Showing papers by "Polytechnic University of Catalonia published in 1985"
TL;DR: It is shown that any of such operators is generated by a family of fuzzy subsets, which gives the way to construct F-indistinguishabilities, and facilitates new applications of fuzzy relations.
428 citations
TL;DR: The general solution of the functional equation S ∗ (T(x, y), T (x, N(y))) = x is found, which yields a family of connectives for fuzzy sets.
104 citations
TL;DR: In this paper, a mathematical model of the magnetically stabilized fluidized bed, based on the arrangement of particles following field lines, is proposed, which can be applied not only to the fluidization of magnetizable materials but also to non-magnetizable particles.
61 citations
01 Jan 1985
TL;DR: In this article, for a given e > 0, the inequality is solved for the case where dL is the modified Levy metric in the space Δ+ of probability distribution functions of non-negative random variables, F is in Δ+, a, b in (O, ∞), and τ is a binary operation on Δ+ to be found.
Abstract: In this paper we solve for a given e > 0 the inequality
$${{\text{d}}_{\text{L}}}\left( {\tau \left( {F\left( {j/a} \right),F\left( {j/b} \right.} \right)} \right),F\left( {j/a + \left. b \right)} \right) \leqslant \varepsilon ,$$
>where dL is the modified Levy metric in the space Δ+ of probability distribution functions of non-negative random variables, F is in Δ+, a, b in (O, ∞) are arbitrary and τ is a binary operation on Δ+ to be found.
34 citations
TL;DR: In the present paper, a smoothing algorithm for bicubic spline surfaces is presented, having the piecewise cubic boundaries of the patches fixed, the algorithm chooses adequate twists factors in order to increase the smoothness.
22 citations
01 Jan 1985
TL;DR: In this article, the authors used CAD methods to design a milling cutters or a form grinding wheel for a short series of special twist drills, which are often required by the motor industry and are manufactured by means of milling or form grinding.
Abstract: Short series of special twist drills, which are often required by the motor industry, are manufactured by means of milling or form grinding. Trial and error procedures to design suitable milling cutters or grinding wheels, have been common practice. How ever CAD methods can be a decisive help in the difficult case of subland drills.
21 citations
TL;DR: In this paper, a new method to find the shape factor and density of porous and non-porous particles is proposed, based on pressure-drop data and the Blake-Kozeny equation.
15 citations
TL;DR: In this paper, a predictive control methodology is used to formulate a discrete-time structural control algorithm, which computes the control forces by using not only the information provided by the structural response but also that given by the measurement of the seismic ground acceleration.
Abstract: The concept of active control has been introduced in recent years in order to reduce the seismic response of structures. A predictive control methodology is used to formulate a discrete‐time structural control algorithm. This algorithm computes the control forces by using not only the information provided by the structural response but also that given by the measurement of the seismic ground acceleration. Results for checking the effectiveness of the control algorithm in reducing the structural response are presented.
11 citations
TL;DR: In this article, the authors give some numerical results about natural families of periodic orbits, which emanate from limiting orbits around the equilateral equilibrium points of the Restricted Three-Body Problem, when the mass ratio is greater than Routh's critical one.
Abstract: In the present paper we give some numerical results about natural families of periodic orbits, which emanate from limiting orbits around the equilateral equilibrium points of the Restricted Three-Body Problem, when the mass ratio is greater than Routh's critical one.
9 citations
01 Mar 1985
TL;DR: A specialized image processor has been designed to deal with the tasks of selection of outstanding points of objects and continuous tracking of these points between consecutive images when displacing the mirrors in order to obtain a short time of calculation as well as a low cost system.
Abstract: The first results of a vision system which adds to a 2D image the depth information of certain points are presented. The goal of the system is to provide the control unit of a robot with an approximate 3D description of the industrial part to be manipulated or of the working area. Depth information about the selected points of the scene is obtained by stereo vision. The determination of disparity is solved by changing the point of view of the TV camera employed by means of two oscillating mirrors which allow continuous tracking of the selected points. A specialized image processor has been designed to deal with the tasks of selection of outstanding points of objects (vertices) and continuous tracking of these points between consecutive images when displacing the mirrors in order to obtain a short time of calculation as well as a low cost system. That way at the end of each sweep of the mirrors we get the information needed to solve triangulation from pairs of homologe points. The time spent to get the three dimensional information of the scene is about one second, which corresponds to the time need to get enough intermediate images to guarantee the correct tracking of vertices.
