Consistency Checking

The work reported here is part of the PROGRES (PROgrammed Graph Rewriting Systems) project. PROGRES is a very high level multi paradigm language for the specification of complex structured data types and their operations. The data structures are modelled as directed, attributed, node and edge labelled graphs (diane graphs). The basic programming constructs of PROGRES are graph rewriting rules (productions and tests) and derived relations on nodes (paths and restrictions). These basic operations may be combined to build partly imperative, partly rule based, complex graph transformations by special control structures which regard the nondeterministic nature of graph rewriting rules. PROGRES offers its users a convenient, partly textual, partly graphical concrete syntax and a rich system of consistency checking rules for the underlying calculus of programmed diane-graph rewriting systems. This paper presents the key techniques used for the execution of PROGRES programs. We will discuss...

In recent years, the significance of automated generation of object-oriented code from UML diagrams has increased due to its benefits, such as, cost reduction and accuracy. Consistency Checking between UML diagrams, and ensuring accuracy, maintainability, efficiency, and completeness of the generated code are the main concerns in this area. This paper extends our work on a tool called UJECTOR for automatic generation of executable Java code from UML diagrams. A set of three UML diagrams, ie, class diagram, sequence ...

In recent years, the significance of automated generation of object-oriented code from UML diagrams has increased due to its benefits, such as, cost reduction and accuracy. Consistency Checking between UML diagrams, and ensuring accuracy, maintainability, efficiency, and completeness of the generated code are the main concerns in this area. This paper extends our work on a tool called UJECTOR for automatic generation of executable Java code from UML diagrams. A set of three UML diagrams, ie, class diagram, sequence ...

In recent years, the significance of automated generation of object-oriented code from UML diagrams has increased due to its benefits, such as, cost reduction and accuracy. Consistency Checking between UML diagrams, and ensuring accuracy, maintainability, efficiency, and completeness of the generated code are the main concerns in this area. This paper extends our work on a tool called UJECTOR for automatic generation of executable Java code from UML diagrams. A set of three UML diagrams, ie, class diagram, sequence ...

We describe an algorithm for deciding the first-order multisorted theory BAPA, which combines Boolean algebras of sets of uninterpreted elements (BA) and Presburger arithmetic operations (PA). BAPA can express the relationship between integer variables and ...

This position paper comprises six theses that are intentionally formulated in a provocative way to motivate the development of information techniques and systems to support the Warfighter in future operations. The authors are convinced that such C4ISR systems 1 must integrate M&S methods & technology to fulfill the users’ operational needs for Alternative Course of Action Analysis, Consistency Checks of Decisions, Planning and Mission Rehearsal, After-Action Analysis, etc. Well-accepted Grand Challenges are the development of methods and algorithms in various simulation domains like Human Behavior Representation, Modeling Uncertainty, Techniques supporting DecisionMaking, etc. Some C4ISR domains that need M&S support will be dealt with in this paper explicitly. However, as important as the development of new methods is, the necessity of using the same conceptual and architectural approaches in the C4ISR & M&S Development Communities is equally vital for operational systems. Formulat...

Early phases of software development are known to be problematic, difficult to manage and errors occurring during these phases are expensive to correct. Many systems have been developed to aid the transition from informal Natural Language requirements to semi-structured or formal specifications. Furthermore, consistency checking is seen by many software engineers as the solution to reduce the number of errors occurring during the software development life cycle and allow early verification and validation of software systems. However, this is confined to the models developed during analysis and design and fails to include the early Natural Language requirements. This excludes proper user involvement and creates a gap between the original requirements and the updated and modified models and implementations of the system. To improve this process, we propose a system that generates Natural Language specifications from UML class diagrams. We first investigate the variation of the input language used in naming the components of a class diagram based on the study of a large number of examples from the literature and then develop rules for removing ambiguities in the subset of Natural Language used within UML. We use WordNet, a linguistic ontology, to disambiguate the lexical structures of the UML string names and generate semantically sound sentences. Our system is developed in Java and is tested on an independent though academic case study.

An RLC bridge based on an automated synchronous sampling system has been developed using commercially available high-resolution analog-to-digital and digital-to-analog converters. This bridge allows the comparison of any kind of impedance standards in the four-terminal-pair configuration at frequencies between 50 Hz and 20 kHz within a range from 1 Ω to 100 kΩ. An automatic balance of the bridge is carried out using a downhill simplex algorithm. Consistency checks have been realized by comparing resistance, inductance, and capacitance standards at different frequencies. The consistency of the measured voltage ratio is better than 20 μV/V over the whole frequency range and even smaller than 5 μV/V around 1 kHz. Finally, the results of the calibration of a 10-nF capacitance standard have been compared to those obtained using a commercial high-accuracy capacitance bridge. The difference is smaller than the commercial bridge specifications over the whole frequency range.

