Proceedings of the 20th European Conference on Pattern Languages of Programs, 2015
Cloud computing has brought a large variety of services available to potential consumers. A recen... more Cloud computing has brought a large variety of services available to potential consumers. A recent type of services are the provision of network functions using virtualization. Network Functions Virtualization (NFV) is a network architecture where network node functions such as load balancers, firewalls, IDS, and accelerators are built in software and offered as services. This approach results in reduced complexity in network design, better scalability and agility, as well as faster deployment. We present here a pattern for the NFV architecture.
2016 21st International Conference on Engineering of Complex Computer Systems (ICECCS), 2016
Securing critical systems such as Cyber-Physical Systems (CPS) is an important feature especially... more Securing critical systems such as Cyber-Physical Systems (CPS) is an important feature especially when it comes to critical transmitted data in a real-time environment. At the same time, the implementation of security countermeasures in such systems may impact transmission delays of critical tasks. For this reason selecting proper security mechanisms in such critical systems is an important issue. In this context, we propose a model-based approach for selecting proper security solution alternatives composed of security patterns at early design stage against real-time requirements. We provide a generalizable and tool-supported solution to support the approach using UML and its profiles. A validation of the work is presented via a simplified version of SCADA (Supervisory Control and Data Acquisition) system case study.
Abstract The existence of security threats in software designs can significantly impact the safe ... more Abstract The existence of security threats in software designs can significantly impact the safe and reliable operation of systems. Threats need to be precisely specified before a tool can manipulate them, and though several approaches for threat specification have been proposed, they do not provide the scalability and flexibility required in practice. We take this problem towards an integrated approach for threat detection and treatment by means of security requirements, during the software architecture design time. The general idea of the approach is to: (1) specify threats as properties of a modeled system in a technology-independent specification language; (2) express conditions that reveal these threats in a suitable language with automated tool support for threat detection through model verification; and (3) suggest a set of security requirements to protect against detected threats. The formalized threats and security requirements are then provided as formal model libraries to foster reuse. To validate our work, we explore a set of representative threats from categories based on Microsoft’s STRIDE threat classification in the context of secure component-based software architecture development. In addition, we use model-driven engineering techniques for the development of a tool set to support our approach.
This work is devoted to the problem of spanning tree maintenance in the presence of crash failure... more This work is devoted to the problem of spanning tree maintenance in the presence of crash failures in a distributed environment using only local knowledge. Using a pre-constructed spanning tree of a k-connected graph, we present a protocol to maintain a spanning tree in the presence of k−1 consecutive failures. The contribution of this paper is twofold. First, the problem is formalized as an occurrence of the Menger's theorem in distributed setting. The second result shows an implementation of the protocol which is composed of a set of modules encoded in the asynchronous message passing model. After each failure occurrence, our algorithm maintains a spanning tree in O(N) time using O(M + N) messages and O(∆) bits per node. Here ∆ is the degree, M the number of edges and N the number of nodes of the graph to be maintained. Furthermore, the studied network is semi-anonymous: Only the root needs to be identified.
