6% of high risk IEs, 64.5% medium risk and 32.9% low risk. The high-risk IEs are related to errors in the calculation of the shielding requirements of the facility that
A Bayesian method for inferring transmission chains in a partially observed epidemic.
Energy Technology Data Exchange (ETDEWEB)
Marzouk, Youssef M.; Ray, Jaideep
2008-10-01
We present a Bayesian approach for estimating transmission chains and rates in the Abakaliki smallpox epidemic of 1967. The epidemic affected 30 individuals in a community of 74; only the dates of appearance of symptoms were recorded. Our model assumes stochastic transmission of the infections over a social network. Distinct binomial random graphs model intra- and inter-compound social connections, while disease transmission over each link is treated as a Poisson process. Link probabilities and rate parameters are objects of inference. Dates of infection and recovery comprise the remaining unknowns. Distributions for smallpox incubation and recovery periods are obtained from historical data. Using Markov chain Monte Carlo, we explore the joint posterior distribution of the scalar parameters and provide an expected connectivity pattern for the social graph and infection pathway.
Application of molecular methods for monitoring transmission stages of malaria parasites
International Nuclear Information System (INIS)
Babiker, Hamza A; Schneider, Petra
2008-01-01
Recent technical advances in malaria research have allowed specific detection of mRNA of genes that are expressed exclusively in sexual stages (gametocytes) of malaria parasites. The specificity and sensitivity of these techniques were validated on cultured laboratory clones of both human malaria parasites (Plasmodium falciparum) and rodent parasites (P. chabaudi). More recently, quantitative molecular techniques have been developed to quantify these sexual stages and used to monitor gametocyte dynamics and their transmission to mosquitoes. Molecular techniques showed that the infectious reservoir for malaria is larger than expected from previous microscopic studies; individual parasite genotypes within an infection can simultaneously produce infectious gametocytes; gametocyte production can be sustained for several months, and is modulated by environmental factors. The above techniques have empowered approaches for in-depth analysis of the biology of the transmission stages of the parasite and epidemiology of malaria transmission
Rodgers, M. Steven; Sniegowski, Jeffry J.; Miller, Samuel L.; McWhorter, Paul J.
2000-01-01
A process for forming complex microelectromechanical (MEM) devices having five layers or levels of polysilicon, including four structural polysilicon layers wherein mechanical elements can be formed, and an underlying polysilicon layer forming a voltage reference plane. A particular type of MEM device that can be formed with the five-level polysilicon process is a MEM transmission for controlling or interlocking mechanical power transfer between an electrostatic motor and a self-assembling structure (e.g. a hinged pop-up mirror for use with an incident laser beam). The MEM transmission is based on an incomplete gear train and a bridging set of gears that can be moved into place to complete the gear train to enable power transfer. The MEM transmission has particular applications as a safety component for surety, and for this purpose can incorporate a pin-in-maze discriminator responsive to a coded input signal.
Energy Technology Data Exchange (ETDEWEB)
Rodgers, M.S.; Sniegowski, J.J.; Miller, S.L.; McWhorter, P.J.
2000-07-04
A process is disclosed for forming complex microelectromechanical (MEM) devices having five layers or levels of polysilicon, including four structural polysilicon layers wherein mechanical elements can be formed, and an underlying polysilicon layer forming a voltage reference plane. A particular type of MEM device that can be formed with the five-level polysilicon process is a MEM transmission for controlling or interlocking mechanical power transfer between an electrostatic motor and a self-assembling structure (e.g. a hinged pop-up mirror for use with an incident laser beam). The MEM transmission is based on an incomplete gear train and a bridging set of gears that can be moved into place to complete the gear train to enable power transfer. The MEM transmission has particular applications as a safety component for surety, and for this purpose can incorporate a pin-in-maze discriminator responsive to a coded input signal.
A new method for soldering particle-reinforced aluminum metal matrix composites
Energy Technology Data Exchange (ETDEWEB)
Lu, Jinbin; Mu, Yunchao [Zhongyuan University of Technology, Zhengzhou 450007 (China); Luo, Xiangwei [Zhengzhou University, Zhengzhou 450002 (China); Niu, Jitai, E-mail: niujitai@163.com [Zhongyuan University of Technology, Zhengzhou 450007 (China)
2012-12-01
Highlights: Black-Right-Pointing-Pointer Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. Black-Right-Pointing-Pointer The nickel plating is required on the surface of the composites before soldering. Black-Right-Pointing-Pointer Low welding temperature is set to avoid overheating of the matrix. Black-Right-Pointing-Pointer Chemical and metallurgical bonding of composites and Kovar is carried out. Black-Right-Pointing-Pointer High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al-SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe-Ni-Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn-Cd-Ag-Cu) with a melting point of about 400 Degree-Sign C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)-Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al-SiC composite.
