A Framework for Model-Driven Development of Mobile Applications with Context Support

Model-driven development (MDD) of software systems has been a serious trend in different application domains over the last 15 years. While technologies, platforms, and architectural paradigms have changed several times since model-driven development processes were first introduced, their applicability and usefulness are discussed every time a new technological trend appears. Looking at the rapid market penetration of smartphones, software engineers are curious about how model-driven development technologies can deal with this novel and emergent domain of software engineering (SE). Indeed, software engineering of mobile applications provides many challenges that model-driven development can address. Model-driven development uses a platform independent model as a crucial artifact. Such a model usually follows a domain-specific modeling language and separates the business concerns from the technical concerns. These platform-independent models can be reused for generating native program code for several mobile software platforms. However, a major drawback of model-driven development is that infrastructure developers must provide a fairly sophisticated model-driven development infrastructure before mobile application developers can create mobile applications in a model-driven way. Hence, the first part of this thesis deals with designing a model-driven development infrastructure for mobile applications. We will follow a rigorous design process comprising a domain analysis, the design of a domain-specific modeling language, and the development of the corresponding model editors. To ensure that the code generators produce high-quality application code and the resulting mobile applications follow a proper architectural design, we will analyze several representative reference applications beforehand. Thus, the reader will get an insight into both the features of mobile applications and the steps that are required to design and implement a model-driven development infrastructure. As a result of the domain analysis and the analysis of the reference applications, we identified context-awareness as a further important feature of mobile applications. Current software engineering tools do not sufficiently support designing and implementing of context-aware mobile applications. Although these tools (e.g., middleware approaches) support the definition and the collection of contextual information, the adaptation of the mobile application must often be implemented by hand at a low abstraction level by the mobile application developers. Thus, the second part of this thesis demonstrates how context-aware mobile applications can be designed more easily by using a model-driven development approach. Techniques such as model transformation and model interpretation are used to adapt mobile applications to different contexts at design time or runtime. Moreover, model analysis and model-based simulation help mobile application developers to evaluate a designed mobile application (i.e., app model) prior to its generation and deployment with respected to certain contexts. We demonstrate the usefulness and applicability of the model-driven development infrastructure we developed by seven case examples. These showcases demonstrate the designing of mobile applications in different domains. We demonstrate the scalability of our model-driven development infrastructure with several performance tests, focusing on the generation time of mobile applications, as well as their runtime performance. Moreover, the usability was successfully evaluated during several hands-on training sessions by real mobile application developers with different skill levels

A taxonomic backbone for the global synthesis of species diversity in the angiosperm order Caryophyllales

The Caryophyllales constitute a major lineage of flowering plants with approximately 12500 species in 39 families. A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the order. A detailed review of the literature of the past two decades shows that enormous progress has been made in understanding overall phylogenetic relationships in Caryophyllales. The process of re-circumscribing families in order to be monophyletic appears to be largely complete and has led to the recognition of eight new families (Anacampserotaceae, Kewaceae, Limeaceae, Lophiocarpaceae, Macarthuriaceae, Microteaceae, Montiaceae and Talinaceae), while the phylogenetic evaluation of generic concepts is still well underway. As a result of this, the number of genera has increased by more than ten percent in comparison to the last complete treatments in the Families and genera of vascular plants” series. A checklist with all currently accepted genus names in Caryophyllales, as well as nomenclatural references, type names and synonymy is presented. Notes indicate how extensively the respective genera have been studied in a phylogenetic context. The most diverse families at the generic level are Cactaceae and Aizoaceae, but 28 families comprise only one to six genera. This synopsis represents a first step towards the aim of creating a global synthesis of the species diversity in the angiosperm order Caryophyllales integrating the work of numerous specialists around the world

Modellgestützte Analyse und Optimierung der Energieeffizienz betrieblicher Informations- und Kommunikationstechnik

Die Energieeffizienz von Informationssystemen (IS) wird zu einer wichtigen Kennzahl für Entscheider im Informationsmanagement. Derzeitige Unternehmensarchitekturmodelle (EAM) unterstützen allerdings nur unzureichend die automatisierte Bestimmung der Energieeffizienz und die Bewertung von Maßnahmen zur Erhöhung der Energieeffizienz. Der Grund liegt darin, dass diese Modelle auf die Planung und Dokumentation von Informationssystemen ausgerichtet sind und hierzu die energieeffizienzrelevanten Informationen nicht ausreichend erfasst werden. Folglich ist es notwendig, derzeitige EAM-Ansätze um eine Methode zur Energieeffizienzanalyse und -optimierung zu erweitern. Die vorliegende Arbeit schlägt eine Methode für die modellgestützte Energieeffizienzanalyse und -optimierung im Rahmen von EAM vor. Die Evaluation durch ein Simulationsexperiment mit einem Prototyp zeigt die Wirksamkeit und Nützlichkeit der entwickelten Methode

