The construction industry's overall project performance is significantly reduced by numerous interface issues that also hinder its industrialization. Interface Management (IM) is becoming critical to the success of multidisciplinary construction projects. This research deals with three challenging problems associated with IM: 1) how to build a holistic understanding of interface issues for developing all-around IM solutions; 2) how to define and present interface information in a unified, accurate, and efficient way to improve information sharing, coordination, and implementation; and 3) how to resolve interface issues as a whole to optimize IM performance. Comprehensive cause factors of interface issues are investigated from different yet interrelated perspectives. These cause factors allow for the development of an object data model and a systematic IM strategy. The findings of this multi-perspective approach not only add a holistic view of interface issues to the existing body of knowledge but also provide a theoretical base for researchers and practitioners to seek all-around IM solutions. As a key innovation, an object view of interfaces is defined, resulting in a unified way of presenting interface information. This new technique of modeling interfaces as knowledgeable, intelligent, and active objects is far superior to the traditional use of simple relationships. The proposed Interface Object Model (IOM) framework is the first in the literature to present a comprehensive data structure and its dependencies of interface information for object modeling. This can greatly improve the quality and interoperability of modeled interface information. When integrated into a Building Information Modeling (BIM) approach, this technique can significantly enhance BIM capabilities for interface-related coordination, decision-making, operation, and management. As a first application, a systematic model-based IM strategy is conceptually developed, which provides a good foundation for creating an implementation environment for the developed interface model. This strategy aims to resolve interface issues as a whole throughout a complete project process. The multi-perspective approach, the generically structured IOM, and the conceptual, systematic IM strategy all target broad applications. Individually or jointly, they can also be applied to other domains beyond construction. / Ph. D.

Interface modeling is a critical aspect in any multi-material system modeling. Even a small change in the interface model may lead to significant changes in material behavior of the microscale, and these changes may transfer up to higher scales influencing the strain and stress fields, and damaging behavior in the macroscale material. This work focuses on the effects of different interface models in nanocomposites composed of carbon nanotubes in polymer matrix materials and their applications as nanocomposite binders in energetic materials. These material systems include materials that span multiple scales from nano to macroscale, and thus require a detailed multiscale analysis. A hierarchical multiscale framework is employed here, where the effective material properties from subscales are obtained by solving the subscale boundary value problem. The information obtained from the subscale simulations are transferred up to higher scales to be used as input properties. A nonlocal continuum mechanics framework known as peridynamics is used to perform the computational simulations. Peridynamics uses integro-differential equations for conservation laws instead of partial differential equations as in the classical continuum mechanics. This makes it possible for peridynamics to inherently account for nonlocal effects such as damage initiation, crack growth, and crack branching without any modifications such as element deletion, adaptive mesh refinement, using enrichment functions and so on, which are commonly used in other numerical methods. Peridynamics is a particle-based method where the particles are allowed to interact with other particles within their horizon which serves as a cut-off distance for forming particle-to-particle bonds and therefore defines the extent of nonlocality. Peridynamics has different formulations regarding the bond interactions. A bond-based peridynamics framework is used here. A verified and validated in-house code is used for the simulations. The simulations for the carbon nanotube and nanofiber-based nanocomposites, and for nanocomposite bonded energetic materials start from the microscale and range up to the macroscale. For only the carbon nanotube-polymer nanocomposites, the interfaces include the CNT-polymer interfaces. For the energetic materials, the interfaces consider the CNT-polymer interfaces in the microscale and the grain-nanocomposite binder interfaces in the mesoscale. Peridynamics, being a nonlocal continuum mechanics method, by default will have nonlocal interfaces. The material systems investigated in this work first use different nonlocal interfaces in peridynamics which consider the bond between two particles at the interface to be connected in series or in parallel. The nonlocal interface model in peridynamics makes it challenging to control the interface properties and leads to fuzzy interfaces, i.e. interfaces of finite thickness. In this work, a local cohesive interface model is implemented in the peridynamics framework. Cohesive zones were originally used for modeling the growth of cracks by introducing cohesive forces that hold the crack surfaces together, thereby removing the stress singularity problem in linear elastic fracture mechanics. The idea of cohesive zones are applied to peridynamics interfaces, which introduces locality into the nonlocal framework. This interface model does not only remove the nonlocality at the peridynamics interfaces, but it leads to a higher fidelity interface model that is controllable by the user. The differences between the nonlocal and local interfaces are studied in detail in different scales and for different material systems. Implementing a local model into a nonlocal framework brings some challenges, namely obtaining and calibrating the cohesive interface properties for the materials used, the numerical problems with material interpenetration in extreme compression, and very small time steps that are required to resolve the material response. Some remedies are proposed for the problems encountered. The cohesive zone model used in this work can have different functional forms in normal and tangential direction to reflect differences in opening mode and frictional sliding behaviors. / Doctor of Philosophy / Multi-material systems have interface regions where a transition from one material to another occurs. How the interface region is modeled can change the response of a material to external loads even if the interface model is slightly different. This work focuses on the effect of different interface models in nanocomposites based on carbon nanotubes and in nanocomposite bonded energetic materials. These material systems include materials that span multiple scales from nano to the macroscale, and thus require a detailed multiscale analysis. Multiscale analysis of a material means analyzing the material at each scale that is involved for the given material system separately and passing relevant information between the scales. A hierarchical multiscale framework is employed here which is based on a bottom-up approach, where the material properties are obtained at the smaller scales and passed up to the larger scales to be used as the input properties. A nonlocal continuum mechanics in the form of peridynamics is used to perform the computational simulations. The nonlocality stems from the fact that the particles can interact not only with their closest neighbors, but with other particles within their horizon, which is the cut-off distance that dictates how far a material particle can make bonds with other particles. The main advantage of peridynamics is to be able to model cracks without any a priori knowledge about crack growth directions or patterns. Peridynamics has different formulations for representing the bond interactions. A bond-based peridynamics framework is used here. A verified and validated in-house code is used for the simulations. The simulations for the carbon nanotube-polymer nanocomposites and nanocomposite bonded energetic materials take place starting from the microscale up to the macroscale. For the carbon nanotube nanocomposite scale, the interfaces include the fiber-matrix interfaces. For the nanocomposite bonded energetic materials, the interfaces considered include the fiber-matrix interfaces in the microscale and the grain-binder interfaces in the mesoscale. Peridynamics, being a nonlocal continuum mechanics method, nominally includes nonlocal interfaces. The material systems investigated in this work first use different nonlocal interfaces in peridynamics which consider the bond between two particles at the interface to be connected in series or in parallel. The nonlocal interface model in peridynamics makes it challenging to control the interface properties and leads to fuzzy, or finite thickness interfaces. A local cohesive interface model is implemented in the peridynamics framework. Cohesive zones are originally used for modeling cracks by introducing cohesive forces that hold the crack surfaces together to remove the stress singularity at the crack in classical linear elastic fracture mechanics. The idea of cohesive zones are applied to peridynamics interfaces which introduces locality into the nonlocal framework. This interface model does not only remove the nonlocality at the peridynamics interfaces, but it leads to a higher fidelity interface model that is controllable by the user. The differences between the nonlocal and local interfaces are studied in detail in different scales and for different material systems. Implementing a local model into a nonlocal framework brings some challenges, namely obtaining and calibrating the cohesive interface properties for the materials used, the numerical problems with material interpenetration in extreme compression, and very small time steps that are required to resolve the material response. Some remedies are proposed to address these issues. The cohesive zone model used in this work have different mathematical models in normal and tangential directions. It is therefore capable of modeling mechanical and thermal problems including frictional heating. The mechanical results obtained by using cohesive interfaces show potential for developing similar local interface models for thermal and electrical conduction allowing for the expanded application of the approach to multiphysics problems in multiscale composite materials.

