Representação da informação incerta por meio de ontologias: um framework para smart homes

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação, Programa de Pós-Graduação em Ciência da Informação, Florianópolis, 2019.Nas smart homes e outros cenários da Internet das Coisas (IoT), muitas vezes, as informações coletadas estão sujeitas a interferências externas. Além disso, pode ser necessário representar situações nas quais não é possível se obter informações completas ou precisas sobre determinado fenômeno, gerando a necessidade de se lidar com a informação incerta. As ontologias apresentam um formato amplamente utilizado para a representação das informações coletadas nas smart homes. Sendo assim, atualmente existem várias abordagens não padronizadas na literatura baseadas em ontologias para a representação da informação incerta, ou ontologias incertas . Diante desse contexto, o objetivo deste trabalho é propor um framework para ser utilizado como ferramenta de referência no processo de seleção de ontologias incertas para cenários de smart homes. Para isso, foram identificadas ontologias incertas para smart homes por meio de uma Revisão Sistemática da Literatura (RSL) e foram realizadas pesquisas nos anais do International Workshop on Uncertainty Reasoning for the Semantic Web (URSW). O framework proposto é composto por dois artefatos gerados a partir de informações extraídas das ontologias incertas identificadas: a) questionário para auxiliar na identificação das necessidades de representação da informação incerta; e b) quadro de referência para ser consultado durante a seleção de uma ontologia incerta de acordo com as necessidades de representação da informação incerta. Ao todo, foram identificados 16 trabalhos que propõem ontologias incertas. Com base nestes trabalhos, elaborou-se o questionário com seis questões e diferentes opções de respostas que remetem as ontologias incertas. O quadro de referência foi elaborado contendo os 16 trabalhos identificados e as características das ontologias incertas propostas por cada trabalho. O framework foi aplicado em nove cenários de smart homes que utilizam ontologias, mas não representam a informação incerta, de modo a exemplificar o papel do framework como ferramenta de referência. Como resultado de sua aplicação, para cada cenário, exceto um, identificou-se uma ou mais opções de ontologias incertas. Isto indica que as ontologias incertas disponíveis cobrem grande parte das necessidades de representação atualmente, mas não completamente. Espera-se que o framework proposto possa ser utilizado como referência para facilitar o acesso e uso das ontologias incertas pelos profissionais interessados na construção de ontologias. Finalmente, espera-se gerar oportunidades para que sejam desenvolvidas aplicações que elevem a qualidade e capacidade dos cenários de smart homes tendo em vista principalmente as necessidades e bem-estar das pessoas.Abstract : In smart homes and other Internet of Things (IoT) scenarios, often information collected is subject to external interference. Moreover, it may be necessary to represent situations in which it is not possible to obtain complete or accurate information about a specific phenomenon, causing the need to deal with uncertain information. Ontologies provides a widespread format for representing information collected in smart homes. This way, nowadays there are many non-standard ontology-based approaches in literature focused in the task of uncertain information representation, or \"uncertain ontologies\". Given this context, the objective of this work is to propose a framework to be used as a reference tool in the process of selecting uncertain ontologies for smart home scenarios. For this purpose, uncertain ontologies for smart homes and other IoT scenarios are identified by means of a Systematic Review of Literature (RSL) and by research in proceedings from International Workshop on Uncertainty Reasoning for the Semantic Web (URSW). The proposed framework is composed by two artifacts generated from information extracted from identified uncertain ontologies: a) a survey to assist in identifying the needs for representing uncertain information; and b) a reference table which can be used for selection of uncertain ontologies according to the representation needs. Altogether, 16 uncertain ontologies proposals have been identified. Based on these proposals, the questionnaire was elaborated with six questions and different options of answers referring to uncertain ontologies. The reference table was built containing the 16 ontologies proposals and its specific features. The framework was applied in nine scenarios of smart homes which use ontologies, but do not represent the uncertain information, in order to exemplify the role of the framework as a reference tool. As a result of its application one or more uncertain ontologies options were identified for most of the work. This indicates that the available uncertain ontologies cover most of the representation needs currently, but not all. It is expected that the proposed framework will be used as a reference to ease the access and use of uncertain ontologies by professionals interested in the creation of ontologies. Finally, it is expected to generate opportunities to develop applications which raise the quality and capacity of smart home scenarios especially in view of the needs and well-being of people

Context-aware Knowledge-based Systems: A Literature Review

Context awareness systems, a subcategory of intelligent systems, are concerned with suggesting relevant products/services to users' situations as smart services. One key element for improving smart services’ quality is to organize and manipulate contextual data in an appropriate manner to facilitate knowledge generation from these data. In this light, a knowledge-based approach, can be used as a key component in context-aware systems. Context awareness and knowledge-based systems, in fact, have been gaining prominence in their respective domains for decades. However, few studies have focused on how to reconcile the two fields to maximize the benefits of each field. For this reason, the objective of this paper is to present a literature review of how context-aware systems, with a focus on the knowledge-based approach, have recently been conceptualized to promote further research in this area. In the end, the implications and current challenges of the study will be discussed

Fudge: Fuzzy ontology building with consensuated fuzzy datatypes

An important problem in Fuzzy OWL 2 ontology building is the definition of fuzzy membership functions for real-valued fuzzy sets (so-called fuzzy datatypes in Fuzzy OWL 2 terminology). In this paper, we present a tool, called Fudge, whose aim is to support the consensual creation of fuzzy datatypes by aggregating the specifications given by a group of experts. Fudge is freeware and currently supports several linguistic aggregation strategies, including the convex combination, linguistic OWA, weighted mean and fuzzy OWA, and easily allows to build others in. We also propose and have implemented two novel linguistic aggregation operators, based on a left recursive form of the convex combination and of the linguistic OWA

