Prototype muon detectors for the AMIGA component of the Pierre Auger Observatory

AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to extend its range of detection and to directly measure the muon content of the particle showers. It consists of an infill of surface water-Cherenkov detectors accompanied by buried scintillator detectors used for muon counting. The main objectives of the AMIGA engineering array, referred to as the Unitary Cell, are to identify and resolve all engineering issues as well as to understand the muon-number counting uncertainties related to the design of the detector. The mechanical design, fabrication and deployment processes of the muon counters of the Unitary Cell are described in this document. These muon counters modules comprise sealed PVC casings containing plastic scintillation bars, wavelength-shifter optical fibers, 64 pixel photomultiplier tubes, and acquisition electronics. The modules are buried approximately 2.25 m below ground level in order to minimize contamination from electromagnetic shower particles. The mechanical setup, which allows access to the electronics for maintenance, is also described in addition to tests of the modules' response and integrity. The completed Unitary Cell has measured a number of air showers of which a first analysis of a sample event is included here.Peer Reviewe

Towards Integrated Variant Management in Global Software Engineering: An Experience Report

In the automotive domain, customer demands and market constraints are progressively realized by electric/ electronic components and corresponding software. Variant traceability in SPL is crucial in the context of different tasks, like change impact analysis, especially in complex global software projects. In addition, traceability concepts must be extended by partly automated variant configuration mechanisms to handle restrictions and dependencies between variants. Such variant configuration mechanism helps to reduce complexity when configuring a valid variant and to establish an explicit documentation of dependencies between components. However, integrated variant management has not been sufficiently addressed so far. Especially, the increasing number of software variants requires an examination of traceable and configurable software variants over the software lifecycle. This paper emphasizes variant traceability achievements in a large global software engineering project, elaborates existing challenges, and evaluates an industrial usage of an integrated variant management based on experiences

An Approach to Detect the Origin and Distribution of Software Defects in an Evolving Cyber-Physical System

Cyber-Physical Systems (CPS) are usually developed by an incremental approach. A changing environment like demanding user requirements or legislation amendments lead often to multiple development paths in an evolving CPS. Hence, software variability plays an increasingly important role adapting the characteristics of such CPS to different contexts. This paper focuses on software variability realized through a Software Product Line (SPL) more specifically. Thereby, variability and evolution are usually managed in different tools. However with respect to software defects, a holistic handling of variability and evolution is necessary to ensure a reliable software defect removal. Particularly, detecting software defects in different evolution stages and derived variants is ordinary, but complex and error-prone. To close the gap between variability and evolution, this paper presents a systematic approach to combine both disciplines. In particular, we apply existing variant management techniques in combination with software configuration management methods to determine a software defect's origin and distribution in an evolving SPL. We apply our approach to a CPS from the automotive domain to show its industrial relevance and usefulness