A Time-Triggered Constraint-Based Calculus for Avionic Systems

The Integrated Modular Avionics (IMA) architec- ture and the Time-Triggered Ethernet (TTEthernet) network have emerged as the key components of a typical architecture model for recent civil aircrafts. We propose a real-time constraint-based calculus targeted at the analysis of such concepts of avionic embedded systems. We show our framework at work on the modelisation of both the (IMA) architecture and the TTEthernet network, illustrating their behavior by the well-known Flight Management System (FMS)

Modeling and analysis of real-time software systems using UML

Real-Time Systems (RTS) should not only function correctly but should also satisfy time constraints. RTS include embedded systems, which are used nowadays in a variety of applications. These are, for instance, house appliances, automotive, aeronautic/aerospace, and health monitoring systems, to mention just a few. The design of such systems is complex and challenging. In order to cope with the complexity of RTS, there is shift in their development to follow a model-driven approach, such as the Model Driven Architecture (MDA), which relies on using models of high level of abstraction. The Unified Modeling Language (UML) is the Object Management Group (OMG) standard modeling language to support MDA. UML is appropriate for software systems because it allows for a multi-view modeling approach through its multitude of diagrams covering the structure, the behavior and the deployment architecture. Moreover, UML is also used in the domain of real-time software systems. This is achieved through its profiles, including, the OMG standard profile for Schedulability, Performance and Time (UML/SPT) or the upcoming standard UML Profile for Modeling and Analysis of Real-Time and Embedded Systems (MARTE). However, UML modeling faces some challenging issues such as model consistency. This issue becomes worse in the context of real-time software systems because additional aspects should be taken into consideration, including time, concurrency and schedulability. In this thesis, we address several issues related to modeling and validation of RTS with UML. We focus in particular on the consistency of UML/SPT models. We adopt an incremental approach to check the consistency of these models by distinguishing the syntactic and semantic levels. The latter is further decomposed into behavioral, concurrency-related and time consistency. Our contributions in this thesis are fourfold. First, we leverage the extensibility mechanisms of UML to propose an extension to UML/SPT. This extension enables the modeling of multicast communications, which is required for the description of the behavior of certain real-time protocols. Second, we propose a formalization of the concurrency modeling capability in UML/SPT using timed automata. This formal semantics allows for applying well-established model checking techniques to check concurrency related consistency in UML/SPT models. Third, we propose an MDA-compliant approach to enable schedulability analysis of UML/SPT models. We present a proof of concept for this approach through a prototype implementation using the Atlas Transformation Language (ATL) and XML-based technologies. Finally, we use the schedulability analysis applied to UML/SPT models in order to check the time consistency of a system design modeled by means of a set of state machines with respect to time constraints modeled using a set of sequence diagrams annotated with UML/SPT time stereotypes. Keywords : Real-time systems, Model-driven Architecture, UML, UML/SPT, Model transformation, ATL, XML, XSLT, Consistency, Concurrency, Model Checking, Schedulability Analysis

A Modeling and Verification Approach to the Design of Distributed IMA Architectures Using TTEthernet

AbstractIntegrated Modular Avionics (IMA) architectures complemented with Time-Triggered Ethernet (TTEthernet) provides a strong platform to support the design and deployment of distributed avionic software systems. The complexity of the design and continuous integration of such systems can be managed using a model-based methodology. In this paper, we build on top of our extension of the AADL modeling language to model TTEthernet-based distributed systems and leverage model transformations to enable undertaking the verification of the system models produced with this methodology. In particular, we propose to transform the system models to a model suitable for a simulation with DEVS. We illustrate the proposed approach using an example of a navigation and guidance system and we use this example to show the verification of the contention-freedom property of TTEthernet schedule

Improving Semantic Transparency of Committee-Designed Languages through Crowd-sourcing

International audienceCommittee-designed languages such as those of the OMG consor-tium are widely used in both industry and academia. These lan-guages seem to be used increasingly by users with no technical background for the visualization, documentation and specification of workflows, data and software systems. However, according to several studies on these languages, the used visual notations do not seem to convey any particular semantics and the recognition of such notations is not perceptually immediate. This lack of se-mantic transparency increases the cognitive load to differentiate concepts from each other and slows down recognition and learning of the language constructs. This paper proposes a process, which leverages the crowd-sourcing to improve the semantic transparency of such languages. We believe that involving end-users in the de-sign process of the languages visual notations should increase the expressiveness of these languages and then their acceptance for a wide range of novice-users

Collaborative Multi-domain Routing in SDN Environments

Today’s Internet is a collection of multi-domain networks where each domain is usually administrated and managed by a single network operator. Unfortunately, network operators share minimal information with each other and do not collaborate much to improve their routing decisions and the overall performance of the resulting large-scale mutli-domain network. Motivated by the need to solve this problem, in this paper, we look at this particular challenge and propose a novel collaborative multi-domain routing framework that is able to efficiently route the incoming flows through the different domains while ensuring their performance requirements in terms of delay and bandwidth and maximizing the overall network utilization. We hence propose an integer linear program to solve this problem and develop a greedy algorithm to cope with large-scale instances of the problem. Simulation results show that the proposed collaboration mechanism is able to significantly optimize network utilization and maximize the number of routed flows with guaranteed performance

