Model Design using Hierarchical
Web-Based Libraries
F. Bernardi
Pr. J.F. Santucci
{bernardi, santucci}@univ-corse.fr
University of Corsica
SPE Laboratory
UMR CNRS 6134
Studied Problem
 Objective of this work: to build a generic models
library
 Interests:



Reusability of models seen as modeling components
Ease of new models building
Ease of new models validation
 Main Requirements:




Ease of use
Inheritance between models management
Abstraction Hierarchy between models management
Remote access capacity
Summary
 Basic Notions of M&S
 Basics of the Models Library
 Web-Based Architecture
 Screenshots
 Conclusion and Perspectives
Summary
 Basic Notions of M&S
 Basics of the Models Library
 Web-Based Architecture
 Screenshots
 Conclusion and Perspectives
Basic Notions of M&S
 Three complementary concepts
1. The Multi-Views concept:



Allows a gradual complexity introduction
Each model of these views represents a
particular
part of the global system
Structural view, behavioral view, system
view,…
2. The description hierarchy

Allows a recursive subsystems hiding
Basic Notions of M&S
3. The abstraction hierarchy
General problem for modeling: choosing a
good level of details
 Abstraction level:

 Determines
the amount of informations contained
in a model
 Allows taking efficiently into account the relevant
informations
Basic Notions of M&S
 The abstraction hierarchy
Summary
 Basic Notions of M&S
 Basics of the Models Library
 Web-Based Architecture
 Screenshots
 Conclusion and Perspectives
Basics of the Models Library
 Software Component:
Software object presenting well-defined
interfaces
 Can be personified
 Reusable in different contexts

 Modeling Component:
Software component
 Can be described following different
abstraction levels
 Can be « context-in » or « context-out »

Basics of the Models Library
 Context-in and Context-out models
notions:
 Context-out
model:
 Abstraction
of a model
 Presents a structure allowing it to be stored
in a library
 Context-in
model:
 Context-out
model extracted from its library
 Directly reusable in the environment
Basics of the Models Library
 Models Library: Object-Oriented architecture
allowing to store and retrieve persistent
context-out models
 Structuration mainly based on two paradigms:
Application domains
 Inheritance hierarchy

 Provides the abstraction hierarchy
management
Basics of the Models Library
 Core of the architecture: The Storage Engine
Build on the model of an Object-Oriented
Database Management System
 Uses XML to describe and store models
 Modular and extensible: based on the notion
of service
 Can use six different element types

Basics of the Models Library
 Six elements able to be stored:






Library: root object
Domains: DEVS Simulation, VHDL Descriptions,…
Application Domains: Science part of the models
Classification Intermediate Models (CIM): allow a
classification hierarchy between models
Inheritance Intermediate Models (IIM): storage object
allowing the share of properties
Model File: storage object (context-out model)
Basics of the Models Library
 UML Diagram: Links Between Elements
0..1
Library
0..1
Inheritance Intermediate Model
*
*
contains
*
Domain
0..1
0..1 *
Application Domain
0..1
0..1
*
*
Model File
*
*
0..1
0..1
*
*
0..1
Classification Intermediate Model
0..1
Basics of the Models Library
 Service: set of functions for the structuring,
the management or the maintenance of a
library
 Five Main Services:
Name Service
 Classification Service
 Abstraction Hierarchy Service
 Inheritance Service
 Persistence Service

Basics of the Models Library
 Abstraction Service:
Based on an Abstraction Matrix
 Manage relative abstraction levels between
context-out models

 Inheritance Service
Not performed directly on context-in models
 Applied on context-out models
 Performed through XML tags

Basics of the Models Library
 XML-based Persistence Service
Context-in to context-out

JDEVS
Source
Code
XML
Transition
Procedure
Context-in
Model

XML
Context-out
Model
Context-out to context-in
XML
Context-out
Model
XML
Reconstitution
Procedure
JDEVS
Source
Code
Context-in
Model
Summary
 Basic Notions of M&S
 Basics of the Models Library
 Web-Based Architecture
 Screenshots
 Conclusion and Perspectives
Web-Based Architecture
 Set of tools allowing a design team to work
on the same models stored on a server
 Basic idea: two possibilities offered for
accessing the storage engine:
Using
a Web browser
Directly from the M&S environment
Web-Based Architecture
 First possibility: simple management,
documentation and/or consultation
 Second possibility: uses APIs for the M&S
environment
Web Browser
Modeling and Simulation
Environment
Network
Application Server
Storage Engine
Server
Network
Application Server
Storage Engine
Server
Web-Based Architecture
 Implementation: Servlets/Applets/Java Web Start
 Technological Choices:
 Servlets:





Applets:



Persistents
Fasts
Platform-independents
Extensible
Very well known
Ease of use
Java Web Start:


Fast
Always up to date
Summary
 Basic Notions of M&S
 Basics of the Models Library
 Web-Based Architecture
 Screenshots
 Conclusion and Perspectives
Screenshots
Screenshots
Summary
 Basic notions of M&S
 Basics of the Models Library
 Web-Based Architecture
 Screenshots
 Conclusion and Perspectives
Conclusion and Perspectives
 Main Points and Originalities:



Inheritance Links
Abstraction Links
Traduction of DEVS models in XML
 Validation using the JDEVS environment:


Environmental Studies
CORBA Architecture Study
 Perspectives:



Management of other modeling formalisms
Improvement of the performances of the
storage engine
Study of the distribution of storage engines
on a network