05 Fakultät Informatik, Elektrotechnik und Informationstechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6
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Item Open Access Sub-lexical investigations: German particles, prefixes and prepositions(2013) Roßdeutscher, AntjeThe papers investigate constructions with P(repositional) elements in German. It aims at a comprehensive theory of the syntax-semantics interface for the different verbal constructions in German, including verb plus prepostional phrase, (separable) particle verbs, and (inseparable) prefix verbs. The constructions are given syntactic representations following minimalist principles as known from \textit{Distributive Morphology} (DM) according to which a single syntactic engine drives formation of both words and phrases. Among the syntactic principles the Split-P hypothesis plays a central role. A crucial feature of the approach is that the syntactic structures are used as input to the computation of semantic representations according to principles of Discourse Representation Theory (DRT). Several challenges that present themselves for a compositional theory of word- and phrase- formation with P-elements in German are accounted for in the paper: syntactic separability of verb-particle constructions vs non-separability of prefix-verbs; semantic restrictions in the P-elements to build constructions of the former and the latter type; syntactic alternations w.r.t. the realisation of figure and ground arguments and the semantic basis of these alternations. A particular challenge are the differences in the conceptual and aspectual contribution of the same prepositional root in different syntactic contexts.Item Open Access Propagation of states from BPEL process instances to Chevron models(2011) Schumm, David; Karastoyanova, Dimka; Leymann, Frank; Lie, SumadiThis report describes key aspects of a code library that we developed for the purpose of state propagation for business process monitoring on different levels of abstraction. The library supports the propagation of execution states of process instances based on the Business Process Execution Language (BPEL) to process models specified in the "Chevron" language. The Chevron language is an abstract, non-executable process language that we especially designed for abstract process instance monitoring purposes. The look and feel of this graphical language is similar to value chains. The basic concept of the Chevron language is based on Chevron-shaped charts which can be modeled in Microsoft PowerPoint to describe a process on a high level of abstraction. We aim at enabling the use of high-level process in order to monitor the instance status of a much more detailed, lower-level model. We describe the overall procedure of performing state projections along a concrete scenario. We describe a format for state propagation rules which define how the status of activities of a BPEL process instance should be projected to the elements of a Chevron model. We present a format to serialize process models in the Chevron language. We present a graphical template based on Scalable Vector Graphics (SVG) which we employ to render a stateful Chevron model graphically. The Chevron language is just one language to be used for abstract representation of process instances. However, the approach for state propagation is generic and can be applied for other languages, too.Item Open Access First-order fragments with successor over infinite words(2010) Kallas, Jakub; Kufleitner, Manfred; Lauser, AlexanderWe consider fragments of first-order logic and as models we allow finite andinfinite words simultaneously. The only binary relations apart from equalityare order comparison < and the successor predicate +1. We givecharacterizations of the fragments Sigma2 = Sigma2[<,+1] and FO2 = FO2[<,+1] interms of algebraic and topological properties. To this end we introduce thefactor topology over infinite words. It turns out that a language L is in theintersection of FO2 and Sigma2 if and only if L is the interior of an FO2language. Symmetrically, a language is in the intersection of FO2 and Pi2 ifand only if it is the topological closure of an FO2 language. The fragmentDelta2, which by definition is the intersection Sigma2 and Pi2 contains exactlythe clopen languages in FO2. In particular, over infinite words Delta2 is astrict subclass of FO2. Our characterizations yield decidability of themembership problem for all these fragments over finite and infinite words; andas a corollary we also obtain decidability for infinite words. Moreover, wegive a new decidable algebraic characterization of dot-depth 3/2 over finitewords. Decidability of dot-depth 3/2 over finite words was first shown by Glaßer andSchmitz in STACS 2000, and decidability of the membership problem for FO2 overinfinite words was shown 1998 by Wilke in his habilitation thesis whereasdecidability of Sigma2 over infinite words was not known before.Item Open Access Rankers over infinite words(2010) Dartois, Luc; Kufleitner, Manfred; Lauser, AlexanderWe consider the fragments FO2, the intersection of Sigma2 and FO2, the intersection of Pi2 and FO2, and Delta2 of first-order logic FO[<] over finite and infinite words. For all four fragments, we give characterizations in terms of rankers. In particular, we generalize the notion of a ranker to infinite words in two possible ways. Both extensions are natural in the sense that over finite words, they coincide with classical rankers and over infinite words, they both have the full expressive power of FO2. Moreover, the first extension of rankers admits a characterization of the intersection of Sigma2 and FO2 while the other leads to a characterization of the intersection of Pi2 and FO2. Both versions of rankers yield characterizations of the fragment Delta2. As a byproduct, we also obtain characterizations based on unambiguous temporal logic and unambiguous interval temporal logic.Item Open Access Methods for coreference visualization and