A new method for soldering particle-reinforced aluminum metal matrix composites
International Nuclear Information System (INIS)
Lu, Jinbin; Mu, Yunchao; Luo, Xiangwei; Niu, Jitai
2012-01-01
Highlights: ► Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. ► The nickel plating is required on the surface of the composites before soldering. ► Low welding temperature is set to avoid overheating of the matrix. ► Chemical and metallurgical bonding of composites and Kovar is carried out. ► High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al–SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe–Ni–Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn–Cd–Ag–Cu) with a melting point of about 400 °C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)–Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al–SiC composite.
Shimada, Wataru
In order to bring up talented people, it is a most important subject how to awake ‘Emotional Human Power’ , which is the origin of Autonomy and Creativity. A Practical Method ‘Discussion using Matrix Diagram’ developed for improving ‘Emotional Human Power’ including ‘Communication Skill’ , is confirmed to be useful for connecting Human Base-Liberal-and Engineering Base-Professional-.
Radiating nonuniform transmission-line systems and the partial element equivalent circuit method
Nitsch, Juergen; Wollenberg, Gunter
2009-01-01
High frequencies of densely packed modern electronic equipment turn even the smallest piece of wire into a transmission line with signal retardation, dispersion, attenuation, and distortion. In electromagnetic environments with high-power microwave or ultra-wideband sources, transmission lines pick up noise currents generated by external electromagnetic fields. These are superimposed on essential signals, the lines acting not only as receiving antennas but radiating parts of the signal energy into the environment. This book is outstanding in its originality. While many textbooks rephrase
Analysis of carburizing steel with lath bainite in matrix by magnetic method
Directory of Open Access Journals (Sweden)
Weiwu ZOU
2017-12-01
Full Text Available The cryogenic treatment is used to reduce the large amount of retained austenite in the steel infiltration layer which affects the hardness. The vibrating sample magnetometer (VSM and direct reading spectroscopy are combined to compare and analyze the organization structure status of the test carburizing steel after air-cooling and low temperature tempering (T at 453 K × 1 h, or after cryogenic treatment at 113 K × 30 min and low temperature tempering (T at 453 K × 1 h. The cryopreservation effect of the 1 203 K × 9 h carburizing air-cooled bainitic steel is carried out. The results show that both the effective hardening layer depths are about 1.35 mm. The retained austenite mass fractions of T and CT in the effective hardened layer are approximately 29.8% and 12.6%, respectively, and the highest hardnesses of the effective hardened layer of T and CT are 679 HV and 821 HV, respectively. The matrix structure is lath bainite, and the retained austenite mass fractions in the matrix are approximately 7.4% for T and 6.9% for CT, respectively, and both the hardnesses of the matrixes are approximately 430 HV. After the cryogenic treatment, the austenite content in the infiltration layer is effectively reduced, so that the maximum hardness of the hardened layer increases by 20% or more. It can be widely used because of the decreased material cost and remarkable economical benefit.
Bisetti, Fabrizio
2012-06-01
Recent trends in hydrocarbon fuel research indicate that the number of species and reactions in chemical kinetic mechanisms is rapidly increasing in an effort to provide predictive capabilities for fuels of practical interest. In order to cope with the computational cost associated with the time integration of stiff, large chemical systems, a novel approach is proposed. The approach combines an exponential integrator and Krylov subspace approximations to the exponential function of the Jacobian matrix. The components of the approach are described in detail and applied to the ignition of stoichiometric methane-air and iso-octane-air mixtures, here described by two widely adopted chemical kinetic mechanisms. The approach is found to be robust even at relatively large time steps and the global error displays a nominal third-order convergence. The performance of the approach is improved by utilising an adaptive algorithm for the selection of the Krylov subspace size, which guarantees an approximation to the matrix exponential within user-defined error tolerance. The Krylov projection of the Jacobian matrix onto a low-dimensional space is interpreted as a local model reduction with a well-defined error control strategy. Finally, the performance of the approach is discussed with regard to the optimal selection of the parameters governing the accuracy of its individual components. © 2012 Copyright Taylor and Francis Group, LLC.
Keow, Jonathan Y; Herrmann, Kurt M; Crawford, Bryan D
2011-04-01
Investigations into the molecular mechanisms of, and cellular signaling pathways modulating ECM remodeling are especially challenging due to the complex post-translational regulation of the primary effectors of ECM catabolism - the matrix metalloproteinases (MMPs). Recently a variety of approaches to the detection of MMP activity have been developed, and the prospect of visualizing ECM remodeling activity in living tissues is now opening exciting avenues of research for matrix biologists. In particular the use of FRET-quenched MMP substrates, which generate a fluorescent signal upon hydrolysis, is becoming increasingly popular, especially because linkers with defined and/or restricted proteolytic sensitivity can be used to bind fluorophore-quencher pairs, making these probes useful in characterizing the activity of specific proteases. We have taken advantage of the transparency and amenability to reverse genetics of the zebrafish embryo, in combination with these fluorogenic MMP substrates, to develop a multiplex in vivo assay for MMP activity that we dub "differential in vivo zymography." Copyright © 2011 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.