Resource constrained embedded systems (RCES) refers to systems which have memory and/or computati... more Resource constrained embedded systems (RCES) refers to systems which have memory and/or computational processing power constraints. They can be found literally everywhere, in many application sectors such as automotive, aerospace, and home control. They are in many types of devices, like sensors, automotive electronic control units, intelligent switches, and home appliances such as washing machines and meters. RCES are becoming increasingly complex and have various communication interfaces. Therefore, they have to be seen in the context of bigger systems or complete infrastructures. Consequently, their non functional requirements such as security and dependability (S&D) become more important as well as more difficult to achieve. The integration of S&D requires the availability of both application expertise and S&D expertise at the same time. In fact, S&D could also require both specific security expertise and specific dependability expertise. Model-Driven Engineering (MDE) provides a very useful contribution to the design of RCES applications since it bridges the gap between design issues and implementation concerns. Significant research is being carried out concerning MDE for embedded systems, at the level of system architecture, design techniques, testing, validation, proof of correctness, modeling, software reliability, operating systems, parallel processing and real-time processing. More research is needed on the use of MDE to enforce the integration of S&D requirements into the engineering process and to support the reuse of S&D mechanisms. The objective of this workshop is to foster the exchange of ideas among practitioners, researchers and industry involved in the deployment of secure and dependable resource-constrained embedded systems. Special emphasis will be devoted to promote discussion and interaction between researchers and practitioners focused on the particularly challenging task of efficiently integrating security and dependability solutions within the restricted available design space for RCES. Furthermore, one important focus is on the potential benefits of the combination of model-driven engineering with pattern-based representation of security and dependability solutions. Of particular interest is the exchange of concepts, prototypes, research ideas, and other results which contribute to the academic area and also benefit business and industrial communities. Some of the topics that we seek to include in the workshop are related to the development of models and tools to support the inclusion of SD issues into the RCES engineering process. Among the 12 initial submissions, 07 papers have been selected and organized in tow sessions, covering a wide spectrum of the subject of Security and Dependability for Resource Constrained Embedded Systems (secure and dependable RCES by design). In "ongoing project and new visions" category, we accepted 03 papers. It is our wish that the workshop provides an appropriate and relaxed environment to discuss these new ideas and approaches. In order to facilitate it each speaker will have 30 minutes for the presentation and discussion. Moreover, we will close the workshop with a working and a discussion session about: Trusted Computing Challenges in Resource Constrained Embedded Systems, Why, What and How.
Proceedings of the 20th European Conference on Pattern Languages of Programs, 2015
Security pattern-based system and software engineering (PBSE) approaches aim at building secure s... more Security pattern-based system and software engineering (PBSE) approaches aim at building secure software and systems by capturing and reusing artifacts that encapsulate security expert's knowledge called security patterns. In this context, security patterns are selected by developers based on security requirements. On the other hand, security risk management is an iterative approach that consists of: (1) a risk assessment activity for identifying, analyzing and evaluating security risks and (2) a risk treatment activity to mitigate these risks which result in issuing security requirements. Hence, risk management and security PBSE can be used together. In this context, this paper aims at guiding the selection of security patterns in security PBSE based on security risk management results and pattern classification. For illustration purposes, we consider an example of a SCADA (Supervisory Control And Data Acquisition) system.
2015 20th International Conference on Engineering of Complex Computer Systems (ICECCS), 2015
Development processes for software construction are common knowledge and widely used in most deve... more Development processes for software construction are common knowledge and widely used in most development organizations. Unfortunately, these processes often offer only little or no support in order to meet security requirements. In our work, we propose a methodology to enhance these process models with security concepts, backed by a securityoriented process model specification language. The methodology supports existing process models, which will be extended by established security approaches, as well as information security risk management standards, to fulfill the demand for secure software engineering. The methodology and the process modeling language we propose, have been successfully evaluated by the TERESA project for specifying development processes for trusted applications and integrating security concepts into existing process models.
Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing, 2005
We present a formal method to design self-stabilizing algorithms by using graph rewriting systems... more We present a formal method to design self-stabilizing algorithms by using graph rewriting systems (GRS). This method is based on two phases. The first phase consists of defining the set of illegitimate configurations (GRSIC). The second phase allows to construct some local correction rules to eliminate the illegitimate configurations. Then the graph relabeling system composed of the initial graph rewriting
Repositories of modeling artefacts have gained more attention recently to enforce reuse in softwa... more Repositories of modeling artefacts have gained more attention recently to enforce reuse in software engineering. In fact, repository-centric development processes are more adopted in software/system development, such as architecture-centric or pattern-centric development processes. In our work, we deal with a specification language for development methodologies centered around a model-based repository, by defining both a metamodel enabling process engineers to represent repository management and interaction and an architecture for development tools. The modeling language we propose, has been successfully evaluated by the TERESA project for specifying development processes for trusted applications centered around a model-based repository of security and dependability (S&D) patterns.
