28 research outputs found

    The 2nd Conference of PhD Students in Computer Science

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    Seventh Biennial Report : June 2003 - March 2005

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    RML: Runtime Monitoring Language

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    Runtime verification is a relatively new software verification technique that aims to prove the correctness of a specific run of a program, rather than statically verify the code. The program is instrumented in order to collect all the relevant information, and the resulting trace of events is inspected by a monitor that verifies its compliance with respect to a specification of the expected properties of the system under scrutiny. Many languages exist that can be used to formally express the expected behavior of a system, with different design choices and degrees of expressivity. This thesis presents RML, a specification language designed for runtime verification, with the goal of being completely modular and independent from the instrumentation and the kind of system being monitored. RML is highly expressive, and allows one to express complex, parametric, non-context-free properties concisely. RML is compiled down to TC, a lower level calculus, which is fully formalized with a deterministic, rewriting-based semantics. In order to evaluate the approach, an open source implementation has been developed, and several examples with Node.js programs have been tested. Benchmarks show the ability of the monitors automatically generated from RML specifications to effectively and efficiently verify complex properties

    Capture and Maintenance of Constraints in Engineering Design

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    The thesis investigates two domains, initially the kite domain and then part of a more demanding Rolls-Royce domain (jet engine design). Four main types of refinement rules that use the associated application conditions and domain ontology to support the maintenance of constraints are proposed. The refinement rules have been implemented in ConEditor and the extended system is known as ConEditor+. With the help of ConEditor+, the thesis demonstrates that an explicit representation of application conditions together with the corresponding constraints and the domain ontology can be used to detect inconsistencies, redundancy, subsumption and fusion, reduce the number of spurious inconsistencies and prevent the identification of inappropriate refinements of redundancy, subsumption and fusion between pairs of constraints.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    An Argumentation-Based Approach to Normative Practical Reasoning

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    Session-based concurrency, declaratively

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    Session-based concurrency is a type-based approach to the analysis of message-passing programs. These programs may be specified in an operational or declarative style: the former defines how interactions are properly structured; the latter defines governing conditions for correct interactions. In this paper, we study rigorous relationships between operational and declarative models of session-based concurrency. We develop a correct encoding of session 휋-calculus processes into the linear concurrent constraint calculus (횕회회), a declarative model of concurrency based on partial information (constraints). We exploit session types to ensure that our encoding satisfies precise correctness properties and that it offers a sound basis on which operational and declarative requirements can be jointly specified and reasoned about. We demonstrate the applicability of our results by using our encoding in the specification of realistic communication patterns with time and contextual information

    Sixth Biennial Report : August 2001 - May 2003

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    An incremental prototyping methodology for distributed systems based on formal specifications

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    This thesis presents a new incremental prototyping methodology for formally specified distributed systems. The objective of this methodology is to fill the gap which currently exists between the phase where a specification is simulated, generally using some sequential logical inference tool, and the phase where the modeled system has a reliable, efficient and maintainable distributed implementation in a main-stream object-oriented programming language. This objective is realized by application of a methodology we call Mixed Prototyping with Object-Orientation (in short: OOMP). This is an extension of an existing approach, namely Mixed Prototyping, that we have adapted to the object-oriented paradigm, of which we exploit the flexibility and inherent capability of modeling abstract entities. The OOMP process proceeds as follows. First, the source specifications are automatically translated into a class-based object-oriented language, thus providing a portable and high-level initial implementation. The generated class hierarchy is designed so that the developer may independently derive new sub-classes in order to make the prototype more efficient or to add functionalities that could not be specified with the given formalism. This prototyping process is performed incrementally in order to safely validate the modifications against the semantics of the specification. The resulting prototype can finally be considered as the end-user implementation of the specified software. The originality of our approach is that we exploit object-oriented programming techniques in the implementation of formal specifications in order to gain flexibility in the development process. Simultaneously, the object paradigm gives the means to harness this newly acquired freedom by allowing automatic generation of test routines which verify the conformance of the hand-written code with respect to the specifications. We demonstrate the generality of our prototyping scheme by applying it to a distributed collaborative diary program within the frame of CO-OPN (Concurrent Object-Oriented Petri Nets), a very powerful specification formalism which allows expressing concurrent and non-deterministic behaviours, and which provides structuring facilities such as modularity, encapsulation and genericity. An important effort has also been accomplished in the development or adaptation of distributed algorithms for cooperative symbolic resolution. These algorithms are used in the run-time support of the generated CO-OPN prototypes

    Verzeichnis von Softwarekomponenten für natürlichsprachliche Systeme : Ergebnisse einer Umfrage im Rahmen der VERBMOBIL-Vorbereitung

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    Das DFKI (Deutsches Forschungszentrum für Künstliche Intelligenz) wurde vom BMFT (Bundesministerium für Forschung und Technologie) mit der Durchführung einer Umfrage zu existierenden Software-Komponenten im Bereich Verarbeitung natürlicher Sprache beauftragt (413 - 4001 - 01 IV 201). Das Ziel der Umfrage war die Erstellung einer Übersicht von in Deutschland verfügbaren Software-Komponenten, die im Bereich der natürlichsprachlichen Systeme für das Projekt VERBMOBIL relevant sein könnten. Das Ergebnis dieser Umfrage liegt nun vor. Zur Durchführung der Umfrage wurde ein Fragebogen erstellt, der im März 1992 über die News-Gruppe mod-ki verbreitet und außerdem an ca. 400 Adressen geschickt wurde (Mitglieder der Gesellschaft für Informatik e. V. FA 1.3 1 "Natürliche Sprache", Mitglieder der DGfS, Sektion Computerlinguistik). Das Verzeichnis ist auf in Deutschland entwickelte Software beschränkt und enthält akademische, kommerzielle und geschützte Software, wobei jeweils angegeben ist, unter welchen Bedingungen die Komponenten erhältlich sind

    Kiel Declarative Programming Days 2013

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    This report contains the papers presented at the Kiel Declarative Programming Days 2013, held in Kiel (Germany) during September 11-13, 2013. The Kiel Declarative Programming Days 2013 unified the following events: * 20th International Conference on Applications of Declarative Programming and Knowledge Management (INAP 2013) * 22nd International Workshop on Functional and (Constraint) Logic Programming (WFLP 2013) * 27th Workshop on Logic Programming (WLP 2013) All these events are centered around declarative programming, an advanced paradigm for the modeling and solving of complex problems. These specification and implementation methods attracted increasing attention over the last decades, e.g., in the domains of databases and natural language processing, for modeling and processing combinatorial problems, and for high-level programming of complex, in particular, knowledge-based systems
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