Bolourchian, Noushin; Rangchian, Maryam; Foroutan, Seyed Mohsen
2012-07-01
The aim of this study was to design and optimize a prolonged release matrix formulation of pyridostigmine bromide, an effective drug in myasthenia gravis and poisoning with nerve gas, using hydrophilic - hydrophobic polymers via D-optimal experimental design. HPMC and carnauba wax as retarding agents as well as tricalcium phosphate were used in matrix formulation and considered as independent variables. Tablets were prepared by wet granulation technique and the percentage of drug released at 1 (Y(1)), 4 (Y(2)) and 8 (Y(3)) hours were considered as dependent variables (responses) in this investigation. These experimental responses were best fitted for the cubic, cubic and linear models, respectively. The optimal formulation obtained in this study, consisted of 12.8 % HPMC, 24.4 % carnauba wax and 26.7 % tricalcium phosphate, had a suitable prolonged release behavior followed by Higuchi model in which observed and predicted values were very close. The study revealed that D-optimal design could facilitate the optimization of prolonged release matrix tablet containing pyridostigmine bromide. Accelerated stability studies confirmed that the optimized formulation remains unchanged after exposing in stability conditions for six months.
Takiya, C; Peyrol, S; Cordier, J F; Grimaud, J A
1983-01-01
In the interstitium of the alveolar septa in the peripheral parts of the lung, four molecular types of collagen (I, III, IV and V) each with different morphological appearances, can be identified. The structural integrity of collagens accounts for the physiological efficiency of the lung. Fibrous thickening of alveolar septa is an invariable result of various diseases affecting the interstitium of the lung. The light and electron microscopic findings, and the immunological typing of collagens in six cases of fibrotic alveolar disease, are described. In the alveolar septa, two different compartments (the alveolo-capillary junction and the supportive axis) were affected by fibrosis: the alveolo-capillary junction was widened by the addition of interstitial collagens to basement membranes. In the axis, the increase of interstitial (types I and III) collagen gave rise to different patterns of connective matrix organization, graded as Loose or Dense depending on quantitative alterations of the type I/III ratio. The mode of organization of the fibrotic lung connective matrix, which depends on the quality of deposits in the matrix, may be correlated with the evolution of interstitial pulmonary fibrosis, in terms of its stability, remodelling ability and reversibility.
Directory of Open Access Journals (Sweden)
Hai-gen Yang
2015-09-01
Full Text Available The complex mechanical systems such as high-speed trains, multiple launch rocket system, self-propelled artillery, and industrial robots are becoming increasingly larger in scale and more complicated in structure. Designing these products often requires complex model design, multibody system dynamics calculation, and analysis of large amounts of data repeatedly. In recent 20 years, the transfer matrix method of multibody system has been widely applied in engineering fields and welcomed at home and in abroad for the following features: without global dynamic equations of the system, low orders of involved system matrices, high computational efficiency, and high programming. In order to realize the rapid and visual simulation for complex mechanical system virtual design using transfer matrix method of multibody system, a virtual design software named MSTMMSim is designed and implemented. In the MSTMMSim, the transfer matrix method of multibody system is used as the solver for dynamic modeling and calculation; the Open CASCADE is used for solid geometry modeling. Various auxiliary analytical tools such as curve plot and animation display are provided in the post-processor to analyze and process the simulation results. Two numerical examples are given to verify the validity and accuracy of the software, and a multiple launch rocket system engineering example is given at the end of this article to show that the software provides a powerful platform for complex mechanical systems simulation and virtual design.
Reflection Matrix Method for Controlling Light After Reflection From a Diffuse Scattering Surface
2016-12-22
of Philosophy Kenneth W. Burgi, BS, MS Major, USAF 22 December 2016 DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT...refocusing light through thin films of a turbid medium. When coherent light is trans- mitted through a stationary diffuser (i.e. a turbid medium), a fine...resultant light scatter [14, 15, 21, 23]. Transmission matrices were measured with microscopic objectives and thin films of turbid media, resulting in
International Nuclear Information System (INIS)
Meor Yusoff Meor Sulaiman; Masliana Muhammad; Wilfred, P.
2013-01-01
Even though EDXRF analysis has major advantages in the analysis of stainless steel samples such as simultaneous determination of the minor elements, analysis can be done without sample preparation and non-destructive analysis, the matrix issue arise from the inter element interaction can make the the final quantitative result to be in accurate. The paper relates a comparative quantitative analysis using standard and standard less methods in the determination of these elements. Standard method was done by plotting regression calibration graphs of the interested elements using BCS certified stainless steel standards. Different calibration plots were developed based on the available certified standards and these stainless steel grades include low alloy steel, austenitic, ferritic and high speed. The standard less method on the other hand uses a mathematical modelling with matrix effect correction derived from Lucas-Tooth and Price model. Further improvement on the accuracy of the standard less method was done by inclusion of pure elements into the development of the model. Discrepancy tests were then carried out for these quantitative methods on different certified samples and the results show that the high speed method is most reliable for determining of Ni and the standard less method for Mn. (Author)
Optical modeling of fiber organic photovoltaic structures using a transmission line method.
