Dissertations / Theses on the topic 'REAL-TIME TASKS'
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Singh, Abhishek Jeffay Kevin. "Co-scheduling real-time tasks and non real-time tasks using empirical probability distribution of execution time requirements." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2009. http://dc.lib.unc.edu/u?/etd,2724.
Full textTitle from electronic title page (viewed Mar. 10, 2010). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Computer Science." Discipline: Computer Science; Department/School: Computer Science.
Zhu, Wenjing. "Adaptive threshhold-based scheduling for real-time and non-real-time tasks." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29913.
Full textScience, Faculty of
Computer Science, Department of
Graduate
DI, FRISCHIA STEFANO. "Real-Time Algorithms for Spectral Classification Tasks." Doctoral thesis, Università degli Studi dell'Aquila, 2021. http://hdl.handle.net/11697/177860.
Full textNemati, Farhang. "Partitioned Scheduling of Real-Time Tasks on Multi-core Platforms." Licentiate thesis, Mälardalen University, School of Innovation, Design and Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-9595.
Full textIn recent years multiprocessor architectures have become mainstream, and multi-core processors are found in products ranging from small portable cell phones to large computer servers. In parallel, research on real-time systems has mainly focused on traditional single-core processors. Hence, in order for real-time systems to fully leverage on the extra capacity offered by new multi-core processors, new design techniques, scheduling approaches, and real-time analysis methods have to be developed.
In the multi-core and multiprocessor domain there are mainly two scheduling approaches, global and partitioned scheduling. Under global scheduling each task can execute on any processor at any time while under partitioned scheduling tasks are statically allocated to processors and migration of tasks among processors is not allowed. Besides simplicity and efficiency of partitioned scheduling protocols, existing scheduling and synchronization methods developed for single-core processor platforms can more easily be extended to partitioned scheduling. This also simplifies migration of existing systems to multi-cores. An important issue related to partitioned scheduling is distribution of tasks among processors which is a bin-packing problem.
In this thesis we propose a partitioning framework for distributing tasks on the processors of multi-core platforms. Depending on the type of performance we desire to achieve, the framework may distribute a task set differently, e.g., in an application in which tasks process huge amounts of data the goal of the framework may be to decrease cache misses.Furthermore, we propose a blocking-aware partitioning heuristic algorithm to distribute tasks onto the processors of a multi-core architecture. The objective of the proposed algorithm is to decrease blocking overhead of tasks which reduces the total utilization and has the potential to reduce the number of required processors.Finally, we have implemented a tool to facilitate evaluation and comparison of different multiprocessor scheduling and synchronization approaches, as well as different partitioning heuristics. We have applied the tool in the evaluation of several partitioning heuristic algorithms, and the tool is flexible to which any new scheduling or synchronization protocol as well as any new partitioning heuristic can easily be added.
Chang, Tzu-Chiang. "Static scheduler for hard real-time tasks on multiprocessor systems." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/24043.
Full textHan, Kai. "Scheduling Distributed Real-Time Tasks in Unreliable and Untrustworthy Systems." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/26917.
Full textPh. D.
Qamhieh, Manar. "Scheduling of parallel real-time DAG tasks on multiprocessor systems." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1030/document.
Full textThe interest for multiprocessor systems has recently been increased in industrial applications, and parallel programming API's have been introduced to benefit from new processing capabilities. The use of multiprocessors for real-time systems, whose execution is performed based on certain temporal constraints is now investigated by the industry. Real-time scheduling problem becomes more complex and challenging in that context. In multiprocessor systems, a hard real-time scheduler is responsible for allocating ready jobs to available processors of the systems while respecting their timing parameters. In this thesis, we study the problem of real-time scheduling of parallel Directed Acyclic Graph (DAG) tasks on homogeneous multiprocessor systems. In this model, a DAG task consists of a set of subtasks that execute under precedence constraints. At all times, the real-time scheduler is responsible for determining how subtasks execute, either sequentially or in parallel, based on the available processors of the system. We propose two DAG scheduling approaches to determine the execution form of DAG tasks. The first approach is the DAG Stretching algorithm, from the Model Transformation approach, which forces DAG tasks to execute as sequentially as possible. The second approach is the Direct Scheduling, which aims at scheduling DAG tasks while respecting their internal dependencies. We provide real-time schedulability analyses for Direct Scheduling at DAG-Level and at Subtask-Level. Due to the incomparability of DAG scheduling approaches, we use extensive simulations to compare performance of global EDF with global DM scheduling using our simulation tool YARTISS
Haugli, Fredrik Bakkevig. "Using online worst-case execution time analysis and alternative tasks in real time systems." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26100.
