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Aichernig B.K.,University of Graz | Jobstl E.,University of Graz | Tiran S.,University of Graz | Tiran S.,Austrian Institute of Technology GmbH
Science of Computer Programming

In model-based mutation testing, a test model is mutated for test case generation. The resulting test cases are able to detect whether the faults in the mutated models have been implemented in the system under test. For this purpose, a conformance check between the original and the mutated model is required. The generated counterexamples serve as basis for the test cases. Unfortunately, conformance checking is a hard problem and requires sophisticated verification techniques. Previous attempts using an explicit conformance checker suffered state space explosion. In this paper, we present several optimisations of a symbolic conformance checker using constraint solving techniques. The tool efficiently checks the refinement between non-deterministic test models. Compared to previous implementations, we could reduce our runtimes by 97%. In a new industrial case study, our optimisations can reduce the runtime from over 6 hours to less than 3 minutes. © 2014 Elsevier B.V. All rights reserved. Source

Tajmar M.,Institute of Space Technology | Tajmar M.,KAIST | Vasiljevich I.,Institute of Space Technology | Grienauer W.,Austrian Institute of Technology GmbH

We recently developed an indium Liquid-Metal-Ion-Source that can emit currents from sub-γA up to several mA. It is based on a porous tungsten crown structure with 28 individual emitters, which is manufactured using Micro-Powder Injection Molding (γPIM) and electrochemical etching. The emitter combines the advantages of internal capillary feeding with excellent emission properties due to micron-size tips. Significant progress was made on the homogeneity of the emission over its current-voltage characteristic as well as on investigating its long-term stability. This LMIS seems very suitable for space propulsion as well as for micro/nano manufacturing applications with greatly increased milling/drilling speeds. This paper summarizes the latest developments on our porous multiemitters with respect to manufacturing, emission properties and long-term testing. © 2010 Elsevier B.V. Source

Kral C.,Austrian Institute of Technology GmbH | Haumer A.,Technical Consulting and Electrical Engineering | Lee S.B.,Korea University
IEEE Transactions on Power Electronics

A thermal model for the determination of the temperatures of interior permanent magnets and stator windings is presented in this paper. The innovation of the model relies on one temperature sensor being located in the stator core of the machine. Such sensor is simple to implement in many applications such as traction or EV, where reliability is critical. The estimated stator winding and permanent magnet temperatures are determined by a simplified thermal lumped element network model with only two time constants. It is shown that the proposed thermal model is very robust due to the structure of the model and the measured stator core temperature. The distortion of the temperature estimates caused by the cooling circuit is inherently accounted for such that the model can be used for robust online prediction of temperatures. Experimental results based on a forced water-cooled interior permanent magnet synchronous machine setup are presented to validate the effectiveness of the presented model. © 1986-2012 IEEE. Source

Li J.,University of Helsinki | Brader G.,University of Helsinki | Helenius E.,University of Helsinki | Helenius E.,Austrian Institute of Technology GmbH | And 2 more authors.
Plant Journal

In addition to its essential metabolic functions, biotin has been suggested to play a critical role in regulating gene expression. The first committed enzyme in biotin biosynthesis in Arabidopsis, 7-keto-8-aminopelargonic acid synthase, is encoded by At5g04620 (BIO4). We isolated a T-DNA insertion mutant of BIO4 (bio4-1) with a spontaneous cell death phenotype, which was rescued both by exogenous biotin and genetic complementation. The bio4-1 plants exhibited massive accumulation of hydrogen peroxide and constitutive up-regulation of a number of genes that are diagnostic for defense and reactive oxygen species signaling. The cell-death phenotype was independent of salicylic acid and jasmonate signaling. Interestingly, the observed increase in defense gene expression was not accompanied by enhanced resistance to bacterial pathogens, which may be explained by uncoupling of defense gene transcription from accumulation of the corresponding protein. Characterization of biotinylated protein profiles showed a substantial reduction of both chloroplastic biotinylated proteins and a nuclear biotinylated polypeptide in the mutant. Our results suggest that biotin deficiency results in light-dependent spontaneous cell death and modulates defense gene expression. The isolation and molecular characterization of the bio4-1 mutant provides a valuable tool for elucidating new functions of biotin. © 2011 Blackwell Publishing Ltd. Source

Simko M.,Austrian Academy of Sciences | Simko M.,Austrian Institute of Technology GmbH | Nosske D.,Federal office for Radiation Protection | Kreyling W.G.,Helmholtz Center for Environmental Research
International Journal of Environmental Research and Public Health

In order to calculate the dose for nanoparticles (NP), (i) relevant information about the dose metrics and (ii) a proper dose concept are crucial. Since the appropriate metrics for NP toxicity are yet to be elaborated, a general dose calculation model for nanomaterials is not available. Here we propose how to develop a dose assessment model for NP in analogy to the radiation protection dose calculation, introducing the so-called "deposited and the equivalent dose". As a dose metric we propose the total deposited NP surface area (SA), which has been shown frequently to determine toxicological responses e.g. of lung tissue. The deposited NP dose is proportional to the total surface area of deposited NP per tissue mass, and takes into account primary and agglomerated NP. By using several weighting factors the equivalent dose additionally takes into account various physico-chemical properties of the NP which are influencing the biological responses. These weighting factors consider the specific surface area, the surface textures, the zeta-potential as a measure for surface charge, the particle morphology such as the shape and the length-to-diameter ratio (aspect ratio), the band gap energy levels of metal and metal oxide NP, and the particle dissolution rate. Furthermore, we discuss how these weighting factors influence the equivalent dose of the deposited NP. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

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