| 1. |
- Jägemar, Marcus, 1972-
(författare)
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Utilizing Hardware Monitoring to Improve the Quality of Service and Performance of Industrial Systems
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The drastically increased use of information and communications technology has resulted in a growing demand for telecommunication network capacity. The demand for radically increased network capacity coincides with industrial cost-reductions due to an increasingly competitive telecommunication market. We have addressed the capacity and cost-reduction problems in three ways.Our first contribution is a method to support shorter development cycles for new functionality and more powerful hardware. We reduce the development time by replicating the hardware usage of production systems in our test environment. Having a realistic test environment allows us to run performance tests at early design phases and therefore reducing the overall system development time.Our second contribution is a method to improve the communication performance through selective and automatic message compression. The message compression functionality monitors transmissions continuously and selects the most efficient compression algorithm. The message compression functionality evaluates several parameters such as network congestion level, CPU usage, and message content. Our implementation extends the communication capacity of a legacy communication API running on Linux where it emulates a legacy real-time operating system.In our third an final contribution, we implement a process allocation and scheduling framework to allow higher system performance and quality of service. The framework continuously monitors selected processes and correlate their performance to hardware usage such as caches, floating point unit and similar. The framework uses the performance-hardware correlation to minimize shared hardware resource congestion by efficiently allocate processes on multi-core CPUs. We have also designed a shared hardware resource aware process scheduler that makes it possible for multiple processes to co-exist on a CPU without affecting the performance of each other through hardware resource congestions. The allocation and scheduling techniques can be used to consolidate several functions on shared hardware thus reducing the system cost. We have implemented and evaluated our process scheduler as a new scheduling class in Linux.We have conducted several case studies in an industrial environment and verified all contributions in the scope of a large telecommunication system manufactured by Ericsson.%We have deployed all techniques in a complicated industrial legacy system with minimal impact. We show that we can provide a cost-effective solution, which is an essential requirement for industrial systems.
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| 2. |
- Struhar, Vaclav
(författare)
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Improving Soft Real-time Performance of Fog Computing
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fog computing is a distributed computing paradigm that brings data processing from remote cloud data centers into the vicinity of the edge of the network. The computation is performed closer to the source of the data, and thus it decreases the time unpredictability of cloud computing that stems from (i) the computation in shared multi-tenant remote data centers, and (ii) long distance data transfers between the source of the data and the data centers. The computation in fog computing provides fast response times and enables latency sensitive applications. However, industrial systems require time-bounded response times, also denoted as RT. The correctness of such systems depends not only on the logical results of the computations but also on the physical time instant at which these results are produced. Time-bounded responses in fog computing are attributed to two main aspects: computation and communication. In this thesis, we explore both aspects targeting soft RT applications in fog computing in which the usefulness of the produced computational results degrades with real-time requirements violations. With regards to the computation, we provide a systematic literature survey on a novel lightweight RT container-based virtualization that ensures spatial and temporal isolation of co-located applications. Subsequently, we utilize a mechanism enabling RT container-based virtualization and propose a solution for orchestrating RT containers in a distributed environment. Concerning the communication aspect, we propose a solution for a dynamic bandwidth distribution in virtualized networks.
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| 3. |
- Al-Dulaimy, Auday, et al.
(författare)
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Fault Tolerance in Cloud Manufacturing : An Overview
- 2023
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Ingår i: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST. - : Springer Science and Business Media Deutschland GmbH. - 9783031318900 ; , s. 89-101
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Konferensbidrag (refereegranskat)abstract
- Utilizing edge and cloud computing to empower the profitability of manufacturing is drastically increasing in modern industries. As a result of that, several challenges have raised over the years that essentially require urgent attention. Among these, coping with different faults in edge and cloud computing and recovering from permanent and temporary faults became prominent issues to be solved. In this paper, we focus on the challenges of applying fault tolerance techniques on edge and cloud computing in the context of manufacturing and we investigate the current state of the proposed approaches by categorizing them into several groups. Moreover, we identify critical gaps in the research domain as open research directions. © 2023, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.
