Two methods to find analytical redundancy relations for fault diagnosis

2017 ◽  
Vol 65 (4) ◽  
Author(s):  
Jan Lunze
Keyword(s):  
Structural Analysis ◽  
Linear System ◽  
State Variables ◽  
Vector Representation ◽  
New Methods ◽  
Starting Point ◽  
Analytical Redundancy ◽  
Matrix Vector ◽  
Analytical Expressions ◽  
Derivatives Of

AbstractThe paper deals with methods to derive analytical redundancy relations for diagnosable systems. The starting point is an over-determined set of constraints, which is obtained by a structural analysis of the linear system under consideration. The problem is to find analytical expressions for residuals in terms of the measured signals and the derivatives of these signals. Two new methods are described. The first method provides a representation of the residual in terms of the observability matrix of the diagnosable subsystem. The second method replaces the derivative constraints by a series of equations that include the derivatives of the state variables and the outputs. The result is a matrix-vector representation of the over-determined set of equations, which leads to the analytical redundancy relations. The methods are illustrated by their application to an automotive example.

scholarly journals Determination of synchronous generator nonlinear model parameters based on power rejection tests using a gradient optimization algorithm

2017 ◽  
Vol 65 (4) ◽  
pp. 479-488 ◽  
Author(s):  
A. Boboń ◽  
A. Nocoń ◽  
S. Paszek ◽  
P. Pruski
Keyword(s):  
Parameter Estimation ◽  
Objective Function ◽  
Optimization Algorithm ◽  
Least Squares Method ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Model Parameters ◽  
State Variables ◽  
Starting Point ◽  
Gradient Optimization

AbstractThe paper presents a method for determining electromagnetic parameters of different synchronous generator models based on dynamic waveforms measured at power rejection. Such a test can be performed safely under normal operating conditions of a generator working in a power plant. A generator model was investigated, expressed by reactances and time constants of steady, transient, and subtransient state in the d and q axes, as well as the circuit models (type (3,3) and (2,2)) expressed by resistances and inductances of stator, excitation, and equivalent rotor damping circuits windings. All these models approximately take into account the influence of magnetic core saturation. The least squares method was used for parameter estimation. There was minimized the objective function defined as the mean square error between the measured waveforms and the waveforms calculated based on the mathematical models. A method of determining the initial values of those state variables which also depend on the searched parameters is presented. To minimize the objective function, a gradient optimization algorithm finding local minima for a selected starting point was used. To get closer to the global minimum, calculations were repeated many times, taking into account the inequality constraints for the searched parameters. The paper presents the parameter estimation results and a comparison of the waveforms measured and calculated based on the final parameters for 200 MW and 50 MW turbogenerators.

Synthesis and Structural Analysis of Branched-Chain Derivatives of Methyl Oleate

2008 ◽  
Vol 85 (7) ◽  
pp. 647-653 ◽  
Author(s):  
Oliver D. Dailey ◽  
Nicolette T. Prevost ◽  
Gary D. Strahan
Keyword(s):  
Structural Analysis ◽  
Methyl Oleate ◽  
Branched Chain ◽  
Derivatives Of

Elastoviscoplastic Models with Relaxed Configurations and Internal State Variables

1990 ◽  
Vol 43 (7) ◽  
pp. 131-151 ◽  
Author(s):  
Sanda Cleja T¸igoiu ◽  
Eugen Soo´s
Keyword(s):  
Experimental Data ◽  
Structural Analysis ◽  
Internal State ◽  
State Variables ◽  
Internal State Variables ◽  
Local Current

We present the microstructural basis, the initial macroscopical formulations, and a possible axiomatic reconstruction of the elastoviscoplastic model for metals based on the use of the local, current, relaxed configurations. Structural analysis and experimental data show that using these configurations offers advantages for the formulation of the material laws when the deformations are small or moderately large. Our review aims to be a concise, historical, and critical exposition of the main stages, contributions and results, which led, during the late sixties and the beginning of seventies, to the formulation of the fundamental ideas lying at the basis of the model. We delineate the role played by Lee, Liu, Teodosiu, Sidoroff, Mandel, and Kratochvil in the first formulation of the theory between 1966 and 1972, as well as the contributions of Dafalias and Loret to the development of the model between 1983 and 1985. Finally, we discuss some results obtained between 1985 and 1988 with models based on local current relaxed configurations.

scholarly journals Derivatives of 2-Aminopyridines as Inhibitors of Multidrug Resistant Staphylococcus Aureus Strains

