Šiame darbe nagrinėjamos išskirstytos sistemos ir jų kūrimui naudojamos technologijos. Kadangi technologijų yra daug, o visas jas ištirti ir palyginti būtų labai sunku, todėl didžiausias dėmesys skiriamas Java RMI ir .Net Remoting – tai dvi populiarios išskirstytų objektų paradigmos šiuo metu naudojamos programų sistemų kūrimui Pagrindinis darbo tikslas yra išanalizuoti ir visapusiškai palyginti pasirinktas technologijas, didelį dėmesį skiriant jų veikimo greičiui. Darbas sudarytas iš keturių dalių. Pirmoje dalyje pateikiama bendra informacija apie išskirstytas sistemas, jų vystymąsi, architektūras, technologijų raidą ir t.t.. Antroje dalyje nagrinėjama Java RMI ir .Net Remoting veikimo principai, kuriais remiasi šios technologijos. Trečioje dalyje pateikiami šių dviejų technologijų veikimo principų panašumai ir skirtumai. Ir galiausiai siekiant išsiaiškinti Java RMI ar .Net Remoting realiomis sąlygomis veikia greičiau, ketvirtoje dalyje pateikiamas atlikto vykdymo greičio tyrimo aprašymas. Atlikti darbai leidžia teigti, kad Java RMI ir .Net Remoting idėjiškai yra panašios technologijos, bet skirtumų, įtakojančių veikimą, tarp jų irgi yra. Greičio tyrimo metu gauti rezultatai parodė, kad .Net Remoting beveik visais atvejais yra lėtesnė nei Java RMI. / Distributed systems and technologies used for this type of software are analyzed in this paper. Since there are a lot of technologies and it would be very difficult to explore and compare all of them, therefore this paper mainly focuses on Java and RMI. Net Remoting - two popular distributed objects paradigms currently used in distributed systems development. The first part provides general information about distributed systems, their development, architectures, technologies, and so on. The second part of the paper analyses the operating principles of Java RMI and. Net Remoting. The third section determines technological similarities and differencies. And finally, in order to clarify the fact Java RMI or. Net Remoting works faster in real terms, the fourth part provides the results of the implemented speed test. Although Java RMI and. Net Remoting are similar technologies, but the analysis showed that the there are quite a lot differences between them. The speed survey showed that. Net Remoting is slower than Java RMI in almost all cases.

This master thesis design and implement new software which can help children learn and practice "Wubi" Chinese typewriting. The purpose of designing this software is to effectively reduce the phenomenon in China known as "forget how to write while taking pen", so-called character amnesia. First we interviewed two experienced teachers and one class of pupils from an elementary school to collect data. Based on the data we collected, we built a set of prototypes by using PowerPoint on computer and evaluated it by three invited children who belonged to our target user group. After we modified our prototype, we implemented it on a computer using the Java programming language. When the process came to the evaluation part, we invited four students who had background knowledge on the field of HCI and its evaluation methods, to help us finish a cognitive walkthrough evaluation. Although some part of our software, such as certain interfaces and sequences, should be improved in the future work, the opinions of the evaluators were mostly positive.

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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

<p>The aim of this work is to design an experiment, where client-server systems can be compared. They belong to the group of systems that are called component systems. Client-server systems are difficult to compare, because they are complex. The client-server systems are documented in different ways. Notations in the implementation of them are in different ways. There is a large difference in the communication between the client and server. The architectures between the client-server systems differ also, but they are not totally different. Therefore it is possible to construct an experiment for comparing them. Client-server systems that will be compared are Java RMI, Web Services, CORBA, and Enterprise JavaBeans. We are going to use Java as the programming language. Some of these systems, for example CORBA, can be implemented in other languages. The designed experiment is among other things going to answer how long time is needed to implement a specific application, how fast a specific client-server system is, and how long time is spent for learning about a specific system.</p>

