Merging the autoview image processing language with prolog

A new computer language, called provision, is defined. It combines features of both prolog (for artificial intelligence) and autoview (for image processing). Predicates for image processing, controlling cameras, illumination sources, optics, a video multiplexor and simple robotic devices are all integrated with PROLOG2, an extension of standard core prolog. The result is a powerful medium for expressing a wide range of algorithms for the visual control of robots and advanced industrial inspection. Several provision applications (i.e. ‘programs’) are presented.     

Citius altius fortius: Lessons learned from the Theorem Prover Waldmeister

In the last years, the development of automated theorem provers has been advancing in a so to speak Olympic spirit, following the motto “faster, higher, stronger”; and the Waldmeister system has been a part of that endeavour. We will survey the concepts underlying this prover, which implements Knuth-Bendix completion in its unfailing variant. The system architecture is based on a strict separation of active and passive facts, and is realized via specifically tailored representations for each of the central data structures: indexing for the active facts, set-based compression for the passive facts, successor sets for the conjectures. In order to cope with large search spaces, specialized redundancy criteria are employed, and the empirically gained control knowledge is integrated to ease the use of the system. We conclude with a discussion of strengths and weaknesses, and a view of future prospects.     

CoCasl at Work — Modelling Process Algebra

CoCasl[11], a recently developed coalgebraic extension of the algebraic specification language Casl[2], allows for modelling systems in terms of inductive datatypes as well as of co-inductive process types. Here, we demonstrate how to specify process algebras, namely CCS[10] and CSP[8,17], within such an algebraic-coalgebraic framework. It turns out that CoCasl can deal with the fundamental concepts of process algebra in a natural way: The type system of communications, the syntax of processes and their structural operational semantics fit well in the algebraic world of Casl, while the additional coalgebraic constructs of CoCasl cover the various process equivalences (bisimulation, weak bisimulation, observational congruence, and trace equivalence) and provide fully abstract semantic domains. CoCasl hence becomes a meta-framework for studying the semantics and proof theory of reactive systems.     

A verified Common Lisp implementation of Buchberger’s algorithm in ACL2

In this article, we present the formal verification of a Common Lisp implementation of Buchberger’s algorithm for computing Gröbner bases of polynomial ideals. This work is carried out in ACL2, a system which provides an integrated environment where programming (in a pure functional subset of Common Lisp) and formal verification of programs, with the assistance of a theorem prover, are possible. Our implementation is written in a real programming language and it is directly executable within the ACL2 system or any compliant Common Lisp system. We provide here snippets of real verified code, discuss the formalization details in depth, and present quantitative data about the proof effort.     

Improved Invariant Generation for Tvoc

The NYU Tvoc project applies the method of translation validation to verify that optimized code is semantically equivalent to the unoptimized code, by establishing, for each run of the optimizing compiler, a set of verification conditions (VCs) whose validity implies the correctness of the optimized run. The core of Tvoc is Tvoc-sp, that handles structure preserving optimizations, i.e., optimizations that do not alter the inner loop structures. The underlying proof rule, Val, on whose soundness Tvoc-sp is based, requires, among other things, to generating invariants at each “cutpoint” of the control graph of both source and target codes. The current implementation of Tvoc-sp employs somewhat naïve fix-point computations to obtain the invariants. In this paper, we propose an alternative method to compute invartiants which is based on simple data-flow analysis techniques.     

Synthesis of Optimal Strategies Using HyTech

Priced timed (game) automata extend timed (game) automata with costs on both locations and transitions. The problem of synthesizing an optimal winning strategy for a priced timed game under some hypotheses has been shown decidable in [P. Bouyer, F. Cassez, E. Fleury, and K.G. Larsen. Optimal strategies in priced timed game automata. Research Report BRICS RS-04-4, Denmark, Feb. 2004. Available at http://www.brics.dk/RS/04/4/]. In this paper, we present an algorithm for computing the optimal cost and for synthesizing an optimal strategy in case there exists one. We also describe the implementation of this algorithm with the tool HyTech and present an example.     

Visual Language Parsing in GenGEd

GenGEd supports the visual specification of visual languages and the generation of syntax-directed editors. However, syntax-directed editing is not always desired by the user. Therefore we extended GenGEd by parsing facilities which allow for free editing as well.     

Supervised ranking in the weka environment

Software for solving the supervised ranking problem is presented. Four variants of the Ordinal Stochastic Dominance Learner (OSDL) are given, together with the space and time complexity of their implementations. It is shown that the described software, which includes two further algorithms for supervised ranking, fits seamlessly into the weka environment.     

An Isodata algorithm for straight line fitting

This note describes a method of fitting κ straight lines to a set of data points using an algorithm analogous to the Isodata, or κ-means, clustering technique for partitioning a set of data points into κ compact clusters.     