Full textHuang, Chiao Ching Baskiyar Sanjeev. "Minimum power consumption for rate monotonic tasks." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/FALL/Computer_Science_and_Software_Engineering/Thesis/Huang_Chiao_10.pdf.
Full textRafiq, Salman. "Measuring Performance of Soft Real-Time Tasks on Multi-core Systems." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-37219.
Full textLiberg, Tim, and Per-Erik Måhl. "GPU-accelerated Model Checking of Periodic Self-Suspending Real-Time Tasks." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-14661.
Full textNie, Yonggao. "Limited-preemptive fixed priority scheduling of real-time tasks on multiprocessors." Thesis, Mälardalens högskola, Inbyggda system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28265.
Full textAULUCK, NITIN. "REAL-TIME SCHEDULING ALGORITHMS FOR PRECEDENCE RELATED TASKS ON HETEROGENEOUS MULTIPROCESSORS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1109288052.
Full textKatre, Kedar Maheshwar. "Policies for Migration of Real-Time tasks in Embedded Multicore Systems." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/264.
Full textMotakpalli, Sankalpanand. "Aperiodic Job Handling in Cache-Based Real-Time Systems." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/dissertations/1474.
Full textZhu, Kaiqian. "Limited Preemptive Earliest Deadline First Scheduling of Real-Time Tasks on Multiprocessors." Thesis, Mälardalens högskola, Inbyggda system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28252.
Full textZahaf, Houssam-Eddine. "Energy efficient scheduling of parallel real-time tasks on heterogeneous multicore systems." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10100/document.
Full textCyber physical systems (CPS) and Internet of Objects (IoT) are generating an unprecedented volume and variety of data that needs to be collected and stored on the cloud before being processed. By the time the data makes its way to the cloud for analysis, the opportunity to trigger a reply might be late. One approach to solve this problem is to analyze the most time-sensitive data at the network edge, close to where it is generated. Thus, only the pre-processed results are sent to the cloud. This computation model is know as *Fog Computing* or *Edge computing*. Critical CPS applications using the fog computing model may have real-time constraints because results must be delivered in a pre-determined time window. Furthermore, in many relevant applications of CPS, the processing can be parallelized by applying the same processing on different sub-sets of data at the same time by the mean parallel programming techniques. This allow to achieve a shorter response time, and then, a larger slack time, which can be used to reduce energy consumption. In this thesis we focus on the problem of scheduling a set of parallel tasks on multicore processors, with the goal of reducing the energy consumption while all deadlines are met. We propose several realistic task models on architectures with identical and heterogeneous cores, and we develop algorithms for allocating threads to processors, select the core frequencies, and perform schedulability analysis. The proposed task models can be realized by using OpenMP-like APIs
Gaid, MEMB, AS Cela, and Y. Hamam. "Optimal Real-Time Scheduling of Control Tasks with State Feedback Resource Allocation." IEEE Transactions on Control Systems Technology, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001370.
Full textZuhily, Areej. "Scheduling analysis of fixed priority hard real-time systems with multiframe tasks." Thesis, University of York, 2009. http://etheses.whiterose.ac.uk/11090/.
Full textBabbar, Davender. "On-line hard real-time scheduling of parallel tasks on partitionable multiprocessors /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487858417983777.
Full textCraig, David W. (David William) Carleton University Dissertation Engineering Electrical. "Light traffic loss of random hard real-time tasks in a network." Ottawa, 1988.
Find full textLennvall, Tomas. "Handling aperiodic tasks and overload in distributed off-line scheduled real-time systems /." Västerås : Mälardalen University, 2003. http://www.mrtc.mdh.se/publications/0541.pdf.
Full textDevarasetty, Ravi Kiran. "Heuristic Algorithms for Adaptive Resource Management of Periodic Tasks in Soft Real-Time Distributed Systems." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/31219.
Full textMaster of Science
Satka, Zenepe, and Hena Hodžić. "Minimizing the unpredictability that real-time tasks suffer due to inter-core cache interference." Thesis, Mälardalens högskola, Inbyggda system, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-48542.
Full textCourbin, Pierre. "Scheduling sequential or parallel hard real-time pre-emptive tasks upon identical multiprocessor platforms." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1081/document.
Full textThe scheduling of tasks on a hard real-time system consists in finding a way to choose, at each time instant, which task should be executed on the processor so that each succeed to complete its work before its deadline. In the uniprocessor case, this problem is already well studied and enables us to do practical applications on real systems (aerospace, stock exchange etc.). Today, multiprocessor platforms are widespread and led to many issues such as the effective use of all processors. In this thesis, we explore the existing approaches to solve this problem. We first study the partitioning approach that reduces this problem to several uniprocessor systems and leverage existing research. For this one, we propose a generic partitioning algorithm whose parameters can be adapted according to different goals. We then study the semi-partitioning approach that allows migrations for a limited number of tasks. We propose a solution with restricted migration that could be implemented rather simply on real systems. We then propose a solution with unrestricted migration which provides better results but is more difficult to implement. Finally, programmers use more and more the concept of parallel tasks that can use multiple processors simultaneously. These tasks are still little studied and we propose a new model to represent them. We study the possible schedulers and define a way to ensure the schedulability of such tasks for two of them
Varghese, B., M. Alamgir Hossain, and Keshav P. Dahal. "Scheduling of tasks in multiprocessor system using hybrid genetic algorithms." Springer Verlag, 2007. http://hdl.handle.net/10454/2552.
Full textValentin, Eduardo Bezerra, and 92-36710870. "Scheduling hard real-time tasks in heterogeneous multiprocessor platforms subject to energy and temperature constraints." Universidade Federal do Amazonas, 2017. http://tede.ufam.edu.br/handle/tede/6148.
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The power wall is a barrier to improvement in the processor design process due to the power consumption of components. The production of energy optimum systems demands knowledge of different disciplines. The usage of heterogeneous multicore platforms is appealing for recent applications, e.g., hard real-time systems. The motivation is the potential reduced energy consumption offered by such platforms. Hard real-time systems are present in life critical environments. Reducing the energy consumption on such systems is an onerous process. Scheduling becomes particularly challenging to improve system utilization and minimize system energy consumption and peak temperature on such platforms, specially subject to hard real-time constraints. Therefore, we propose a study to effectively answer the pertinent research question: “How to offer users timing correctness and guarantees of hard real-time systems executed on heterogeneous multicore systems with energy and temperature constraints?”. Finding optimal solutions for such question has still several open research questions. The main aim of this thesis is to propose an energy optimization method for hard realtime system on heterogeneous multicore platform demonstrating that it is possible to timely compute timing correctness and guarantees using a sufficient and necessary condition; accounting for energy, temperature, preemption, precedence, shared resources constraints, and architectural interference. The proposal is a two fold approach. First, we investigate the process of finding the optimal task to core and frequency to task processes by means of applying exact schedulability tests for heterogeneous multicore platforms. Second, the outcome of the optimization analysis shall be used as reference to the on-line scheduler. We believe that we have achieved the main objective of this research by combining: (a) schedulability analysis from hard real-time systems, (b) representative mathematical formulations, based on integer linear programming, covering modern processors technological characteristics and using a classical combinatorial mathematical formulation (Multilevel Generalized Assignment Problem), and (c) robust exact implicit enumeration algorithmic strategies from combinatorial optimization, such as branch-and-cut and branch-and-price. The systematic literature review in the research subject reveals that the field has open questions to be answered. For instance, to the knowledge of the author only five works in the state-of-the-art literature deal with the problem by providing optimal solutions. Typically, the existing approaches focus on either heuristics or approximation algorithms. Also, only one work has a proposal to evaluate the schedulability in this scenario with an exact test. The typical formulation in the specialized literature is a 0/1 integer linear programming model which considers a continuous processor frequency domain and determines a single operating frequency per processor. One of the hypotheses tested in this research is: stronger feasibility analysis offers tighter bounds for the problem. We believe that this can be observed, for example, in the results produced by solvers for fixed priority schedulers, by means of an analysis based on a comparative study. By applying less accurate schedulability tests, such as utilization based, the solvers take longer to converge to optimal solutions, when compared to solvers that apply exact schedulability tests based on response time analysis. Another hypothesis tested in this research is: practical instances of the problem are timely solvable to optimal. We have experimented, by means of a comparative study, on finding feasible solutions for workload for fixed priority schedulers with up to 50 tasks distributed on four processors with seven different available frequencies. On independent hard real-time tasks scheduled using EDF policy, we found optimal distribution of up to 90 tasks on four processors with seven different available frequencies. In both cases, the solutions were found within 30 min of execution time. Similarly, on dependent tasks workload, we have optimally distributed 22 tasks, from an automotive control hard real-time application, on four processors with seven different available frequencies, with two shared resources and 23 precedence constraints within 1.5 h. We consider a few hours in the design phase a price worth paying in this context.
