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This paper gives an overview on some classes of binary connectives that play a key role in fuzzy logic. We start with left-continuous triangular norms, by recalling some facts about the nilpotent minimum and its extensions. Some standard construction methods are also described. We also deal with two possible extensions of t-norms: the classes of uninorms and nullnorms.
One of the challenges of SOA is to deal with service matching which is uncertain and ambiguous. A service requester must be prepared to cope with situations where no required services are found or, on the other hand, multiple matching services are found. The paper proposes a formal model of service matching with incomplete information. The model is defined using set theory and description logics....
In this paper a genetic-type-2 fuzzy approach is proposed to optimize the parameters of the membership functions (MFs) of a type-2 fuzzy logic system (FLS) applied to control, we design a chromosome to represent the parameters of the MFs of a preestablished type-2 FLS, design a fitness function and select genetic operators. A case of study is proposed to evaluate the optimization process, this is...
Hybrid models combine different technologies to obtain a product that shares their advantages and minimizes their deficiencies. The solutions given by a case-based system (CBS) rely on similar past experiences, which are commonly described in terms of both symbolic and continuous attributes. The nearest neighbor (NN) principle commonly followed to develop CBS for classification task proceeds from...
The idea of linguistic variable in fuzzy logic allows the representation of the subjective meaning of a measure at a given instant of time. This paper explores possibilities of extending the concept of linguistic term to create the linguistic description of the temporal evolution of a signal. We focus our effort in signals that, having potentially an infinite duration, present more or less repetitive...
This paper addresses a new approach for automatically extraction of the type-2 fuzzy rules from input-output data. In this approach, the structure identification and parameter optimization are carried out automatically without any assumption about the structure of the data, which is capable of finding the optimal number of the rules with an acceptable accuracy. The fuzzy modeling algorithm proposed...
In this paper, a bibliometric study on the interconnections between the fuzzy logic theory field and the other soft-computing techniques is presented. Bibliometric maps showing the associations between the main concepts between these research fields are provided for the periods 1990-1999, 2000-2003 and 2004-2007. The maps provide insight into the structure of these fields. They visualize the division...
In this paper we propose a multi-objective genetic algorithm to generate Mamdani fuzzy rule-based systems with optimal trade-offs between complexity and accuracy. The main novelty of the algorithm is that both rule base and granularity of the uniform partitions defined on the input and output variables are learned concurrently. To this aim, we exploit a chromosome composed of two parts, which codify...
The Web has become an important medium for access to information and users increasingly depend on it for their routine activities. Hence, the demand for higher quality services has grown strong and overload control has become a key problem to be addressed in Web servers. This paper analyzes the implementation of a fuzzy admission controller in a QoS-enabled Web server architecture and compares its...
Rapid developments in computing-related technologies have enabled the collection of large amounts of data at unprecedented rates from diverse systems, both natural and engineered. The availability of such data has motivated the development of intelligent systems to gain new insights into how these systems work, leading thereby to superior decision making. In this paper we present recent advances in...
The dimension of a knowledge domain can impact the use of genetic algorithms to automatically design fuzzy rule bases, since the search space for the genetic algorithm increases exponentially with the number of features. Filters are a possible approach to reduce the number of features. However, the filter approach does not take into consideration the particular aspects of fuzzy logic when selecting...
One of the most important problems to be solved in direct sequence spread spectrum systems is to achieve a robust acquisition of the pseudo noise sequence. In multiuser time-varying environments this fact becomes even more important because acquisition and tracking performance can heavily degrade communication reliability. In this paper a new neural network estimator is presented, and it is compared...
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