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21.
Service-oriented architectures (SOA) have been successfully adapted by agile businesses to support dynamic outsourcing of business processes and the maintenance of business ecosystems. Still, businesses need to comply with applicable laws and regulations. Abstract service interfaces, distributed ownership and cross-domain operations introduce new challenges for the implementation of compliance controls and the assessment of their effectiveness. In this paper, we analyze the challenges for automated support of the enforcement and evaluation of IT security controls in a SOA. We introduce these challenges by means of an example control, and outline a methodology and a high-level architecture that supports the phases of the control lifecycle through dedicated components for observation, evaluation, decision support and reaction. The approach is model-based and features policy-driven controls. A monitoring infrastructure assesses observations in terms of key indicators and interprets them in business terms. Reaction is supported through components that implement both automated enforcement and the provision of feedback by a human user. The resulting architecture essentially is a decoupled security architecture for SOA with enhanced analysis capabilities and will be detailed and implemented in the MASTER project.  相似文献   
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Aluminum compounds, especially complexes of alcohols, are known as additional crosslinkers for air-drying alkyd paints. Particularly, the drying behavior of high-solids alkyd systems applied under adverse conditions may be improved distinctly. Besides the ether- and peroxy-crosslinks resulting from oxidative drying, coordinative crosslinking occurs. However, exterior weathering of paint films containing Al-complexes frequently results in severe embrittlement. In order to cope with these problems, drying and aging of alkyds and Al-complexes were investigated. All ligands in the complex appeared to get lost during drying, a probable cause of poor weathering performance. Using specially developed alkyd paints for Al-compounds, possible ways of controlling embrittlement are discussed. P.O. Box 9300, 6800 SB Arnhem, The Netherlands. P.O. Box 3, 2170 BA Sassenheim, The Netherlands.  相似文献   
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SiC-B4C composites with various values of SiC-to-B4C ratio and grain size were fabricated by pressureless sintering. This paper presents the results of current investigations of this composite material. This includes the parameters of manufacture (shrinkage, density, and open porosity), thermoelectric properties (electrical and thermal conductivity, and thermopower), and material characterization (x-ray diffraction, scanning electron microscopy, oxidation resistance, and thermal expansion). The results indicate high potential of this composite as an alternative material for thermoelectric applications at high temperatures. The Seebeck coefficient of the composite was higher than that of the single-component materials B4C and SiC and reached 400 μV/K at 500°C.  相似文献   
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The cobalt-catalysed autoxidative drying of alkyd resins was studied using (Z,Z)-3,6-nonadiene and (E,E)-3,6-nonadiene as model compounds. A large number of reaction products were isolated from the autoxidation mixture using HPLC and preparative size exclusion chromatography and identified with 1H- and 13C-NMR. The identified compounds comprised C9 hydroperoxides, endoperoxides, epoxides, aldehydes and ketones and some other oxidation products. Their chemical structures pointed to three different types of oxidation processes taking place. Besides the main radical autoxidation reaction, evidence was found for photo-sensitized oxidation involving singlet oxygen. Thirdly, epoxidation occurs via peracids or hydroperoxides formed as intermediates. Because of the large number of possible isomers having very similar physical properties, isolation of dimers required considerable effort. Nevertheless, two dimers were isolated and characterized. Their structures indicate crosslinking to occur by recombination of radicals as termination reaction.  相似文献   
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Due to the loss of range information, projections as input data for a 3-D object recognition algorithm are expected to increase the computational complexity. In this work, however, we demonstrate that this deficiency carries potential for complexity reduction of major vision problems. We show that projections provide a reduction of feature dimensions, and lead to structures exhibiting simple combinatorial properties. The theoretical framework is embedded in a probabilistic setting which deals with uncertainties and variations of observed features. In statistics marginal densities and the assumption of independency prove to be the key tools when one encounters projections. The examples discussed in this paper include feature matching, pose estimation as well as classification of 3-D objects. The final experimental evaluation demonstrates the practical importance of the marginalization concept and independency assumptions.  相似文献   
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