2018 ◽  
Vol 10 (1) ◽  
pp. 153
Author(s):  
Iniobong E. Ante ◽  
Sherifat A Aboaba ◽  
Hina Siddiqui ◽  
Muhammad A Bashir ◽  
Muhammad I Choudhary
Keyword(s):  
Staphylococcus Aureus ◽  
Mass Spectra ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Acid Chlorides ◽  
Alamar Blue ◽  
Standard Drug ◽  
Starting Point ◽  
New Compounds ◽  
Derivatives Of

A new series of 2-aminopyridine derivatives were synthesised. N-acylation of 2-amino-3-chloro-5-(trifluoromethyl) pyridine and 2-amino-5-(trifluoromethyl) pyridine with series of acid chlorides afforded a total of fourteen (14) amide compounds. The structures of the new compounds have been established by their IR, NMR and mass spectra data. All the compounds were tested for their activity against four (4) multi-drug resistant (MDR) bacteria Staphylococcus aureus strains using microplate alamar blue assay. The MDR-Staphylococcus aureus strains employed for this study were Epidermic Methicilin Resistant Staphylococcus aureus (EMRSA-17), Methicilin Resistant Staphylococcus aureus (MRSA-252), Epidermic Methicilin Resistant Staphylococcus aureus (EMRSA-16) and Pakistani Drug resistant clinical isolate of Staphylococcus aureus (PRSA). Other bacteria strains also used include Escherichia coli (ATCC 2592), Shigella flexenari (ATCC 12022), Staphylococcus aureus (NCTC 6571) and Pseudomonas aeruginosa (NCTC 10662). The synthesised compounds exhibited very good activity against the four MDR-Staphylococcus aureus strains of which most of the compounds showed higher potencies for inhibiting the growth of the strains than vancomycin, the standard drug employed. The compounds reported here may serve as the starting point for the design and development of MDR-S.aureus inhibitors as antibacterial agents.

Analytical expressions for gravity anomalies due to homogeneous polyhedral bodies and translations into magnetic anomalies

Geophysics ◽  
1979 ◽  
Vol 44 (4) ◽  
pp. 730-741 ◽  
Author(s):  
M. Okabe
Keyword(s):  
Gravitational Potential ◽  
Computing Time ◽  
Gravity Anomalies ◽  
Magnetic Anomalies ◽  
Two Dimensions ◽  
First Derivative ◽  
Second Derivatives ◽  
Analytical Expressions ◽  
Derivatives Of ◽  
The Magnetic Field

Complete analytical expressions for the first and second derivatives of the gravitational potential in arbitrary directions due to a homogeneous polyhedral body composed of polygonal facets are developed, by applying the divergence theorem definitively. Not only finite but also infinite rectangular prisms then are treated. The gravity anomalies due to a uniform polygon are similarly described in two dimensions. The magnetic potential due to a uniformly magnetized body is directly derived from the first derivative of the gravitational potential in a given direction. The rule for translating the second derivative of the gravitational potential into the magnetic field component is also described. The necessary procedures for practical computer programming are discussed in detail, in order to avoid singularities and to save computing time.

Embodied Timing − Passing Time

2013 ◽  
Vol 4 (2) ◽  
pp. 12-17
Author(s):  
Cecilia Roos
Keyword(s):  
Artistic Production ◽  
New Methods ◽  
Starting Point

Abstract In this article1 I am discussing how traditions are reenacted by dance revival and reconstruction. My starting point is the experience I have of restaging choreographic works by the Swedish choreographer Per Jonsson (1956-1998), of whose artistic production I am in charge. Through examples from working with repertoire, I will develop my thoughts around how new interpretations of a movement material reformulate the tradition and inform the present. I will also discuss how dancers of today are researching and developing new methods for processing a movement material. This in turn leads to new ways of dealing with quality, dynamics and timing in reconstruction of a written material.