Moshonas, N; Stathopoulos, N A; O'Connor, B T; Bedeloglu, A Celik; Savaidis, S P; Vasiliadis, S
2017-12-01
An optical model has been developed and evaluated for the calculation of the external quantum efficiency of cylindrical fiber photovoltaic structures. The model is based on the transmission line theory and has been applied on single and bulk heterojunction fiber-photovoltaic cells. Using this model, optimum design characteristics have been proposed for both configurations, and comparison with experimental results has been assessed.
International Nuclear Information System (INIS)
Sakaguchi, K; Yamashita, S; Yamamoto, K; Nishio, T; Morikura, M; Huang, Y; Shinohara, N
2014-01-01
This paper proposes to improve effectiveness of supplying a sensor with energy using microwave power transmission (MPT) and energy harvesting (EH). The MPT duration should be as short as possible to avoid serious interference between the MPT and wireless local area network data transmission when co-channel operation of both microwave power transmission (MPT) and wireless data transmissions is performed. To shorten the MPT duration, we use multiple power sources such as an MPT source and an EH source to supply a sensor with power. Here, an overcharge or an energy shortage could occur at the sensor if the power supplied by both the MPT and EH sources is not adjusted appropriately. To solve this problem, the power supplied by multiple sources should be estimated precisely. In this paper, we propose a scheme for estimating the power supplied by multiple sources on the basis of an existing MPT scheduling system and then conducted an experiment using the scheme. From the experimental results, it is confirmed to estimate the power supplied by multiple sources successfully. In addition, the required MPT duration when the EH source is used is reduced compared to that when it is not used. Moreover, it is confirmed that the sensor station successfully estimates the power supplied by an MPT source and that by an EH source and adequately configures the MPT duration
Transmission problem for the Laplace equation and the integral equation method
Czech Academy of Sciences Publication Activity Database
Medková, Dagmar
2012-01-01
Roč. 387, č. 2 (2012), s. 837-843 ISSN 0022-247X Institutional research plan: CEZ:AV0Z10190503 Keywords : transmission problem * Laplace equation * boundary integral equation Subject RIV: BA - General Mathematics Impact factor: 1.050, year: 2012 http://www.sciencedirect.com/science/article/pii/S0022247X11008985
Selection of methods for evaluating the cost of transmission wheeling services
International Nuclear Information System (INIS)
Happ, H.H.
1995-01-01
Wheeling has been defined as the use of a utility's transmission facilities to transmit power for other buyers and sellers. On October 26, 1994, the Federal Energy Regulatory Commission (FERC) announced a POLICY STATEMENT, concerning the Commission's Pricing transmission services. It follows a Pricing inquiry conducted by FERC in 1993, and an analysis of the 165 responses FERC had received to that inquiry including one from the Department with which this author is associated. The single most important new element introduced in FERC's Policy Statement of October 26, is flexibility in methodologies which are allowed for determining costs and, thus, prices for transmission services. FERC stated that the respondents to the Pricing Inquiry of 1993 almost unanimously requested that the Commission allow such flexibility. The Policy Statement may lead to experimentation on the part of users of transmission systems, to determine the magnitude of costs predicted by various cost of wheeling methodologies. It is the objective of this paper to outline the steps which New York State has taken and started over five years ago, in executing an investigation of wheeling costs which are generated by a number of cost of wheeling methodologies; documents which are available will be indicated, which should help other investigators in the execution of a similar study. A summary of FERC's Policy Statement dated October 26, 1994 appears in the Appendix
Tian, Liang
This study investigated the processing-structure-properties relationships in an Al/Ca composites using both experiments and modeling/simulation. A particular focus of the project was understanding how the strength and electrical conductivity of the composite are related to its microstructure in the hope that a conducting material with light weight, high strength, and high electrical conductivity can be developed to produce overhead high-voltage power transmission cables. The current power transmission cables (e.g., Aluminum Conductor Steel Reinforced (ACSR)) have acceptable performance for high-voltage AC transmission, but are less well suited for high-voltage DC transmission due to the poorly conducting core materials that support the cable weight. This Al/Ca composite was produced by powder metallurgy and severe plastic deformation by extrusion and swaging. The fine Ca metal powders have been produced by centrifugal atomization with rotating liquid oil quench bath, and a detailed study about the atomization process and powder characteristics has been conducted. The microstructure of Al/Ca composite was characterized by electron microscopy. Microstructure changes at elevated temperature were characterized by thermal analysis and indirect resistivity tests. The strength and electrical conductivity were measured by tensile tests and four-point probe resistivity tests. Predicting the strength and electrical conductivity of the composite was done by micro-mechanics-based analytical modeling. Microstructure evolution was studied by mesoscale-thermodynamics-based phase field modeling and a preliminary atomistic molecular dynamics simulation. The application prospects of this composite was studied by an economic analysis. This study suggests that the Al/Ca (20 vol. %) composite shows promise for use as overhead power transmission cables. Further studies are needed to measure the corrosion resistance, fatigue properties and energized field performance of this composite.