This paper presents an approach to model features and function nets of automotive systems comprehen- sively. In order to bridge the gap between feature requirements and function nets, we describe an ap- proach to describe both using a SysML-based nota- tion. If requirements on the automotive system are changed by several developers responsible for differ- ent features, it is important

Loop Quantum Cosmology (LQC), mainly due to Bojowald, is not the cosmological sector of Loop Quantum Gravity (LQG). Rather, LQC consists of a truncation of the phase space of classical General Relativity to spatially homogeneous situations which is then quantized by the methods of LQG. Thus, LQC is a quantum mechanical toy model (finite number of degrees of freedom) for LQG(a genuine QFT with an infinite number of degrees of freedom) which provides important consistency checks. However, it is a non trivial question whether the predictions of LQC are robust after switching on the inhomogeneous fluctuations present in full LQG. Two of the most spectacular findings of LQC are that 1. the inverse scale factor is bounded from above on zero volume eigenstates which hints at the avoidance of the local curvature singularity and 2. that the Quantum Einstein Equations are non -- singular which hints at the avoidance of the global initial singularity. We display the result of a calculation for LQG which proves that the (analogon of the) inverse scale factor, while densely defined, is {\it not} bounded from above on zero volume eigenstates. Thus, in full LQG, if curvature singularity avoidance is realized, then not in this simple way. In fact, it turns out that the boundedness of the inverse scale factor is neither necessary nor sufficient for curvature singularity avoidance and that non -- singular evolution equations are neither necessary nor sufficient for initial singularity avoidance because none of these criteria are formulated in terms of observable quantities.After outlining what would be required, we present the results of a calculation for LQG which could be a first indication that our criteria at least for curvature singularity avoidance are satisfied in LQG.

The critical role played by observations during ocean data assimilation was explored when the Regional Ocean Modeling System (ROMS) 4-dimensional variational (4D-Var) data assimilation system was applied sequentially to the California Current circulation. The adjoint of the 4D-Var gain matrix was used to quantify the impact of individual observations and observation platforms on different aspects of the 4D-Var circulation estimates during both analysis and subsequent forecast cycles. In this study we focus on the alongshore and cross-shore transport of the California Current System associated with wind-induced coastal upwelling along the central California coast. The majority of the observations available during any given analysis cycle are from satellite platforms in the form of SST and SSH, and on average these data exert the largest controlling influence on the analysis increments and forecast skill of coastal transport. However, subsurface in situ observations from Argo floats, CTDs, XBTs and tagged marine mammals often have a considerable impact on analyses and forecasts of coastal transport, even though these observations represent a relatively small fraction of the available data at any particular time.During 4D-Var the observations are used to correct for uncertainties in the model control variables, namely the initial conditions, surface forcing, and open boundary conditions. It is found that correcting for uncertainties in both the initial conditions and surface forcing has the largest impact on the analysis increments in alongshore transport, while the cross-shore transport is controlled mainly by the surface forcing. The memory of the circulation associated with the control variable increments was also explored in relation to 7 day forecasts of the coastal circulation. Despite the importance of correcting for surface forcing uncertainties during analysis cycles, the coastal transport during forecast cycles initialized from the analyses has less memory of the surface forcing corrections, and is controlled primarily by the analysis initial conditions.Using the adjoint of the entire 4D-Var system we have also explored the sensitivity of the coastal transport to changes in the observations and the observation array. A single integration of the adjoint of 4D-Var can be used to predict the change that occurs when observations from different platforms are omitted from the 4D-Var analysis. Thus observing system experiments can be performed for each data assimilation cycle at a fraction of the computational cost that would be required to repeat the 4D-Var analyses when observations are withheld. This is the third part of a three part series describing the ROMS 4D-Var systems.► The impact of observations on California Current circulation estimates is assessed. ► All observations are found to be important in controlling coastal transports. ► In situ observations have significant impact despite their relatively small number. ► The adjoint of 4D-Var can be used reliably for observing system experiments. ► The impact of uncertainties in the observations on coastal transports is assessed.

The aim of this position statement is to describe our work to support Web service technology as contribution to SOA by providing semantically "rich" descriptions of Web services together with methods and techniques to handle and to manipulate them by introducing Semantic Web technologies and additional logical formalisms into the annotation process. The annotation proc- ess will thus be enriched by new features and techniques to solve inference tasks (for instance with respect to consistency checking), to allow automated reasoning about annotation contents, to support automated search and complex query design, and to realize information derivation and interpretation based on different foci.