A Framework for Classifying and Comparing Graphical Object Oriented Modeling Languages

EOOLT 2010 was the third edition of the EOOLT workshop series. The workshop is intended to bring together researchers and practitioners from-different equation-based object-oriented (EOO) modeling language communities. This year's workshop also expands the scope to include the whole design space of languages for cyber-physical systems, where physical dynamics are mixed with networks and software. The workshop gathered 31 participants to present and discuss thirteen different papers grouped into the four areas of realtime oriented modeling languages and tools, modeling language design, simulation and model compilation, and modeling and simulation tools.

The Unified Modeling Language (UML) has been widely accepted as the standard object-oriented (OO) modeling language for modeling various aspects of software and information systems. The UML is an extensible language, in the sense that it provides mechanisms to introduce new elements for specific domains if necessary, such as web applications, database applications, business modeling, software development processes, data warehouses and so on. Furthermore, the latest work of the Object Management Group (OMG) on UML [1] resulted in a larger and more complicated specification, with even more diagrams for some good reasons. Although providing different diagrams for modeling specific parts of a software system, not all of them need to be applied in most cases. Therefore, heuristics, design guidelines, and lessons learned from experiences are extremely important for the effective use of UML and to avoid unnecessary complication.

Efficient and high-quality design of the substation automation systems has always been a real challenge. The problem of identification and location of information in the system and the description of information processing activities is a significant design problem. Information modeling is aimed at resolving it. An efficient approach to information modeling can significantly improve substation automation system development process. In this paper we propose the usage of the Unified Modeling Language (UML) as a main modeling language for expressing substation information models. UML was specified by Rational Software Corporation in 1997. Today, UML is adopted by the Object Management Group as an object-oriented modeling language with formally defined syntax and semantics. As expected, UML could be widely accepted in various industries (software, telecommunications, medicine, electro-industry, aero-industry etc.). The modeling approach is explained on one typical small-range 35 kV/10 kV distribution substation. Modeling steps: system usage specification, system structure specification, and behavior and constraints specification are described together with explanation of usage of some UML diagrams and modeling concepts.

Regardless of the large number of Object-Oriented (OO) modeling languages currently being used in the Information Systems (IS) modeling process, unavailability of an OO modeling language that can be used in both the analysis and design phases disintegrates the two phases. The problem is, such disintegration can lead to a high level of missing information in the real world system from the analysis phase to the design phase. The approach of this study is to propose a framework to produce design phase models from analysis phase models using ontology based Unified Modeling Language (UML), thereby integrating the two phases. The results obtained from the porposed framework involve: a consructed language which can be used in generating the analysis phase scripts; and the development of script files based on the UML constructs at the analysis and design phases to automatically generate the UML scripts for those two phases. Since this study is a part of an ongoing research study, it can be concluded that, at the end of this study (1) both analysis and design phases would be able to integrate using a common OO modeling language (2) the manual work involved in the current analysis and design modeling would be reduced (3) the complexities and difficulties faced by the modelers (By modelers we mean the analysts and designers who are doing the analysis and design phase modeling) in using UML modeling tools would be reduced.

Distributed real-time systems call for expressive modeling languages to capture and express their functional and nonfunctional requirements at early stages of the development process. The UML profile for Schedulability, Performance and Time (UML/SPT) is an object-oriented real-time modeling language. UML/SPT has been designed using the built-in extension mechanisms of UML, which makes it flexible and customizable. In this paper, we propose an extension for UML/SPT to capture multicast communications. We define a metamodel that encapsulates the main concepts involved in multicast communications, we show its relationship to UML/SPT domain model, and we introduce new stereotypes corresponding to these concepts. We illustrate the extension with the modeling of the Reliable Multicast Transport Protocol (RMTP2). Finally, we compare our approach to extend UML/SPT for multicast communications with an extension for MSC having the same purpose.

Modelling and simulation are key tools for analysis and design of systems and processes from almost any scientific or engineering discipline. Models of complex systems are typically built on acausal Differential-Algebraic Equations (DAE) and discrete events using Object-Oriented Modelling (OOM) languages, and some of their key concepts can be explained as symmetries. To obtain a computer executable version from the original model, several algorithms, based on bipartite symmetric graphs, must be applied for automatic equation generation, removing alias equations, computational causality assignment, equation sorting, discrete-event processing or index reduction. In this paper, an open source tool according to OOM paradigm and developed in MATLAB is introduced. It implements such algorithms adding an educational perspective about how they work, since the step by step results obtained after processing the model equations can be shown. The tool also allows to create models using its own OOM language and to simulate the final executable equation set. It was used by students in a modelling and simulation course of the Automatic Control and Industrial Electronics Engineering degree, showing a significant improvement in their understanding and learning of the abovementioned topics after their assessment.

DeSpec: Modeling the Windows Driver Environment11This work was partially supported by the Czech Academy of Sciences project 1ET400300504 and the Grant Agency of the Czech Republic project GD201/05/H014.

Modelling is one of the most difficult tasks of software engineering. UML (unified modelling language) is an object-oriented standard modelling language, which can express both the dynamic and static information during the processes of software analysis and design. Among the over 100 UML modelling tools, Rational Rose and Visio are the most extensively used ones. Here we comprehensively compare the performance of these two tools in software engineering teaching and discuss their advantages and disadvantages. The points presented in this review provide guidance for the selection of modelling tools and arrangement of teaching activities for software engineering.