Takahashi, Tomoko; Thornton, Blair
2017-12-01
This paper reviews methods to compensate for matrix effects and self-absorption during quantitative analysis of compositions of solids measured using Laser Induced Breakdown Spectroscopy (LIBS) and their applications to in-situ analysis. Methods to reduce matrix and self-absorption effects on calibration curves are first introduced. The conditions where calibration curves are applicable to quantification of compositions of solid samples and their limitations are discussed. While calibration-free LIBS (CF-LIBS), which corrects matrix effects theoretically based on the Boltzmann distribution law and Saha equation, has been applied in a number of studies, requirements need to be satisfied for the calculation of chemical compositions to be valid. Also, peaks of all elements contained in the target need to be detected, which is a bottleneck for in-situ analysis of unknown materials. Multivariate analysis techniques are gaining momentum in LIBS analysis. Among the available techniques, principal component regression (PCR) analysis and partial least squares (PLS) regression analysis, which can extract related information to compositions from all spectral data, are widely established methods and have been applied to various fields including in-situ applications in air and for planetary explorations. Artificial neural networks (ANNs), where non-linear effects can be modelled, have also been investigated as a quantitative method and their applications are introduced. The ability to make quantitative estimates based on LIBS signals is seen as a key element for the technique to gain wider acceptance as an analytical method, especially in in-situ applications. In order to accelerate this process, it is recommended that the accuracy should be described using common figures of merit which express the overall normalised accuracy, such as the normalised root mean square errors (NRMSEs), when comparing the accuracy obtained from different setups and analytical methods.
Shin, Sangmun; Choi, Du Hyung; Truong, Nguyen Khoa Viet; Kim, Nam Ah; Chu, Kyung Rok; Jeong, Seong Hoon
2011-04-04
A new experimental design methodology was developed by integrating the response surface methodology and the time series modeling. The major purposes were to identify significant factors in determining swelling and release rate from matrix tablets and their relative factor levels for optimizing the experimental responses. Properties of tablet swelling and drug release were assessed with ten factors and two default factors, a hydrophilic model drug (terazosin) and magnesium stearate, and compared with target values. The selected input control factors were arranged in a mixture simplex lattice design with 21 experimental runs. The obtained optimal settings for gelation were PEO, LH-11, Syloid, and Pharmacoat with weight ratios of 215.33 (88.50%), 5.68 (2.33%), 19.27 (7.92%), and 3.04 (1.25%), respectively. The optimal settings for drug release were PEO and citric acid with weight ratios of 191.99 (78.91%) and 51.32 (21.09%), respectively. Based on the results of matrix swelling and drug release, the optimal solutions, target values, and validation experiment results over time were similar and showed consistent patterns with very small biases. The experimental design methodology could be a very promising experimental design method to obtain maximum information with limited time and resources. It could also be very useful in formulation studies by providing a systematic and reliable screening method to characterize significant factors in the sustained release matrix tablet. Copyright © 2011 Elsevier B.V. All rights reserved.
Positron collisions with acetylene calculated using the R-matrix with pseudo-states method
Zhang, Rui; Galiatsatos, Pavlos G.; Tennyson, Jonathan
2011-10-01
Eigenphase sums, total cross sections and differential cross sections are calculated for low-energy collisions of positrons with C2H2. The calculations demonstrate that the use of appropriate pseudo-state expansions very significantly improves the representation of this process giving both realistic eigenphases and cross sections. Differential cross sections are strongly forward peaked in agreement with the measurements. These calculations are computationally very demanding; even with improved procedures for matrix diagonalization, fully converged calculations are too expensive with current computer resources. Nonetheless, the calculations show clear evidence for the formation of a virtual state but no indication that acetylene actually binds a positron at its equilibrium geometry.
Matrix Analytic Methods in Applied Probability with a View towards Engineering Applications
DEFF Research Database (Denmark)
Nielsen, Bo Friis
contributions and a summary introductory paper. The outline of the summary is as follows. The class of MAPs and the related class of Phase Type (PH) distributions belong to the slightly larger classes of what have been termed Rational Arrival Processes (RAP) and Matrix Exponential (ME) distributions......-trivial mathematical and theoretical questions. If just some of these problems can be solved satisfactorily it will pave the way for a huge application potential, and it is very likely that the distributions can and will be useful in statistical analysis too. The research on multivariate distributions lead...
