Hammad AhmedUniversity of Franche-Comté | UFC · UFR des Sciences et Techniques
Hammad Ahmed
PHD and HDR Data Analysis and science computer
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56
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Introduction
Publications
Publications (56)
With the increasing complexity of cyber-physical systems (CPS), it is interesting to decompose a CPS into sub-systems. This provides greater modularity and flexibility so that each system can be developed independently, making it easier to maintain. Also, it can improve its fault tolerance. However, this decomposition of the system can lead to inco...
Through a Bluetooth connection between the Muse 2 device and the meditation app, leveraging IoT capabilities. The methodology encompasses data collection, preprocessing, feature extraction, and model training, all while utilizing Internet of Things (IoT) functionalities. The Muse 2 device records EEG data from multiple electrodes, which is then pro...
Modeling and verifying the behavior of Cyber-Physical Systems (CPS) with complex interactions is challenging. Traditional languages such as SysML diagrams are not enough to capture CPS coordination. In this paper, we propose a novel approach called SysReo, which extends SysML diagrams (RD, BDD, IBD, SD) with the Reo coordination language. Our main...
In order to satisfy their requirements, the verification and validation of the design of complex systems is a primary task. The main goal of the present work is to propose a model-based system engineering specification and verification methodology for the design and performance evaluation of an example of these systems, namely Wireless Sensor Netwo...
Requirements verification at early phases of the design process is one of the main challenges when developing critical and complex systems. In this paper, we focus on the verification of SysML functional requirements on activity diagrams. Our contribution consists in the proposition of a slicing based verification approach guided by the SysML relat...
In the component paradigm, the system is seen as an assembly of heterogeneous components, where the system reliability depends on these components compatibility. In our approach, we focus on verifying compatibility of components modelled with SysML diagrams. Thus, we model component interactions with sequence diagrams (SDs) and components with SysM...
When developing complex systems, the requirement for the verification of the systems’ design is one of the main challenges. Wireless Sensor Networks (WSNs) are examples of such systems. We address the problem of how WSNs must be designed to fulfil the system requirements. Using the SysML Language, we propose a Model Based System Engineering (MBSE)...
Designing complex and critical systems needs a methodology to ensure the correctness of their specifications. Within an overall approach which considers the validation of SysML designs, this paper proposes a methodology for verifying SysML requirements on activity diagrams. The objective is to define a complete process to formalize and verify SysML...
Reusing and adapting existing components is the central topic of component-based development. The major differences between the existing approaches concern the models used to represent the components and the detail given to generate the adapters. In this paper, we present our approach which bases on the hierarchy to generate the adapters. Our compo...
The increasing interactions between huge amount of software and hardware subsystem (hydraulics, mechanics, electronics, etc.) lead to a new kind of complexity that is difficult to manage during the validation of safety-critical and complex embedded systems. This paper introduces a formal SysML-based framework to combine both discrete and continuous...
Regarding the increasing complexity of today’s systems, system engineering domain knows a constant evolution in term of processes and paradigms (Object Oriented, Component Oriented). SysML constitutes a new trends of system engineering which allows to model the system as a set of blocks. In this paper, we propose a bottom-up approach to build a sys...
System Modelling Language (SysML) is a modelling language that allows system description with various integrated diagrams. The SysML activity diagram (SAD) is widely used to graphically describe system behaviours. Nevertheless, despite the various advantages of SysML, it lacks for formal semantics to achieve the verification of behavioural requirem...
The increasing complexity and heterogeneity of systems require engineers to consider the verification and validation aspects in the earliest stages of the system development life cycle. To meet these expectations, Model-Based Systems Engineering (MBSE) is identified as a key practice for efficient system development while simulation is still widely...
Ensuring the correction of heterogeneous and complex systems is an essential stage in the process of engineering systems. In this paper, we propose an approach to verify and validate complex systems specified by SysML language. We translate SysML specifications into Promela models in order to validate the designed systems by model checking SPIN. Th...
For ad hoc networks, clustering is the organization method that groups the nodes into clusters managed by nodes called cluster-heads. This hierarchical organization allows an effective way of improving performance, security, fault tolerance and scalability of the platform. In this paper, we introduce a new approach to self-organize an ad hoc networ...
In this paper, we propose a SysML model and a Modelica simulation of an air-jet conveyor for micro objects. Indeed, modeling and simulation are part of verification & validation activities, which are important tasks during the conception of a complex system. This article focuses mainly on the modeling and simulation of air-jet nozzles and on their...
The complexity of heterogeneous systems has been increased during last years. One challenge of designing these systems is to deal with the application of methodologies based on Model Driven Architecture (MDA). MDA is a development framework that enables the description of systems by means of different models with transformations. This is an importa...
The validation of SysML specifications needs a complete process for extracting, formalizing and verifying SysML requirements. Within an overall approach which considers an automatic verification of SysML designs by translating both requirement and behavioral diagrams, this paper proposes a modular verification of SysML functional requirements on ac...