A new fuzzy ontology development methodology (FODM) proposal

There is an upsurge in applying fuzzy ontologies to represent vague information in the knowledge representation field. Current research in the fuzzy ontologies paradigm mainly focuses on developing formalism languages to represent fuzzy ontologies, designing fuzzy ontology editors, and building fuzzy ontology applications in different domains. Less focus falls on establishing a formal methodological approach for building fuzzy ontologies. Existing fuzzy ontology development methodologies, such as the IKARUS-Onto methodology and Fuzzy Ontomethodology, provide formalized schedules for the conversion from crisp ontologies into fuzzy ones. However, a formal guidance on how to build fuzzy ontologies from scratch still lacks in current research. Therefore, this paper presents the first methodology, named FODM, for developing fuzzy ontologies from scratch. The proposed FODM can provide a very good guideline for formally constructing fuzzy ontologies in terms of completeness, comprehensiveness, generality, efficiency, and accuracy. To explain how the FODM works and demonstrate its usefulness, a fuzzy seabed characterization ontology is built based on the FODM and described step-by-step

A hybrid approach of knowledge-driven and data-driven reasoning for activity recognition in smart homes

Accurate activity recognition plays a major role in smart homes to provide assistance and support for users, especially elderly and cognitively impaired people. To realize this task, knowledge-driven approaches are one of the emerging research areas that have shown interesting advantages and features. However, several limitations have been associated with these approaches. The produced models are usually incomplete to capture all types of human activities. This resulted in the limited ability to accurately infer users’ activities. This paper presents an alternative approach by combining knowledge-driven with data-driven reasoning to allow activity models to evolve and adapt automatically based on users’ particularities. Firstly, a knowledge-driven reasoning is presented for inferring an initial activity model. The model is then trained using data-driven techniques to produce a dynamic activity model that learns users’ varying action. This approach has been evaluated using a publicly available dataset and the experimental results show the learned activity model yields significantly higher recognition rates compared to the initial activity model

Sensor-based datasets for human activity recognition - a systematic review of literature

The research area of ambient assisted living has led to the development of activity recognition systems (ARS) based on human activity recognition (HAR). These systems improve the quality of life and the health care of the elderly and dependent people. However, before making them available to end users, it is necessary to evaluate their performance in recognizing activities of daily living, using data set benchmarks in experimental scenarios. For that reason, the scientific community has developed and provided a huge amount of data sets for HAR. Therefore, identifying which ones to use in the evaluation process and which techniques are the most appropriate for prediction of HAR in a specific context is not a trivial task and is key to further progress in this area of research. This work presents a systematic review of the literature of the sensor-based data sets used to evaluate ARS. On the one hand, an analysis of different variables taken from indexed publications related to this field was performed. The sources of information are journals, proceedings, and books located in specialized databases. The analyzed variables characterize publications by year, database, type, quartile, country of origin, and destination, using scientometrics, which allowed identification of the data set most used by researchers. On the other hand, the descriptive and functional variables were analyzed for each of the identified data sets: occupation, annotation, approach, segmentation, representation, feature selection, balancing and addition of instances, and classifier used for recognition. This paper provides an analysis of the sensor-based data sets used in HAR to date, identifying the most appropriate dataset to evaluate ARS and the classification techniques that generate better results

Sensor-based datasets for human activity recognition - a systematic review of literature

The research area of ambient assisted living has led to the development of activity recognition systems (ARS) based on human activity recognition (HAR). These systems improve the quality of life and the health care of the elderly and dependent people. However, before making them available to end users, it is necessary to evaluate their performance in recognizing activities of daily living, using data set benchmarks in experimental scenarios. For that reason, the scientific community has developed and provided a huge amount of data sets for HAR. Therefore, identifying which ones to use in the evaluation process and which techniques are the most appropriate for prediction of HAR in a specific context is not a trivial task and is key to further progress in this area of research. This work presents a systematic review of the literature of the sensor-based data sets used to evaluate ARS. On the one hand, an analysis of different variables taken from indexed publications related to this field was performed. The sources of information are journals, proceedings, and books located in specialized databases. The analyzed variables characterize publications by year, database, type, quartile, country of origin, and destination, using scientometrics, which allowed identification of the data set most used by researchers. On the other hand, the descriptive and functional variables were analyzed for each of the identified data sets: occupation, annotation, approach, segmentation, representation, feature selection, balancing and addition of instances, and classifier used for recognition. This paper provides an analysis of the sensor-based data sets used in HAR to date, identifying the most appropriate dataset to evaluate ARS and the classification techniques that generate better results

Development of a Digital Twin of a Flexible Manufacturing System for Assisted Learning

Learning Factories provide a propitious learning environment for nurturing production related competencies. However, several problems continue to plague their widespread adoption. Further, assessment of attained competencies continue to remain a concern. This study proposes the use of digital twins as an alternative learning platform for production engineering courses. It is proposed that in the context of manufacturing pedagogy, digital twins of manufacturing processes can play a significant role in delivering efficacious learning experiences. The high-fidelity replication of the physical system aids with reflective observation of the entailed processes in the greatest possible detail, fostering concrete learning experiences. An iterative research methodology towards modelling a pedagogic digital twin is undertaken to build a learning environment that is characterized by ontologies that model learning objectives, learning outcomes and assessment of the said outcomes. This environment facilitates automated assessment of the learner via ontological reasoning mechanisms. The underlying schema takes into account the learner’s profile and focuses on competency attainment through reasoning of behavioural assessment of aligned learning outcomes. The thesis presents also a case study that demonstrates how the learner’s competency level may be evaluated and compared with other learners thus warranting its use a learning tool that proves beneficial in an academic setting