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Stanhope, Austin. "A control architecture for dynamic execution of robot tasks trained in real-time using particle filters." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1472980.
Full textBelaid, Ikbel. "On line-off line placement and scheduling of real time hardware tasks on dynamically reconfigurable platforms." Nice, 2011. http://www.theses.fr/2011NICE4019.
Full textThe placement and scheduling of hardware tasks are the cores of the real-time operating system. Both problems must be solved efficiently to enhance the placement quality expressed by the rate of resource fragmentation and configuration overhead, and to improve the scheduling quality represented by the temporal spanning of the application and the guarantee of real-time constraints. In the context of the mixed architectures such as System on Programmable Chip (SoPC), we suggest exploiting the physical features of these architectures especially the partial run-time reconfiguration. The first part of the thesis deals with preemptive independents tasks. It suggests analytic resolution by means of mixed integer programming solver using the Branch and Bound method to achieve off-line placement of these tasks on a SoPC. The Bees metaheuristic is also proposed to handle this problem and we suggest employing dynamically the Earliest Deadline First algorithm to perform the real-time scheduling. The second part of the thesis focuses on dependent tasks where each one runs after the completion of all its proposed to resolve statically the placement and scheduling of periodic hardware tasks in a sole directed acyclic graph (DAG) on a SoPC. . Four dynamic approaches are also proposed to place and schedule dynamically multiple DAGs with unknown behavior on several SoPCs. Basing on prefetch and reuse techniques, these approaches aim to reduce the temporal spanning of DAGs, and to improve the guarantee of real-time constraints and resource efficiency
Rajnoha, Peter. "Analýza jader real-time operačních systémů běžících na platformě FITkit." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2009. http://www.nusl.cz/ntk/nusl-236754.
Full textPoluri, Kaushik. "Bounding the Worst-Case Response Times of Hard-Real-Time Tasks under the Priority Ceiling Protocol in Cache-Based Architectures." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1213.
Full textCalafiore, Andrea. "Studio e sviluppo di un'infrastruttura di supporto alla schedulazione di hard/soft real-time tasks in ambiente QNX." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8312/.
Full textNelissen, Geoffrey. "Efficient optimal multiprocessor scheduling algorithms for real-time systems." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209528.
Full textThese last years, we have witnessed a paradigm shift in the computing platform architectures. Uniprocessor platforms have given place to multiprocessor architectures. While the real-time scheduling theory can be considered as being mature for uniprocessor systems, it is still an evolving research field for multiprocessor architectures. One of the main difficulties with multiprocessor platforms, is to provide an optimal scheduling algorithm (i.e. scheduling algorithm that constructs a schedule respecting all the task deadlines for any task set for which a solution exists). Although optimal multiprocessor real-time scheduling algorithms exist, they usually cause an excessive number of task preemptions and migrations during the schedule. These preemptions and migrations cause overheads that must be added to the task execution times. Therefore, task sets that would have been schedulable if preemptions and migrations had no cost, become unschedulable in practice. An efficient scheduling algorithm is therefore an algorithm that either minimize the number of preemptions and migrations, or reduce their cost.
In this dissertation, we expose the following results:
- We show that reducing the "fairness" in the schedule, advantageously impacts the number of preemptions and migrations. Hence, all the scheduling algorithms that will be proposed in this thesis, tend to reduce or even suppress the fairness in the computed schedule.
- We propose three new online scheduling algorithms. One of them --- namely, BF2 --- is optimal for the scheduling of sporadic tasks in discrete-time environments, and reduces the number of task preemptions and migrations in comparison with the state-of-the-art in discrete-time systems. The second one is optimal for the scheduling of periodic tasks in a continuous-time environment. Because this second algorithm is based on a semi-partitioned scheme, it should favorably impact the preemption overheads. The third algorithm --- named U-EDF --- is optimal for the scheduling of sporadic and dynamic task sets in a continuous-time environment. It is the first real-time scheduling algorithm which is not based on the notion of "fairness" and nevertheless remains optimal for the scheduling of sporadic (and dynamic) systems. This important result was achieved by extending the uniprocessor algorithm EDF to the multiprocessor scheduling problem.