<p>A Transaction Reproduction System (ARTSY) is a distributed system that enables secure transactions and reproductions of digital content over an insecure network. A field of application is reproductions of visual arts: A print workshop could for example use ARTSY to print a digital image that is located at a remote museum. The purpose of this master thesis project was to propose a specification for ARTSY and to show that it is technically feasible to implement it. </p><p>An analysis of the security threats in the ARTSY context was performed and a security model was developed. The security model was approved by a leading computer security expert. The security mechanisms that were chosen for the model were: Asymmetric cryptology, digital signatures, symmetric cryptology and a public key registry. A Software Requirements Specification was developed. It contains extra directives for image reproduction systems but it is possible to use it for an arbitrary type of reproduction system. A prototype of ARTSY was implemented using the Java programming language. The prototype uses XML to manage information and Java RMI to enable remote communication between its components. It was built as a platform independent system and it has been tested and proven to be operational on the Sun Solaris platform as well as the Win32 platform.</p>

A Transaction Reproduction System (ARTSY) is a distributed system that enables secure transactions and reproductions of digital content over an insecure network. A field of application is reproductions of visual arts: A print workshop could for example use ARTSY to print a digital image that is located at a remote museum. The purpose of this master thesis project was to propose a specification for ARTSY and to show that it is technically feasible to implement it. An analysis of the security threats in the ARTSY context was performed and a security model was developed. The security model was approved by a leading computer security expert. The security mechanisms that were chosen for the model were: Asymmetric cryptology, digital signatures, symmetric cryptology and a public key registry. A Software Requirements Specification was developed. It contains extra directives for image reproduction systems but it is possible to use it for an arbitrary type of reproduction system. A prototype of ARTSY was implemented using the Java programming language. The prototype uses XML to manage information and Java RMI to enable remote communication between its components. It was built as a platform independent system and it has been tested and proven to be operational on the Sun Solaris platform as well as the Win32 platform.

Made available in DSpace on 2016-06-02T19:05:23Z (GMT). No. of bitstreams: 1 DissLAFB.pdf: 1617842 bytes, checksum: 0e04147b28caae9983df30e2b3a878bd (MD5) Previous issue date: 2006-12-14 / This master thesis deals with the involved aspects for the creation of a framework for connectivity in JAMP (Java Architecture for Media Processing). The conception of this framework aims to make possible the use of mobile devices by means of other wireless network technologies. Such technologies, as Bluetooth, used for the publication/localization of services registered in the JBroker, the broker of JAMP Platform developed in Java/RMI, as well as the communication of devices that make use of such technologies through this broker, had been used in the implementation and tests of the framework developed. The implementation aims to access, from devices with Bluetooth network interface, the available remote services in the Internet. These services are requested by mobile devices, such as PDAs, cellular or smartphones, that they consult access points, in Bluetooth communication. The access points consult the JBroker that returns a reference for the service to be consumed. The access points then direct the result to the mobile devices. The experiments developed in this work had been based on scenes where a mobile device, in Bluetooth communication, requests services to a point of access in a PC and this, saw TCP/IP, invokes remote methods in the servers who disponibilizam the services, saw Java/RMI. JAMP already all presented the mechanism of localization of services saw Java/RMI, however it did not present the extension developed with this work, where they had been created one proxy, that it is executed in the access point, and the use of services of the JAMP to break mobile devices that if communicate through technology of different net of TCP/IP. Being thus, its innovation is in the capacity of use of devices that make use of technology of Bluetooth net, being able to be extended to other technologies, without needing would reengeneering previously existing in the architecture. / Esta dissertação de mestrado trata dos aspectos envolvidos para a criação de um framework de conectividade na JAMP (Java Architecture for Media Processing). A concepção desse framework tem por objetivo possibilitar a utilização de dispositivos móveis por meio de outras tecnologias de rede sem fio. Tais tecnologias, como Bluetooth, usadas para a publicação/localização de serviços registrados no JBroker, broker da Plataforma JAMP desenvolvido em Java/RMI, bem como a comunicação de dispositivos que dispõem de tal tecnologia, foram empregadas na implementação e testes do framework desenvolvido. A implementação visa ao acesso, a partir de dispositivos com interface de rede Bluetooth, a serviços remotos disponíveis na Internet. Esses serviços são requisitados por dispositivos móveis, tais como PDAs, celulares ou smartphones, que consultam pontos de acesso, via Bluetooth. Os pontos de acesso consultam o JBroker que retorna uma referência para o serviço a ser consumido. Os pontos de acesso então encaminham o resultado aos dispositivos móveis. Os experimentos desenvolvidos neste trabalho basearam-se no cenário onde um dispositivo móvel, em comunicação Bluetooth, requisita serviços a um ponto de acesso em um PC e este, via TCP/IP, invoca métodos remotos nos servidores que disponibilizam os serviços, via Java/RMI. A JAMP já apresentava todo o mecanismo de localização de serviços via Java/RMI, porém não apresentava a extensão desenvolvida neste trabalho. Nesta, foram criados um proxy, que é executado no ponto de acesso, e a utilização de serviços da JAMP a partir de dispositivos móveis que se comunicam através de tecnologia de rede diferente de TCP/IP. Sendo assim, sua inovação está na capacidade de utilização de dispositivos que dispõem de tecnologia de rede Bluetooth, podendo ser estendido a outras tecnologias, sem necessitar da reengenharia previamente existente na arquitetura