Proceedings of the International Workshop on Security and Dependability for Resource Constrained Embedded Systems - S&D4RCES '10, 2010
... Safety-Critical Model-Driven Product-Line Case Salvador Trujillo, Antonio Perez, David Gonzal... more ... Safety-Critical Model-Driven Product-Line Case Salvador Trujillo, Antonio Perez, David Gonzalez IKERLAN-IK4 Mondragon, Spain [email protected] Brahim Hamid IRIT, University of Toulouse Toulouse, France [email protected] ...
Nowadays, many practitioners express their worries about current software engineering practices. ... more Nowadays, many practitioners express their worries about current software engineering practices. New recommendations should be considered to ground software engineering on solid theory and on proven principles. We took such an approach towards software engineering process modeling for embedded system applications with security and dependability requirements, focusing on the problem of integrating safety during the process design to clarify assessment
Proceedings of the workshop on ACadeMics Tooling with Eclipse - ACME '13, 2013
In our work, we promote a new discipline for secure and dependable system engineering using a pat... more In our work, we promote a new discipline for secure and dependable system engineering using a pattern as its first class citizen: Pattern-Based System Engineering (PBSE). Therefore, PBSE addresses two kind of processes: the one of pattern development and the one of system development with patterns. To interconnect these two processes we promote a structured model-based repository of patterns and
2013 IEEE 14th International Conference on Information Reuse & Integration (IRI), 2013
The requirement for higher Security and Dependability (S&D) of systems is continuously increasing... more The requirement for higher Security and Dependability (S&D) of systems is continuously increasing, even in domains traditionally not deeply involved in such issues. Nowadays, many practitioners express their worries about current S&D software engineering practices. New recommendations should be considered to ground this discipline on two pillars: solid theory and proven principles. We took the second pillar towards software engineering for embedded system applications, focusing on the problem of integrating S&D by design to foster reuse. Model driven approaches combined with patterns can be extremely helpful to deal with these strong requirements. In this work, we present a framework for trusted Resource Constrained Embedded Systems (RCES) development by design, by defining both a model to represent S&D pattern language and an architecture for development tools. The implementation of a repository of S&D patterns and their complementary property models is discussed in detail.
2012 38th Euromicro Conference on Software Engineering and Advanced Applications, 2012
ABSTRACT This paper proposes a model based framework for the design of dependable embedded system... more ABSTRACT This paper proposes a model based framework for the design of dependable embedded systems. First we define a meta-model to encompass the different concepts to capture fault tolerance. This will be used to derive a UML profile for the specification and the management of the redundancy. Based on this profile, we propose a model library as reusable and composable UML components to construct a fault tolerant infrastructure. As proof of concept, a GPS use case with fault tolerance requirements is evaluated using the proposed framework.
2012 IEEE 14th International Conference on High Performance Computing and Communication & 2012 IEEE 9th International Conference on Embedded Software and Systems, 2012
Abstract In this paper, we propose a framework allowing the modeling and verification of reconfig... more Abstract In this paper, we propose a framework allowing the modeling and verification of reconfigurable Distributed Real-time Embedded (DRE) systems. In fact, as reconfiguration significantly complicates system design and execution, many non-functional properties and constraints cannot be easily preserved. Verifying the continuous satisfaction of non-functional properties should be thus accomplished after applying reconfiguration actions. For this purpose, we develop an integrated model-based development approach allowing ...
Proceedings of the International Workshop on Security and Dependability for Resource Constrained Embedded Systems - S&D4RCES '10, 2010
Abstract The requirement for higher reliability and availability of systems is continuously incre... more Abstract The requirement for higher reliability and availability of systems is continuously increasing even in domains not traditionally deeply involved in such issues. In particular Resource Constrained Embedded Systems solutions are expected to be efficient, flexible, ...
