Made available in DSpace on 2015-02-04T21:45:28Z (GMT). No. of bitstreams: 1 Cayton Marques.pdf: 891116 bytes, checksum: e853859839384d700926d77414c4a3d1 (MD5) Previous issue date: 2006-02-09 / Modelos de componentes são evoluções naturais para as tecnologias de objetos distribuídos, o modelo de componentes CORBA (CCM ou CORBA Component Model) descreve um framework para a criação de aplicações CORBA baseadas em componentes e que encapsulam os detalhes de implementação de servidores CORBA. Componentes criados usando CCM são mais flexíveis do que os criados usando outros modelos de componentes como: COM+/.NET e EJB, em especial quanto a customização de seu comportamento. O trabalho tem como objetivo geral avaliar os aspectos funcionais internos de um contêiner que suporta componentes CCM, para este fim desenvolveu-se um protótipo funcional que implementa um subconjunto da especificação do modelo de componentes CORBA sobre o qual se executou uma aplicação de exemplo. Os resultados das experiências realizadas durante o estudo, interpretação da especificação, a implementação e execução tanto do contêiner quanto da aplicação de testes são descritos e comentados.

Le domaine d'application des cartes à microprocesseur est de plus en plus vaste (le secteur monétaire, la téléphonie, la santé). Dorénavant, la carte s'intègre dans des systèmes distribués (paiement sur Internet, téléphonie mobile). Ainsi, malgré l'apparition de nouvelles cartes utilisant des langages de programmation répandus (comme Java pour la JavaCard), le développement des applications carte, dans un milieu distribué et très sujet aux pannes, se révèle de plus en plus complexe. Le modèle transactionnel, de par ses propriétés (Atomicité, Cohérence, Isolation et Durabilité) représente une bonne solution au traitement de ces problèmes. L'implantation de ce modèle dans les cartes à microprocesseur impose l'adaptation de deux mécanismes (la reprise sur panne, et le contrôle de concurrence sur les données) bien connus des systèmes transactionnels classiques. Pour cela, il a notamment fallu tenir compte de la faible taille mémoire disponible et du processeur peu puissant. L'utilisation de cartes gérant les mécanismes cités précédemment (la COST) dans des systèmes distribués s'effectue grâce à une architecture (appelée STIC), utilisant un service de validation distribuée (OTS pour CORBA). Un composant d'adaptation prend en charge les contraintes de la carte (notamment en terme de protocole de communication), de manière à ne pas modifier l'architecture des systèmes existants. Une maquette, basée sur la JavaCard et le service OTS de CORBA, a été réalisée dans le but de simuler une application de paiement sur Internet.

<p>For a long time radio devices have been constructed in hardware with a fixed functionality. This way of constructing radio devices is starting to change with the concept of Software Defined Radio (SDR) evolving. The SDR concept leads to more flexible and long lasting radio devices. In order to make the radio software more standardized and portable, the U.S. military has defined the Software Communication Architecture (SCA). Internal communication within the SCA is done by CORBA, which limit waveforms to be only distributed over CORBA-capable hardware. The U.S. military has defined the Modem Hardware Abstraction Layer(MHAL) to enable distribution over devices not supporting CORBA. This thesis presents an implementation of MHAL and an underlying transport mechanism based on Ethernet. The implementation is done for the OSSIE package. The implementation is evaluated both in terms of real-time and throughput performance. The results show that MHAL achieves good performance, in comparison to CORBA, and can greatly be used to distribute waveforms over both CORBA and non-CORBA capable devices.</p>

<p>Software Defined Radio (SDR) is a conception of implementing radio functions in computer software, instead of having electronics performing the functions. This thesis aims to compare two different ways of implementing these functions, or waveforms.</p><p>The Software Communications Architecture (SCA) is an open standard developed by the United States Department of Defense. It uses a CORBA interface environment to make waveform applications interoperable and platform independent. This method of developing SDR is compared to an open-source initiative going by the name GNU Radio.</p><p>Two waveform applications are developed, one transmitter using SCA, and one receiver using GNU Radio. The analog radio interface is simulated using the sound cards of two regular PCs. The development is done using the C++ and Python programming languages.</p><p>This thesis examines pros and cons of the two SDR methods, as well as performing studies of Software Defined Radio in general.</p>

