Energy-Efficient GPS-Based Positioning in the Android Operating System

We present our ongoing collaborative work on EnDroid, an energy-efficient GPS-based positioning system for the Android Operating System. EnDroid is based on the EnTracked positioning system, developed at the University of Aarhus, Denmark. We describe the current prototypical state of our implementation and present our experiences and conclusions from preliminarily evaluating EnDroid on the Google Nexus One Smartphone. Although the preliminary results seem to support the approach, there are still several open questions, both at the application interface, as well as at the hardware management level

Towards Adjusting Mobile Devices To User's Behaviour

Mobile devices are a special class of resource-constrained em- bedded devices. Computing power, memory, the available energy, and network bandwidth are often severely limited. These constrained re- sources require extensive optimization of a mobile system compared to larger systems. Any needless operation has to be avoided. Time- consuming operations have to be started early on. For instance, load- ing files ideally starts before the user wants to access the file. So-called prefetching strategies optimize system’s operation. Our goal is to ad- just such strategies on the basis of logged system data. Optimization is then achieved by predicting an application’s behavior based on facts learned from earlier runs on the same system. In this paper, we ana- lyze system-calls on operating system level and compare two paradigms, namely server-based and device-based learning. The results could be used to optimize the runtime behaviour of mobile devices

The Astropy Problem

The Astropy Project (http://astropy.org) is, in its own words, "a community effort to develop a single core package for Astronomy in Python and foster interoperability between Python astronomy packages." For five years this project has been managed, written, and operated as a grassroots, self-organized, almost entirely volunteer effort while the software is used by the majority of the astronomical community. Despite this, the project has always been and remains to this day effectively unfunded. Further, contributors receive little or no formal recognition for creating and supporting what is now critical software. This paper explores the problem in detail, outlines possible solutions to correct this, and presents a few suggestions on how to address the sustainability of general purpose astronomical software

Providing Information by Resource- Constrained Data Analysis

The Collaborative Research Center SFB 876 (Providing Information by Resource-Constrained Data Analysis) brings together the research fields of data analysis (Data Mining, Knowledge Discovery in Data Bases, Machine Learning, Statistics) and embedded systems and enhances their methods such that information from distributed, dynamic masses of data becomes available anytime and anywhere. The research center approaches these problems with new algorithms respecting the resource constraints in the different scenarios. This Technical Report presents the work of the members of the integrated graduate school

Data Modeling of Ubiquitous System Software

The multitude of events and internal data structures in complex modern system software are an excellent target for data analysis. The tools to collect the data range from low-level tracing frameworks to more sophisticated ones with specialized data collection and processing languages. However, these lack information on the relationship between different data sources and between currently and already collected data. We describe a formal data model that captures the structure of data streams in the system software as well as the relationships between them

Energy-Efficient GPS-Based Positioning in the Android Operating System

We present our ongoing collaborative work on EnDroid, an energy-efficient GPS-based positioning system for the Android Operating System. EnDroid is based on the EnTracked positioning system, developed at the University of Aarhus, Denmark. We describe the current prototypical state of our implementation and present our experiences and conclusions from preliminarily evaluating EnDroid on the Google Nexus One Smartphone. Although the preliminary results seem to sup- port the approach, there are still several open questions, both at the application interface, as well as at the hardware management level

Interrupt synchronization in the CiAO operating system

Configurability is a major issue in the domain of embedded sys-tem software. Existing systems specifically lack good techniques to implement configurability of architectural OS concerns, such as the choice of isolation or synchronization policies to use. As such policies have a very cross-cutting character, aspects should provide good means to implement them in a configurable way. While our results show that this is in fact the case, 1) things could have been easier if additional language features were available, and, 2) addi-tional means to influence the back-end code generation turned out to be very important. This paper presents our experiences in using AspectC++ to design and implement interrupt synchronization as a configurable property in the CiAO operating system

Configurable Memory Protection by Aspects

We describe the implementation of memory protection by means of aspect-oriented programming (AOP) in CiAO, an AUTOSARlike family of embedded operating systems. The use of AOP was originally motivated by the fact that memory protection is a crosscutting policy, which, furthermore, has to be configurable at buildtime in AUTOSAR. We learned, however, that besides switching between full protection and no protection, an AOP-based approach also makes it easy to apply completely different models of protection. For the domain of statically configured embedded systems, where certain failure scenarios can often be excluded by means of code analysis or even probability, this facilitates tailored and light-weight “pay-as-you-use” protection strategies