OntoTrack: A semantic approach for ontology authoring

OntoTrackis an ontology authoring tool that combines a graph-based hierarchical layout and instant reasoning feedback within one single view. Currently OntoTrack can handle ontologies with an expressivity almost comparable to OWL Lite. The graphical representation provides an animated and zoomable subsumption graph with context sensitive features such as click-able miniature branches or selective detail views, together with drag-and-drop editing. Each editing step is instantly synchronised with an external reasoner in order to provide appropriate graphical feedback about relevant modeling consequences. A recent extention of OntoTrack provides an on-demand textual explanation for subsumption relationships between classes. This paper describes the key features of the current implementation and discusses future work, as well as some development issues. OntoTrack can be downloaded at http://www.informatik.uni-ulm.de/ki/ontotrack/.     

Syntax-driven Behavior Partitioning for Model-checking of Esterel Programs

We consider the issue of exploiting the structural form of Esterel programs to partition the algorithmic RSS (reachable state space) fix-point construction used in model-checking techniques. The basic idea sounds utterly simple, as seen on the case of sequential composition: in P; Q, first compute entirely the states reached in P, and then only carry on to Q, each time using only the relevant transition relation part. Here a brute-force symbolic breadth-first search would have mixed the exploration of P and Q instead, in case P had different behaviors of various lengths, and that would result in irregular BBD representation of temporary state spaces, a major cause of complexity in symbolic model-checking.Difficulties appear in our decomposition approach when scheduling the different transition parts in presence of parallelism and local signal exchanges. Program blocks (or “Macro-states”) put in parallel can be synchronized in various ways, due to dynamic behaviors, and considering all possibilities may lead to an excessive division complexity. The goal is here to find a satisfactory trade-off between compositional and global approaches. Concretely we use some of the features of the TiGeR BDD library, and heuristic orderings between internal signals, to have the transition relation progress through the program behaviors to get the same effect as a global RSS computation, but with much more localized transition applications. We provide concrete benchmarks showing the usefulness of the approach.     

Algebraic–coalgebraic specification in CoCasl

We introduce CoCasl as a light-weight but expressive coalgebraic extension of the algebraic specification language Casl. CoCasl allows the nested combination of algebraic datatypes and coalgebraic process types. Moreover, it provides syntactic sugar for an observer-indexed modal logic that allows e.g. expressing fairness properties. This logic includes a generic definition of modal operators for observers with structured equational result types. We prove existence of final models for specifications in a format that allows the use of equationally specified initial datatypes as observations, as well as modal axioms. The use of CoCasl is illustrated by specifications of the process algebras CSP and CCS.     

Kanga(ROO): Handling the micro-DST of the BaBar experiment with ROOT

A system based on ROOT for handling the micro-DST of the BaBar experiment is described. The purpose of the Kanga system is to have micro-DST data available in a format well suited for data distribution within a world-wide collaboration with many small sites. The design requirements, implementation and experience in practice after three years of data taking by the BaBar experiment are presented.     

Revised and extended Utilities for the Ratip package

During the last years, the Ratip package has been found useful for calculating the excitation and decay properties of free atoms. Based on the (relativistic) multiconfiguration Dirac-Fock method, this program is used to obtain accurate predictions of atomic properties and to analyze many recent experiments. The daily work with this package made an extension of its Utilities [S. Fritzsche, Comput. Phys. Comm. 141 (2001) 163] desirable in order to facilitate the data handling and interpretation of complex spectra. For this purpose, we make available an enlarged version of the Utilities which mainly supports the comparison with experiment as well as large Auger computations. Altogether 13 additional tasks have been appended to the program together with a new menu structure to improve the interactive control of the program.

