Search results for "Linear Algebra."
showing 10 items of 552 documents
Gabor filters in industrial inspection: a review. Application to semiconductor industry
2005
This paper focuses on reviewing some recent works of the use of Gabor filters dealing with industrial applications. After a brief recall of Gabor filter basis, the two usual uses of Gabor filters are recalled: filter bank approach and filter design approach. The third part presents recent published works domain by domain. A fourth part exposes our own work with Gabor Filters for defect detection on semiconductor. A short conclusion summarizes the paper.
ALE Simulation of Orthogonal Cutting: a New Approach to Model Heat Transfer Phenomena at the Tool-Chip Interface
2007
This paper presents a new procedure to evaluate the global heat transfer coefficient in orthogonal cutting. The knowledge of the actual heat transfer conditions is a fundamental issue as far as the life, tool wear and tool substitution interval are regarded. More in detail, an Arbitrary Lagrangian-Eulerian approach was utilised to model orthogonal cutting process and the numerical simulations were validated by making experimental tests for identifying cutting forces and internal tool temperatures. A mild steel was cut utilising both an uncoated (WC) and a coated (TiN) tool. On the basis of both experimental and simulative data, a consistent model of the global heat transfer coefficient as f…
On the reliability of ASHRAE conduction transfer function coefficients of walls
2000
The transfer function method recommended by the ASHRAE can be considered the most modern tool currently available for the thermal analysis of a building. It is particularly well suited for use with a computer as it makes it possible to describe with great accuracy the internal heat gain of walls using a small set of coefficients. The present paper shows how to calculate sets of coefficients diverse from that proposed by Mitalas who first developed the method and on the basis of an unequivocal criterion, to prove the advantages in using them. The authors also investigated some of the paramount mathematical and physical aspects which affect the approximation degree of the ASHRAE method and, w…
Seismic response of braced frames with and without friction dampers
1995
Abstract The dynamic response of friction damped bracing systems and ordinary cross-bracing systems inserted into surrounding frames without lateral stiffness is analysed in order to compare the typical behaviour of the two different bracing systems. The cyclic force-displacement relationship in the two cases is accurately modelled on the basis of experimental and related numerical models which are available in the literature, and the structural dimensionless parameters defining the shapes of the cycles are stressed. Systems having the same average period of vibration in the elastic phase of the response are assumed to be comparable with one another, which leads to a relationship linking th…
Modeling traffic safety at urban four leg-signalized intersections
2013
According to the state-of-the-art of the methodologies, the development of safety performance functions (SPFs) for road sections and intersections requires the employment of statistical models to predict expected crash frequencies on the basis of traffic volumes and site characteristics to be surveyed and used as input to models. Nevertheless, literature reports several studies on issues deriving from data features or methodological approaches that may invalidate the efficiency of the models and the accuracy of the estimates. Drawing inspiration from the above mentioned considerations, the objective of this study is to develop safety performance functions for a sample of urban four leg-sign…
Neural Sensorless Control of Linear Induction Motors by a Full-Order Luenberger Observer Considering the End Effects
2012
This paper proposes a neural based full-order Luenberger adaptive speed observer for sensorless linear induction motor (LIM) drives, where the linear speed is estimated with the total least squares (TLS) EXIN neuron. A novel state space-vector representation of the LIM has been deduced, taking into consideration its dynamic end effects. The state equations of the LIM have been rearranged into a matrix form to be solved, in terms of the LIM linear speed, by any least squares technique. The TLS EXIN neuron has been used to compute online, in recursive form, the machine linear speed. A new gain matrix choice of the Luenberger observer, specifically taking into consideration the LIM dynamic end…
An Object-Oriented Approach to Discrete-Event Simulation Applied to Underground Railway Systems
1999
This paper describes the implementation of an object-oriented simulator that supports the determination of timetables and the design of on-line control policies for underground rail way systems. The simulator has been developed on the basis of a new approach to object- oriented modelling. Such an approach has been used to design a development tool that supports the generation of simulation codes and is able to automatically define the skeleton of a code.
Feasibility issues in static output-feedback controller design with application to structural vibration control
2014
Recent results in output-feedback controller design make possible an efficient computation of static output-feedback controllers by solving a single-step LMI optimization problem. This new design strategy is based on a simple transformation of variables, and it has been applied in the field of vibration control of large structures with positive results. There are, however, some feasibility problems that can compromise the effectiveness and applicability of the new approach. In this paper, we present some relevant properties of the variable transformations that allow devising an effective procedure to deal with these feasibility issues. The proposed procedure is applied in designing a static…
Corrigendum to “A procedure to calculate the five-parameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance…
2014
Only few manufactures provide the wide set of graphical data that are necessary to use high performance predictive tools for PV systems. On the other hand, reliable graphical data require accurate laboratory measurements that increase manufacturing costs. For this reason PV system designers have to choose between the use of cheap PV modules, lacking in technical data, and the reliable energy predictions that are possible only if the current–voltage characteristics are provided by the PV module manufacturers. This paper describes the procedure to evaluate the parameters of a one-diode equivalent circuit able to accurately epresent the electrical behaviour of a PV panel by means of the minimu…
A procedure to calculate the five-parameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance data
2013
Abstract Only few manufactures provide the wide set of graphical data that are necessary to use high performance predictive tools for PV systems. On the other hand, reliable graphical data require accurate laboratory measurements that increase manufacturing costs. For this reason PV system designers have to choose between the use of cheap PV modules, lacking in technical data, and the reliable energy predictions that are possible only if the current–voltage characteristics are provided by the PV module manufacturers. This paper describes the procedure to evaluate the parameters of a one-diode equivalent circuit able to accurately represent the electrical behaviour of a PV panel by means of …