ABSTRACT In computer-aided design, geometric modelling by constraints enables users to describe s... more ABSTRACT In computer-aided design, geometric modelling by constraints enables users to describe shapes by relationships called constraints between geometric elements. The problem is to derive automatically these geometric elements. Many resolution methods have been proposed for solving systems of geometric constraints [2]. Geometric methods [3,5,8] can be very efficient but are only applicable to particular kinds of problems (typically rule and compass constructive problems). Some schemes can't be solved by any geometric method. A numerical method is then necessary [1]. Thus, numerical methods are very useful to solve "difficult" configurations. Geometric constraints are translated into a system of equations and then solved with a numerical method. The most popular numerical method is Newton-Raphson’s iteration. It was used, among many others, by Serrano [9] and Perez et al [10]. This method needs an initial guess, typically given by the sketch of the desired geometric scheme. However, there is a well-known problem. If Newton-Raphson’s method often works well, sometimes it does not converge or it converges to an unwanted solution [6]. In this last case, the user changes his initial guess until Newton-Raphson’s method works if it does. We use the bisection method [4,7] to solve these "difficult" cases. The bisection method avoids the drawbacks of the Newton iteration. The bisection method enables users to reliably find all solutions to a system of non-linear equations within a region defined by bounds on each individual co-ordinate of the geometric objects. The bisection method avoids the drawbacks of the Newton iteration. It enables users to reliably find all solutions to a system of non-linear equations within a region defined by bounds on each individual co-ordinate of the geometric objects.
2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing, 2010
... Recently, in [22], they described a UML/MDA approach, called MoPCoM methodology, to design hi... more ... Recently, in [22], they described a UML/MDA approach, called MoPCoM methodology, to design high quality real ... The MoPCoM co-design methodology is based on MARTE profile. ... Specifically, [8] proposed a co-design environment based on the Java lan-guage which supports ...
The requirement for higher security and dependability of systems is continuously increasing even ... more The requirement for higher security and dependability of systems is continuously increasing even in domains not traditionally deeply involved in such issues. Yet, evolution of embedded systems towards devices connected via Internet, wireless communication or other ...
In this work, we investigate the problem of resolving conflicts in a distributed environment usin... more In this work, we investigate the problem of resolving conflicts in a distributed environment using only local knowledge. The contribution of this paper is twofold. First, we present a self-stabilizing algorithm to deal with this problem. Self-stabilizing algorithms protect against transient failures. The second result gives a particular implementation and analysis based on probabilistic procedures. Thus, the stabilization time is
Proceedings of the 20th European Conference on Pattern Languages of Programs, 2015
Cloud computing has brought a large variety of services available to potential consumers. A recen... more Cloud computing has brought a large variety of services available to potential consumers. A recent type of services are the provision of network functions using virtualization. Network Functions Virtualization (NFV) is a network architecture where network node functions such as load balancers, firewalls, IDS, and accelerators are built in software and offered as services. This approach results in reduced complexity in network design, better scalability and agility, as well as faster deployment. We present here a pattern for the NFV architecture.
2016 21st International Conference on Engineering of Complex Computer Systems (ICECCS), 2016
Securing critical systems such as Cyber-Physical Systems (CPS) is an important feature especially... more Securing critical systems such as Cyber-Physical Systems (CPS) is an important feature especially when it comes to critical transmitted data in a real-time environment. At the same time, the implementation of security countermeasures in such systems may impact transmission delays of critical tasks. For this reason selecting proper security mechanisms in such critical systems is an important issue. In this context, we propose a model-based approach for selecting proper security solution alternatives composed of security patterns at early design stage against real-time requirements. We provide a generalizable and tool-supported solution to support the approach using UML and its profiles. A validation of the work is presented via a simplified version of SCADA (Supervisory Control and Data Acquisition) system case study.
Abstract The existence of security threats in software designs can significantly impact the safe ... more Abstract The existence of security threats in software designs can significantly impact the safe and reliable operation of systems. Threats need to be precisely specified before a tool can manipulate them, and though several approaches for threat specification have been proposed, they do not provide the scalability and flexibility required in practice. We take this problem towards an integrated approach for threat detection and treatment by means of security requirements, during the software architecture design time. The general idea of the approach is to: (1) specify threats as properties of a modeled system in a technology-independent specification language; (2) express conditions that reveal these threats in a suitable language with automated tool support for threat detection through model verification; and (3) suggest a set of security requirements to protect against detected threats. The formalized threats and security requirements are then provided as formal model libraries to foster reuse. To validate our work, we explore a set of representative threats from categories based on Microsoft’s STRIDE threat classification in the context of secure component-based software architecture development. In addition, we use model-driven engineering techniques for the development of a tool set to support our approach.
