Protokollierung in der Praxis

Die in den IT-Komponenten integrierten Protokollierungsfunktionen sind zum Zwecke der Kontrolle und zur Erfüllung der gesetzlichen Vorschriften nur sehr bedingt einsetzbar. Die automatisiert erstellten Protokolle sind h?ufig sehr lückenhaft und wenig aussagekr?ftig. In der Praxis finden die Protokollierungsfunktionen aufgrund fehlender Standards und ihrer unzureichenden Auspr?gung kaum Anwendung. Gleichwohl ist die Protokollierung ein unverzichtbarer Bestandteil der Sicherheitskonzeption. In der Praxis muss man sich derzeit mangels geeigneter Werkzeuge mit einer Kombination aus einer automatisierten und manuellen Protokollierung behelfen. Sie bedarf einer sorgf?ltigen Konzeptionierung.     

An implementation of syntax directed functional programming on nested-stack machines

This paper contributes to the field of functional programming languages. We investigate the call-by-name and call-by-need implementation of a restricted type of functional programming, calledsyntax directed functional programming; the target of this implementation is an abstract machine that is based on nested stacks. In fact, the technical kernel of this paper is a refinement of an automata theoretical result that, roughly speaking, investigates the well-known relationship recursion = iteration + stack in the framework of tree transducers. More precisely, in the underlying result the class of functions computed by total deterministic macro tree-to-string transducers with the call-by-name computation strategy is characterized by total deterministic checking-tree nested-stack transducers. Note that total deterministic macro tree-to-string transducers are term rewriting systems by means of which the reduction semantics of syntax directed functional programming languages can be described.The work of this author has been supported by the Deutsche Forschungsgemeinschaft (DFG).     

Visual‐Interactive Preprocessing of Multivariate Time Series Data

Pre‐processing is a prerequisite to conduct effective and efficient downstream data analysis. Pre‐processing pipelines often require multiple routines to address data quality challenges and to bring the data into a usable form. For both the construction and the refinement of pre‐processing pipelines, human‐in‐the‐loop approaches are highly beneficial. This particularly applies to multivariate time series, a complex data type with multiple values developing over time. Due to the high specificity of this domain, it has not been subject to in‐depth research in visual analytics. We present a visual‐interactive approach for preprocessing multivariate time series data with the following aspects. Our approach supports analysts to carry out six core analysis tasks related to pre‐processing of multivariate time series. To support these tasks, we identify requirements to baseline toolkits that may help practitioners in their choice. We characterize the space of visualization designs for uncertainty‐aware pre‐processing and justify our decisions. Two usage scenarios demonstrate applicability of our approach, design choices, and uncertainty visualizations for the six analysis tasks. This work is one step towards strengthening the visual analytics support for data pre‐processing in general and for uncertainty‐aware pre‐processing of multivariate time series in particular.     

An a posteriori error estimate for the generalized finite element method for transient heat diffusion problems

We propose the study of a posteriori error estimates for time‐dependent generalized finite element simulations of heat transfer problems. A residual estimate is shown to provide reliable and practically useful upper bounds for the numerical errors, independent of the heuristically chosen enrichment functions. Two sets of numerical experiments are presented. First, the error estimate is shown to capture the decrease in the error as the number of enrichment functions is increased or the time discretization refined. Second, the estimate is used to predict the behaviour of the error where no exact solution is available. It also reflects the errors incurred in the poorly conditioned systems typically encountered in generalized finite element methods. Finally, we study local error indicators in individual time steps and elements of the mesh. This creates a basis towards the adaptive selection and refinement of the enrichment functions. Copyright © 2016 John Wiley & Sons, Ltd.     

Accessible user interface support for multi-device ubiquitous applications: architectural modifiability considerations

The market for personal computing devices is rapidly expanding from PC, to mobile, home entertainment systems, and even the automotive industry. When developing software targeting such ubiquitous devices, the balance between development costs and market coverage has turned out to be a challenging issue. With the rise of Web technology and the Internet of things, ubiquitous applications have become a reality. Nonetheless, the diversity of presentation and interaction modalities still drastically limit the number of targetable devices and the accessibility toward end users. This paper presents webinos, a multi-device application middleware platform founded on the Future Internet infrastructure. Hereto, the platform’s architectural modifiability considerations are described and evaluated as a generic enabler for supporting applications, which are executed in ubiquitous computing environments.     

