Hybrid Algorithms Based on Integer Programming for the Search of Prioritized Test Data in Software Product Lines

In Software Product Lines (SPLs) it is not possible, in general, to test all products of the family. The number of products denoted by a SPL is very high due to the combinatorial explosion of features. For this reason, some coverage criteria have been proposed which try to test at least all feature interactions without the necessity to test all products, e.g., all pairs of features (pairwise coverage). In addition, it is desirable to first test products composed by a set of priority features. This problem is known as the Prioritized Pairwise Test Data Generation Problem. In this work we propose two hybrid algorithms using Integer Programming (IP) to generate a prioritized test suite. The first one is based on an integer linear formulation and the second one is based on a integer quadratic (nonlinear) formulation. We compare these techniques with two state-of-the-art algorithms, the Parallel Prioritized Genetic Solver (PPGS) and a greedy algorithm called prioritized-ICPL. Our study reveals that our hybrid nonlinear approach is clearly the best in both, solution quality and computation time. Moreover, the nonlinear variant (the fastest one) is 27 and 42 times faster than PPGS in the two groups of instances analyzed in this work.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Partially funded by the Spanish Ministry of Economy and Competitiveness and FEDER under contract TIN2014-57341-R, the University of Málaga, Andalucía Tech and the Spanish Network TIN2015-71841-REDT (SEBASENet)

Cathodoluminescence Studies of Polytype Structure in Zn1−x\text{}_{1-x}Mgx\text{}_{x}Se

Zn$\text{}_{1-x}$Mg$\text{}_{x}$Se crystals grown by Bridgman method show spatial transition from sphalerite (3C) to wurzite structure (2H) with increasing Mg content (x). Within the transition range, near x=0.19, coexistence of hexagonal and cubic structure results in the formation of polytype sequences of 3C-8H-4H-2H. We have investigated the spatial distribution of the polytypes in Zn$\text{}_{1-x}$Mg$\text{}_{x}$Se mixed crystals with a value of x close to that of the phase transition using spectrally as well as spatially resolved cathodoluminescence. Three emission bands in the cathodoluminescence spectrum have been observed, two strong lines at 2.99 eV and 2.965 eV, and a weak shoulder at 2.95 eV. The lines at 2.965 and 2.99 eV are known in the literature as an exciton recombination in the 8H and 4H polytype structure. We have found the third one at 2.95 eV to be due to luminescence in the 3C structure. These results demonstrate the usefulness of cathodoluminescence measurements for investigations of spatial distribution of inhomogeneities of mixed semiconductors

Entfernung und Rueckgewinnung von Zn, Cu, Cd und anderen toxischen Schwermetallen aus Abfluessen alter Entwaesserungsstollen Abschlussbericht

Im Einzugsgebiet des Erzgebirges gelangen durch Abfluesse aus gefluteten Bergbaurevieren zum Teil betraechtliche Schadstoffmengen in die Gewaesser. Fuer das als Modellfall betrachtete Freiberger Gebiet sind dies jaehrlich mehr als 150 t Zn, 1 t Cd, 1,5 t Cu und 0,6 t Pb bei Abflussmengen von ueber 1500 m"3/h. Zielstellung des Vorhabens war die Entwicklung eines Verfahrens zur Schwermetalleliminierung, das Restgehalte weit unter den Grenzwerten relevanter AbwVwV ermoeglicht. Die abgetrennten Schadstoffe waren in einem verwertbaren Produkt zu konzentrieren. Ausgehend von Laboruntersuchungen wurde eine Versuchsanlage mit einem Nenndurchsatz von 0,5 m"3/h errichtet und im Bypass vor Ort betrieben. Die angewandte Technologie beruht auf einer stufenweisen Hydroxid-Carbonatfaellung bei pH-Werten von 9 bis 9,5. Die Flockenabtrennung erfolgte durch Sedimentation und Tiefbettfiltration. Bei einer gemeinsamen Behandlung der verschiedenen Stollenabwaesser werden Restgehalte < 100 #mu#g/l Zn und < 5 #mu#g/l Cd, Cu, Pb bzw. As erreicht. Das entwaesserte Faellprodukt weist einen Zinkgehalt von 18 bis 20% auf. Der Einsatz dieses Produktes ist im Rahmen eines sekundaermetallurgischen Prozesses moeglich. Anhand der aus den Untersuchungen abgeleiteten Bemessungsgroessen wurden die fuer die Grossanlage erforderlichen Hauptausruestungen ermittelt. Es sind spezifische Behandlungskosten von 0,90 DM/m"3 Wasser zu erwarten. (orig.)In the area of Ore Mountains to some extent considerable amounts of harmful substances enter the flowing waters originating from drainage of flooded mines. For the mining region of Freiberg, considered as a model case here, these are more than 150 t Zn, 1 t Cd, 1.5 t Cu and 0.6 t Pb per year based on a drainage flow of more than 1500 m"3/h. The subject of this research work was to develop a process of heavy metal elimination which ensures residual loads far below the legitimate limiting values. Moreover the separated metals had to be concentrated in a usable product. Proceeding from laboratory studies a pilot plant of throughput of 0.5 m"3/h was constructed and tested with a by-pass flow directly at the effluent. The technology applied is based on a stepwise hydroxide-carbonate precipitation at pH values of 9 to 9.5. Floc separation occured by sedimentation and deep bed filtration. With a complex treatment of different drainage waters residual values of < 100 #mu#g/l Zn and < 5 #mu#g/l Cu, Cd, Pb or As were obtained. The dewatered precipitates containing 18 to 20% zinc are suited for recycling by a secondary metallurgical process. The chemical engineering parameters derived from the investigations are the basis for sizing the main equipment of the technical plant. Specific operating costs of 0.90 DM/m"3 water are expected. (orig.)SIGLEAvailable from TIB Hannover: F94B1491+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Experimentalstudie zur Sanierung einer Deponie mit leicht wasserloeslichen Salzen (Glaubersalzdeponie Plauen) Abschlussbericht

Bench-scale tests were made to assess the efficiency of H_2O_2 treatments which eliminate H_2S degassing on a H_2S-degassing landfill for disposal of large quantities of spinning substances and Glauber's salts. After technical characterization of the landfill material a first basic concept was developed for treatments which ensure a 40-50% reduction in volume through Glauber's salt recovery. (orig.)SIGLEAvailable from TIB Hannover: F95B82+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman