New time-varying fuzzy sets based on a PSO midpoint of the universe of discourse

2016 ◽  
Vol 13 (4) ◽  
pp. 392-400 ◽  
Author(s):  
Ziani Salim
Keyword(s):  
Fuzzy Sets ◽  
Time Varying ◽  
The Universe ◽  
Universe Of Discourse ◽  
New Time

scholarly journals Mathematical Models of the Simplest Fuzzy Two-Term (PI/PD) Controllers Using Algebraic Product Inference

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Murali Bosukonda ◽  
Naresh Kelothu
Keyword(s):  
Mathematical Models ◽  
Fuzzy Sets ◽  
Output Variable ◽  
Control Rules ◽  
Variable Control ◽  
Control Community ◽  
Input Variables ◽  
The Universe ◽  
Control Output ◽  
Universe Of Discourse

This paper reveals mathematical models of the simplest Mamdani PI/PD controllers which employ two fuzzy sets (N: negative and P: positive) on the universe of discourse (UoD) of each of two input variables (displacement and velocity) and three fuzzy sets (N: negative, Z: zero, and P: positive) on the UoD of output variable (control output in the case of PD, and incremental control output in the case of PI). The basic constituents of these models are algebraic product/minimum AND, bounded sum/algebraic sum/maximum OR, algebraic product inference, three linear fuzzy control rules, and Center of Sums (CoS) defuzzification. Properties of all these models are investigated. It is shown that all these controllers are different nonlinear PI/PD controllers with their proportional and derivative gains changing with the inputs. The proposed models are significant and useful to control community as they are completely new and qualitatively different from those reported in the literature.

New Similarity Measure Between Two Fuzzy Sets

2006 ◽  
Vol 10 (6) ◽  
pp. 946-953 ◽  
Author(s):  
Hassan Rezaei ◽  
◽  
Masashi Emoto ◽  
Masao Mukaidono
Keyword(s):  
Fuzzy Sets ◽  
Similarity Measure ◽  
The Universe ◽  
Universe Of Discourse

We propose a new similarity measure between two fuzzy sets based on their relative sigma count and extend it to define two other measures, one a similarity measure between elements in fuzzy sets and the second a similarity measure between fuzzy sets in which all elements in the universe of discourse are weighted. We compare our proposal to several previous measures proposed in [1-6].

scholarly journals Mixed fluid cosmological model in f(R, T) gravity

2020 ◽  
Vol 98 (11) ◽  
pp. 1015-1022 ◽  
Author(s):  
Parbati Sahoo ◽  
Barkha Taori ◽  
K.L. Mahanta
Keyword(s):  
Cosmological Model ◽  
Bianchi Type ◽  
Type I ◽  
Time Varying ◽  
Eos Parameter ◽  
Barotropic Fluid ◽  
Rotationally Symmetric ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Mixed Fluid

We construct a locally rotationally symmetric (LRS) Bianchi type-I cosmological model in f(R, T) theory of gravity when the source of gravitation is a mixture of barotropic fluid and dark energy (DE) by employing a time-varying deceleration parameter. We observe through the behavior of the state finder parameters (r, s) that our model begins from the Einstein static era and goes to ΛCDM era. The equation of state (EOS) parameter (ωd) for DE varies from the phantom (ω < –1) phase to quintessence (ω > –1) phase, which is consistent with observational results. It is found that the discussed model can reproduce the current accelerating phase of the expansion of the universe.

scholarly journals Bianchi type–I Model with Time Varying Λ and G: The Generalized Solution

2020 ◽  
Vol 29 (1) ◽  
pp. 89-93
Author(s):  
Alnadhief H. A. Alfedeel
Keyword(s):  
Analytical Solution ◽  
Bianchi Type ◽  
Generalized Solution ◽  
Type I ◽  
Time Varying ◽  
Field Equations ◽  
Geometric Function ◽  
Varying Λ ◽  
The Universe ◽  
Average Scale Factor

AbstractIn this paper, we have investigated the homogeneous and anisotropic Bianchi type–I cosmological model with a time-varying Newtonian and cosmological constant. We have analytically solved Einstein’s field equations (EFEs) in the presence of a stiff-perfect fluid. We show that the analytical solution for the average scale factor for the generalized Friedman equation involves the hyper-geometric function. We have studied the physical and kinematical quantities of the model, and it is found that the universe becomes isotropic at late times.