International Nuclear Information System (INIS)
Yoriyaz, H.
1986-01-01
In this work a spatial burnup scheme and feedback effects has been implemented into the FERM ( 'Finite Element Response Matrix' )program. The spatially dependent neutronic parameters have been considered in three levels: zonewise calculation, assembly wise calculation and pointwise calculation. Flux and power distributions and the multiplication factor were calculated and compared with the results obtained by CITATIOn program. These comparisons showed that processing time in the Ferm code has been hundred of times shorter and no significant difference has been observed in the assembly average power distribution. (Author) [pt
International Nuclear Information System (INIS)
Badalov, S.A.; Filippov, G.F.
1986-01-01
The receipts to calculate the generating matrix elements of the algebraic version of resonating group method (RGM) are given for two- and three-cluster nucleon systems, the center of mass motion being separeted exactly. For the Hamiltonian with Gaussian nucleon-nucleon potential dependence the generating matrix elements of the RGM algebraic version can be written down explictly if matrix elements of the corresponding system on wave functions of the Brink cluster model are known
Energy Technology Data Exchange (ETDEWEB)
Mansur, Ralph S.; Moura, Carlos A., E-mail: ralph@ime.uerj.br, E-mail: demoura@ime.uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Departamento de Engenharia Mecanica; Barros, Ricardo C., E-mail: rcbarros@pq.cnpq.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Departamento de Modelagem Computacional
2017-07-01
Presented here is an application of the Response Matrix (RM) method for adjoint discrete ordinates (S{sub N}) problems in slab geometry applied to energy-dependent source-detector problems. The adjoint RM method is free from spatial truncation errors, as it generates numerical results for the adjoint angular fluxes in multilayer slabs that agree with the numerical values obtained from the analytical solution of the energy multigroup adjoint SN equations. Numerical results are given for two typical source-detector problems to illustrate the accuracy and the efficiency of the offered RM computer code. (author)
Due diligence in the characterization of matrix effects in a total IL-13 Singulex™ method.
Fraser, Stephanie; Soderstrom, Catherine
2014-04-01
After obtaining her PhD in Cellular and Molecular biology from the University of Nevada, Reno, Stephanie has spent the last 15 years in the field of bioanalysis. She has held positions in academia, biotech, contract research and large pharma where she has managed ligand binding assay (discovery to Phase IIb clinical) and flow cytometry (preclinical) laboratories as well as taken the lead on implementing new/emergent technologies. Currently Stephanie leads Pfizer's Regulated Bioanalysis Ligand Binding Assay group, focusing on early clinical biomarker support. Interleukin (IL)-13, a Th2 cytokine, drives a range of physiological responses associated with the induction of allergic airway diseases and inflammatory bowel diseases. Analysis of IL-13 as a biomarker has provided insight into its role in disease mechanisms and progression. Serum IL-13 concentrations are often too low to be measured by standard enzyme-linked immunosorbent assay techniques, necessitating the implementation of a highly sensitive assay. Previously, the validation of a Singulex™ Erenna(®) assay for the quantitation of IL-13 was reported. Herein we describe refinement of this validation; defining the impact of matrix interference on the lower limit of quantification, adding spiked matrix QC samples, and extending endogenous IL-13 stability. A fit-for-purpose validation was conducted and the assay was used to support a Phase II clinical trial.
International Nuclear Information System (INIS)
Dubois, J.; Calvin, Ch.; Dubois, J.; Petiton, S.