Novel Fast Lithium Ion Conduction in Garnet-Type Li5La3M2O12 (M = Nb, Ta)

Lithium metal oxides with the nominal composition Li₅La₃M₂O₁₂ (M = Nb, Ta), possessing a garnetlike structure, have been investigated with regard to their electrical properties. These compounds form a new class of solid-state lithium ion conductors with a different crystal structure compared with all those known so far. The materials are prepared by solid-state reaction and characterized by powder XRD and ac impedance to determine their lithium ionic conductivity. Both the niobium and tantalum members exhibit the same order of magnitude of bulk conductivity (∼10⁻⁶ S/cm at 25°C). The activation energies for ionic conductivity (<300°C) are 0.43 and 0.56 eV for Li₅La₃Nb₂O₁₂ and Li₅La₃Ta₂O₁₂, respectively, which are comparable to those of other solid lithium conductors, such as Lisicon, Li₁₄ZnGe₄O₁₆. Among the investigated materials, the tantalum compound Li₅La₃Ta₂O₁₂ is stable against reaction with molten lithium. Further tailoring of the compositions by appropriate chemical substitutions and improved synthesizing methods, especially with regard to minimizing grain-boundary resistance, are important issues in view of the potential use of the new class of compounds as electrolytes in practical lithium ion batteries.     

Racemic lactones from butterfat: An advanced approach that includes stereodifferentiation

A new method was developed to obtain lactones from butterfat. The application of lipases and capillary gas-liquid chromatography with chiral phases for the separation of γ-lactone enantiomers resulted in elucidation of the racemic composition of γ-lactones from butterfat. The seasonal distribution of lactones in butterfat was determined.     

Analysis of platinum adducts with DNA nucleotides and nucleosides by capillary electrophoresis coupled to ESI-MS: indications of guanosine 5'-monophosphate O6-N7 chelation

DNA is the ultimate target of platinum-based anticancer therapy. Since the N7 of guanine is known to be the major binding site of cisplatin and its analogues, adduct formation with model nucleotides, especially 2'-deoxyguanosine 5'-monophosphate (dGMP), has been studied in detail. During the last few years a coupled capillary eletrophoresis/electrospray-ionization mass spectrometry (CE/ESI-MS) method has been advantageously used in order to separate and identify platinum adducts with nucleotides in submillimolar concentrations in aqueous solutions. Beside the bisadduct, [Pt(NH(3))(2)(dNMP)(2)](2-) (NMP=2'-deoxynucleoside 5'-monophosphate), and the well-known monochloro and monohydroxo adducts, [Pt(NH(3))(2)Cl(dNMP)](-) and [Pt(NH(3))(2)(dNMP)OH](-), respectively, a third kind of monoadduct species with a composition of [Pt(NH(3))(2)(dNMP)](-) can be separated by CE and detected through the m/z values measured with ESI-MS. Different experimental setups indicate the existence of an O(6)-N7 chelate, whereas the formation of N7-alphaPO(4) macrochelates or dinuclear species is unlikely. Additionally, offline MS experiments with 2'-deoxyguanosine (dG) and stabilization of the controversially discussed O(6)-N7 chelate by oxidation with hydrogen peroxide support the assumption of the existence of O(6)-N7 chelation.     

A model of motion transparency processing with local center-surround interactions and feedback

Motion transparency occurs when multiple coherent motions are perceived in one spatial location. Imagine, for instance, looking out of the window of a bus on a bright day, where the world outside the window is passing by and movements of passengers inside the bus are reflected in the window. The overlay of both motions at the window leads to motion transparency, which is challenging to process. Noisy and ambiguous motion signals can be reduced using a competition mechanism for all encoded motions in one spatial location. Such a competition, however, leads to the suppression of multiple peak responses that encode different motions, as only the strongest response tends to survive. As a solution, we suggest a local center-surround competition for population-encoded motion directions and speeds. Similar motions are supported, and dissimilar ones are separated, by representing them as multiple activations, which occurs in the case of motion transparency. Psychophysical findings, such as motion attraction and repulsion for motion transparency displays, can be explained by this local competition. Besides this local competition mechanism, we show that feedback signals improve the processing of motion transparency. A discrimination task for transparent versus opaque motion is simulated, where motion transparency is generated by superimposing large field motion patterns of either varying size or varying coherence of motion. The model's perceptual thresholds with and without feedback are calculated. We demonstrate that initially weak peak responses can be enhanced and stabilized through modulatory feedback signals from higher stages of processing.