8 citations
TL;DR: In this article, the results of the temperature and enthalpy change measurements for the transformations II → I, I → III, III → II and III → I were obtained by the DTA technique and correspond to various thermal cycles characterized by the initial and final temperatures.
TL;DR: In this article, the RC model for the case of the real II → I transition of KNO 3, which occurs around 400 K at atmospheric pressure, was analyzed for the DTA system and the values of the kinetic parameters found from direct signals and from previously filtered signals.
09 Sep 1985
TL;DR: The initial index of languages is introduced by means of several computational models and is shown to be closely related to context-free cost, boolean circuits, straight line programs, and Turing machines with sparse oracles and time or space bounds.
Abstract: Non-uniform complexity measures arising in Automata and Formal Language Theory are characterized in terms of well-known uniform complexity classes. The initial index of languages is introduced by means of several computational models. It is shown to be closely related to context-free cost, boolean circuits, straight line programs, and Turing machines with sparse oracles and time or space bounds.
TL;DR: In this paper, a theoretical study of an RC-model constituted only by one heat capacity and one coupling with the thermostat is presented, where the temperature varies as a function of time, and the heat capacity variation is due to its dependence either on temperature or on the mass exchange with the exterior.
TL;DR: In this paper, the specific activities of all the gamma rays emisors present in fourteen differents samples have been determined, in all the cases, only low activities (under 2 Bq/g) have been found for these samples collected from the surroundings of Barcelona.
Abstract: Some materials usually employed in building edification have been analyzed for their radioactive contents. The specific activities of all the gamma rays emisors present in fourteen differents samples have been determined. In all the cases, only low activities (under 2 Bq/g) have been found for these samples collected from the surroundings of Barcelona.
TL;DR: In this article, the authors show that TGS-C crystals have polygonal inclusions with different electric behavior which correspond to a non-ferroelectric phase and explain the delay-time effect, existing residual domains and the wide range of permitivity values, measured by different investigators.
Abstract: Virgin TGS crystals, observed by SEM and TEM replicae, show many polygonal inclusions with different electric behaviour which corresponds to a non-ferroelectric phase. Such inclusions would explain the delay-time effect, the existing residual domains and the wide range of permitivity values, in the phase transition, measured by different investigators. SEM observations of switching fatigued and thermally fatigued samples demonstrate a strong secondary emission contrast which is due to an increase in its conductivity. In the electrically-aged samples the surface layers are altered, but no ion diffusion from the electrode has been observed through EDAX. However, in thermally-aged samples such diffusion is observed. Carbon replicae TEM observation shows a polygonal form matrix which must be due to TGS-C crystals. These results allow one to interpret the ageing process origin and development in both cases, electrically and thermally fatigued crystals, and also the phase transition in partially-aged samples.
01 Jan 1985
TL;DR: In this paper, a multivariate linear regression analysis between the peak discharge and rainfall measured at one station is not advisable given the irregularities in rainfall distribution, and a better agreement is found with multivariate Linear Regression Analysis.
Abstract: The Besos river basin has a typical mediterranean climate showing periodical sudden floods. The geographical configuration of the basin imply short concentration and lag times which are also influenced by the short duration and high intensity of storms. The simple linear regression analysis between the peak discharge and rainfall measured at one station is not advisable given the irregularities in rainfall distribution. A better agreement is found with multivariate linear regression analysis. With this analysis the peak discharge is better correlated with the short rainfall records (less than 6 hours) than with longer records (24 hours).
TL;DR: A mechanism of detection and recovery based on recovery back points that is implemented in industrial controllers and compared with a classical watch-dog timer mechanism is presented.
TL;DR: In this paper, the authors characterize all non-strict Archimedeant-norms whose level curves are homothetic and show that they can be characterized as follows:
Abstract: We characterize all non-strict Archimedeant-norms whose level curves are homothetic.