Wireless Sensor Networks (WSN) have large industrial applications, however the modelling is still a very complex task in view of the nature of these networks, namely because they are distributed, embedded and have strong interactions between the hardware and software parts. In addition, industrials use semi-formal methods to design their systems an...
Non-functional requirements of component based systems are important as their functional requirements, therefore they must be considered in components assembly. These properties are beforehand specified with SysML requirement diagrams. We specify component based system architecture with SysML block definition diagram, and component behaviors with s...
Wireless Sensor Networks (WSN) have registered a large success in the scientific and industrial communities for their broad application domains. Furthermore, the WSN specification is a complex task considering to their distributed and embedded nature and the strong interactions between their hardware and software parts. Moreover, most of approaches...
This paper proposes an approach to verify SysML models consistency and to validate the transformation of SysML models to VHDL-AMS code. This approach is based on two main solutions: the use of model-to-model transformation to verify SysML models consistency and writing unit tests to validate model transformations. The translation of SysML models in...
Wireless Sensor Networks (WSN) have large industrial applications. However, the modelisation is still a very complex task in view of the nature of these networks, namely because they are distributed, embedded and have strong interactions between the hardware and software parts. In addition, industrials use semi-formal methods to design their system...
Model-based development for complex system design has been used to support the increase of systems complexity. SysML is a modeling language that allows a system description with various integrated diagrams, but SysML lacks formality for the requirement verification. Translating SysML-based specification into Petri nets allows to enable rigorous sys...
In this paper, we propose an approach to translate the Sys ML language to VHDL-AMS code. This approach is the first step to the generation of the VHDL-AMS code from the structural diagrams Sys ML. In this step, we address the Block Definition Diagram and the Internal Block Diagram. The translation uses Model Driven Engineer (MDE) methods as the tra...
We propose an approach which combines component SysML models and interface automata in order to assemble components and to verify formally their interoperability. So we propose to verify formally the assembly of components specified with the expressive and semi-formal modeling language, SysML. We specify component-based system architecture with Sys...
A smart surface is a distributed Micro-Electro- Mechanical System (MEMS) designed for conveying microscopic objects over a meso-scale distance, by the coordinated action of several microcells composed of microsensors, microactuators and control units. We present a high-level description of a smart surface with the System Modeling Language (SysML)....
A big challenge in designing a distributed application is the partitioning which consists of optimizing the system component inter-communication. In this paper we introduce a new approach of Ad Hoc network group formation based on two level hierarchy structure: many groups with one leader per group at the first level and a super-leader for the whol...
This article describes a work-in-progress in the framework of a research project aiming at combining requirements engineering
methods with formal methods. The main idea is to extend the SysML language with concepts of existing requirements engineering
methods. In this article we present extensions to SysML with concepts from the goal model of the K...
The need of conceiving reliable real-time systems is crucial for the software engineering. This paper is dedicated to the specification and the verification of land transportation systems taken as an application domain. We present a case study in the area of transportation. The system consists of several automated vehicles called CyCab, that have t...
Summary : Using of Epragma system in the E&T project. The digitization of the different filled questionnaires from young students in the East and South-east of France and methods. Résumé : Utilisation du système Epragma dans le cadre du projet E&T. Numérisation des différents questionnaires saisies des écoliers de l'est et sud-est de la France et m...
Hierarchical automata are used to model hierarchical systems. The semantics used is the Kripke structure where states are valued by atomic propositions. This structure can be large in number of states. This paper presents some heuristics to check properties expressed in LTL logic (Linear Temporal Logic). Hierarchical systems are defined in an hiera...
Ce papier a pour objectif de montrer l'intérêt d'utiliser les méthodes formelles pour spécifier et valider un système médical, nous utilisons les automates hiérarchiques pour modéliser ces systèmes. La sémantique utilisée est celle d'une structure de Kripke où les états sont valués par des propositions atomiques. Cette structure peut être de grande...
In this paper, we are interested in verifying temporal properties of hierarchical systems when states are refined by automata. The system is modeled by hierarchical automata and temporal properties are expressed by the LTL (linear temporal logic). We present a technique to cope with state explosion problem induced by the complexity of the system. T...
This article treats the specification and verification by model-checking the reactive hierarchical systems. The model used is the hierarchical automata which exploits the decomposition of a state in to a set of acyclic automata. In order to deal with the problem of the state explosion induced by the model-checking, we propose to use the technique o...
The French BOM (B with Optimised Memory) project has analysed issues related to code generation from B specifications. This
analysis was built upon the shortcoming of the existing translators, and led to proposals to generate optimised code suitable
for embedding in highly memory-constrained devices, such as smart cards. Two code translators have b...
B is a formal method (and a specification language) which enables the automatic generation of an executable code through a succession of refinements stemming from an abstract specification. The industrial tools provide support for all the development process (type-checking facilities, automatic and interactive proof support, ...). A B specification...
This paper works on two specifications of a same problem. The first specification uses the B method and the second the UML (Unified Modeling Lan-guage) notation, which integrates the OCL (Object Constraint Language) lan-guage. This language allows us to express invariant, pre-conditions, guards, and so on. The case studied is system controlling acc...