A modeling and verification approach to the design of distributed IMA architectures using TTEthernet

ABSTRACT: Integrated Modular Avionics (IMA) architectures complemented with Time-Triggered Ethernet (TTEthernet) provides a strong platform to support the design and deployment of distributed avionic software systems. The complexity of the design and continuous integration of such systems can be managed using a model-based methodology. In this paper, we build on top of our extension of the AADL modeling language to model TTEthernet-based distributed systems and leverage model transformations to enable undertaking the verification of the system models produced with this methodology. In particular, we propose to transform the system models to a model suitable for a simulation with DEVS. We illustrate the proposed approach using an example of a navigation and guidance system and we use this example to show the verification of the contention-freedom property of TTEthernet schedule

MID: A MetaCASE Tool For A Better Reuse Of Visual Notations

International audienceModeling tools facilitate the development process from modeling to coding. Such tools can be designed using a Model-Driven approach into metamodeling environments called metaCASE tools. It turned out that current metaCASE tools still require, in most cases, manual programming to build full tool support for the modeling language. First of all, we want to specify, using models, diagrams editors with a high graphical expressiveness without any need for manual intervention to perform this task. The second axis is dedicated to this specification reuse in other contexts of use. The redundancy of diagrams editors specification raises the problem of inconsistency during the evolution or the update of this specification. We propose then MID, a tool based on a set of meta-models supporting the easy specification of modeling editors with reusable components

Improving Semantic Transparency of Committee-Designed Languages through Crowd-sourcing

International audienceCommittee-designed languages such as those of the OMG consor-tium are widely used in both industry and academia. These lan-guages seem to be used increasingly by users with no technical background for the visualization, documentation and specification of workflows, data and software systems. However, according to several studies on these languages, the used visual notations do not seem to convey any particular semantics and the recognition of such notations is not perceptually immediate. This lack of se-mantic transparency increases the cognitive load to differentiate concepts from each other and slows down recognition and learning of the language constructs. This paper proposes a process, which leverages the crowd-sourcing to improve the semantic transparency of such languages. We believe that involving end-users in the de-sign process of the languages visual notations should increase the expressiveness of these languages and then their acceptance for a wide range of novice-users

UML Profiles for Real-Time Systems and their Applications

Real-time systems (RTS) have strict timing constraints and limited resources. The satisfaction of RTS timing constraints is required for their correction. In order to reduce the cost due to late discovery of design flaws and/or violations of timing constraints of RTS as well as to speed up their development to cope with time-to-market requirements, it is important to validate, at early stages of the development process, the functional and nonfunctional properties of RTS. In addition, RTS complexity is continuously increasing which makes their design very challenging. UML, a graphical object-oriented modeling language, is suitable to deal with this complexity. UML also supports predictive, quantitative analysis through its real-time profiles. The objective of this paper is to review the most important UML profiles for real-time from the academia, the industry and/or standard organizations; and the research activity that revolves around these profiles

Intuitive Development to Examine Collaborative IoT Supply Chain System Underlying Privacy and Security Levels and Perspective Powering through Proactive Blockchain

Undoubtedly, the supply chain management (SCM) system is an important part of many organizations worldwide; over time, the technologies used to manage a supply chain ecosystem have, therefore, a great impact on businesses’ effectiveness. Among others, numerous developments have been made that targeted to have robust supply chain systems to efficiently manage the growing demands of various supplies, considering the underlying requirements and main challenges such as scalability, specifically privacy and security, of various business networks. Internet of things (IoT) comes with a solution to manage a complex, scalable supply chain system, but to provide and attain enough security during information exchange, along with keeping the privacy of its users, is the great inherent challenge of IoT. To fulfill these limitations, this study designs and models a scaled IoT-based supply chain (IoT-SC) system, comprising several operations and participants, and deploys mechanisms to leverage the security, mainly confidentially, integrity, authentication (CIA), and a digital signature scheme to leverage potentially secured non-repudiation security service for the worst-case scenario, and to leverage privacy to keep users sensitive personal and location information protected against adversarial entities to the IoT-SC system. Indeed, a scaled IoT-SC system certainly opens new challenges to manage privacy and security while communicating. Therefore, in the IoT-SC system, each transaction writes from edge computing nodes to the IoT-SC controller is thoroughly examined to ensure the proposed solutions in bi-directional communication, and their robustness against adversarial behaviors. Future research works, employing blockchain and its integrations, are detailed as paces to accelerate the privacy and security of the IoT-SC system, for example, migrating IoT-centric computing to an immutable, decentralized platform