Program summary

Title of program: RATIPCatalogue identifier: ADPD_v2_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADPD_v2_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneReference in CPC to previous version: S. Fritzsche, Comput. Phys. Comm. 141 (2001) 163Catalogue identifier of previous version: ADPDAuthors of previous version: S. Fritzsche, Department of Physics, University of Kassel, Heinrich-Plett-Strasse 40, D-34132 Kassel, GermanyDoes the new version supersede the original program?: yesComputer for which the new version is designed and others on which it has been tested: IBM RS 6000, PC Pentium II-IVInstallations: University of Kassel (Germany), University of Oulu (Finland)Operating systems: IBM AIX, Linux, UnixProgram language used in the new version: ANSI standard Fortran 90/95Memory required to execute with typical data: 300 kBNo. of bits in a word: All real variables are parameterized by a selected kind parameter and, thus, can be adapted to any required precision if supported by the compiler. Currently, the kind parameter is set to double precision (two 32-bit words) as used also for other components of the Ratip package [S. Fritzsche, C.F. Fischer, C.Z. Dong, Comput. Phys. Comm. 124 (2000) 341; G. Gaigalas, S. Fritzsche, Comput. Phys. Comm. 134 (2001) 86; S. Fritzsche, Comput. Phys. Comm. 141 (2001) 163; S. Fritzsche, J. Elec. Spec. Rel. Phen. 114-116 (2001) 1155]No. of lines in distributed program, including test data, etc.:231 813No. of bytes in distributed program, including test data, etc.: 3 977 387Distribution format: tar.gzip fileNature of the physical problem: In order to describe atomic excitation and decay properties also quantitatively, large-scale computations are often needed. In the framework of the Ratip package, the Utilities support a variety of (small) tasks. For example, these tasks facilitate the file and data handling in large-scale applications or in the interpretation of complex spectra.Method of solution: The revised Utilities now support a total of 29 subtasks which are mainly concerned with the manipulation of output data as obtained from other components of the Ratip package. Each of these tasks are realized by one or several subprocedures which have access to the corresponding modules of the main components. While the main menu defines seven groups of subtasks for data manipulations and computations, a particular task is selected from one of these group menus. This allows to enlarge the program later if technical support for further tasks will become necessary. For each selected task, an interactive dialog about the required input and output data as well as a few additional information are printed during the execution of the program.Reasons for the new version: The requirement for enlarging the previous version of the Utilities [S. Fritzsche, Comput. Phys. Comm. 141 (2001) 163] arose from the recent application of the Ratip package for large-scale radiative and Auger computations. A number of new subtasks now refer to the handling of Auger amplitudes and their proper combination in order to facilitate the interpretation of complex spectra. A few further tasks, such as the direct access to the one-electron matrix elements for some given set of orbital functions, have been found useful also in the analysis of data.Summary of revisions: extraction and handling of atomic data within the framework of Ratip. With the revised version, we now ‘add’ another 13 tasks which refer to the manipulation of data files, the generation and interpretation of Auger spectra, the computation of various one- and two-electron matrix elements as well as the evaluation of momentum densities and grid parameters. Owing to the rather large number of subtasks, the main menu has been divided into seven groups from which the individual tasks can be selected very similarly as before.Typical running time: The program responds promptly for most of the tasks. The responding time for some tasks, such as the generation of a relativistic momentum density, strongly depends on the size of the corresponding data files and the number of grid points.Unusual features of the program: A total of 29 different tasks are supported by the program. Starting from the main menu, the user is guided interactively through the program by a dialog and a few additional explanations. For each task, a short summary about its function is displayed before the program prompts for all the required input data.     

TiReX: Replica-exchange molecular dynamics using Tinker

We present a driver program for performing replica-exchange molecular dynamics simulations with the Tinker package. Parallelization is based on the Message Passing Interface, with every replica assigned to a separate process. The algorithm is not communication intensive, which makes the program suitable for running even on loosely coupled cluster systems. Particular attention is paid to the practical aspects of analyzing the program output.

Program summary

Program title: TiReXCatalogue identifier: AEEK_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEK_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 43 385No. of bytes in distributed program, including test data, etc.: 502 262Distribution format: tar.gzProgramming language: Fortran 90/95Computer: Most UNIX machinesOperating system: LinuxHas the code been vectorized or parallelized?: parallelized with MPIClassification: 16.13External routines: TINKER version 4.2 or 5.0, built as a libraryNature of problem: Replica-exchange molecular dynamics.Solution method: Each replica is assigned to a separate process; temperatures are swapped between replicas at regular time intervals.Running time: The sample run may take up to a few minutes.     

A zero-one SUBEXP-dimension law for BPP

We show that BPP has either SUBEXP-dimension zero (randomness is easy) or BPP=EXP (randomness is intractable).     

ReSpecT Nets: Towards an Analysis Methodology for ReSpecT Specifications

A key feature for infrastructures providing coordination services is the ability to define the behaviour of coordination abstractions according to the requirements identified at design-time. We take as a representative for this scenario the logic-based language ReSpecT (Reaction Specification Tuples), used to program the reactive behaviour of tuple centres. ReSpecT specifications are at the core of the engineering methodology underlying the TuCSoN infrastructure, and are therefore the “conceptual place” where formal methods can be fruitfully applied to guarantee relevant system properties.In this paper we introduce ReSpecT nets, a formalism that can be used to describe reactive behaviours that can succeed and fail, and that allows for an encoding to Petri nets with inhibitor arcs. ReSpecT nets are introduced to give a core model to a fragment of the ReSpecT language, and to pave the way for devising an analysis methodology including formal verification of safety and liveness properties. In particular, we provide a semantics to ReSpecT specifications through a mapping to ReSpecT nets. The potential of this approach for the analysis of ReSpecT specifications is discussed, presenting initial results for the analysis of safety properties.