- Because the coding techniques are also evolving as the degree of parallelism increases in computing platforms, we provide solutions enabling the scheduling of parallel tasks with the currently existing scheduling algorithms, which were initially designed for the scheduling of sequential independent tasks.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
RAMACHANDRAN, GOWRI SANKAR. "Integration of enhanced slot-shifting in uc/os-II." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-12981.
Full textMüller, Dirk, and Matthias Werner. "Improved Heuristics for Partitioned Multiprocessor Scheduling Based on Rate-Monotonic Small-Tasks." Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-80762.
Full textKrappman, Alfred. "Identifying and alleviating shared cache contention : Achieving reliability of real-time tasks on a multi-OS and multi-core system." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207857.
Full textAl, Sheikh Ahmad. "Resource allocation in hard real-time avionic systems : scheduling and routing problems." Phd thesis, INSA de Toulouse, 2011. http://tel.archives-ouvertes.fr/tel-00631443.
Full textOliveira, Wilson Prates de. "Arquitetura de software para sistemas de tempo real." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-13012012-103355/.
Full textThe development of real-time platform control systems is a task that involves Control Engineering and Computer Science. In the last decade, these areas have developed independent from each other. This paper seeks to decrease the distance between this areas, by proposing the use of Software Engineering methods in a software control modeling phase. One of the propositions in this paper is the use of object orientated frameworks in the Rapid Control Prototyping (RCP) process to substitute the automatic code generation, thus eliminating the problems with the legacy code and making the RCP process more interactive. Another proposition is the use of RCP directed platforms composed by a real hardware layer, a RTOS layer and an application layer formed by the framework for the analysis and development of the centralized or distributed control systems.
Lam, Barbara. "LOW-COST MISSION SUPPORT CONCEPT." International Foundation for Telemetering, 1996. http://hdl.handle.net/10150/607606.
Full textThis paper presents a new architecture of the end-to-end ground system to reduce overall mission support costs. The present ground system of the Jet Propulsion Laboratory (JPL) is costly to operate, maintain, deploy, reproduce, and document. In the present climate of shrinking NASA budgets, this proposed architecture takes on added importance as it will dramatically reduce all of the above costs. Currently, the ground support functions (i.e., receiver, tracking, ranging, telemetry, command, monitor and control) are distributed among several subsystems that are housed in individual rack-mounted chassis. These subsystems can be integrated into one portable laptop system using established MultiChip Module (MCM) packaging technology. The large scale integration of subsystems into a small portable system will greatly reduce operations, maintenance and reproduction costs. Several of the subsystems can be implemented using Commercial Off-The-Shelf (COTS) products further decreasing non-recurring engineering costs. The inherent portability of the system will open up new ways for using the ground system at the “point-of-use” site as opposed to maintaining several large centralized stations. This eliminates the propagation delay of the data to the Principal Investigator (PI), enabling the capture of data in real-time and performing multiple tasks concurrently from any location in the world. Sample applications are to use the portable ground system in remote areas or mobile vessels for real-time correlation of satellite data with earth-bound instruments; thus, allowing near real-time feedback and control of scientific instruments. This end-to-end portable ground system will undoubtedly create opportunities for better scientific observation and data acquisition.
Djokic, Jelena. "Investigation into Air Traffic Complexity as a Driver of a Controller‘s Workload." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-208110.