2011-01-01
This paper presents a parallelized hybrid single-vector Arnoldi algorithm for computing approximations to Eigen-pairs of a nonsymmetric matrix. We are interested in the use of accelerators and multi-core units to speed up the Arnoldi process. The main goal is to propose a parallel version of the Arnoldi solver, which can efficiently use multiple multi-core processors or multiple graphics processing units (GPUs) in a mixed coarse and fine grain fashion. In the proposed algorithms, this is achieved by an auto-tuning of the matrix vector product before starting the Arnoldi Eigen-solver as well as the reorganization of the data and global communications so that communication time is reduced. The execution time, performance, and scalability are assessed with well-known dense and sparse test matrices on multiple Nehalems, GT200 NVidia Tesla, and next generation Fermi Tesla. With one processor, we see a performance speedup of 2 to 3x when using all the physical cores, and a total speedup of 2 to 8x when adding a GPU to this multi-core unit, and hence a speedup of 4 to 24x compared to the sequential solver. (authors)
Measurement of single top quark production at D0 using a matrix element method
International Nuclear Information System (INIS)
Mitrevski, Jovan Pavle
2007-01-01
Until now, the top quark has only been observed produced in pairs, by the strong force. According to the standard model, it can also be produced singly, via an electroweak interaction. Top quarks produced this way provide powerful ways to test the charged-current electroweak interactions of the top quark, to measure |V tb |, and to search for physics beyond the standard model. This thesis describes the application of the matrix element analysis technique to the search for single top quark production with the D0 detector using 0.9 fb -1 of Run II data. From a comparison of the matrix element discriminants between data and the background model, assuming a Standard Model s-channel to t-channel cross section ratio of σ s /σ t = 0.44, we measure the single top quark production cross section: σ(p(bar p) → tb + X, tqb + X) = 4.8 -1.4 +1.6 pb. This result has a p-value of 0.08%, corresponding to a 3.2 standard deviation Gaussian equivalent significance
Shi, Yingzhong; Chung, Fu-Lai; Wang, Shitong
2015-09-01
Recently, a time-adaptive support vector machine (TA-SVM) is proposed for handling nonstationary datasets. While attractive performance has been reported and the new classifier is distinctive in simultaneously solving several SVM subclassifiers locally and globally by using an elegant SVM formulation in an alternative kernel space, the coupling of subclassifiers brings in the computation of matrix inversion, thus resulting to suffer from high computational burden in large nonstationary dataset applications. To overcome this shortcoming, an improved TA-SVM (ITA-SVM) is proposed using a common vector shared by all the SVM subclassifiers involved. ITA-SVM not only keeps an SVM formulation, but also avoids the computation of matrix inversion. Thus, we can realize its fast version, that is, improved time-adaptive core vector machine (ITA-CVM) for large nonstationary datasets by using the CVM technique. ITA-CVM has the merit of asymptotic linear time complexity for large nonstationary datasets as well as inherits the advantage of TA-SVM. The effectiveness of the proposed classifiers ITA-SVM and ITA-CVM is also experimentally confirmed.
Energy Technology Data Exchange (ETDEWEB)
Toh, K.C.; Trefethen, L.N. [Cornell Univ., Ithaca, NY (United States)
1994-12-31
What properties of a nonsymmetric matrix A determine the convergence rate of iterations such as GMRES, QMR, and Arnoldi? If A is far from normal, should one replace the usual Ritz values {r_arrow} eigenvalues notion of convergence of Arnoldi by alternative notions such as Arnoldi lemniscates {r_arrow} pseudospectra? Since Krylov subspace iterations can be interpreted as minimization processes involving polynomials of matrices, the answers to questions such as these depend upon mathematical problems of the following kind. Given a polynomial p(z), how can one bound the norm of p(A) in terms of (1) the size of p(z) on various sets in the complex plane, and (2) the locations of the spectrum and pseudospectra of A? This talk reports some progress towards solving these problems. In particular, the authors present theorems that generalize the Kreiss matrix theorem from the unit disk (for the monomial A{sup n}) to a class of general complex domains (for polynomials p(A)).
Degirmenci, Elif; Landais, Pascal
2013-10-20
Photonic band gap and transmission characteristics of 2D metallic photonic crystals at THz frequencies have been investigated using finite element method (FEM). Photonic crystals composed of metallic rods in air, in square and triangular lattice arrangements, are considered for transverse electric and transverse magnetic polarizations. The modes and band gap characteristics of metallic photonic crystal structure are investigated by solving the eigenvalue problem over a unit cell of the lattice using periodic boundary conditions. A photonic band gap diagram of dielectric photonic crystal in square lattice array is also considered and compared with well-known plane wave expansion results verifying our FEM approach. The photonic band gap designs for both dielectric and metallic photonic crystals are consistent with previous studies obtained by different methods. Perfect match is obtained between photonic band gap diagrams and transmission spectra of corresponding lattice structure.
Fleming, K. M.; Zschau, J.; Gasparini, P.; Modaressi, H.; Matrix Consortium
2011-12-01
Scientists, engineers, civil protection and disaster managers typically treat natural hazards and risks individually. This leads to the situation where the frequent causal relationships between the different hazards and risks, e.g., earthquakes and volcanos, or floods and landslides, are ignored. Such an oversight may potentially lead to inefficient mitigation planning. As part of their efforts to confront this issue, the European Union, under its FP7 program, is supporting the New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe or MATRIX project. The focus of MATRIX is on natural hazards, in particular earthquakes, landslides, volcanos, wild fires, storms and fluvial and coastal flooding. MATRIX will endeavour to develop methods and tools to tackle multi-type natural hazards and risks within a common framework, focusing on methodologies that are suited to the European context. The work will involve an assessment of current single-type hazard and risk assessment methodologies, including a comparison and quantification of uncertainties and harmonization of single-type methods, examining the consequence of cascade effects within a multi-hazard environment, time-dependent vulnerability, decision making and support for multi-hazard mitigation and adaption, and a series of test cases. Three test sites are being used to assess the methods developed within the project (Naples, Cologne, and the French West Indies), as well as a "virtual city" based on a comprehensive IT platform that will allow scenarios not represented by the test cases to be examined. In addition, a comprehensive dissemination program that will involve national platforms for disaster management, as well as various outreach activities, will be undertaken. The MATRIX consortium consists of ten research institutions (nine European and one Canadian), an end-user (i.e., one of the European national platforms for disaster reduction) and a partner from industry.
