Electronic Communications of the EASST (European Association of Software Science and Technology)
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String-based Multi-adjoint Lattices for Tracing Fuzzy Logic Computations
Get PDFClassically, most programming languages use in a predefined way thenotion of “string” as an standard data structure for a comfortable management of arbitrary sequences of characters. However, in this paper we assign a different role to this concept: here we are concerned with fuzzy logic programming, a somehow recent paradigm trying to introduce fuzzy logic into logic programming. In this setting, the mathematical concept of multi-adjoint lattice has been successfully exploited into the so-called Multi-adjoint Logic Programming approach, MALP in brief, for modeling flexible notions of truth-degrees beyond the simpler case of true and false. Our main goal points out not only our formal proof verifying that stringbased lattices accomplish with the so-called multi-adjoint property (as well as its Cartesian product with similar structures), but also its correspondence with interesting debugging tasks into the FLOPER system (from “Fuzzy LOgic Programming Environment for Research”) developed in our research group
Model-Based Engineering for the support of Models of Computation: The Cometa Approach
Get PDFThe development of Real-Time Embedded Systems (RTES) increasingly requires the integration of several parts with different purposes. Consequently, the heterogeneous appearance of such systems creates a need to manage their growing complexity mainly due to the difficulty to interconnect the different parts composing them. Model-Based Engineering (MBE) has significantly participated in recent decades to find solutions in terms of methodologies and technical support tailored to the design of RTES. Indeed, several models are used to represent different aspects of the system. However, the interconnection of different modeling paradigms is still a difficult challenge. The handling of such problems requires a clear definition of the execution and interconnection semantics of the different models composing the system. Indeed, the abstraction of the execution semantics of machines or Models of Computation (MoC) can highlight properties for the whole system’s execution. In this paper, we propose an approach that captures these semantics at the earliest modeling phases with the aim of exhibiting properties that ease the design space exploration and performance analysis of systems. Our approach extends the Modeling and Analysis of Real-Time Embedded Systems profile (MARTE) by providing means to express communication semantics of models. We also review existing approaches for defining such execution semantics
Decentralized Coordination in Self-Organizing Systems based on Peer-to-Peer Coordination Spaces
Get PDFCoordination is an important aspect to realize Self-organizing Systemsusually implemented as part of the functional properties of the system. This paper promotes a separation of concerns via a declarative approach to realize decentralized coordination in Self-organizing Multi-Agent Systems (MAS). In previous work the concept of Coordination Spaces was developed which provides explicit support for the task of coordination in MAS. Coordination Spaces are part of the agent environment and handle a declarative description of the coordination process. Thereby, this approach allows developers rather focusing on what to coordinate than on how to coordinate. Also by releasing the developer from programming coordination manually, the approach offers benefits like reusability and interoperability of coordination processes. This paper extends the approach by a distribution concept for coordination spaces. By using different techniques like remote service calls, group communicationand publish/subscribe models the distribution of information among multiple platforms in a peer-to-peer like approach is achieved
Analysis of Collaboration Effectiveness and Individuals’ Contribution in FLOSS Communities
Get PDFFree/Libre Open Source Software (FLOSS) development has proven itself over the years to be able to deliver high-quality software products. However, it is not clear how quality emerges from the large amount of loosely organised activities of a FLOSS community. This makes it difficult to apply traditional quality metrics and certification processes to FLOSS products. This paper investigates possible indicators of collaboration effectiveness and quality of individuals’ contribution that could be extracted from the data available in repositories of FLOSS projects. The ultimate purpose of this effort is to develop quantitative metrics for these indicators and merge such metrics into a global metric for FLOSS software quality to be used in a certification process
A Graph Transformational View on Reductions in NP
Get PDFMany decision problems in the famous and challenging complexity class NP are graph problems and can be adequately specified by polynomial graph transformation units. In this paper, we propose to model the reductions in NP by means of a special type of polynomial graph transformation units, too. Moreover, we present some first ideas how the semantic requirements of reductions including their correctness can be proved in a systematic way
Learning Minimal and Maximal Rules from Observations of Graph Transformations
Get PDFGraph transformations have been used to model services and systems where rules describe pre and post conditions of operations changing a complex state. However, despite their intuitive nature, creating such models is a time-consuming and error-prone process. In this paper we investigate the possibility of extracting rules from observations of transformations, i.e., pairs of input and output graphs resulting from successful transformations and individual input graphs were they have failed. From such positive and negative examples, minimal rules are extracted, to be extended by context that is present in all positive examples and missing in at least one negative example. The result is are a maximal and a required rule, jointly with the minimal rule defining the range of possible rules that could have created the observed transformations. We report on an implementation of the approach, evaluate its accuracy, scalability and limitations, and discuss applications to reverse engineering visual constructs from observations of object states of components under test
On the whereabouts of CSP-CASL – A survey
Get PDFCSP-CASL is but one of the many languages for which Bernd Krieg-Brueckner (BKB) had a great deal of influence throughout its development process: from the initial idea of working towards an integration of the process algebra CSP with the algebraic specification language CASL, to the design of the concrete syntax, and also to tool support for CSP-CASL, where the theorem prover Isabelle should provide the common platform. In all this, BKB provided inspiration and guidance, funding, and also a helping hand when needed. This paper provides a survey on the technology developed so far for CSP-CASL, covering results of a theoretical nature, an industrial case study, theorem proving support as well as a testing approach. In honour of BKB’s 60th birthday, this survey documents what has become out of one of BKB’s visions
XL4C4D - Adding the Graph Transformation Language XL to CINEMA 4D
Get PDFA plug-in for the 3D modeling application CINEMA 4D is presented which allows to use the graph transformation language XL to transform the 3D scene graph of CINEMA 4D. XL extends Java by graph query and rewrite facilities via a data model interface, the default rewrite mechanism is that of relational growth grammars which are based on parallel single-pushout derivations. We illustrate the plug-in at several examples, some of which make use of advanced 3D features
Fractional Permissions and Non-Deterministic Evaluators in Interval Temporal Logic
Get PDFWe propose Interval Temporal Logic as a basis for reasoning about concurrent programs with fine-grained atomicity due to the generality it provides over reasoning with standard pre/post-state relations. To simplify the semantics of parallel composition over intervals, we use fractional permissions, which allows one to ensure that conflicting reads and writes to a variable do not occur simultaneously. Using non-deterministic evaluators over intervals, we enable reasoning about the apparent states over an interval, which may differ from the actual states in the interval. The combination of Interval Temporal Logic, non-deterministic evaluators and fractional permissions results in a generic framework for reasoning about concurrent programs with fine-grained atomicity. We use our logic to develop rely/guarantee-style rules for decomposing a proof of a large system into proofs of its subcomponents, where fractional permissions are used to ensure that the behaviours of a program and its environment do not conflict