Reuse-based test planning for core-based systems-on-chip

Electronic applications are currently developed under the reuse-based paradigm. This design methodology presents several advantages for the reduction of the design complexity, but brings new challenges for the test of the final circuit. The access to embedded cores, the integration of several test methods, and the optimization of the several cost factors are just a few of the several problems that need to be tackled during test planning. Within this context, this thesis proposes two test planning approaches that aim at reducing the test costs of a core-based system by means of hardware reuse and integration of the test planning into the design flow. The first approach considers systems whose cores are connected directly or through a functional bus. The test planning method consists of a comprehensive model that includes the definition of a multi-mode access mechanism inside the chip and a search algorithm for the exploration of the design space. The access mechanism model considers the reuse of functional connections as well as partial test buses, cores transparency, and other bypass modes. The test schedule is defined in conjunction with the access mechanism so that good trade-offs among the costs of pins, area, and test time can be sought. Furthermore, system power constraints are also considered. This expansion of concerns makes it possible an efficient, yet fine-grained search, in the huge design space of a reuse-based environment. Experimental results clearly show the variety of trade-offs that can be explored using the proposed model, and its effectiveness on optimizing the system test plan. Networks-on-chip are likely to become the main communication platform of systemson- chip. Thus, the second approach presented in this work proposes the reuse of the on-chip network for the test of the cores embedded into the systems that use this communication platform. A power-aware test scheduling algorithm aiming at exploiting the network characteristics to minimize the system test time is presented. The reuse strategy is evaluated considering a number of system configurations, such as different positions of the cores in the network, power consumption constraints and number of interfaces with the tester. Experimental results show that the parallelization capability of the network can be exploited to reduce the system test time, whereas area and pin overhead are strongly minimized. In this manuscript, the main problems of the test of core-based systems are firstly identified and the current solutions are discussed. The problems being tackled by this thesis are then listed and the test planning approaches are detailed. Both test planning techniques are validated for the recently released ITC’02 SoC Test Benchmarks, and further compared to other test planning methods of the literature. This comparison confirms the efficiency of the proposed methods.

Ontology-based metadata for e-learning content

Nowadays, the popularity of the Web encourages the development of Hypermedia Systems dedicated to e-learning. Nevertheless, most of the available Web teaching systems apply the traditional paper-based learning resources presented as HTML pages making no use of the new capabilities provided by the Web. There is a challenge to develop educative systems that adapt the educative content to the style of learning, context and background of each student. Another research issue is the capacity to interoperate on the Web reusing learning objects. This work presents an approach to address these two issues by using the technologies of the Semantic Web. The approach presented here models the knowledge of the educative content and the learner’s profile with ontologies whose vocabularies are a refinement of those defined on standards situated on the Web as reference points to provide semantics. Ontologies enable the representation of metadata concerning simple learning objects and the rules that define the way that they can feasibly be assembled to configure more complex ones. These complex learning objects could be created dynamically according to the learners’ profile by intelligent agents that use the ontologies as the source of their beliefs. Interoperability issues were addressed by using an application profile of the IEEE LOM- Learning Object Metadata standard.

Concepção, desenvolvimento e validação de instrumentos de coleta de dados para estudar a percepção do processo decisório e as diferenças culturais

A presente dissertação insere-se no contexto de um projeto global de pesquisa, em desenvolvimento no GESID-PPGA/EA/UFRGS, com a cooperação de algumas universidades estrangeiras. Tal projeto tem como tema a percepção do processo decisório individual e a influência da cultura nacional e da experiência decisória. Para estudar a inter-relação destes assuntos é preciso, antes de mais nada, elaborar um conjunto de instrumentos que permitam investigar a percepção das pessoas sobre a tomada de decisão. Este é o objetivo principal do presente trabalho, que refere-se à primeira fase desse projeto global: a partir da literatura, e do conhecimento de um grupo de pesquisadores, conceber e desenvolver um conjunto de instrumentos (quantitativos e qualitativos) válidos para estudar a decisão. E ainda estabelecer uma metodologia de aplicação desse instrumental, a qual possa determinar uma seqüência (ordem) e forma de aplicação mais adequada. Para tanto, primeiramente foram definidas as 3 questões de pesquisa, que nortearam o desenvolvimento dos instrumentos de pesquisa, as quais deverão ser investigadas no contexto do projeto global de pesquisa, e que podem ser resumidas da seguinte forma: (1) Independentemente da cultura nacional ou do nível de experiência decisória dos indivíduos é possível identificar fatores comuns (passos, princípios, insights) a respeito da forma como as pessoas percebem o processo decisório individual, especialmente se tomado o modelo de processo decisório da “Racionalidade limitada” de Simon (1947) como padrão de comparação? (2) A cultura atua como fator de diferenciação na percepção do processo decisório individual? (3) A Experiência Decisória (vivência) dos indivíduos influencia a forma como eles percebem o processo decisório individual? A definição destas 3 questões de pesquisa possibilitou a concepção dos instrumentos, nos quais posteriormente foi realizada uma validação de conteúdo (por uma comissão de juízes) e de sua seqüência de aplicação (testando-se diferentes ordens), bem como a verificação da sua fidedignidade (através do Teste-reteste). Com este processo obteve-se os seguintes resultados: (1) projeto global consolidado; (2) conjunto de instrumentos de pesquisa concebido e validado; (3) seqüência de aplicação do instrumental definida e validada; (4) quadro de construtos definido fornecendo subsídios para a definição de um protocolo de análise de dados; (5) concepção de um método para verificação da "contaminação" de instrumentos de pesquisa.