278 research outputs found
A new dialect of SOFL-Syntax formal semantics and tool support
Structured Object Orientated Formal Language (SOFL) is a formal method design methodology that
combines data flows diagrams and predicates in order to describe processes that can be refined. This
methodology creates a very versatile method of describing a system, which system properties can
be proven rigorously. Data flows are grouped by ports that define from which data flows data can be
consumed or on which flows data can be generated. For predicates, Logic of Partial Functions
(LFP) are used; and an undefined element that is also used to indicate if a data flows do not contain
any data.
Over time SOFL “evolved organically” and a number of features were added: usability was the
main consideration for a feature being added. For a formal language to be useful there must be no
uncertainty of a specific design’s meaning. With SOFL, there is a possible contradiction between
the requirement that a process's precondition must be true when the process fire, and the fire rules.
This contradiction is due to the use of LPF.
Semantics (the meaning) of SOFL was not always updated to keep track of the changes made to
SOFL which resulted in an outdated and incomplete semantic. The incompleteness of the semantics
is a significant factor motivating the work done in this dissertation.
In this dissertation, a dialect of SOFL is created to define a semantic. Not all the elements of SOFL
are added in order that a simpler semantic can be defined. Elements that were removed include:
LPF,
Classes, and
Non-deterministic broadcast nodes.
Semantics of the dialect is created by a two-step process: firstly, an intuitive understanding of the
dialect is created, and secondly, both static and dynamic semantics are defined by means of
translations.
A translation is a mapping from the dialect to a formal language that describes a certain aspect of
the dialect. Static semantics defines the meaning of the elements that are “fixed” in their state:
SMT-LIB is used as the target language to describe the static semantics of the dialect. Dynamic
semantics describes how an element in a design changes over time: the process algebra mCRL2 is
used as the formal language which describes the dynamic behaviour of the dialect.
The SMT-Solver Z3 and tools included in mCLR2 are used to analyse the translation of the dialect.
Use of these tools allows properties that are necessary for a design to have a well defined meaning,
to be proven. Properties that can be proven include: a process can fire, a process can fire an infinite
number of times, and a predicate that described a property.
An Eclipse plug-in is created so that translation is not required to be done manually. After a design
is translated the tools Z3 and mCRL2 are run using script files and the results of the analysis are
displayed on the screen. The desired properties could be proven but for a moderate size design, but
as the size of the design increased the analysis of the translation could not be completed due to
computational problem. Usability of the tool can be improved by not only using a textual
representation of a design, but also visual representations as in SOFL.
As a result, properties that are necessary for a design to have a well-defined meaning, can be proven
using these tools.Dissertation (MSc)--University of Pretoria, 2018.Computer ScienceMScUnrestricte
Mathematics in Software Reliability and Quality Assurance
This monograph concerns the mathematical aspects of software reliability and quality assurance and consists of 11 technical papers in this emerging area. Included are the latest research results related to formal methods and design, automatic software testing, software verification and validation, coalgebra theory, automata theory, hybrid system and software reliability modeling and assessment
A Review of Software Reliability Testing Techniques
In the era of intelligent systems, the safety and reliability of software have received more attention. Software reliability testing is a significant method to ensure reliability, safety and quality of software. The intelligent software technology has not only offered new opportunities but also posed challenges to software reliability technology. The focus of this paper is to explore the software reliability testing technology under the impact of intelligent software technology. In this study, the basic theories of traditional software and intelligent software reliability testing were investigated via related previous works, and a general software reliability testing framework was established. Then, the technologies of software reliability testing were analyzed, including reliability modeling, test case generation, reliability evaluation, testing criteria and testing methods. Finally, the challenges and opportunities of software reliability testing technology were discussed at the end of this paper
FREPA: An Automated and Formal Approach to Requirement Modeling and Analysis in Aircraft Control Domain
Formal methods are promising for modeling and analyzing system requirements.
However, applying formal methods to large-scale industrial projects is a
remaining challenge. The industrial engineers are suffering from the lack of
automated engineering methodologies to effectively conduct precise requirement
models, and rigorously validate and verify (V&V) the generated models. To
tackle this challenge, in this paper, we present a systematic engineering
approach, named Formal Requirement Engineering Platform in Aircraft (FREPA),
for formal requirement modeling and V\&V in the aerospace and aviation control
domains. FREPA is an outcome of the seamless collaboration between the academy
and industry over the last eight years. The main contributions of this paper
include 1) an automated and systematic engineering approach FREPA to construct
requirement models, validate and verify systems in the aerospace and aviation
control domain, 2) a domain-specific modeling language AASRDL to describe the
formal specification, and 3) a practical FREPA-based tool AeroReq which has
been used by our industry partners. We have successfully adopted FREPA to seven
real aerospace gesture control and two aviation engine control systems. The
experimental results show that FREPA and the corresponding tool AeroReq
significantly facilitate formal modeling and V&V in the industry. Moreover, we
also discuss the experiences and lessons gained from using FREPA in aerospace
and aviation projects.Comment: 12 pages, Published by FSE 202
TBFV-M : Testing-Based Formal Verification for SysML Activity Diagrams
SysML activity diagrams are often used as models for software systems and its correctness is likely to significantly affect the reliability of the implementation. However, how to effectively verify the correctness of SysML diagrams still remains a challenge. In this paper, we propose a testing-based formal verification (TBFV) approach to the verification of SysML diagrams, called TBFV-M, by creatively applying the existing TBFV approach for code verification. We describe the principle of TBFV-M and present a case study to demonstrate its feasibility and usability. Finally, we conclude the paper and point out future research directions
Recommended from our members
Using formal methods to support testing
Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent
years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing
Security Requirements Specification and Tracing within Topological Functioning Model
Specification and traceability of security requirements is still a challenge since modeling and analysis of security aspects of systems require additional efforts at the very beginning of software development. The topological functioning model is a formal mathematical model that can be used as a reference model for functional and non-functional requirements of the system. It can also serve as a reference model for security requirements. The purpose of this study is to determine the approach to how security requirements can be specified and traced using the topological functioning model. This article demonstrates the suggested approach and explains its potential benefits and limitations
Radiation effects in high speed III-V integrated circuits
The article of record as published may be found at http://dx.doi.org/10.1142/S0129156403001612International Journal of High Speed Electronics and Systems, v. 13, p. 277 (2003).The types of applications affected by radiation effects in W-V devices have significantly changed
over the last four decades. For most applications W-V ICs have provided sufficient radiation
hardness. Some expectations for hardened soft error applications did not materialize until much later.
Years of research defined that not only material properties. but device structures. layout practices
and circuit design influenced how m-v devices were susceptible to certain radiation effects. The
highest performance ill-V ICs due to their low power-speed energy products will provide challenges
in ionizing radiation environments from sea level to space
- …