This work is devoted to the problem of spanning tree maintenance in the presence of crash failure... more This work is devoted to the problem of spanning tree maintenance in the presence of crash failures in a distributed environment using only local knowledge. Using a pre-constructed spanning tree of a k-connected graph, we present a protocol to maintain a spanning tree in the presence of k−1 consecutive failures. The contribution of this paper is twofold. First, the problem is formalized as an occurrence of the Menger's theorem in distributed setting. The second result shows an implementation of the protocol which is composed of a set of modules encoded in the asynchronous message passing model. After each failure occurrence, our algorithm maintains a spanning tree in O(N) time using O(M + N) messages and O(∆) bits per node. Here ∆ is the degree, M the number of edges and N the number of nodes of the graph to be maintained. Furthermore, the studied network is semi-anonymous: Only the root needs to be identified.
Resource constrained embedded systems (RCES) refers to systems which have memory and/or computati... more Resource constrained embedded systems (RCES) refers to systems which have memory and/or computational processing power constraints. They can be found literally everywhere, in many application sectors such as automotive, aerospace, and home control. They are in many types of devices, like sensors, automotive electronic control units, intelligent switches, and home appliances such as washing machines and meters. RCES are becoming increasingly complex and have various communication interfaces. Therefore, they have to be seen in the context of bigger systems or complete infrastructures. Consequently, their non functional requirements such as security and dependability (S&D) become more important as well as more difficult to achieve. The integration of S&D requires the availability of both application expertise and S&D expertise at the same time. In fact, S&D could also require both specific security expertise and specific dependability expertise. Model-Driven Engineering (MDE) provides a very useful contribution to the design of RCES applications since it bridges the gap between design issues and implementation concerns. Significant research is being carried out concerning MDE for embedded systems, at the level of system architecture, design techniques, testing, validation, proof of correctness, modeling, software reliability, operating systems, parallel processing and real-time processing. More research is needed on the use of MDE to enforce the integration of S&D requirements into the engineering process and to support the reuse of S&D mechanisms. The objective of this workshop is to foster the exchange of ideas among practitioners, researchers and industry involved in the deployment of secure and dependable resource-constrained embedded systems. Special emphasis will be devoted to promote discussion and interaction between researchers and practitioners focused on the particularly challenging task of efficiently integrating security and dependability solutions within the restricted available design space for RCES. Furthermore, one important focus is on the potential benefits of the combination of model-driven engineering with pattern-based representation of security and dependability solutions. Of particular interest is the exchange of concepts, prototypes, research ideas, and other results which contribute to the academic area and also benefit business and industrial communities. Some of the topics that we seek to include in the workshop are related to the development of models and tools to support the inclusion of SD issues into the RCES engineering process. Among the 12 initial submissions, 07 papers have been selected and organized in tow sessions, covering a wide spectrum of the subject of Security and Dependability for Resource Constrained Embedded Systems (secure and dependable RCES by design). In "ongoing project and new visions" category, we accepted 03 papers. It is our wish that the workshop provides an appropriate and relaxed environment to discuss these new ideas and approaches. In order to facilitate it each speaker will have 30 minutes for the presentation and discussion. Moreover, we will close the workshop with a working and a discussion session about: Trusted Computing Challenges in Resource Constrained Embedded Systems, Why, What and How.
Proceedings of the 20th European Conference on Pattern Languages of Programs, 2015
Security pattern-based system and software engineering (PBSE) approaches aim at building secure s... more Security pattern-based system and software engineering (PBSE) approaches aim at building secure software and systems by capturing and reusing artifacts that encapsulate security expert's knowledge called security patterns. In this context, security patterns are selected by developers based on security requirements. On the other hand, security risk management is an iterative approach that consists of: (1) a risk assessment activity for identifying, analyzing and evaluating security risks and (2) a risk treatment activity to mitigate these risks which result in issuing security requirements. Hence, risk management and security PBSE can be used together. In this context, this paper aims at guiding the selection of security patterns in security PBSE based on security risk management results and pattern classification. For illustration purposes, we consider an example of a SCADA (Supervisory Control And Data Acquisition) system.
