scholarly journals Speed-up of the Matrix Computation on the Ridge Regression

2021 ◽  
Vol 15 (10) ◽  
Keyword(s):  
Ridge Regression ◽  
Matrix Computation ◽  
The Matrix ◽  
Speed Up

MRHS solver based on linear algebra and exhaustive search

2018 ◽  
Vol 12 (3) ◽  
pp. 143-157 ◽  
Author(s):  
Håvard Raddum ◽  
Pavol Zajac
Keyword(s):  
Linear Algebra ◽  
Matrix Representation ◽  
Equation System ◽  
Exhaustive Search ◽  
Binary Matrix ◽  
Algebraic Attacks ◽  
The Matrix ◽  
Speed Up ◽  
Symmetric Key

Abstract We show how to build a binary matrix from the MRHS representation of a symmetric-key cipher. The matrix contains the cipher represented as an equation system and can be used to assess a cipher’s resistance against algebraic attacks. We give an algorithm for solving the system and compute its complexity. The complexity is normally close to exhaustive search on the variables representing the user-selected key. Finally, we show that for some variants of LowMC, the joined MRHS matrix representation can be used to speed up regular encryption in addition to exhaustive key search.

scholarly journals Guidelines for assessing the knowledge management maturity of organizations

2007 ◽  
Vol 9 (3) ◽  
Author(s):  
C. J. Kruger ◽  
M. M.M. Snyman
Keyword(s):  
Knowledge Management ◽  
Public Management ◽  
Management Service ◽  
The Public ◽  
University Of Pretoria ◽  
The Matrix ◽  
Speed Up ◽  
Level Of Knowledge ◽  
Strategic Perspective ◽  
The University

In a recent article Kruger and Snyman hypothesized that progressions in knowledge management maturity (from a strategic perspective) are directly related to an increased ability to speed up the strategic cycle of imitation, consolidation and innovation. The arguments proposed, however, neglected to supply the reader with a practical toolkit or even a roadmap (a time-related matrix, or questionnaire) to successfully measure succession in knowledge management maturity. This article builds on the previous one and proposes a questionnaire consisting of six sections, containing 101 descriptive questions, to enable organizations to test and assess their knowledge management maturity empirically. The development of an instrument to measure knowledge management maturity required adhering to a research design that combined theoretical propositions with practical experimentation. As a point of departure, a knowledge management maturity matrix consisting of seven maturity levels was formulated. All questions contained within the matrix were benchmarked against a survey questionnaire developed by the public management service of the OECD (PUMA) and were also pre-tested and validated. This process of refinement led to the formulation of the Knowledge Management Maturity Questionnaire. To avoid any taint of this research being based only on theoretical propositions, the questionnaire was tested by 178 master students of the University of Pretoria, South Africa, in nine different industries. The proposed questionnaire provides a bridge between theoretical propositions and practical usability, not only enabling knowledge management practitioners to assess the level of knowledge management maturity reached successfully but, more importantly, also serving as a guideline to institutionalize further and future knowledge management endeavours.

The crystal neutron diffractometer resolution function, spatial effects included

2000 ◽  
Vol 33 (4) ◽  
pp. 1067-1074 ◽  
Author(s):  
I. Ionita ◽  
A. D. Stoica
Keyword(s):  
Spatial Configuration ◽  
Experimental Setup ◽  
General Description ◽  
Spatial Effects ◽  
Resolution Function ◽  
Matrix Computation ◽  
Neutron Diffractometer ◽  
Computation Technique ◽  
The Matrix

A procedure for computing the resolution function for a crystal neutron diffractometer, taking into account the spatial configuration of the experimental setup and the monochromator curvature, is presented. A brief general description of the matrix computation technique is given. The programDAX, which employs this technique, is presented.