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| 4. |
- Behnam, Moris, 1973-
(författare)
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Synchronization Protocols for a Compositional Real-Time Scheduling Framework
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis we propose techniques to simplify the integration of subsystems while minimizing the overall amount of CPU resources needed to guarantee the schedulability of real-time tasks. In addition, we provide solutions to the problem of allowing for the use of logical resources requiring mutual exclusion.The contribution of the thesis is presented in three parts. In the first part, we propose a synchronization protocol, called SIRAP, to facilitate sharing of logical resources in a hierarchical scheduling framework. In addition, we extend an existing synchronization protocol, called HSRP, such that each subsystem can be developed independently. The performance of the proposed protocols is evaluated by extensive simulations. In the second part, we present an efficient schedulability analysis that exploits the lower scheduling overhead introduced by each of the proposed protocols. Finally, in the third part, we propose new methods and algorithms that find the optimal system parameters (e.g., optimal resource ceiling), that minimize the amount of CPU resources required to ensure schedulability, when using the proposed synchronization protocols in a hierarchical scheduling framework.The motivation of this work comes from an emerging industrial trend in embedded software systems development to integrate multiple applications (subsystems) on a small number of processors. The purpose of this integration is to reduce the hardware related costs as well as the communication complexity between processors. In this setting a large number of industrial applications face the problem of preserving their real-time properties after their integration onto a single processor. In addition, temporal isolation between the applications during runtime may be required to prevent failure propagation between different applications.Specifically, we propose a hierarchical scheduling framework that allows for a simplified integration of subsystems. The framework preserves the essential temporal characteristics of the subsystems, both when running in isolation as well as when they are integrated with other subsystems. In this thesis, we assume a model where a system consists of a number of subsystems. The subsystems can interact with each other using shared logical resources. The framework ensures that the individual subsystem respects its allocated share of the processor. The difficulty lies in allowing two or more subsystems to share logical resources, which introduces an additional complexity in the schedulability analysis and also increases the system load.
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| 5. |
- Chirumalla, Koteshwar, Associate Professor, et al.
(författare)
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Navigating Production Automation as a Service : Unveiling Drivers, Benefits, and Challenges in Manufacturing Companies
- 2024
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Ingår i: Sustainable Production Through Advanced Manufacturing, Intelligent Automation And Work Integrated Learning, Sps 2024. - : IOS Press BV. - 9781643685106 ; , s. 206-218
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Konferensbidrag (refereegranskat)abstract
- The integration of production automation drives innovation in manufacturing by enhancing efficiency, quality, and cost reduction. However, the capital requirements of conventional automation solutions hinder many manufacturing companies. Production Automation as a Service (PAaaS) emerges as a cost-effective alternative, offering improved flexibility and efficiency. Yet, adopting PAaaS faces challenges: a lack of expertise, awareness, and cultural resistance. This study explores PAaaS implementation in manufacturing, identifying its specific needs and challenges. Qualitative research across ten diverse manufacturing companies reveals two key drivers: technological advancement and evolving business models. It highlights four primary benefits—cost-effectiveness, flexibility, efficiency, and product quality. Simultaneously, it addresses five significant challenges—legacy system integration, cybersecurity, internet dependency, expertise gaps, and downtime risks. To aid early decision-making, the study proposes a framework covering drivers, benefits, challenges, and suitable strategies. This study contributes to the ongoing discussion on smart production and automation development by focusing on business model innovation and the pay-as-a-service approach.
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| 6. |
- Fattouh, Anas, et al.
(författare)
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Remote integration of advanced manufacturing technologies into production systems : integration processes, key challenges and mitigation actions
- 2023
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Ingår i: Journal of Manufacturing Technology Management. - : Emerald. - 1741-038X .- 1758-7786.
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Tidskriftsartikel (refereegranskat)abstract
- The study examines the remote integration process of advanced manufacturing technology (AMT) into the production system and identifies key challenges and mitigating actions for a smoother introduction and integration process.Design/methodology/approach: The study adopts a case study approach to a cyber-physical production system at an industrial technology center using a mobile robot as an AMT.Findings: By applying the plug-and-produce concept, the study exemplifies an AMT's remote integration process into a cyber-physical production system in nine steps. Eleven key challenges and twelve mitigation actions for remote integration are described based on technology–organization–environment theory. Finally, a remote integration framework is proposed to facilitate AMT integration into production systems.Practical implications: The study presents results purely from a practical perspective, which could reduce dilemmas in early decision-making related to smart production. The proposed framework can improve flexibility and decrease the time needed to configure new AMTs in existing production systems.Originality/value: The area of remote integration for AMT has not been addressed in depth before. The consequences of lacking in-depth studies for remote integration imply that current implementation processes do not match the needs and the existing situation in the industry and often underestimate the complexity of considering both technological and organizational issues. The new integrated framework can already be deployed by industry professionals in their efforts to integrate new technologies with shorter time to volume and increased quality but also as a means for training employees in critical competencies required for remote integration.