Kinematic Synthesis of Spatial R-R Dyads for Path Following Revisited Using the Rotation Matrix Approach

1999 ◽  
Author(s):  
Venkat Krovi ◽  
G. K. Ananthasuresh ◽  
Vijay Kumar
Keyword(s):  
Linear System ◽  
Path Following ◽  
Rotation Matrix ◽  
Dimensional Synthesis ◽  
Kinematic Synthesis ◽  
End Effector ◽  
Serial Chain ◽  
Systematic Development ◽  
Matrix Vector ◽  
Selection Of

Abstract We revisit the dimensional synthesis of a spatial two-link, two revolute-jointed serial chain for path following applications, focussing on the systematic development of the design equations and their analytic solution for the three precision point synthesis problem. The kinematic design equations are obtained from the equations of loop-closure for end-effector position in rotation-matrix/vector form at the three precision points. These design equations form a rank-deficient linear system in the link-vector components. The nullspace of the rank deficient linear system is then deduced analytically and interpreted geometrically. Tools from linear algebra are applied to systematically create the auxiliary conditions required for synthesis and to verify consistency. An analytic procedure for obtaining the link-vector components is then developed after a suitable selection of free choices. Optimization over the free choices is possible to permit the matching of additional criteria and explored further. Examples of the design of optimal two-link coupled spatial R-R dyads are presented where the end-effector interpolates three positions exactly and closely approximates an entire desired path.

New methods of metaphor identification in various types of discourse (Review of publications)

2021 ◽  
Vol 1 (6) ◽  
pp. 19-31
Author(s):  
Peter M. Shitikov ◽  
◽  
Svetlana V. Vershinina
Keyword(s):  
Corpus Linguistics ◽  
Large Scale ◽  
Historical Background ◽  
Great Success ◽  
Research Groups ◽  
Identification Procedure ◽  
New Methods ◽  
Starting Point ◽  
Different Types ◽  
Theoretical Foundations

This article presents a review of the latest procedures for identifying metaphor in multilingual texts and different types of discourse. The choice of methods for identifying and decoding metaphorical expressions is the starting point of any research in the field of metaphorology. With the development of corpus linguistics methods, the volume of analyzed material has grown thousands of times. So, the identification of linguistic expressions in discourse that realize conceptual metaphors has become one of the most challenging issues of modern metaphorology. The paper describes theoretical foundations and historical background for the solution of this issue. It is shown that it is impossible to verify this or that method without a large-scale approbation; in this connection, the developments of research groups (PALASIGMET, PRAGGLEJAZ) proved to be the most perspective. The MIP (metaphor identification procedure) was finalized in the metaphor laboratory of the Free University of Amsterdam with the name MIPVU. This methodology was a great success all over the world, however, in Russia only a few articles of introductory character have appeared. This article summarizes the experience of applying the procedures of metaphor identification in different languages and types of discourse.

A General Time Dependent Constitutive Model: Part I— Theoretical Developments1

2000 ◽  
Vol 123 (1) ◽  
pp. 51-64 ◽  
Author(s):  
A. F. Saleeb ◽  
S. M. Arnold
Keyword(s):  
Response Characteristic ◽  
Structure Type ◽  
Internal Variable ◽  
Integral Representations ◽  
State Variables ◽  
Qualitative Response ◽  
Response Range ◽  
Starting Point ◽  
Potential Structure ◽  
Hereditary Integral

Using an internal-variable formalism as a starting point, we describe the viscoelastic complement of a previously-developed viscoplasticity formulation of the complete potential structure type. It is mainly motivated by experimental evidence for the presence of rate/time effects in the so-called quasilinear, reversible, material response range. Several possible generalizations are described, in the general format of hereditary-integral representations for nonequilibrium, stress-type, state variables, both for isotropic as well as anisotropic materials. In particular, thorough discussions are given on the important issues of thermodynamic admissibility requirements for such general descriptions, resulting in a set of explicit mathematical constraints on the associated kernel (relaxation and creep compliance) functions. In addition, a number of explicit, integrated forms are derived, under stress and strain control to facilitate the parametric and qualitative response characteristic studies reported here, as well as to help identify critical factors in the actual experimental characterizations from test data that will be reported in Part II.

Stability analysis of continuous-time linear systems consisting of n subsystems with different fractional orders

2012 ◽  
Vol 60 (2) ◽  
pp. 279-284 ◽  
Author(s):  
M. Busłowicz
Keyword(s):  
Linear Systems ◽  
Continuous Time ◽  
State Equation ◽  
The State ◽  
Natural Order ◽  
State Variables ◽  
The Stability ◽  
Derivatives Of ◽  
Fractional Orders ◽  
Time Linear

Abstract. The stability problem of continuous-time linear systems described by the state equation consisting of n subsystems with different fractional orders of derivatives of the state variables has been considered. The methods for asymptotic stability checking have been given. The method proposed in the general case is based on the Argument Principle and it is similar to the modified Mikhailov stability criterion known from the stability theory of natural order systems. The considerations are illustrated by numerical examples.

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