A Framework for Model-Driven Development of Mobile Applications with Context Support

Model-driven development (MDD) of software systems has been a serious trend in different application domains over the last 15 years. While technologies, platforms, and architectural paradigms have changed several times since model-driven development processes were first introduced, their applicability and usefulness are discussed every time a new technological trend appears. Looking at the rapid market penetration of smartphones, software engineers are curious about how model-driven development technologies can deal with this novel and emergent domain of software engineering (SE). Indeed, software engineering of mobile applications provides many challenges that model-driven development can address. Model-driven development uses a platform independent model as a crucial artifact. Such a model usually follows a domain-specific modeling language and separates the business concerns from the technical concerns. These platform-independent models can be reused for generating native program code for several mobile software platforms. However, a major drawback of model-driven development is that infrastructure developers must provide a fairly sophisticated model-driven development infrastructure before mobile application developers can create mobile applications in a model-driven way. Hence, the first part of this thesis deals with designing a model-driven development infrastructure for mobile applications. We will follow a rigorous design process comprising a domain analysis, the design of a domain-specific modeling language, and the development of the corresponding model editors. To ensure that the code generators produce high-quality application code and the resulting mobile applications follow a proper architectural design, we will analyze several representative reference applications beforehand. Thus, the reader will get an insight into both the features of mobile applications and the steps that are required to design and implement a model-driven development infrastructure. As a result of the domain analysis and the analysis of the reference applications, we identified context-awareness as a further important feature of mobile applications. Current software engineering tools do not sufficiently support designing and implementing of context-aware mobile applications. Although these tools (e.g., middleware approaches) support the definition and the collection of contextual information, the adaptation of the mobile application must often be implemented by hand at a low abstraction level by the mobile application developers. Thus, the second part of this thesis demonstrates how context-aware mobile applications can be designed more easily by using a model-driven development approach. Techniques such as model transformation and model interpretation are used to adapt mobile applications to different contexts at design time or runtime. Moreover, model analysis and model-based simulation help mobile application developers to evaluate a designed mobile application (i.e., app model) prior to its generation and deployment with respected to certain contexts. We demonstrate the usefulness and applicability of the model-driven development infrastructure we developed by seven case examples. These showcases demonstrate the designing of mobile applications in different domains. We demonstrate the scalability of our model-driven development infrastructure with several performance tests, focusing on the generation time of mobile applications, as well as their runtime performance. Moreover, the usability was successfully evaluated during several hands-on training sessions by real mobile application developers with different skill levels

Wi-Fi attitude and position tracking

An approach for pedestrian navigation in indoor environments is presented. It addresses mobile platforms with low processing power and low-cost sensors. Outdoors the horizontal attitude of a device can be easily detected using electronic compasses. Indoors magnetic disturbances lead to unreliable compass outputs. In this paper a novel approach for attitude and position tracking is introduced. Four horizontally arranged directional antennas are used to collect the Wi-Fi signal strengths of transmitters (access points) in range. For attitude estimation an extended Kalman filter is used, and for position tracking Wi-Fi fingerprinting. With this approach the attitude of a mobile device can be estimated and the position can be tracked in indoor environments like e.g. museums. This enables the use of electronic guides that offer additional information by means of augmented reality on exhibits in visual range. Possible accuracies are evaluated in simulations. A test with measurements collected in a museum demonstrates the functionality of the approach

Empirische Forschung in der Deutschdidaktik. Band 1: Grundlagen

Wie wird aus einer ersten Idee ein konkretes Forschungsprojekt? Der vorliegende Band widmet sich im ersten Teil den theoretischen Grundlagen empirischen Forschens: Was unterscheidet qualitative und quantitative Forschung? Welcher Forschungsansatz ist für meine Fragestellung der richtige und was sind die Vor- und Nachteile verschiedener Untersuchungsdesigns? Im zweiten Teil werden praxisrelevante Hilfestellungen für die Organisation, Durchführung und Auswertung der Erhebung gegeben, wobei der gesamte Prozess von der Auswahl der Probanden über Datenschutzfragen, Softwareeinsatz bis hin zu statistischen Grundlagenkenntnissen berücksichtigt wird