2015 20th International Conference on Engineering of Complex Computer Systems (ICECCS), 2015
Development processes for software construction are common knowledge and widely used in most deve... more Development processes for software construction are common knowledge and widely used in most development organizations. Unfortunately, these processes often offer only little or no support in order to meet security requirements. In our work, we propose a methodology to enhance these process models with security concepts, backed by a securityoriented process model specification language. The methodology supports existing process models, which will be extended by established security approaches, as well as information security risk management standards, to fulfill the demand for secure software engineering. The methodology and the process modeling language we propose, have been successfully evaluated by the TERESA project for specifying development processes for trusted applications and integrating security concepts into existing process models.
Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing, 2005
We present a formal method to design self-stabilizing algorithms by using graph rewriting systems... more We present a formal method to design self-stabilizing algorithms by using graph rewriting systems (GRS). This method is based on two phases. The first phase consists of defining the set of illegitimate configurations (GRSIC). The second phase allows to construct some local correction rules to eliminate the illegitimate configurations. Then the graph relabeling system composed of the initial graph rewriting
Repositories of modeling artefacts have gained more attention recently to enforce reuse in softwa... more Repositories of modeling artefacts have gained more attention recently to enforce reuse in software engineering. In fact, repository-centric development processes are more adopted in software/system development, such as architecture-centric or pattern-centric development processes. In our work, we deal with a specification language for development methodologies centered around a model-based repository, by defining both a metamodel enabling process engineers to represent repository management and interaction and an architecture for development tools. The modeling language we propose, has been successfully evaluated by the TERESA project for specifying development processes for trusted applications centered around a model-based repository of security and dependability (S&D) patterns.
Proceedings of the International Workshop on Security and Dependability for Resource Constrained Embedded Systems - S&D4RCES '10, 2010
... Safety-Critical Model-Driven Product-Line Case Salvador Trujillo, Antonio Perez, David Gonzal... more ... Safety-Critical Model-Driven Product-Line Case Salvador Trujillo, Antonio Perez, David Gonzalez IKERLAN-IK4 Mondragon, Spain [email protected] Brahim Hamid IRIT, University of Toulouse Toulouse, France [email protected] ...
Nowadays, many practitioners express their worries about current software engineering practices. ... more Nowadays, many practitioners express their worries about current software engineering practices. New recommendations should be considered to ground software engineering on solid theory and on proven principles. We took such an approach towards software engineering process modeling for embedded system applications with security and dependability requirements, focusing on the problem of integrating safety during the process design to clarify assessment
Proceedings of the workshop on ACadeMics Tooling with Eclipse - ACME '13, 2013
In our work, we promote a new discipline for secure and dependable system engineering using a pat... more In our work, we promote a new discipline for secure and dependable system engineering using a pattern as its first class citizen: Pattern-Based System Engineering (PBSE). Therefore, PBSE addresses two kind of processes: the one of pattern development and the one of system development with patterns. To interconnect these two processes we promote a structured model-based repository of patterns and
2013 IEEE 14th International Conference on Information Reuse & Integration (IRI), 2013
The requirement for higher Security and Dependability (S&D) of systems is continuously increasing... more The requirement for higher Security and Dependability (S&D) of systems is continuously increasing, even in domains traditionally not deeply involved in such issues. Nowadays, many practitioners express their worries about current S&D software engineering practices. New recommendations should be considered to ground this discipline on two pillars: solid theory and proven principles. We took the second pillar towards software engineering for embedded system applications, focusing on the problem of integrating S&D by design to foster reuse. Model driven approaches combined with patterns can be extremely helpful to deal with these strong requirements. In this work, we present a framework for trusted Resource Constrained Embedded Systems (RCES) development by design, by defining both a model to represent S&D pattern language and an architecture for development tools. The implementation of a repository of S&D patterns and their complementary property models is discussed in detail.