Are “All-and-Some” Statements Falsifiable After All?: The Example of Utility Theory

1986 ◽  
Vol 2 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Philippe Mongin
Keyword(s):  
Melting Point ◽  
Utility Theory ◽  
Logical Form ◽  
Empirical Science ◽  
Demarcation Criterion ◽  
Existential Sentences ◽  
The Universe ◽  
Universe Of Discourse

Popper's well-known demarcation criterion has often been understood to distinguish statements of empirical science according to their logical form. Implicit in this interpretation of Popper's philosophy is the belief that when the universe of discourse of the empirical scientist is infinite, empirical universal sentences are falsifiable but not verifiable, whereas the converse holds for existential sentences. A remarkable elaboration of this belief is to be found in Watkins's early work (1957, 1958) on the statements he calls “all-and-some,” such as: “For every metal there is a melting point.” All-and-some statements (hereafter AS) are both universally and existentially quantified in that order. Watkins argued that AS should be regarded as both nonfalsifiable and nonverifiable, for they partake in the logical fate of both universal and existential statements. This claim is subject to the proviso that the bound variables are “uncircumscribed” (in Watkins's words); i.e., that the universe of discourse is infinite.

Relationship between Selic rate and Basel III parameters - A statistics approach and a fuzzy forecasting model

2021 ◽  
pp. 1-14
Author(s):  
Thiago Henrique Barbosa de Carvalho Tavares ◽  
Bruno Pérez Ferreira ◽  
Eduardo Mazoni Andrade Marçal Mendes
Keyword(s):  
Cross Correlation ◽  
Data Distribution ◽  
Forecasting Model ◽  
Basel Iii ◽  
Output Data ◽  
Basel Accords ◽  
Proposed Model ◽  
The Relationship ◽  
The Universe ◽  
Universe Of Discourse

In this work the relationship between the Selic rate and some bank parameters defined by the so-called Basel Accords is studied. The cross-correlation between the Selic rate and the parameters is used to explain how these parameters affect the Selic rate and vice-versa so as to define the predictability of the Selic rate using (some of) these parameters as inputs. A model is then proposed for predicting the Selic rate based on some specific parameters using fuzzy logic ideas, which dealt with a partitioning of the universe of discourse using clusters related to the output data distribution. The proposed model is compared to four other known models in the literature and showed to have better performance in average compared to all other models.

scholarly journals Time Series Seasonal Analysis Based on Fuzzy Transforms

2017 ◽  
Author(s):  
Ferdinando Di Martino ◽  
Salvatore Sessa
Keyword(s):  
Time Series ◽  
Seasonal Forecasting ◽  
Weather Station ◽  
Fuzzy Transform ◽  
Italian Region ◽  
Mean Temperature ◽  
Forecasting Method ◽  
Seasonal Analysis ◽  
The Universe ◽  
Universe Of Discourse

We define a new seasonal forecasting method based on fuzzy transforms. We use the best interpolating polynomial for extracting the trend of the time series and generate the inverse fuzzy transform on each seasonal subset of the universe of discourse for predicting the value of a an assigned output. Like first example, we use the daily weather dataset of the municipality of Naples (Italy) starting from data collected from 2003 till to 2015 making predictions on the following outputs: mean temperature, max temperature and min temperature, all considered daily. Like second example, we use the daily mean temperature measured at the weather station &ldquo;Chiavari Caperana&rdquo; in the Liguria Italian Region. We compare the results with our method, the average seasonal variation, ARIMA and the usual fuzzy transforms concluding that the best results are obtained under our approach in both examples.

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