The usability of web applications today often suffers from the page-based medium’s lack of intrinsic support for hierarchical dialog sequences mirroring the parent-child relationships between dialog boxes in window-based user interfaces. For multi-channel applications, an additional challenge lies in reconciling the device-independent business logic with the device-specific interaction patterns necessitated by different clients’ input/output capabilities.We therefore present a graphical Dialog Flow Notation that allows the specification of nestable dialog sequences for different presentation channels. These specifications serve as input for a Dialog Control Framework that controls the dialog flows of complex web applications.

Hypertext-based user interfaces have become attractive for many distributed applications today, but they do not reach the usability level of window-based UIs. Because of insufficient dialog control logic, they cannot manage nested and hierarchical dialog structures that users have come to expect from window-based UIs. We therefore present a framework that implements a dialog control logic capable of handling complex, nested dialog structures, and introduce a notation and an XML-based language for specifying such dialog structures. Key concepts are the encapsulation of multiple dialog steps in context-independent dialog modules that can be nested arbitrarily, and the specification of multiple devicespecific interaction patterns for a single deviceindependent application logic. The framework allows black box reuse, leaving only the implementation of the application logic, the design of the user interface and the specification of the dialog flow to application developers.

In der Reihe .NET Business wird mit Agile MDA ein Lösungsansatz für die Umsetzung großer Softwareprojekte vorgestellt. Auch wenn die beschriebene Lösung nicht mit dem .NET Framework, sonderm mit Java umgesetzt wurde, lassen sich die aus dem Projekt gewonnenen Erkenntnisse grundsätzlich auch auf .NET-Projekte übertragen

Web services are increasingly used to integrate heterogeneous and autonomous applications in cross-organizational cooperations. A key problem is to support a high execution quality of complex cooperative processes, e.g. in e-business or health care. One important aspect that has received little attention so far is the dynamic handling of exceptions during process execution. To address this problem, we propose a rule-based approach to automatically control and enforce quality constraints for web-service-based cooperative processes.

Der zunehmende Einsatz von Web-Technologien steigert die Notwendigkeit, kooperative Geschäftsprozesse und Workflows zwischen verschiedenen Unternehmen oder Abteilungen webbasiert abzuwickeln. Eine treibende Kraft hierfür ist die wachsende Verfügbarkeit von Web-Service-Realisierungen zur Interoperabilität. Die derzeit verfügbaren Ansätze unterstützen jedoch keine ausreichende Qualität und Flexibilität kooperativer webbasierter Workflows, insbesondere bzgl. der Ausführungsqualität von Diensten und der dynamischen Ausnahmebehandlung. Diese Defizite sollen mit dem System WEBFLOW abgebaut werden. Es ermöglicht die Definition und Überwachung von Ausführungsbedingungen für unterschiedlich mächtige Dienste verschiedener Kooperationspartner. Zudem unterstützt es eine regelbasierte dynamische Ausnahmebehandlung, mit der die Robustheit kooperativer Workflows deutlich verbessert werden soll.

Die Programmiersprache Java hat sich in den letzten Jahren als ein leistungsfähiges Werkzeug für WWW-orientierte Anwendungen durchgesetzt. Mit den EJB’s und dem J2EE-Standard bemüht man sich, einen objektorientierten Ansatz auch für die Geschäftslogik einzusetzen. Von dem Ziel, existierende Geschäftslogik durch neue EJB-Implementierungen zu ersetzen, sind wir jedoch noch weit entfernt. Dies gilt besonders für die größeren Unternehmen, die in der Regel z/OS mit IMS, CICS, VSAM, DB2, Oracle und Adabas auf ihrem zentralen Server einsetzen. Vorhandene Java-Implementierungen von Internet-Anwendungen benutzen häufig Konnektoren, um mit Hilfe der Java Connector-Architektur (JCA) auf vorhandene Anwendungslogik zuzugreifen, die in der Form von Anwendungen unter CICS, IMS/DC,DB2 Stored Procedures oder Stapelverarbeitungsanwendungen auf dem z/OS Server vorliegen. Der vorliegende Beitrag erläutert, wie mit unterschiedlichen Konnektoren auf existierende CICS-Anwendungen zugegriffen werden kann. Hierbei wird besonders die Internet-Integration mit Hilfe des CICS Transaction Gateways beschrieben. Eine erfolgreiche Integration des Internets in existierende unternehmerische IT-Strukturen ist ein wichtiges Thema für die Ausbildung des akademischen Nachwuchses. Es wird dargestellt, wie an der Universität Leipzig die Studenten mit praktische Übungen am Beispiel des CICS Transaction Gateways an dieses Ziel herangeführt werden.