New method of transmission of substances through membranes with nuclear tracks
International Nuclear Information System (INIS)
Fernandez, M.A.; Gutierrez, M.C.; Magni, M.; Celma, G.; Mazzei, Ruben; Garcia Bermudez, Gerardo; Torres, A.
2007-01-01
In order to produce membranes with pores that react selectively to changes in the environment allowing the transmission of substances and continuing with a systematic study that include different polymers and monomers, the residual active sites produced by heavy ion beams, that remain after the etching process, were used to start the grafting process. To produce tracks, foils of polypropylene (PP) were irradiated with 208 Pb of 25.62 MeV/n. Then were etched and grafted with acrylic acid (AA) monomer. Experimental curves of grafting yield as a function of grafting time with the etching time as a parameter were measured. Also, the grafting yield as a function of the fluence and etching time was obtained. In addition transmission of solutions, with different pH, through PP grafted foils was measured. (author) [es
International Nuclear Information System (INIS)
Sanghavi, Suniti; Davis, Anthony B.; Eldering, Annmarie
2014-01-01
In this paper, we build up on the scalar model smartMOM to arrive at a formalism for linearized vector radiative transfer based on the matrix operator method (vSmartMOM). Improvements have been made with respect to smartMOM in that a novel method of computing intensities for the exact viewing geometry (direct raytracing) without interpolation between quadrature points has been implemented. Also, the truncation method employed for dealing with highly peaked phase functions has been changed to a vector adaptation of Wiscombe's delta-m method. These changes enable speedier and more accurate radiative transfer computations by eliminating the need for a large number of quadrature points and coefficients for generalized spherical functions. We verify our forward model against the benchmarking results of Kokhanovsky et al. (2010) [22]. All non-zero Stokes vector elements are found to show agreement up to mostly the seventh significant digit for the Rayleigh atmosphere. Intensity computations for aerosol and cloud show an agreement of well below 0.03% and 0.05% at all viewing angles except around the solar zenith angle (60°), where most radiative models demonstrate larger variances due to the strongly forward-peaked phase function. We have for the first time linearized vector radiative transfer based on the matrix operator method with respect to aerosol optical and microphysical parameters. We demonstrate this linearization by computing Jacobian matrices for all Stokes vector elements for a multi-angular and multispectral measurement setup. We use these Jacobians to compare the aerosol information content of measurements using only the total intensity component against those using the idealized measurements of full Stokes vector [I,Q,U,V] as well as the more practical use of only [I,Q,U]. As expected, we find for the considered example that the accuracy of the retrieved parameters improves when the full Stokes vector is used. The information content for the full Stokes
DEFF Research Database (Denmark)
Nielsen, Morten; Lundegaard, Claus; Lund, Ole
2007-01-01
the correct alignment of a peptide in the binding groove a crucial part of identifying the core of an MHC class II binding motif. Here, we present a novel stabilization matrix alignment method, SMM-align, that allows for direct prediction of peptide:MHC binding affinities. The predictive performance...... of the method is validated on a large MHC class II benchmark data set covering 14 HLA-DR (human MHC) and three mouse H2-IA alleles. RESULTS: The predictive performance of the SMM-align method was demonstrated to be superior to that of the Gibbs sampler, TEPITOPE, SVRMHC, and MHCpred methods. Cross validation...... between peptide data set obtained from different sources demonstrated that direct incorporation of peptide length potentially results in over-fitting of the binding prediction method. Focusing on amino terminal peptide flanking residues (PFR), we demonstrate a consistent gain in predictive performance...
128 Gb/s TWDM PON system using dispersion-supported transmission method
Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, Abusahmah M.; Idrus, Sevia M.; Salleh, M. S.
2017-11-01
Time and wavelength division multiplexed passive optical network (TWDM-PON) trend is considered as the most extraordinary trend of the next generation solution to accommodate exponential traffic growth for converged new services. In this paper, we briefly review recent progress on TWDM-PON system through the use of low cost directly modulated lasers (DMLs) transmission for various line rate transmissions to date. Furthermore, through simulation, we propose and evaluate a cost effective way to upgrade TWDM-PON up to a symmetric capacity of 128 Gb/s using fiber Bragg gratings (FBGs) in optical line terminal (OLT) as a paramount dispersion manager in high speed light-wave systems in both upstream and downstream directions. A low cost and potential chirpless directed modulated grating laser (DMGL) is employed for downstream link and DML with a single delay-interferometer (DI) is employed for upstream link. After illustrating the demonstrated system architecture and configuration, we present the results and analysis to prove the system feasibility. The results show that a successful transmission is achieved over 40 km single mode fiber with a power budget of 33.7 dB, which could support 1:256 splitting ratio.