annotation(2010) Burkovski, Andre; Heidemann, Gunther; Kobdani, Hamidreza; Schütze, HinrichIn this report we present methods for visualization of coreferences. We use Self Organizing Maps, graph-based models, and text-based techniques to visualize coreference information from a pair-wise model and offer an interactive presentation of the feature space. We introduce our software system and several visualizations of the Self Organizing Map. The visualizations enable the user to explore the feature space, provide insights for feature engineering and allow a fast annotation of data with coreference information.Item Open Access A prototype for view-based monitoring of BPEL processes(2011) Schumm, David; Latuske, Gregor; Leymann, FrankThis report describes the initial version of a tool for business process monitoring based on process viewing techniques. The tool, Business Process Illustrator (BPI), has been developed in the course of a Diploma Thesis which has been conducted at the Institute of Architecture of Application Systems. BPI is a Web-based tool for monitoring the execution of business processes. It displays the current state of a process instance in form of a process graph which is refreshed regularly. The initial version of the prototype supports regular process monitoring of processes based on the Business Process Execution Language (BPEL), plus process view transformations to reduce complexity and to ease analysis of process instances.Item Open Access An event model for WS-BPEL 2.0(2011) Kopp, Oliver; Henke, Sebastian; Karastoyanova, Dimka; Khalaf, Rania; Leymann, Frank; Sonntag, Mirko; Steinmetz, Thomas; Unger, Tobias; Wetzstein, BranimirThis report presents an engine-independent WS-BPEL 2.0 event model. It supports both passive monitoring and active control of process execution by external applications. Some of the assumptions in the presented event model are inspired by a particular implementation, e.g. fault handling and compensation; however they are kept as general as possible, so that they can be mapped on other engine-specific approaches to tackle faults and support compensation. In addition, the report draws on the experience of some of the authors in business process management and software development. The overall BPEL event model consists of a set of event models for the different types of BPEL entities that change their states: processes, process instances, general activities, scope activities, invoke activities, loops, links, variables, partner links, and correlation sets. The event model is used by the authors of the report in several projects, all utilizing process life cycle events in different scenarios.Item Open Access Comparison of standard and Zipf-based document retrieval heuristics(2010) Hoffmann, BenjaminDocument retrieval is the task to retrieve from a possibly huge collection of documents those which are most similar to a given query document. In this paper, we present a new heuristic for inexact top K retrieval. It is similar to the well-known index elimination heuristic and is based on Zipf's law, a statistical law observable in natural language texts. We compare the two heuristics with regard to retrieval performance and execution time. Therefore, we use a text collection consisting of scientific articles from various computer science conferences and journals. It turns out that our new approach is not better than index elimination. Interestingly, a combination of both heuristics yields the best results.Item Open Access A network abstraction for control systems(2014) Carabelli, Ben W.; Dürr, Frank; Koldehofe, Boris; Rothermel, KurtNetworked control systems (NCS), such as the smart power grid, implement feedback control loops by connecting distributed sensors and actuators to a remote controller over a communication network. In order to avoid the costly and time-consuming installation of dedicated networks, NCS can benefit from utilizing readily available IP networks such as the Internet. However, as control systems are typically sensitive to delay and loss, the integration of such systems over best-effort networks becomes a challenge, which we address in this paper with two main contributions. First, we propose an end-to-end transport abstraction for NCS based on a novel probabilistic quality of service specification which (1) is compatible with existing control models and (2) provides the network with application-specific knowledge about the relation between system performance and network-relevant metrics. Second, we realize this abstraction at the network layer with an optimal routing algorithm, which fulfils the required QoS while minimizing the usage of network resources. We show that our approach lends itself to the implementation with state-of-the-art software-defined networking (SDN) technologies, and demonstrate its effectiveness in our evaluation.Item Open Access On the iterated hairpin completion(2010) Kopecki, SteffenThe hairpin completion is a natural operation on formal languages which has been inspired by biochemistry and DNA-computing. In this paper we solve two problems which were posed first in 2008 and 2009, respectively, and still left open: 1.) It is known that the iterated hairpin completion of a regular language is not context-free in general, but it was open whether the iterated hairpin completion of a singleton or finite language is regular or at least context-free. We will show that it can be non-context-free. (It is of course context-sensitive.) 2.) A restricted but also very natural variant of the hairpin completion is the bounded hairpin completion. It was unknown whether the iterated bounded hairpin completion of a regular language remains regular. We prove that this is indeed the case. Actually we derive a more general result. We will present a general representation of the iterated bounded hairpin completion for any language using basic operations. Thus, each language class closed under these basic operations is also closed under iterated bounded hairpin completion.