Full textDie vorliegende Arbeit untersucht die Komplexität der Flugverkehrskontrolle (Air Traffic Control, ATC) als einen wesentlichen Einflussfaktor auf die Arbeitsbelastung des Radarlotsen. Die zentrale Annahme ist dabei, dass die Komplexität der ATC zusammen mit den Anforderungen aus den betrieblichen Rahmenbedingungen (technische Systemschnittstellen und Prozeduren) den Lotsen zu bestimmten Abläufen zwingen, welche die Arbeitsbelastung signifikant beeinflussen. Für die durchgeführten Untersuchungen standen Daten von ATC-Echtzeitsimulationen von EUROCONTROL CRDS Budapest zur Verfügung, die folgende Informationen umfassen: abgeflogene Flugtrajektorien, Kommunikationsprotokolle der Lotsen (untereinander oder zwischen Lotse und Pilot), Daten aus dem flight-data Management und Daten aus der regelmäßigen Selbstbewertung der Lotsen bezüglich ihrer aktuell gefühlten Arbeitsbelastung. Die bereits in früheren Studien identifizierten Komplexitätsvariablen (insbesondere die lokale Flugzeugdichte, spezifische Flugzeugeigenschaften, Konfliktsituationen zwischen Flugzeugen und die Verkehrslage betreffend) sowie hierzu erarbeitete mathematische Vorschriften bilden die Grundlage für die weiterführenden, detaillierten Untersuchungen. Aufgrund der Vielzahl an Komplexitätsvariablen aus diversen wissenschaftlichen Quellen war davon auszugehen, dass Korrelationen unter den Variablen vorliegen. Aus diesem Grund wurden zunächst statistisch redundante Informationen der ursprünglich vorliegenden Variablen reduziert, sodass als Ergebnis neue voneinander unabhängige Faktoren klassifiziert werden konnten. Die hierfür verwendete Hauptkomponentenanalyse (Principal Component Analysis - PCA) führte zu sechs statistisch signifikanten Komplexitätsfaktoren, die anhand der höchsten Korrelation zur zugeordneten Komponente interpretiert wurden. Um die Verbindung zwischen der ATC Komplexität und der subjektiv empfundenen Arbeitsbelastung herzustellen, wurde eine multiple Regressionsanalyse zwischen den Komplexitätsfaktoren und den abgeleiteten Arbeitsbelastungszuständen durchgeführt. Zusätzlich lagen für die Analyse der Arbeitsbelastung auch Daten über die Arbeitsaufgaben des Lotsen vor (bspw. Dateneinträge des Lotsen, Gesamtlänge der Funkanweisungen, durchschnittliche Länge der Funkanweisungen), um zu untersuchen, inwieweit sich aus den aktuell durchgeführten Arbeitsaufgaben bei gegebener Verkehrsnachfrage eine verlässliche Vorhersage über die Arbeitsbelastung ableiten lässt. Die Analyse zur Vorhersage der Arbeitsbelastung konnte zeigen, dass sowohl die ATC Komplexität als auch die aktuellen Arbeitsaufgaben einen individuellen und signifikanten Einfluss haben. Weiterhin wurde unterstellt, dass die spezifischen Komplexitätsfaktoren einen unterschiedlichen Effekt auf die Arbeitsbelastung ausüben. Die Überprüfung dieser Annahme war ebenfalls Bestandteil der umfangreichen statistischen Untersuchungen. Tatsächlich könnte ein fundamentales Verständnis der Komplexitätsgrade den Vergleich einzelner Luftraumsektoren unter verschiedenen operativen Randbedingungen, als auch den Vergleich unterschiedlicher Luftraumsektoren mit vergleichbaren operativen Randbedingungen wesentlich erleichtern. Zuerst wurden die Veränderungen der Arbeitsbelastung und -die Tätigkeiten der Lotsen unter Verwendung einer Varianzanalyse untersucht. Um eine valide Zuordnung zu den Komplexitätsfaktoren sicherzustellen, war es ebenfalls notwendig, die Veränderungen dieser Faktoren und Tätigkeiten unter wechselnden Randbedingungen zu analysieren. Die Analysen zeigen hierbei unterschiedliche Resultate bezüglich der jeweiligen Komplexitätsfaktoren. So beeinflussen die verschiedenen Komplexitätsfaktoren die Handlungsabläufe der Lotsen und die wahrgenommene Arbeitsbelastung, jedoch in Abhängigkeit von den ausgewählten Sektoren und den betrieblichen Randbedingungen. Unter Berücksichtigung dieser erarbeiteten Abhängigkeiten der Arbeitsbelastung des Lotsen können nun die Auswirkungen von Veränderungen im Luftraum zuverlässig bestimmt werden. Gerade in Bezug auf Veränderungen der gegenwärtigen Luftraumstruktur oder die Einführung neuer Prozeduren oder Arbeitsabläufe können die entwickelten Komplexitätsfaktoren bereits frühzeitig Aufschluss darüber geben, welche Konsequenzen solche Veränderungen auf die Arbeitsbelastung der Lotsen nach sich ziehen können und Entscheidungsprozesse unterstützen. Weiterhin sind die entwickelten Komplexitätsfaktoren als Grundlage für die Validierung neuer Konzepte und Technologien, gegebenenfalls unter Verwendung von entwickelten Simulationsszenarien, nutzbar. Darüber hinaus können die Komplexitätsfaktoren für die Gegenüberstellung von verschiedenen Luftraumsektoren genutzt werden und zur Abwägung bzw. Optimierung von Entwürfen eines Luftraumdesigns dienen
Ndoye, Falou. "Ordonnancement temps réel préemptif multiprocesseur avec prise en compte du coût du système d’exploitation." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112056/document.
