Owing to the development of Internet, excessive online data drive users to apply tools to assist them in obtaining desired and useful information. Information retrieval techniques serve as one of the major assistance tools that ease users¡¦ information processing loads. However, most current IR models do not consider processing streaming information which essentially characterizes today¡¦s Web environment. The approach to re-building models based on the full knowledge of data at hand triggered by the new incoming information every time is impractical, inefficient, and costly. Instead, IR models that can be adapted to streaming information incrementally should be considered under the dynamic environment. Therefore, this research is to propose an IR related technique, the incremental aspect model (ISM), which not only uncovers latent aspects from the collected documents but also adapts the aspect model on streaming documents chronologically. There are two stages in ISM: in Stage I, we employ probabilistic latent semantic indexing (PLSI) technique to build a primary aspect model; and in Stage II, with out-of-date data removing and new data folding-in, the aspect model can be expanded using the derived spectral method if new aspects significantly exist. Three experiments are conducted accordingly to verify ISM. Results from the first two experiments show the robust performance of ISM in incremental text clustering tasks. In Experiment III, ISM performs the task of storylines tracking on the 2010 Soccer World Cup event. It illustrates ISM¡¦s incremental learning ability to discover different themes around the event at any time. The feasibility of our proposed approach in real applications is thus justified.

[pt] Programaçãoo Orientada a Aspectos (POA) é um paradigma de programação que propõe um novo tipo de abstração - denominado aspecto - que permite a descrição modular de propriedades que, em geral, se encontram espalhadas por vários pontos de um sistema. Há distintas abordagens que podem ser classificadas como orientadas a aspectos. Cada abordagem propõe tipos de abstração, mecanismos de composição e terminologia específicos. Nesta tese, deslocamos o foco de atenção dos mecanismos de implementação que dão suporte µa tecnologia de programação orientada a aspectos, para os conceitos e propriedades que a caracterizam como um paradigma emergente para o desenvolvimento de software. Em particular, focalizamos em como estes conceitos e propriedades podem ser explorados na fase de design para construir sistemas que sejam mais fáceis de compreender, evoluir e reutilizar. Esta tese aborda questões atuais relacionadas a design e modelagem orientados a aspectos e propõe: (i) o modelo de aspectos, um arcabouço conceitual unificador para POA que fornece terminologia consistente e semântica básica para analisar problemas µa luz dos conceitos e propriedades de POA, (ii) aSideML, uma linguagem de modelagem para especificação e comunicação de designs orientados a aspectos. A linguagem aSideML define uma notação gráfica, semântica e regras que permitem ao projetista construir modelos em que aspectos são tratados explicitamente como cidadãos de primeira classe, e (iii) o metamodelo aSide, um modelo lógico que define a semântica de modelos estruturais e comportamentais representados em aSideML. / [en] Aspect-Oriented Programming (AOP) is a new programming paradigm that promotes advanced separation of concerns by introducing a new modular unit, called aspect, for the modularization of crosscutting concerns. As an emerging programming paradigm, there are many different approaches to AOP, with distinct and varying sets of abstractions and composition mechanisms, specific terminology, properties and language constructs. In this thesis, we shift the focus from the mechanisms that support the aspect-oriented programming technology to the concepts and properties that characterize it as an emerging paradigm for software development. In particular, we focus on how these concepts and properties can be exploited at an early design stage to build systems that are easier to comprehend, evolve and reuse. This thesis addresses current issues related to aspect-oriented design and modeling, and proposes: (i) the aspect model, an unifying conceptual framework for AOP that provides consistent terminology and basic semantics for thinking about a problem in terms of AOP core concepts and properties, (ii) the aSideML, a modeling language for specifying and communicating aspect-oriented designs. The aSideML provides notation, semantics and guidelines that enable the designer to build models in which aspects are explicitly treated as first-class citizens, and (iii) the aSide metamodel, a logical model that defines the semantics of structural and behavioral models supported by the aSideML.