8,190 research outputs found
Embedding Requirements within the Model Driven Architecture
The Model Driven Architecture (MDA) brings benefits to software development, among them the potential for connecting software models with the business domain. This paper focuses on the upstream or Computation Independent Model (CIM) phase of the MDA. Our contention is that, whilst there are many models and notations available within the CIM Phase, those that are currently popular and supported by the Object Management Group (OMG), may not be the most useful notations for business analysts nor sufficient to fully support software requirements and specification.
Therefore, with specific emphasis on the value of the Business Process Modelling Notation (BPMN) for business analysts, this paper provides an example of a typical CIM approach before describing an approach which incorporates specific requirements techniques. A framework extension to the MDA is then introduced; which embeds requirements and specification within the CIM, thus further enhancing the utility of MDA by providing a more complete method for business analysis
An analytical framework for a consensus-based global optimization method
In this paper we provide an analytical framework for investigating the
efficiency of a consensus-based model for tackling global optimization
problems. This work justifies the optimization algorithm in the mean-field
sense showing the convergence to the global minimizer for a large class of
functions. Theoretical results on consensus estimates are then illustrated by
numerical simulations where variants of the method including nonlinear
diffusion are introduced
Schwinger-Keldysh formalism II: Thermal equivariant cohomology
Causally ordered correlation functions of local operators in near-thermal
quantum systems computed using the Schwinger-Keldysh formalism obey a set of
Ward identities. These can be understood rather simply as the consequence of a
topological (BRST) algebra, called the universal Schwinger-Keldysh
superalgebra, as explained in our companion paper arXiv:1610.01940. In the
present paper we provide a mathematical discussion of this topological algebra.
In particular, we argue that the structures can be understood in the language
of extended equivariant cohomology. To keep the discussion self-contained, we
provide a basic review of the algebraic construction of equivariant cohomology
and explain how it can be understood in familiar terms as a superspace gauge
algebra. We demonstrate how the Schwinger-Keldysh construction can be
succinctly encoded in terms a thermal equivariant cohomology algebra which
naturally acts on the operator (super)-algebra of the quantum system. The main
rationale behind this exploration is to extract symmetry statements which are
robust under renormalization group flow and can hence be used to understand
low-energy effective field theory of near-thermal physics. To illustrate the
general principles, we focus on Langevin dynamics of a Brownian particle,
rephrasing some known results in terms of thermal equivariant cohomology. As
described elsewhere, the general framework enables construction of effective
actions for dissipative hydrodynamics and could potentially illumine our
understanding of black holes.Comment: 72 pages; v2: fixed typos. v3: minor clarifications and improvements
to non-equilbirum work relations discussion. v4: typos fixed. published
versio
Search and Result Presentation in Scientific Workflow Repositories
We study the problem of searching a repository of complex hierarchical
workflows whose component modules, both composite and atomic, have been
annotated with keywords. Since keyword search does not use the graph structure
of a workflow, we develop a model of workflows using context-free bag grammars.
We then give efficient polynomial-time algorithms that, given a workflow and a
keyword query, determine whether some execution of the workflow matches the
query. Based on these algorithms we develop a search and ranking solution that
efficiently retrieves the top-k grammars from a repository. Finally, we propose
a novel result presentation method for grammars matching a keyword query, based
on representative parse-trees. The effectiveness of our approach is validated
through an extensive experimental evaluation
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