For a long time radio devices have been constructed in hardware with a fixed functionality. This way of constructing radio devices is starting to change with the concept of Software Defined Radio (SDR) evolving. The SDR concept leads to more flexible and long lasting radio devices. In order to make the radio software more standardized and portable, the U.S. military has defined the Software Communication Architecture (SCA). Internal communication within the SCA is done by CORBA, which limit waveforms to be only distributed over CORBA-capable hardware. The U.S. military has defined the Modem Hardware Abstraction Layer(MHAL) to enable distribution over devices not supporting CORBA. This thesis presents an implementation of MHAL and an underlying transport mechanism based on Ethernet. The implementation is done for the OSSIE package. The implementation is evaluated both in terms of real-time and throughput performance. The results show that MHAL achieves good performance, in comparison to CORBA, and can greatly be used to distribute waveforms over both CORBA and non-CORBA capable devices.

Software Defined Radio (SDR) is a conception of implementing radio functions in computer software, instead of having electronics performing the functions. This thesis aims to compare two different ways of implementing these functions, or waveforms. The Software Communications Architecture (SCA) is an open standard developed by the United States Department of Defense. It uses a CORBA interface environment to make waveform applications interoperable and platform independent. This method of developing SDR is compared to an open-source initiative going by the name GNU Radio. Two waveform applications are developed, one transmitter using SCA, and one receiver using GNU Radio. The analog radio interface is simulated using the sound cards of two regular PCs. The development is done using the C++ and Python programming languages. This thesis examines pros and cons of the two SDR methods, as well as performing studies of Software Defined Radio in general.

In this work an electronic warfare system is restructured to service oriented architecture. Service Oriented Architecture (SOA) is a paradigm that realizes rapid and low cost system development. The most important characteristics of SOA are standard based interoperability, which allows services developed on different platforms to run together, and dynamic composition via discovery, which provides dynamic composition of application at runtime using the existing services. The old warfare system that was developed by ASELSAN Inc. contained embedded software and was designed using traditional object oriented techniques. In this thesis, we have extracted services out of the system and restructured the warfare system based on service oriented principles. In this thesis, we have focused on the dramatic effect of reusability when SOA is introduced to the electronic warfare system. To understand the effect of service orientation, the new system is evaluated in terms of line of code, memory consumption and extra CORBA interface communication overhead.

<p>Event based programming is an important metaphor used in a variety of applications. Research and practice in this field comes primarily from two distinct sources, component software and databases. In both those fields, the need for asynchronous notifications has led to the specification and implementation of event models, but with somewhat different emphasis.</p><p>This dissertation defines an evaluation framework for evaluating event models. In doing so, it defines several factors that are important when reviewing different event models with respect to implementing applications or components that require event notification mechanisms.</p><p>It has been suggested that the event models defined for COM and CORBA can each be used as the basis for implementing advanced event services. The framework presented in this dissertation is used to evaluate these two event models with respect to their capability to support an advanced event service originating from active database research.</p>

<p>En komponentbaserad mjukvaruutveckling syftar till att minska utvecklings- och underhållskostnader för mjukvaruprogram. Trots att det idag inte finns någon enhälligt accepterad definition av en komponent så existerar komponentteknologier som ämnar till att minska utvecklingstiden för mjukvara genom komponenter.</p><p>De olika teknologierna som undersöks i denna rapport är Microsofts COM, OMGs CORBA och Suns JavaBeans. Dessa jämförs på tekniska egenskaper, prestanda, språkberoende, plattformsberoende och distributionsstöd då dessa egenskaper är viktiga för programvaruutvecklare vid val av teknologi. Detta genomförs med hjälp av en litteraturstudie över specifikationerna för respektive teknologi. Litteraturstudien täcker även material av teknologiernas existens på dagens kommersiella komponentmarknad.</p><p>Resultatet från jämförelsen pekar på att COM-teknologin kommer att dominera marknaden för komponenter på Windows-plattformarna och att CORBA kommer att smälta ihop med JavaBeans för att dominera marknaden för icke Windows-plattformar.</p>

Technische Univ., Diplomarbeit--Wien, 2005.