Towards a Universal Representation of DEVS: A Metamodel-Based Definition of DEVS Formal Specification

Author(s):  
Maria Julia Blas ◽  
Silvio Gonnet ◽  
Bernard P. Zeigler
2011 ◽  
pp. 124-144 ◽  
Author(s):  
Goran D Putnik ◽  
Maria M. Cunha ◽  
Rui Sousa ◽  
Paulo Avila

BM_virtual enterprise (BM_VE) is a virtual enterprise (VE) in a total or partial conformance with the BM_virtual enterprise architecture reference model (BM_VEARM). BM_VE is a kind of VE characterized as a dynamically reconfigurable network integrated over the global domain, satisfying the requirements for integrability, distributivity, agility, and virtuality as competitiveness factors. BM_VE uses three main mechanisms, or tools: market of resources, broker, and virtuality. This chapter presents the three fundamental mechanisms for the VE reconfiguration dynamics and virtuality; introduces the basic concept of the BM_VEARM, which serves as the conceptual and formal base for building BM_VE instances; shows the formal specification and theory of the structural aspects of the BM_VE as well as some aspects of the BM_VE reconfiguration dynamics; presents the BM_VE as an agile/virtual enterprise (A/VE); and finally, describes some important consequences of virtuality in BM_VE, i.e., that the BM_VE structure is hierarchical, a new definition of the VE (in which the network as the VE characteristic is irrelevant from the operational unit’s point of view), and the process of a “traditional” enterprise virtualization.


Author(s):  
Nicoletta Fornara ◽  
Marco Colombetti

The specification of open interaction systems is widely recognized to be a crucial issue, which involves the problem of finding a standard way of specifying: a communication language for the interacting agents, the entities that constitute the context of the interaction, and rules that regulate interactions. An approach to solve these problems consists in modelling open interaction systems as a set of artificial institutions. In this chapter we address this issue by formally defining, in the Event Calculus, a repertoire of abstract concepts (like commitment, institutional power, role, and norm) that can be used to specify every artificial institution. We then show how, starting from the formal definition of these concepts and of application-dependent concepts, it is possible to obtain a formal specification of a system. By using a suitable tool, it is then possible to simulate and monitor the system’s evolution through automatic deduction.


SIMULATION ◽  
2021 ◽  
pp. 003754972110456
Author(s):  
María Julia Blas ◽  
Silvio Gonnet

The Discrete-Event System Specification (DEVS) formalism is a modeling formalism based on systems theory that provides a general methodology for hierarchical construction of reusable models in a modular way. When concrete DEVS models are developed using programming languages, it is difficult to ensure they conform to their formal model. Hence, building an implementation of formal models in a way that ensures DEVS formalism correctness is not easy. In this paper, we improve the interplay of abstraction (i.e., formal specification) and concreteness (i.e., programming code implementation) in advancing the theory and practice of DEVS using a specific-designed metamodel. The main contribution is a novel conceptualization of classic DEVS with ports founded on existing approaches but that also includes new improved elements related to the definition of atomic models. That is, our metamodel includes all the concepts and relationships needed to define the formal specification of DEVS atomic models. This allows us to define instances of our conceptualization that comply with the DEVS formal specification. To instantiate our metamodel, we propose a computer-aided environment that has been developed using the Eclipse Modeling Project. As an example, we show how our metamodel can be used to define the classic “switch” model. As a conclusion, we discuss how the final metamodel can be used to support interoperability with DEVS simulation tools.


Author(s):  
Fernando Molina ◽  
Francisco J. Lucas ◽  
Ambrosio Toval Alvarez ◽  
Juan M. Vara ◽  
Paloma Cáceres ◽  
...  

Recent years have seen the arrival of the Internet as the platform that supports most areas within organizations, a fact which has led to the appearance of specific methodologies and tools for the construction of Web information systems (WIS). However, an absence of functionalities for the verification and validation (V&V) has been detected in the methodologies and tools of the models which have been built. This chapter presents one of these methodologies for WIS development (MIDAS) and shows how it has been completed with the definition of a strategy for the formal specification of its models with V&V objectives. This will contribute to increasing the quality of the models used in WIS development. The plug-in architecture which integrates this formal approach within CASE tools for WIS development is also shown.


2020 ◽  
Vol 20 (5) ◽  
pp. 767-782 ◽  
Author(s):  
PEDRO CABALAR ◽  
JORGE FANDINNO ◽  
YULIYA LIERLER

AbstractIn this paper, we study the problem of formal verification for Answer Set Programming (ASP), namely, obtaining a formal proof showing that the answer sets of a given (non-ground) logic program P correctly correspond to the solutions to the problem encoded by P, regardless of the problem instance. To this aim, we use a formal specification language based on ASP modules, so that each module can be proved to capture some informal aspect of the problem in an isolated way. This specification language relies on a novel definition of (possibly nested, first order) program modules that may incorporate local hidden atoms at different levels. Then, verifying the logic program P amounts to prove some kind of equivalence between P and its modular specification.


Author(s):  
Cyrille Dongmo ◽  
John Andrew van der Poll

A Use Case Map (UCM) is a scenario-based visual notation facilitating the requirements definition of complex systems. A UCM may be generated either from a set of informal requirements, or from a set of use cases normally expressed in natural language. Natural languages are, however, inherently ambiguous and as a semi-formal notation, UCMs have the potential to bring more clarity into the functional description of a system. It may furthermore eliminate possible errors in the user requirements. The semi-formal notation of UCMs aims to show how things work generally, but is not suitable to reason formally about system behavior. It is plausible, therefore, that the use of a UCM as an intermediate step may facilitate the construction of a formal specification. To this end this paper proposes a mechanism whereby a UCM may be translated into Object-Z.


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.


1979 ◽  
Vol 46 ◽  
pp. 125-149 ◽  
Author(s):  
David A. Allen

No paper of this nature should begin without a definition of symbiotic stars. It was Paul Merrill who, borrowing on his botanical background, coined the termsymbioticto describe apparently single stellar systems which combine the TiO absorption of M giants (temperature regime ≲ 3500 K) with He II emission (temperature regime ≳ 100,000 K). He and Milton Humason had in 1932 first drawn attention to three such stars: AX Per, CI Cyg and RW Hya. At the conclusion of the Mount Wilson Ha emission survey nearly a dozen had been identified, and Z And had become their type star. The numbers slowly grew, as much because the definition widened to include lower-excitation specimens as because new examples of the original type were found. In 1970 Wackerling listed 30; this was the last compendium of symbiotic stars published.


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