2012 38th Euromicro Conference on Software Engineering and Advanced Applications, 2012
ABSTRACT This paper proposes a model based framework for the design of dependable embedded system... more ABSTRACT This paper proposes a model based framework for the design of dependable embedded systems. First we define a meta-model to encompass the different concepts to capture fault tolerance. This will be used to derive a UML profile for the specification and the management of the redundancy. Based on this profile, we propose a model library as reusable and composable UML components to construct a fault tolerant infrastructure. As proof of concept, a GPS use case with fault tolerance requirements is evaluated using the proposed framework.
2012 IEEE 14th International Conference on High Performance Computing and Communication & 2012 IEEE 9th International Conference on Embedded Software and Systems, 2012
Abstract In this paper, we propose a framework allowing the modeling and verification of reconfig... more Abstract In this paper, we propose a framework allowing the modeling and verification of reconfigurable Distributed Real-time Embedded (DRE) systems. In fact, as reconfiguration significantly complicates system design and execution, many non-functional properties and constraints cannot be easily preserved. Verifying the continuous satisfaction of non-functional properties should be thus accomplished after applying reconfiguration actions. For this purpose, we develop an integrated model-based development approach allowing ...
Proceedings of the International Workshop on Security and Dependability for Resource Constrained Embedded Systems - S&D4RCES '10, 2010
Abstract The requirement for higher reliability and availability of systems is continuously incre... more Abstract The requirement for higher reliability and availability of systems is continuously increasing even in domains not traditionally deeply involved in such issues. In particular Resource Constrained Embedded Systems solutions are expected to be efficient, flexible, ...
ABSTRACT In computer-aided design, geometric modelling by constraints enables users to describe s... more ABSTRACT In computer-aided design, geometric modelling by constraints enables users to describe shapes by relationships called constraints between geometric elements. The problem is to derive automatically these geometric elements. Many resolution methods have been proposed for solving systems of geometric constraints [2]. Geometric methods [3,5,8] can be very efficient but are only applicable to particular kinds of problems (typically rule and compass constructive problems). Some schemes can't be solved by any geometric method. A numerical method is then necessary [1]. Thus, numerical methods are very useful to solve "difficult" configurations. Geometric constraints are translated into a system of equations and then solved with a numerical method. The most popular numerical method is Newton-Raphson’s iteration. It was used, among many others, by Serrano [9] and Perez et al [10]. This method needs an initial guess, typically given by the sketch of the desired geometric scheme. However, there is a well-known problem. If Newton-Raphson’s method often works well, sometimes it does not converge or it converges to an unwanted solution [6]. In this last case, the user changes his initial guess until Newton-Raphson’s method works if it does. We use the bisection method [4,7] to solve these "difficult" cases. The bisection method avoids the drawbacks of the Newton iteration. The bisection method enables users to reliably find all solutions to a system of non-linear equations within a region defined by bounds on each individual co-ordinate of the geometric objects. The bisection method avoids the drawbacks of the Newton iteration. It enables users to reliably find all solutions to a system of non-linear equations within a region defined by bounds on each individual co-ordinate of the geometric objects.
2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing, 2010
... Recently, in [22], they described a UML/MDA approach, called MoPCoM methodology, to design hi... more ... Recently, in [22], they described a UML/MDA approach, called MoPCoM methodology, to design high quality real ... The MoPCoM co-design methodology is based on MARTE profile. ... Specifically, [8] proposed a co-design environment based on the Java lan-guage which supports ...
The requirement for higher security and dependability of systems is continuously increasing even ... more The requirement for higher security and dependability of systems is continuously increasing even in domains not traditionally deeply involved in such issues. Yet, evolution of embedded systems towards devices connected via Internet, wireless communication or other ...
In this work, we investigate the problem of resolving conflicts in a distributed environment usin... more In this work, we investigate the problem of resolving conflicts in a distributed environment using only local knowledge. The contribution of this paper is twofold. First, we present a self-stabilizing algorithm to deal with this problem. Self-stabilizing algorithms protect against transient failures. The second result gives a particular implementation and analysis based on probabilistic procedures. Thus, the stabilization time is
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Papers by brahim hamid