The big data framework applied to smart meters offers an exception platform for data-driven forecasting and decision making to achieve sustainable energy efficiency. Buying-in consumer confidence through respecting occupants' energy consumption behavior and preferences towards improved participation in various energy programs is imperative but difficult to obtain. The key elements for understanding and predicting household energy consumption are activities occupants perform, appliances and the times that appliances are used, and inter-appliance dependencies. This information can be extracted from the context rich big data from smart meters, although this is challenging because: (1) it is not trivial to mine complex interdependencies between appliances from multiple concurrent data streams; (2) it is difficult to derive accurate relationships between interval based events, where multiple appliance usage persist; (3) continuous generation of the energy consumption data can trigger changes in appliance associations with time and appliances. To overcome these challenges, we propose an unsupervised progressive incremental data mining technique using frequent pattern mining (appliance-appliance associations) and cluster analysis (appliance-time associations) coupled with a Bayesian network based prediction model. The proposed technique addresses the need to analyze temporal energy consumption patterns at the appliance level, which directly reflect consumers' behaviors and provide a basis for generalizing household energy models. Extensive experiments were performed on the model with real-world datasets and strong associations were discovered. The accuracy of the proposed model for predicting multiple appliances usage outperformed support vector machine during every stage while attaining accuracy of 81.65\%, 85.90\%, 89.58\% for 25\%, 50\% and 75\% of the training dataset size respectively. Moreover, accuracy results of 81.89\%, 75.88\%, 79.23\%, 74.74\%, and 72.81\% were obtained for short-term (hours), and long-term (day, week, month, and season) energy consumption forecasts, respectively.

Made available in DSpace on 2016-06-02T19:06:09Z (GMT). No. of bitstreams: 1 5554.pdf: 2294386 bytes, checksum: ce6dc6cd7128337c0533ddd23c0bc601 (MD5) Previous issue date: 2013-06-07 / The mining of sequential patterns in data from environmental sensors is a challenging task: the data may show noise and may also contain sparse patterns that are difficult to detect. The knowledge extracted from environmental sensor data can be used to determine climate change, for example. However, there is a lack of methods that can handle this type of database. In order to reduce this gap, the algorithm Incremental Miner of Stretchy Time Sequences with Post-Processing (IncMSTS-PP) was proposed. The IncMSTS-PP applies incremental extraction of sequential patterns with post-processing based on ontology for the generalization of the patterns. The post-processing makes the patterns semantically richer. Generalized patterns synthesize the information and makes it easier to be interpreted. IncMSTS-PP implements the Stretchy Time Window (STW) that allows stretchy time patterns (patterns with temporal intervals) are mined from bases that have noises. In comparison with GSP algorithm, IncMSTS-PP can return 2.3 times more patterns and patterns with 5 times more itemsets. The post-processing module is responsible for the reduction in 22.47% of the number of patterns presented to the user, but the returned patterns are semantically richer. Thus, the IncMSTS-PP showed good performance and mined relevant patterns showing, that way, that IncMSTS-PP is effective, efficient and appropriate for domain of environmental sensor data. / A mineração de padrões sequenciais em dados de sensores ambientais é uma tarefa desafiadora: os dados podem apresentar ruídos e podem, também, conter padrões esparsos que são difíceis de serem detectados. O conhecimento extraído de dados de sensores ambientais pode ser usado para determinar mudanças climáticas, por exemplo. Entretanto, há uma lacuna de métodos que podem lidar com este tipo de banco de dados. Com o intuito de diminuir esta lacuna, o algoritmo Incremental Miner of Stretchy Time Sequences with Post- Processing (IncMSTS-PP) foi proposto. O IncMSTS-PP aplica a extração incremental de padrões sequencias com pós-processamento baseado em ontologia para a generalização dos padrões obtidos que acarreta o enriquecimento semântico desses padrões. Padrões generalizados sintetizam a informação e a torna mais fácil de ser interpretada. IncMSTS-PP implementa o método Stretchy Time Window (STW) que permite que padrões de tempo elástico (padrões com intervalos temporais) sejam extraídos em bases que apresentam ruídos. Em comparação com o algoritmo GSP, o IncMSTS-PP pode retornar 2,3 vezes mais sequencias e sequencias com 5 vezes mais itemsets. O módulo de pós-processamento é responsável pela redução em 22,47% do número de padrões apresentados ao usuário, porém os padrões retornados são semanticamente mais ricos, se comparados aos padrões não generalizados. Assim sendo, o IncMSTS-PP apresentou bons resultados de desempenho e minerou padrões relevantes mostrando, assim, que IncMSTS-PP é eficaz, eficiente e apropriado em domínio de dados de sensores ambientais.