2,476 research outputs found
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A survey of behavioral-level partitioning systems
Many approaches have been developed to partition a system's behavioral description before a structural implementation is synthesized. We highlight the foundations and motivations for behavioral partitioning. We survey behavioral partitioning approaches, discussing abstraction levels, goals, major steps, and key assumptions in each
Managing polyglot systems metadata with hypergraphs
A single type of data store can hardly fulfill every end-user requirements in the NoSQL world. Therefore, polyglot systems use different types of NoSQL datastores in combination. However, the heterogeneity of the data storage models makes managing the metadata a complex task in such systems, with only a handful of research carried out to address this. In this paper, we propose a hypergraph-based approach for representing the catalog of metadata in a polyglot system. Taking an existing common programming interface to NoSQL systems, we extend and formalize it as hypergraphs for managing metadata. Then, we define design constraints and query transformation rules for three representative data store types. Furthermore, we propose a simple query rewriting algorithm using the catalog itself for these data store types and provide a prototype implementation. Finally, we show the feasibility of our approach on a use case of an existing polyglot system.Peer ReviewedPostprint (author's final draft
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Constant-time cost evaluation for behavioral partitioning
Given a system behavioral specification, partitioning can be used to distribute among chips the processes, procedures, and storage elements that comprise the specification. We introduce a technique for constant-time recomputation of pin, area, and execution-time estimates for a behavioral partitioning move. The technique permits fast, accurate estimations of a large number of partitionings, thus enabling better results than approaches which attain tractable computation time by using gross estimates or less thorough partitioning algorithms. The key to our technique is the isolation and extraction before partitioning of the basic design attributes needed for estimation, and the updating of this information in constant-time for each move. The estimation models are almost as detailed as those presented in previous estimation approaches not intended for constant-time update. The results we provide indicate the speed and practicality of our estimation approach in conjunction with sophisticated partitioning algorithms
Tractable Combinations of Global Constraints
We study the complexity of constraint satisfaction problems involving global
constraints, i.e., special-purpose constraints provided by a solver and
represented implicitly by a parametrised algorithm. Such constraints are widely
used; indeed, they are one of the key reasons for the success of constraint
programming in solving real-world problems.
Previous work has focused on the development of efficient propagators for
individual constraints. In this paper, we identify a new tractable class of
constraint problems involving global constraints of unbounded arity. To do so,
we combine structural restrictions with the observation that some important
types of global constraint do not distinguish between large classes of
equivalent solutions.Comment: To appear in proceedings of CP'13, LNCS 8124. arXiv admin note: text
overlap with arXiv:1307.179
Evaluating probabilistic programming languages for simulating quantum correlations
This article explores how probabilistic programming can be used to simulate
quantum correlations in an EPR experimental setting. Probabilistic programs are
based on standard probability which cannot produce quantum correlations. In
order to address this limitation, a hypergraph formalism was programmed which
both expresses the measurement contexts of the EPR experimental design as well
as associated constraints. Four contemporary open source probabilistic
programming frameworks were used to simulate an EPR experiment in order to shed
light on their relative effectiveness from both qualitative and quantitative
dimensions. We found that all four probabilistic languages successfully
simulated quantum correlations. Detailed analysis revealed that no language was
clearly superior across all dimensions, however, the comparison does highlight
aspects that can be considered when using probabilistic programs to simulate
experiments in quantum physics.Comment: 24 pages, 8 figures, code is available at
https://github.com/askoj/bell-ppl
A Graph Rewriting Approach for Transformational Design of Digital Systems
Transformational design integrates design and verification. It combines “correctness by construction” and design creativity by the use of pre-proven behaviour preserving transformations as design steps. The formal aspects of this methodology are hidden in the transformations. A constraint is the availability of a design representation with a compositional formal semantics. Graph representations are useful design representations because of their visualisation of design information. In this paper graph rewriting theory, as developed in the last twenty years in mathematics, is shown to be a useful basis for a formal framework for transformational design. The semantic aspects of graphs which are no part of graph rewriting theory are included by the use of attributed graphs. The used attribute algebra, table algebra, is a relation algebra derived from database theory. The combination of graph rewriting, table algebra and transformational design is new
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