Currently, digital technologies for modeling buildings and infrastructure are successfully used in international and national practice for the implementation of complex construction projects and large-scale programmes. At the same time, the transition to machine-readable standards, implemented in many countries to improve the quality of design documentation and automate its verification, faces serious methodological and technical challenges. First of all, these challenges are due to the complexity of digital models, as well as the variety of requirements formulated in natural languages and imposed on these models at the state, regional, departmental, and corporate levels. Attempts to create catalogs of requirements and software tools for their management and use generally have specific purposes and do not provide necessary completeness, normalization, consistency, interconnectedness, unambiguity, traceability, and validability of requirements description. In this regard, it seems reasonable to use formal methods for specification and verification of requirements that have proven themselves in system and software engineering. This paper provides a comparative analysis of software tools for automated verification of regulatory requirements in the construction domain. There is a growing interest in tools focused on international standards, such as Industry Foundation Classes (IFC) and Information Delivery Specification (IDS), that allow one to control the completeness of the object and attribute composition of models, as well as the clarification of acceptable domains of values values. However, the IDS standard is not formalized and does not enable the specification of requirements expressed in terms of arbitrary algebraic conditions. The EXPRESS object-oriented data modeling language, in which the IFC data schema is specified, seems promising for the formal specification and verification of requirements for digital models used in the construction industry. As a substantiation, it is shown that IDS specifications can be represented by logical expressions and EXPRESS functions, as well as that arbitrary algebraic conditions can be specified as EXPRESS declarative rules. To illustrate the proposed approach, we consider some examples of the formalization of requirements from national construction standards and sets of rules concerning the safety of buildings, structures, and processes. The possibility of harmonizing the proposed formal approach with the IDS standard by defining new facets for the representation of local, uniqueness, and global EXPRESS rules is also discussed.

As a powerful and object-oriented graphical modeling language, Unified Modeling Language (UML) has been introduced into the design and development of safety-critical computer systems. However, UML model is difficult to reflect the concurrency and consistency of constraint rules between objects and impossible to completely demonstrate the dynamic behavior characteristics of a system. Further, it cannot be directly expressed and analyzed by mathematical tools. Petri net modeling technology uses graphical element place and transition to clearly describe the internal interactions of a system. Meanwhile, Petri net has mature mathematical analysis methods. We have proposed to combine these two tools for designing and analyzing a system with a set of transformation rules from UML statecharts to Petri net. In this paper, an automatic conversion tool is introduced. The tool performs the transformation with three steps as follows: (1) Transforming UML model into XML document, which makes information extraction of the UML model become easier. (2) Analyzing semantics of UML model and Petri net model, then designing data structure for transformation, and completing the transformation based on the transformation rules. (3) Analyzing the transformed Petri net model to verify the characteristics of the UML model. The transformation rules and the tools are developed based on a new railway interlocking system.

ISO 10303 is the set of standards that define the Product Data Exchange using STEP or PDES. Part 11 of the standard is the EXPRESS modelling language, an objectoriented modelling language upon which the application protocols for data exchange are based. To display and analyse EXPRESS schema, ISO10303 contains a graphical depiction of a subset of EXPRESS, termed EXPRESS-G. When using EXPRESS-G to design large schema, the authors have found it to be limited in visualizing and interpreting the schema and the implied relations between entities and types. This paper presents a graphical language for designing schema to be represented in EXPRESS. Across between EXPRESS and more traditional ER modelling approaches, Visual-EXPRESS is a more compact diagram when compared to EXPRESS-G. The specification for Visual-EXPRESS also includes the algorithm to convert the graphical schema into a legal EXPRESS schema.

The proper and comprehensive identification of systemlevel failure mode during risk assessment for space systems has difficulty due to the complexity of system-level interactions that involve multi-physics and dynamic phenomena. This study looks into system-level potential failure mode identification by using a system-level modeling and simulation-based approach to risk assessment for space systems. The proposed approach is based on utilization of the modeling language “Modelica”, an equation-based, objectoriented modeling language that allows acausal modeling for complex cyber-physical systems. The Modelica has an important modeling capability for system-level interactions that involve multi-physics phenomena. This paper discusses the technical feasibility and expected effect of this approach based on several trial results of the proposed approach. Furthermore, this paper presents several issues with this approach as future work subjects.

Although the Unified Modeling Language (UML) is by now accepted as a standard and is widely used as an object-oriented modeling language, some languages such as Z or VDM are preferred to formally specify reference models. Here, we present a reference model for hypermedia systems in UML. It is an object-oriented and Dexter-based approach that uses UML to provide an intuitive graphical representation of the model. The class diagrams are supplemented with formal constraints in the Object Constraint Language (OCL), adding invariants on elements as well as preconditions and postconditions on operations. The result is an easily extendable reference model for describing specific hypermedia systems, for example, like adaptive or mobile systems. Our contribution shows how formal and semiformal object-oriented techniques can be integrated in the metamodeling process.

This paper presents a JAVA based framework for RTL modeling and simulation of digital hardware designs. After linking between object-oriented concepts and RTL models, the JAVA analogy to features found in a widely used hardware description language like Verilog is laid down. While focusing primarily on synchronous designs and cycle based simulation, the way to broaden this scope to event driven simulation is pointed out. Using a general object-oriented programming language for RTL modeling and simulation paves way for a more seamless software and hardware integration of a typical digital system.

Modelica is a new object-oriented multi-domain modelling and simulation language used for solving large, complex and heterogeneous physical systems with differential algebraic equations (DAEs). Presently, there is no simulation support available in Modelica for solving partial differential equations (PDEs) problems. In this paper, based on the object-oriented idea, we present a method of consistent representation of PDE and DAE problems. The description of PDE problems in Modelica is introduced. Then the PDE model is transferred into DAE model with the method of lines, and is solved in MWorks simulation platform based on Modelica. To illustrate the application of our method, a heat conduction problem is modelled and simulated in Modelica.