Johannes Kepler University of Linz

About: Johannes Kepler University of Linz is a education organization based out in Linz, Oberösterreich, Austria. It is known for research contribution in the topics: Computer science & Thin film. The organization has 6605 authors who have published 19243 publications receiving 385667 citations.

Spinodal nanodecomposition in semiconductors doped with transition metals

Abstract: This review presents the recent progress in computational materials design, experimental realization, and control methods of spinodal nanodecomposition under three- and two-dimensional crystal-growth conditions in spintronic materials, such as magnetically doped semiconductors. The computational description of nanodecomposition, performed by combining first-principles calculations with kinetic Monte Carlo simulations, is discussed together with extensive electron microscopy, synchrotron radiation, scanning probe, and ion beam methods that have been employed to visualize binodal and spinodal nanodecomposition (chemical phase separation) as well as nanoprecipitation (crystallographic phase separation) in a range of semiconductor compounds with a concentration of transition metal (TM) impurities beyond the solubility limit. The role of growth conditions, codoping by shallow impurities, kinetic barriers, and surface reactions in controlling the aggregation of magnetic cations is highlighted. According to theoretical simulations and experimental results the TM-rich regions appear in the form of either nanodots (the dairiseki phase) or nanocolumns (the konbu phase) buried in the host semiconductor. Particular attention is paid to Mn-doped group III arsenides and antimonides, TM-doped group III nitrides, Mn- and Fe-doped Ge, and Cr-doped group II chalcogenides, in which ferromagnetic features persisting up to above room temperature correlate with the presence of nanodecomposition and account for the application-relevant magneto-optical and magnetotransport properties of these compounds. Finally, it is pointed out that spinodal nanodecomposition can be viewed as a new class of bottom-up approach to nanofabrication.

Educational institutions and the integration of migrants

Abstract: In this paper, I study educational integration of students with migration background using data from five international student assessment studies. First, Blinder–Oaxaca decompositions are used to allow for a comparison of integration of migrant students across countries and time. In a second step, integration is related to institutional characteristics of the schooling system. Pooled, country-group and country fixed effects estimations show that time in school and early education are positively related to the integration of students with migration background. Furthermore, in the OECD countries, educational integration in science is positively related to external student assessment policies.

Concept and application of LPM: A novel 3-D local position measurement system

Abstract: Precise measurement of the local position of moveable targets in three dimensions is still considered to be a challenge. With the presented local position measurement technology, a novel system, consisting of small and lightweight measurement transponders and a number of fixed base stations, is introduced. The system is operating in the 5.8-GHz industrial-scientific-medical band and can handle up to 1000 measurements per second with accuracies down to a few centimeters. Mathematical evaluation is based on a mechanical equivalent circuit. Measurement results obtained with prototype boards demonstrate the feasibility of the proposed technology in a practical application at a race track.

Automating requirements traceability: Beyond the record & replay paradigm

Abstract: Requirements traceability (RT) aims at defining relationships between stakeholder requirements and artifacts produced during the software development life-cycle. Although techniques for generating and validating RT are available, RT in practice often suffers from the enormous effort and complexity of creating and maintaining traces or from incomplete trace information that cannot assist engineers in real-world problems. In this paper we will present a tool-supported technique easing trace acquisition by generating trace information automatically. We will explain the approach using a video-on-demand system and show that the generated traces can be used in various engineering scenarios to solve RT-related problems.