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| 7. |
- Imtiaz, Shamoona
(författare)
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Automated Performance Profiling of Software Applications
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For industrial systems performance, it is desired to keep the IT infrastructure competitive through the efficient use of computer resources. However, modern software applications are complex and often utilize a broad spectrum of available hardware resources. The way how applications utilize these resources may vary from platform to platform due to the different architectural features, requirements and performance levels guaranteed by the hardware as well as due to the type of application under analysis. It becomes challenging to predict how the deployed applications will perform on a particular platform, how to improve the hardware resource utilization, and how to meet the Quality of Service (QoS) requirements. Computers these days enable us to precisely trace down the performance of applications using the Performance Monitoring Counters (PMCs) available in the Performance Monitoring Unit (PMU) of the processors. PMCs can record micro-architectural events, called PMU events, at the CPU cycle level. Tools like perf API and PAPI provide performance information using manual and selective function calls. Nevertheless, it is difficult for humans to make analyses, visualize performance over time and draw conclusions from this wealth of data without automatic and intelligent tools. In this thesis, our first contribution is to propose a cross-platform automated approach to investigate the overall performance profile of the applications. Instead of relying on a static and pre-selected list of hardware and software performance events we avoid the selection bias by capturing the entire range of performance events specific to the platform on which applications are running. The performance data being generated from shared resource environments and hierarchical resource utilization demands makes it harder to represent the behavior in one model. That being the case, it was deemed appropriate to demonstrate the compact representation of behavior. So, our next contribution is to present a simplified model to understand the behavior of performance events. Therefore, we determine segments in performance data by locating the points in their data distribution using the change point detection method. The proposed solution reduces the complexity of data handling, allows the application of further statistical analyses and provides better visualization. Lastly, to reveal the out-of-sight information, we present a customized approach to automatically identify the groups of similar performance events based on the change in their behavior. There can be several ways to group the performance data, we opt to form the groups based on change points in the behavior of the performance events. The knowledge can then be used by the decision-makers as per their interests such as for load balancing, deployments, scheduling and anomalous behavior detection.
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| 8. |
- Struhar, Vaclav, et al.
(författare)
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Resource Adaptation for Real-Time Containers Considering Quality of Control
- 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
- Container-based virtualization has become a promising deployment model for industrial applications mainly due to its benefits, such as providing support for co-located applications in heterogeneous environments. However, such facilitation brings challenges, including full temporal isolation among real-time applications and support for time-critical applications. In this paper, we tackle such challenges, in particular when the applications are time-sensitive Control Applications. The literature suggests that flexible timing constraints for Control Applications are beneficial in responding to disturbances and minimizing response deviation. Therefore, we propose a mechanism to support such a runtime adaptation in container-based virtualization. To show the performance of the proposed mechanism, we implement our approach on a Linux-based hierarchical scheduling platform, and we evaluate it for a Control application.
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| 9. |
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| 10. |
- Tsog, Nandinbaatar
(författare)
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Improving On-Board Data Processing using CPU-GPU Heterogeneous Architectures for Real-Time Systems
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates the efficacy of heterogeneous computing architectures in real-time systems.The goals of the thesis are twofold. First, to investigate various characteristics of the Heterogeneous System Architectures (HSA) compliant reference platforms focusing on computing performance and power consumption. The investigation is focused on the new technologies that could boost on-board data processing systems in satellites and spacecraft. Second, to enhance the usage of the heterogeneous processing units by introducing a technique for static allocation of parallel segments of tasks.The investigation and experimental evaluation show that our method of GPU allocation for the parallel segments of tasks is more energy efficient compared to any other studied allocation. The investigation is conducted under different types of environments, such as process-level isolated environment, different software stacks, including kernels, and various task set scenarios. The evaluation results indicate that a balanced use of heterogeneous processing units (CPU and GPU) could improve schedulability of task sets up to 90% with the proposed allocation technique.
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