An Implementation of a Matrix Cache to Speed up the Conventional Transient Simulation of Piecewise Linear Circuits

1997 ◽  
Vol 07 (04) ◽  
pp. 353-360
Author(s):  
Ekachai Leelarasmee ◽  
Methee Hwangkhunnatham
Keyword(s):  
Linear Equation ◽  
Transient Analysis ◽  
Piecewise Linear ◽  
Management Technique ◽  
Power Electronic ◽  
Electronic Circuits ◽  
Power Electronic Circuits ◽  
The Matrix ◽  
Speed Up ◽  
Linear Circuits

A few techniques based on an efficient use of memory resources, called matrix caches, to speed up the transient analysis of piecewise linear circuits such as power electronic circuits are presented. These techniques use the fact that the matrix in the linear equation solving routines can only have a finite number of different values. Hence, by adding a cache memory management technique to store the LU factor of these matrices for future reuse, the linear equation solver can be performed much faster than that of a general purpose simulation program in which these LU factors have to be recomputed every time. Since most of the CPU analysis time is spent in solving linear equations, these techniques can actually speed up the transient analysis of piecewise linear circuits significantly. An experimental circuit simulator has been developed to implement the matrix cache and tested with a few piecewise linear power electronic circuits. The results indicate a speed increase of 2–10 times as compared with its non-matrix cache version.

The resolution function for a time-of-flight diffractometer with curved slits chopper

2001 ◽  
Vol 34 (3) ◽  
pp. 252-257 ◽  
Author(s):  
I. Ionita
Keyword(s):  
Inclination Angle ◽  
Time Of Flight ◽  
Angular Speed ◽  
Resolution Function ◽  
Matrix Computation ◽  
Computation Technique ◽  
The Matrix ◽  
Optimum Sample

A procedure is presented for computing the resolution function for a time-of-flight diffractometer with curved slits chopper using the matrix computation technique. Some focusing conditions are deduced by compensating the major contributions to the variance of the scan variables; these conditions refer to the optimum sample and detector inclination angle and to the optimum chopper angular speed.

An Efficient Scheduling Technique for Biological Sequence Alignment

2015 ◽  
Vol 754-755 ◽  
pp. 1087-1092
Author(s):  
Mohd Nazrin Md Isa ◽  
Sohiful Anuar Zainol Murad ◽  
Mohamad Imran Ahmad ◽  
Muhammad M. Ramli ◽  
Rizalafande Che Ismail
Keyword(s):  
Sequence Alignment ◽  
Substitution Matrix ◽  
Processing Element ◽  
Biological Sequence ◽  
Matrix Computation ◽  
Logic Block ◽  
Order Of Magnitude ◽  
Speed Up ◽  
A New Technique ◽  
Protein Sequencer

Computing alignment matrix score to search for regions of homology between biological sequences is time consuming task. This is due to the recursive nature of the dynamic programming-based algorithms such as the Smith-Waterman and the Needleman-Wunsch algorithmns. Typical FPGA-based protein sequencer comprises of two main logic blocks. One for computing alignment scores i.e. the processing element (PE), while another logic block for configuring the PE with coefficients. During alignment matrix computation, the logic block for configuring the PE are left unused until the time consuming alignment matrix computation finished. Therefore, a new technique, known as overlap computation and configuration (OCC) is proposed to minimize the time overhead for performing biological sequence alignment. The OCC technique simultaneously updating substitution matrix in a processing element (PE) systolic array, while computing alignment matrix scores. Results showed that, the sequencer achieves more than two order of magnitude speed-up higher compared to the state of the art, at negligible area overhead, if any.

Search for identical regions in images using invariant moments

2021 ◽  
Vol 26 (jai2021.26(2)) ◽  
pp. 55-62
Author(s):  
Sabelnikov P ◽  
◽  
Sabelnikov Yu ◽  
Keyword(s):  
Integral Representation ◽  
Parallel Computations ◽  
Invariant Moments ◽  
Geometric Moments ◽  
The Matrix ◽  
Rectangular Area ◽  
Characteristic Points ◽  
Speed Up ◽  
Almost All ◽  
Local Image

One of the ways to describe objects on images is to identify some of their characteristic points or points of attention. Areas of neighborhoods of attention points are described by descriptors (lots of signs) in such way that they can be identified and compared. These signs are used to search for identical points in other images. The article investigates and establishes the possibility of searching for arbitrary local image regions by descriptors constructed with using invariant moments. A feature of the proposed method is that the calculation of the invariant moments of local areas is carried out with using the integral representation of the geometric moments of the image. Integral representation is a matrix with the same size as the image. The elements of the matrix is the sums of the geometric moments of individual pixels, which are located above and to the left with respect to the coordinates of this element. The number of matrices depends on the order of the geometric moments. For moments up to the second order (inclusively), there will be six such matrices. Calculation of one of six geometric moments of an arbitrary rectangular area of the image comes down up to 3 operations such as summation or subtraction of elements of the corresponding matrix located in the corners of this area. The invariant moments are calculated on base of six geometric moments. The search is performed by scanning the image coordinate grid with a window of a given size. In this case, the invariant moments and additional parameters are calculated and compared with similar parameters of the neighborhoods of the reference point of different size (taking into account the possible change in the image scale). The best option is selected according to a given condition. Almost all mass operations of the procedures for calculating the parameters of standards and searching of identical points make it possible explicitly perform parallel computations in the SIMD mode. As a result, the integral representation of geometric moments and the possibility of using parallel computations at all stages will significantly speed up the calculations and allow you to get good indicators of the search efficiency for identical points and the speed of work

Calculation of Additional Losses in Windings of Permanent Magnet Motors Using the Femm Package

2020 ◽  
Vol 63 (6) ◽  
pp. 5-10
Author(s):  
Leonid Pakhomin ◽  
◽  
Sergey Pakhomin ◽  
Keyword(s):  
Permanent Magnet ◽  
Low Voltage ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
The Matrix ◽  
Speed Up ◽  
Instantaneous Values ◽  
Scripting Language ◽  
Additional Losses

The calculation of additional losses in the windings of permanent magnet synchronous motors is proposed to be performed using the FEMM package. The article describes a system of equations that allows to determine the distribution of instantaneous values of currents in the elementary wires of the winding. As an example, a low-voltage permanent magnet motor with concentrated windings on a stator is considered. To determine the matrix of inductances of elementary phase wires, the FEMM program was used. To speed up the calculations, a control script for FEMM (in the lua scripting language) was used, which made it possible to automatically de-termine the matrix of own and mutual inductances for a given distribution of elementary wires in a slot. The re-sults of calculating the instantaneous values of the currents in the elementary wires of the winding are used to determine the additional losses. Variants of the distribution of elementary conductors in a slot are considered, the corresponding coefficients of increasing losses in the winding are determined.

Molecular Dynamics Simulations of Carbon Nanotube Interactions in Water/Surfactant Systems

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Nasir M. Uddin ◽  
Franco Capaldi ◽  
Bakhtier Farouk
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Potential Of Mean Force ◽  
Quantitative Prediction ◽  
The Matrix ◽  
Adaptive Biasing ◽  
Speed Up ◽  
Dynamics Simulations ◽  
Processing Techniques ◽  
Walled Carbon Nanotubes

The properties of nanocomposite materials depend on the dispersion of the nanoparticles/nanofibers within the matrix. The addition of surfactants and varied processing techniques are used to increase the dispersion of the nanoparticles in the final composite. A method for the quantitative prediction of the interactions between nanoparticles in solution would aid in the design of processing schedules. In this study, molecular dynamics simulations are used to compute for the potential of mean force as a function of the distance and orientation between a pair of single-walled carbon nanotubes (CNTs) in water. An adaptive biasing force method is used to speed up the calculations. Simulation results show that CNT orientation and the addition of surfactant can significantly affect CNT interactions and inturn dispersion.

scholarly journals The selective regularization of a linear regression model

2021 ◽  
Vol 2099 (1) ◽  
pp. 012024
Author(s):  
V N Lutay ◽  
N S Khusainov
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Ridge Regression ◽  
Triangular Decomposition ◽  
System Matrix ◽  
Original Dataset ◽  
The Matrix ◽  
Matrix Conditioning ◽  
Selection Of

Abstract This paper discusses constructing a linear regression model with regularization of the system matrix of normal equations. In contrast to the conventional ridge regression, where positive parameters are added to all diagonal terms of a matrix, in the method proposed only those matrix diagonal entries that correspond to the data with a high correlation are increased. This leads to a decrease in the matrix conditioning and, therefore, to a decrease in the corresponding coefficients of the regression equation. The selection of the entries to be increased is based on the triangular decomposition of the correlation matrix of the original dataset. The effectiveness of the method is tested on a known dataset, and it is performed not only with a ridge regression, but also with the results of applying the widespread algorithms LARS and Lasso.

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