| 1. |
- Abdi, Somayeh, et al.
(författare)
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Cognitive and Time Predictable Task Scheduling in Edge-cloud Federation
- 2022
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Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665499965
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present a hierarchical model for time predictable task scheduling in edge-cloud computing architecture for industrial cyber-physical systems. Regarding the scheduling problem, we also investigate the common problem-solving approaches and discuss our preliminary plan to realize the proposed architecture. Furthermore, an Integer linear programming (ILP) model is proposed for task scheduling problem in the cloud layer. The model considers timing and security requirements of applications and the objective is to minimize the financial cost of their execution.
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| 2. |
- Abdi, Somayeh, et al.
(författare)
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Cost-aware workflow offloading in edge-cloud computing using a genetic algorithm
- 2024
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Ingår i: Journal of Supercomputing. - : Springer. - 0920-8542 .- 1573-0484.
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Tidskriftsartikel (refereegranskat)abstract
- The edge-cloud computing continuum effectively uses fog and cloud servers to meet the quality of service (QoS) requirements of tasks when edge devices cannot meet those requirements. This paper focuses on the workflow offloading problem in edge-cloud computing and formulates this problem as a nonlinear mathematical programming model. The objective function is to minimize the monetary cost of executing a workflow while satisfying constraints related to data dependency among tasks and QoS requirements, including security and deadlines. Additionally, it presents a genetic algorithm for the workflow offloading problem to find near-optimal solutions with the cost minimization objective. The performance of the proposed mathematical model and genetic algorithm is evaluated on several real-world workflows. Experimental results demonstrate that the proposed genetic algorithm can find admissible solutions comparable to the mathematical model and outperforms particle swarm optimization, bee life algorithm, and a hybrid heuristic-genetic algorithm in terms of workflow execution costs.
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| 3. |
- Abdi, Somayeh, et al.
(författare)
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Task Offloading in Edge-cloud Computing using a Q-Learning Algorithm
- 2024
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Ingår i: International Conference on Cloud Computing and Services Science, CLOSER - Proceedings. - : Science and Technology Publications, Lda. - 9789897587016 ; , s. 159-166
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Task offloading is a prominent problem in edge−cloud computing, as it aims to utilize the limited capacityof fog servers and cloud resources to satisfy the QoS requirements of tasks, such as meeting their deadlines.This paper formulates the task offloading problem as a nonlinear mathematical programming model to maximizethe number of independent IoT tasks that meet their deadlines and to minimize the deadline violationtime of tasks that cannot meet their deadlines. This paper proposes two Q-learning algorithms to solve theformulated problem. The performance of the proposed algorithms is experimentally evaluated with respect toseveral algorithms. The evaluation results demonstrate that the proposed Q-learning algorithms perform wellin meeting task deadlines and reducing the total deadline violation time.
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| 4. |
- Alvarez Vadillo, Ines, et al.
(författare)
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Centralised Architecture for the Automatic Self-Configuration of Industrial Networks
- 2023
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Ingår i: IEEE Int. Conf. Emerging Technol. Factory Autom., ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9798350339918
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Konferensbidrag (refereegranskat)abstract
- Novel production paradigms aim at increasing the efficiency and flexibility of production systems. Nonetheless, traditional industrial infrastructures lack the mechanisms needed to support these new paradigms. One of the main limiting factors is the architecture, which follows the automation pyramid in which subsystems are divided in layers depending on their functionalities. This allowed to meet the timing and dependability requirements of the production subsystems, however at the cost of limiting the exchange of information required to provide increased flexibility to the system. For this reason, in this paper we propose a new industrial architecture with a single network infrastructure to connect all the devices that conform to the industrial systems. On top of that, we design an Automatic Network Configurator to support the automatic configuration of the system. To assess the feasibility of our design and evaluate its performance, we implement the first instance of the architecture capable of supporting changes in the traffic requirements during run-time, i.e., without stopping or disrupting the system's operation. Furthermore, we use the implemented instance to measure the time required for reconfigurations.
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| 5. |
- Alvarez Vadillo, Ines, et al.
(författare)
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Implementing a First CNC for Scheduling and Configuring TSN Networks
- 2022
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Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665499965
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Konferensbidrag (refereegranskat)abstract
- Novel industrial applications are leading to important changes in industrial systems. One of the most important changes is the need for systems that are capable to adapt to changes in the environment or the system itself. Because of their nature many of these applications are distributed, and their network infrastructure is key to guarantee the correct operation of the overall system. Furthermore, in order for a distributed system to be able to adapt, its network must be flexible enough to support changes in the traffic during runtime. The Time-Sensitive Networking (TSN) Task Group has proposed a series of standards that aim at providing deterministic real-time communications over Ethernet. TSN also provides centralised online configuration and control architectures which enable the online configuration of the network. A key part in TSN's centralised architectures is the Centralised Network Configuration element (CNC). In this work we present a first implementation of a CNC capable of scheduling time-triggered traffic and deploying such configuration in the network using the Network Configuration (NETCONF) protocol. We also assess the correctness of our implementation using an industrial use case provided by Volvo Construction Equipment.