In diesem Beitrag wird die Berechnung von Differenzen zwischen Prozessmodellen betrachtet. Hierzu werden verschiedene Ansätze undWerkzeuge zur Berechnung von Differenzen beschrieben. Ausgehend von einem konkreten Anwendungsfall – einer EPK-zu-BPEL-Transformation – werden verschiedene Testkriterien aufgestellt, die anschließend zur Evaluierung von zwei Differenzbildungswerkzeugen dienen. Abschließend werden die Ergebnisse der Untersuchung entsprechend dargestellt.

With the advent of multicore processors, there is an increasing amount of interest in building concurrent applications capable of fully utilising their features. Developing applications for these platforms to take full advantage of the power of multicore capabilities remains a complex, error-prone, and challenging endeavour. Unfortunately, concurrency is not uniformly and externally expressed in most existing application models. The result is that concurrency and thread management are hidden within objects or components and intermixed with their functionalities. After demonstrating the tangling of code that results from the interaction of these two major concerns, this thesis describes a method of improving the concurrent program by applying a novel technique to separate the concerns: aspect-oriented programming, which aims to encapsulate concerns that crosscut the main program flow in separate entities into aspects. The most mature aspect-oriented tool available at the time this project was being undertaken is AspectJ, which is an extension of Java. AspectJ can be used to write an aspect to a separate concern in a sequential program to avoid code tangling, but it is often inapplicable for concurrent programs. The problem lies in the fact that the points where parallelisation should occur are not natural join points in AspectJ (i.e. points where AspectJ can intervene). Consequently, this thesis proposes a set of fine-grained join points capable of completely handling concurrent programs. This model goes beyond present AspectJ models and demonstrates the need to recognise complex behaviour for an effective separation of concerns. Finally, aspects for implementing concurrent programs according to different schemes are presented, together with evaluation results. This highlights the flexibility of aspects for implementing concurrent programs, a flexibility which is always a cross-cutting concern with respect to the main concern of base applications.

La construction de logiciels pour des appareils qui ne peuvent pas accueillir localement des outils de développement peut être difficile. Ces appareils ont soit une puissance de calcul trop limitée pour exécuter un IDE, ou manque des interfaces d’entrée / sortie appropriées pour la programmation ou sont tout simplement inaccessibles pour des développements locaux. Dans ces situations, les développeurs ont besoin d’une infrastructure appropriée pour développer et déboguer des applications distantes. Dans cette thèse nous identifions d’abord quatre propriétés désirables qu’une solution idéale pour le débogage à distance doit présenter : l’ interactivité, l’instrumentation, la distribution et la sécurité. Compte tenu de ces propriétés, nous proposons Mercury, un modèle de débogage à distance et une architecture pour des langues réfléxifs à objets. Mercury ouvre (1) l’interactivité grâce à un méta-niveau à distance miroir basé sur un lien de causalité avec sa cible, (2) l’instrumentation à travers une intercession réflective basée sur la réification de l’environnement d’exécution sous-jacent, (3) la distribution grâce à un middleware adaptable et (4) la sécurité par la décomposition et l’authentification de l’accès aux aspects réflexifs. Nous validons notre proposition à travers un prototype dans le langage de programmation Pharo à l’aide d’un cadre expérimental diversifié de multiples dispositifs contraints. Nous illustrons des techniques de débogage à distance soutenus par les propriétés de Mercury, tels que distance agile débogage et instrumentation objet à distance et montrons comment ils peuvent résoudre dans la pratique, les problèmes que nous avons identifiés. / Building software for devices that cannot locally support development tools can be challenging. These devices have either limited computing power to run an IDE, lack appropriate input/output interfaces for programming or are simply unreachable for local development. In these situations developers need appropriate infrastructure to remotely develop and debug applications. In this dissertation we first identify four desirable properties that an ideal solution for remote debugging should exhibit, namely: interactiveness, instrumentation, distribution and security. Given these properties we propose Mercury, a remote debugging model and architecture for reflective OO languages. Mercury supports interactiveness through a mirror-based remote meta-level that is causally connected to its target, instrumentation through reflective intercession by reifying the underlying execution environment, distribution through an adaptable middleware and security by decomposing and authenticating access to reflective facilities. We validate our proposal through a prototype implementation in the Pharo programming language using a diverse experimental setting of multiple constraint devices. We exemplify remote debugging techniques supported by Mercury’s properties, such as remote agile debugging and remote object instrumentation and show how these can solve in practice the problems we have identified.