User interface (UI) has become the key element of modern information systems (ISs) and is commonly viewed as one of the decisive factors for the success of an IS project. Many component-based development tools have been introduced by software vendors to meet the needs of designing a variety of UIs. Such modern design tools offer system developer vehicles to create sophisticated UIs with a few codes. However, the modeling methodology from the stages of user requirement modeling to UI modeling based on the modern design tools is virtually lacking. This study presents an integrated modeling methodology, which integrates the unified modeling language with interface drawing and interface glossary to provide a seamless and graphical approach and specifications for component-based UI modeling from user requirement modeling. A real-world case using the integrated approach is presented and a prototype system is developed to illustrate the concepts, application, and the advantages of using the proposed methodology.

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Made available in DSpace on 2014-07-29T14:57:49Z (GMT). No. of bitstreams: 1 Sofia Larissa da Costa.pdf: 2367903 bytes, checksum: ef9af67f05d333ef7a30026e0e9b9052 (MD5) Previous issue date: 2011-06-15 / Building user interfaces for Information Systems (IS) involves modeling and coding appearance (presentation) and behavioral (interaction) aspects. This work presents a modelbased approach to building these interfaces using tools for automatic transformation of models and for interface code generation. The proposed approach applies the concept of Interface Stereotype, introduced in this work, which identifies, in a high level of abstraction, features of user interface (UI) appearance and behavior, independently of the underlying IS application. A taxonomy of interface elements is proposed as the basis for stereotype definition, along with a interface behavior specification mechanism, which allows expressing actions and restrictions on the stereotypes by precise, objective and independently from the interface implementation platform. It is also proposed a architecture for a software component which manages model-based user interfaces building. The architecture defines how this component can be integrated in IS development process. The approach for model-based user interface development proposed in this work brings benefits in effort and cost construction terms, facilitating the maintenance and the evolution of user interface of IS. Futhermore, the use of stereotypes promotes consistency and standardization of both presentation and behavior of interfaces, improving usability of IS. / A construção de interfaces de usuário para Sistemas de Informação (SI) envolve modelagem e codificação de aspectos de aparência (apresentação) e comportamento (forma de interação). Este trabalho propõe uma abordagem baseada em modelos para construção dessas interfaces com o apoio de ferramentas de transformação automática de modelos e de geração de código de interface. A abordagem utiliza o conceito de Estereótipo de Interface, introduzido neste trabalho, que identifica, em alto nível de abstração, características de aparência e comportamento de interfaces, independentemente da aplicação do Sistema de Informação subjacente. Uma taxonomia para elementos de interface é proposta como base para a definição de estereótipos, juntamente com um mecanismo para especificação do comportamento da interface, que permite expressar ações e restrições sobre estereótipos de interface de maneira precisa, objetiva e independente da plataforma de implementação da interface. Também é proposta uma arquitetura para um componente de software que gerencia a construção de interfaces baseada em modelos. A arquitetura define como este componente pode ser integrado ao processo de desenvolvimento de SI. A abordagem para construção baseada em modelos proposta neste trabalho traz benefícios em termos de esforço e custo de construção facilitando a manutenção e a evolução de interfaces de usuário em SI. Além disso, o uso de estereótipos promove a consistência e a padronização, tanto da apresentação quanto do comportamento das interfaces, melhorando a usabilidade de SI.