The aim of this work is to design an experiment, where client-server systems can be compared. They belong to the group of systems that are called component systems. Client-server systems are difficult to compare, because they are complex. The client-server systems are documented in different ways. Notations in the implementation of them are in different ways. There is a large difference in the communication between the client and server. The architectures between the client-server systems differ also, but they are not totally different. Therefore it is possible to construct an experiment for comparing them. Client-server systems that will be compared are Java RMI, Web Services, CORBA, and Enterprise JavaBeans. We are going to use Java as the programming language. Some of these systems, for example CORBA, can be implemented in other languages. The designed experiment is among other things going to answer how long time is needed to implement a specific application, how fast a specific client-server system is, and how long time is spent for learning about a specific system.

Moderne, objektorientierte Sprachen spielen bei der Entwicklung von Software für eingebettete Systeme bislang kaum eine Rolle. Die Gründe hierfür sind vielfältig, meist wird jedoch die mangelnde Effizienz und der größere Speicherbedarf hervorgehoben. Obwohl Java viele Eigenschaften hat, die sehr für einen Einsatz in eingebetteten Systemen sprechen, so hängt doch gerade Java vielfach immer noch das Vorurteil an, in Systemen mit beschränkter Rechenleistung und Speicher zu viele Ressourcen zu benötigen. Diese Arbeit soll dazu beitragen, diese Vorurteile abzutragen. Sie stellt insbesondere Techniken vor, die den Speicherbedarf einer JVM so gering wie möglich halten und diese effizient mit der zur Verfügung stehenden Rechenleistung umgehen lassen. Viele der dargestellten Verfahren und Algorithmen wurden in der Kertasarie VM implementiert, einer virtuellen Maschine, die speziell für den Einsatz in eingebetteten Systemen konzipiert wurde. Durch die weit verbreitete Vernetzung eingebetteter Systeme über das Internet stellt sich in vielen Fällen zudem das Problem einer modernen, abstrakten und effizienten Form der Kommunikation. Aus diesem Grund liegt der zweite Schwerpunkt dieser Arbeit auf dem Vergleich von objektorientierten Middleware-Architekturen, insbesondere von Java-RMI. Auch auf diesem Gebiet wird eine eigene, speziell an eingebettete Systeme angepasste RMI-Variante vorgestellt. / Modern, object oriented languages do not play an important role when developing software for embedded systems. There are many reasons for it, most often an inadequate performance and a greater memory demand are mentioned. In spite of the fact that Java has many features suitable for embedded systems, Java often faces the prejudice to consume too much resources in systems with limited processing power and memory. This work is a contribution to diminish this prejudices. It presents techniques to limit the memory demands of a Java Virtual Machine and to effectively cope with limited computing power. Many of the presented methods and algorithms are implemented in the Kertasarie VM, a JVM designed to run in embedded systems.Due to the fact of increasing network capabilities embedded systems often face the problem of a modern, abstract and efficient communication. Therefore the second emphasis of this work is put on the comparison of object oriented middleware architectures, especially Java-RMI. An own implementation for embedded systems is also presented.