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| 6. |
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| 7. |
- Ashjaei, Seyed Mohammad Hossein, 1980-, et al.
(författare)
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A Conceptual Framework for Software Modeling of Automation Systems
- 2022
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Ingår i: ITNG 2022 19th International Conference on Information Technology-New Generations. Advances in Intelligent Systems and Computing, vol 1421. - Cham : Springer International Publishing. - 9783030976521
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a conceptual framework to facilitate the design and development of an automation system in which time-sensitive networking (TSN) is utilized for the backbone network and OPC UA is used for modeling of data exchange over TSN. As the configuration of OPC UA over TSN in a large automation setup can be a challenging task and requires specific expertise, we propose to add an abstract modeling layer that adopts the concepts of model-based development and component-based software engineering to facilitate the development of these systems. The proposed conceptual model can be automatically translated to the OPC UA modeling format. Such a modeling view will significantly reduce the complexity of OPC UA configurations, specially in large automation systems. Another benefit of the proposed framework is that the engineers, who do not have high levels of expertise in OPC UA, will be able to easily configure the OPC UA nodes in the automation system that utilize TSN for backbone communication.
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| 8. |
- Ashjaei, Seyed Mohammad Hossein, 1980-, et al.
(författare)
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A novel frame preemption model in TSN networks
- 2021
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Ingår i: Journal of systems architecture. - : Elsevier B.V.. - 1383-7621 .- 1873-6165. ; 116
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Tidskriftsartikel (refereegranskat)abstract
- This paper identifies a limitation in the frame preemption model in the TSN standard (IEEE 802.1Q-2018), due to which high priority frames can experience significantly long blocking delays, thereby exacerbating their worst-case response times. This limitation can have a considerable impact on the design, analysis and performance of TSN-based systems. To address this limitation, the paper presents a novel and more efficient frame preemption model in the TSN standard that allows over 90% reduction in the maximum blocking delay leading to lower worst-case response times of high priority frames compared to the frame preemption model used in the existing works. The paper also shows that the improvement becomes even more significant in multi-switch TSN networks. In order to evaluate the effects of preemption, the paper performs simulations by enabling and disabling preemptions as well as enabling and disabling the Hold/Release mechanism supported by TSN. Furthermore, the paper performs a comparative evaluation of the two models of frame preemption in TSN using simulations. The evaluation shows that the maximum response times of high priority frames can be significantly reduced with very small impact on the response times of lower priority frames. The paper also shows the improvement in the maximum response times of higher priority frames using an automotive industrial use case that employs a multi-hop TSN network for on-board communication.
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| 9. |
- Ashjaei, Seyed Mohammad Hossein, 1980-, et al.
(författare)
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Implications of Various Preemption Configurations in TSN Networks
- 2022
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Ingår i: IEEE Embedded Systems Letters. - 1943-0663 .- 1943-0671. ; 14:1, s. 39-42
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Tidskriftsartikel (refereegranskat)abstract
- Time Sensitive Networking (TSN) is a set of standards developed by the IEEE 802.1 task group to support high-bandwidth and low latency predictable network communication. Configuration of TSN networks is a daunting task as there are several novel features in TSN and numerous possibilities can arise by considering combinations of these features. This letter investigates the impact of various unexplored frame-preemption configurations in TSN networks on the timing behaviours of various traffic classes. These configurations correspond to different combinations of settings in TSN with respect to the credit-based shaper, time-aware shaper, Hold & Release mechanism and frame preemption. The letter provides evaluation of these configurations by means of an analytical discussion and simulation experiments. The results and implications discussed in this letter can serve as useful guidelines for the network designers when configuring TSN networks with regards to the addressed features.
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| 10. |
- Ashjaei, Seyed Mohammad Hossein, 1980-, et al.
(författare)
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Time-Sensitive Networking in automotive embedded systems : State of the art and research opportunities
- 2021
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Ingår i: Journal of systems architecture. - : Elsevier B.V.. - 1383-7621 .- 1873-6165. ; 117
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Tidskriftsartikel (refereegranskat)abstract
- The functionality advancements and novel customer features that are currently found in modern automotive systems require high-bandwidth and low-latency in-vehicle communications, which become even more compelling for autonomous vehicles. In a recent effort to meet these requirements, the IEEE Time-Sensitive Networking (TSN) task group has developed a set of standards that introduce novel features in Switched Ethernet. TSN standards offer, for example, a common notion of time through accurate and reliable clock synchronization, delay bounds for real-time traffic, time-driven transmissions, improved reliability, and much more. In order to fully utilize the potential of these novel protocols in the automotive domain, TSN should be seamlessly integrated into the state-of-the-art and state-of-practice model-based development processes for automotive embedded systems. Some of the core phases in these processes include software architecture modeling, timing predictability verification, simulation, and hardware realization and deployment. Moreover, throughout the development of automotive embedded systems, the safety and security requirements specified on these systems need to be duly taken into account. In this context, this work provides an overview of TSN in automotive applications and discusses the recent technological developments relevant to the adoption of TSN in automotive embedded systems. The work also points at the open challenges and future research directions.
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