Open Access
Use of Choquet integrals in multivalued contexts
(Springer, 2020) Burusco Juandeaburre, Ana; Alcalde, Cristina; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Estadística, Informática y Matemáticas
In this work, multivalued contexts are studied, in which the different observations are related to each other. Continuing the studies already carried out in previous works, the use of Choquet integrals can be an adequate tool for this situations. If in addition the set of objects or attributes of these contexts represent a temporal sequence, we can also represent these contexts as sequences of contexts that evolve in time and we can use tools in this field to extract information. Finally, as illustrative application, the developed theory is used to measure student progress in learning.
Open Access
In search of L-Fuzzy contexts adaptable to variable information: a tool for time-varying data analysis
(MDPI, 2025-01-27) Alcalde, Cristina; Burusco Juandeaburre, Ana; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
This paper sheds light on the study of a new structure, called L-fuzzy hypercontext, which provides an extension of the range of applications of fuzzy concept analysis. The advantage of working with L-fuzzy hypercontexts lies in the fact that we can establish relation among elements such that their values are, in turn, other relations. Thus, they are easily adaptable to different situations that vary over time. The usefulness of the developed theory is illustrated by a practical case in which the valuation made by the different clients of a hotel company is analyzed.
Open Access
New algorithm for the elucidation of functional properties of gelatin-based materials
(Elsevier, 2021) Leceta, Itsaso; Alcalde, Cristina; Urdanpilleta, Marta; Guerrero, Pedro; Caba, Koro de la; Burusco Juandeaburre, Ana; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
In the present work, fish gelatin was employed to develop renewable and biodegradable materials, reducing environmental problems associated with conventional petroleum-based materials. Glycerol was used as plasticizer and gallic acid was added in order to enhance the functional properties of the material. L-fuzzy concept analysis was applied for modelling the formulations and properties of the films. These new methodology is used in the design of the material avoiding the traditional inefficient trial an error approach usually employed. Two applications of the developed bio-based material were analyzed: fatty food packaging application in food area and wound healing in the biomedical field. The functional properties requirements of water contact angle (CA), water vapour transmission rate (WVTR), colour L* and b* values, tensile strength (TS), elongation at break (EB) and gloss values were specified for both applications. Applying the proposed algorithm, the required formulations were estimated and the experimental results showed a high accordance with the predicted values of the final properties, as well as with the requirements. This analysis allowed finding the required formulations in a highly cost-effective way.
Open Access
Evolution of L-fuzzy contexts associated with criteria
(Springer, 2020) Alcalde, Cristina; Burusco Juandeaburre, Ana; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Estadística, Informática y Matemáticas
This paper will delve deeper into the general study of the L-fuzzy contexts associated with criteria analyzing situations with a known evolution over time. These criteria may be independent or dependent on each other. We propose two different studies: to build an aggregated context looking for a simplification of the process and to keep the sequence obtaining interesting nuances over time. In both cases, aggregation operators will be used in order to address the problem. Finally, a practical example about ratings obtained by different tourist accommodations illustrates the results.
Open Access
Knowledge extraction from L-fuzzy contexts associated with criteria evolving over time
(IOS Press, 2020) Alcalde, Cristina; Burusco Juandeaburre, Ana; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Estadística, Informática y Matemáticas
Information extracted from L-fuzzy contexts is substantially improved by taking into account different points of view, which can roughly be represented by criteria. This work addresses the general study of L-fuzzy contexts were a set of criteria is introduced, analyzing situations in which their evolution over time is known. The relationship among criteria is also an important point in the study. In this sense, the treatment will vary depending on whether they are independent criteria or there exists dependency among them. Of special importance will be those elements that stand out for presenting a positive temporal evolution. Four algorithms are proposed in order to analyze the different situations. Finally, the applicability of the results is shown thought an example where the opinion of the clients of several hotels is analyzed taking into account both the type of traveler considered and the different aspects of the establishments on which a score is given.
Open Access
Trend analysis in L-fuzzy contexts with absent values
(University of Sistan and Baluchestan (Irán), 2020) Alcalde, Cristina; Burusco Juandeaburre, Ana; Bustince Sola, Humberto; Sesma Sara, Mikel; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Sometimes we have to work with L-fuzzy context sequences where one or more values are missing. These sequences can represent, among other things, the evolution in time of an L-fuzzy context. The studies of tendencies that we have done so far used tools that are not valid when the L-fuzzy context has unknown values. In this work we address such situations and we propose new methods to tackle the problem. Besides, we use the study of tendencies to analyse relations between the objects and the attributes of L-fuzzy contexts and to replace the absent values taking into account the behaviour of the sequence.