This research focused on the implementation of a reliable intelligent fall detection system so as to reduce accidental falls among the elderly people. A video-based detection system was used because it preserved privacy while monitoring the activities of the senior citizens. Another advantage of the video-based system is that the senior citizens are able to move freely without experiencing any hassles in wearing them as opposed to portable fall detection sensors so that they can have a more independent and happy life. A scientific research method was employed to improve the existing fall detection systems in terms of reliability and accuracy. This thesis consists of four stages where the first stage reviews the literature on the current fall detection systems, the second stage investigates the various algorithms of these existing fall detection systems, the third stage describes the proposed fall detection algorithm in detecting falls using two distinct approaches. The first approach deals with the use of specific features of the silhouette, an extracted binary map obtained from the subtraction of the foreground from the background, to determine the fall angle (FA), the bounding box (BB) ratio, the Hidden Markov Models (HMM) and the combination of FA, BB, and HMM. The second approach used is the neural network approach which is incorporated in the algorithm to identify a predetermined set of situations such as praying, sitting, standing, bending, kneeling, and lying down. The fourth stage involves the evalua- tion of the developed video-based fall detection system using different metrics which measure sensitivity (i.e. the capacity of the fall detection system to detect as well as declare a fall) and specificity (i.e. the capacity of the algorithm to detect only falls) of this algorithm. The video camera was properly positioned to avoid any occluding objects and also to cover a certain range of motion of the stunt participants performing the falls. The silhouette is extracted using an approximate median filtering approach and the threshold criteria value of 30 pixels was used. Morphological filtering methods that were dilation and erosion were used to remove any spurious noises from the extracted image prior to subsequent feature analysis. Then, this extracted silhouette was scaled and quantised using 8 bits/pixel and compared to the set of predetermined scenarios using a neural network of perceptrons. This neural network was trained based on various situations and the falls of the participants which represent inputs to the neural network algorithm during the neural learning process. In this research study, the built neural network consisted of 600 inputs, as well as 10 neurons in the hidden layer together with 7 distinct outputs which represent the set of predefined situations. Furthermore, an alarm generation algorithm was included in the fall detection algorithm such that there were three states that were STATE NULL (set at 0), STATE LYING (set at 1) and STATE ALL OTHERS (set at 2) and the initial alarm count was set to 90 frames (meaning 3 seconds of recorded consecutive images at 30 frames per second). Therefore, an alarm was generated only when the in-built counter surpassed this threshold of 90 frames to signal that a fall occurred. Following the evaluation stage, it was found that the combination of the first approach fall detection algorithm method (fall angle, bounding box, and hidden Markov) was 89% with specificity and 84.2% with sensitivity which is better than individual performance. Moreover, it was found that the second approach fall detection algorithm method (neural network performance) 94.3% of the scenarios were successfully classified whereby the specificity of the developed algorithm was determined to be 94.8% and the sensitivity was 93.8% which altogether show a promising overall performance of the fall detection video-based intelligent system. Moreover, the developed fall detection system were tested using two types of handicaps such as limping and stumbling stunt participants to observe how well this detection algorithm can detect falls as in the practical situations encountered or present in elderly people. In these cases it was found that about 90.2% of the falls were detected which showed still that the developed algorithm was quite robust and reliable subjected to these two physical handicaps motion behaviours.