Full textIn this thesis we studied the problem of multiprocessor preemptive real-time scheduling taking into account the exact cost of the operating system (OS). This cost is composed of two parts: a part easy to determine, corresponding to the scheduler cost and another part difficult to determine, corresponding to the preemption cost. This difficulty is due to the fact that a preemption can involve another one, being able to so create an avalanche phenomenon. First, we studied the off-line multiprocessor real-time scheduling of independent tasks taking into account the exact preemption cost. We proposed a schedulability analysis based on a multiprocessor scheduling heuristic. This heuristic uses the partitioned multiprocessor scheduling approach. In order to take into account the exact preemption cost on every processor we use the schedulability condition proposed by Meumeu and Sorel. This schedulability condition for fixed priorities tasks, is based on a binary scheduling operation which counts the exact number of preemptions and add their cost in the schedulability analysis. The proposed heuristic maximizes the remaining utilization factor to fairly distribute the tasks on processors and to reduce their response time. It produces an off-line scheduling table. Secondly, we studied the off-line multiprocessor real-time scheduling of dependent tasks taking into account the exact preemption cost. Because the schedulability condition used for scheduling independent tasks can be applied only to fixed priorities tasks, it does not allow to manage priorities inversions that are involved by dependent tasks. We proposed a new schedulability condition for dependent tasks which enables fixed and dynamic priorities. This schedulability condition takes into account the exact preemption cost and dependences between tasks without any loss of data. Always with the partitioned scheduling approach, we proposed for dependent tasks a multiprocessor scheduling heuristic which reuses, on every processor, the schedulability condition proposed previously. In addition, this scheduling heuristic takes into account the interprocessors communication costs. It also minimizes on every processor the makespan (total execution time of the tasks on all the processors). This heuristic produces for every processor an off-line scheduling table. Supposing that we have a time-triggered multiprocessor architecture such that all the processors have a unique time reference, we proposed for every processor an on-line scheduler which uses the scheduling table produced during the off-line schedulability analysis. This on-line scheduler has the advantage to have a constant cost that is easy to determine exactly.Indeed, this cost corresponds only to the time necessary to read in the scheduling table the task selected for execution. In the on-line classical scheduler, this cost corresponds to the time necessary to update the list of ready tasks in order to select a task, according to a given scheduling algorithm, for example RM, DM, EDF, etc. In this case, the cost for selecting a task varies with the number of ready tasks which changes from an invocation of the scheduler to another one. Another advantage of the proposed on-line scheduler is that it is not necessary to synchronize the access to the data shared by several tasks, because this synchronization was already done during the off-line schedulability analysis
Davis, Robert Ian. "On exploiting spare capacity in hard real-time systems." Thesis, University of York, 1995. http://etheses.whiterose.ac.uk/10840/.
Full textFisher, Nathan Wayne Baruah Sanjoy K. "The multiprocessor real-time scheduling of general task systems." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,1108.
Full textTitle from electronic title page (viewed Mar. 27, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Computer Science." Discipline: Computer Science; Department/School: Computer Science.
Zhou, Hongyi. "Task scheduling and synchronization for multiprocessor real-time systems." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/9178.
Full textKivelevitch, Elad H. "Robust, Real Time, and Scalable Multi-Agent Task Allocation." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337007279.
Full textNaedele, Martin. "On the modeling and evaluation of real-time systems." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13564.
Full textKrauth, Elfriede Irene. "Real-time planning support : a task-technology fit perspective = Real-time planningsondersteuning : de afstemming tussen taak en technologie /." Rotterdam : Erasmus Universiteit, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?u20=97890589221932.
Full textSandnes, Frode Eika. "New approaches to static task graph scheduling for control." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362290.
Full textEkberg, Pontus. "Models and Complexity Results in Real-Time Scheduling Theory." Doctoral thesis, Uppsala universitet, Avdelningen för datorteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267017.
Full texthu, xiaoxiang. "Analysis of Time-related Properties in Real-time Data Aggregation Design." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-39046.
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