6,735 research outputs found

    Graduate Catalog of Studies, 2023-2024

    Get PDF

    Graduate Catalog of Studies, 2023-2024

    Get PDF

    Resource-aware scheduling for 2D/3D multi-/many-core processor-memory systems

    Get PDF
    This dissertation addresses the complexities of 2D/3D multi-/many-core processor-memory systems, focusing on two key areas: enhancing timing predictability in real-time multi-core processors and optimizing performance within thermal constraints. The integration of an increasing number of transistors into compact chip designs, while boosting computational capacity, presents challenges in resource contention and thermal management. The first part of the thesis improves timing predictability. We enhance shared cache interference analysis for set-associative caches, advancing the calculation of Worst-Case Execution Time (WCET). This development enables accurate assessment of cache interference and the effectiveness of partitioned schedulers in real-world scenarios. We introduce TCPS, a novel task and cache-aware partitioned scheduler that optimizes cache partitioning based on task-specific WCET sensitivity, leading to improved schedulability and predictability. Our research explores various cache and scheduling configurations, providing insights into their performance trade-offs. The second part focuses on thermal management in 2D/3D many-core systems. Recognizing the limitations of Dynamic Voltage and Frequency Scaling (DVFS) in S-NUCA many-core processors, we propose synchronous thread migrations as a thermal management strategy. This approach culminates in the HotPotato scheduler, which balances performance and thermal safety. We also introduce 3D-TTP, a transient temperature-aware power budgeting strategy for 3D-stacked systems, reducing the need for Dynamic Thermal Management (DTM) activation. Finally, we present 3QUTM, a novel method for 3D-stacked systems that combines core DVFS and memory bank Low Power Modes with a learning algorithm, optimizing response times within thermal limits. This research contributes significantly to enhancing performance and thermal management in advanced processor-memory systems

    The Application of Data Analytics Technologies for the Predictive Maintenance of Industrial Facilities in Internet of Things (IoT) Environments

    Get PDF
    In industrial production environments, the maintenance of equipment has a decisive influence on costs and on the plannability of production capacities. In particular, unplanned failures during production times cause high costs, unplanned downtimes and possibly additional collateral damage. Predictive Maintenance starts here and tries to predict a possible failure and its cause so early that its prevention can be prepared and carried out in time. In order to be able to predict malfunctions and failures, the industrial plant with its characteristics, as well as wear and ageing processes, must be modelled. Such modelling can be done by replicating its physical properties. However, this is very complex and requires enormous expert knowledge about the plant and about wear and ageing processes of each individual component. Neural networks and machine learning make it possible to train such models using data and offer an alternative, especially when very complex and non-linear behaviour is evident. In order for models to make predictions, as much data as possible about the condition of a plant and its environment and production planning data is needed. In Industrial Internet of Things (IIoT) environments, the amount of available data is constantly increasing. Intelligent sensors and highly interconnected production facilities produce a steady stream of data. The sheer volume of data, but also the steady stream in which data is transmitted, place high demands on the data processing systems. If a participating system wants to perform live analyses on the incoming data streams, it must be able to process the incoming data at least as fast as the continuous data stream delivers it. If this is not the case, the system falls further and further behind in processing and thus in its analyses. This also applies to Predictive Maintenance systems, especially if they use complex and computationally intensive machine learning models. If sufficiently scalable hardware resources are available, this may not be a problem at first. However, if this is not the case or if the processing takes place on decentralised units with limited hardware resources (e.g. edge devices), the runtime behaviour and resource requirements of the type of neural network used can become an important criterion. This thesis addresses Predictive Maintenance systems in IIoT environments using neural networks and Deep Learning, where the runtime behaviour and the resource requirements are relevant. The question is whether it is possible to achieve better runtimes with similarly result quality using a new type of neural network. The focus is on reducing the complexity of the network and improving its parallelisability. Inspired by projects in which complexity was distributed to less complex neural subnetworks by upstream measures, two hypotheses presented in this thesis emerged: a) the distribution of complexity into simpler subnetworks leads to faster processing overall, despite the overhead this creates, and b) if a neural cell has a deeper internal structure, this leads to a less complex network. Within the framework of a qualitative study, an overall impression of Predictive Maintenance applications in IIoT environments using neural networks was developed. Based on the findings, a novel model layout was developed named Sliced Long Short-Term Memory Neural Network (SlicedLSTM). The SlicedLSTM implements the assumptions made in the aforementioned hypotheses in its inner model architecture. Within the framework of a quantitative study, the runtime behaviour of the SlicedLSTM was compared with that of a reference model in the form of laboratory tests. The study uses synthetically generated data from a NASA project to predict failures of modules of aircraft gas turbines. The dataset contains 1,414 multivariate time series with 104,897 samples of test data and 160,360 samples of training data. As a result, it could be proven for the specific application and the data used that the SlicedLSTM delivers faster processing times with similar result accuracy and thus clearly outperforms the reference model in this respect. The hypotheses about the influence of complexity in the internal structure of the neuronal cells were confirmed by the study carried out in the context of this thesis

    Towards a centralized multicore automotive system

    Get PDF
    Today’s automotive systems are inundated with embedded electronics to host chassis, powertrain, infotainment, advanced driver assistance systems, and other modern vehicle functions. As many as 100 embedded microcontrollers execute hundreds of millions of lines of code in a single vehicle. To control the increasing complexity in vehicle electronics and services, automakers are planning to consolidate different on-board automotive functions as software tasks on centralized multicore hardware platforms. However, these vehicle software services have different and contrasting timing, safety, and security requirements. Existing vehicle operating systems are ill-equipped to provide all the required service guarantees on a single machine. A centralized automotive system aims to tackle this by assigning software tasks to multiple criticality domains or levels according to their consequences of failures, or international safety standards like ISO 26262. This research investigates several emerging challenges in time-critical systems for a centralized multicore automotive platform and proposes a novel vehicle operating system framework to address them. This thesis first introduces an integrated vehicle management system (VMS), called DriveOSℱ, for a PC-class multicore hardware platform. Its separation kernel design enables temporal and spatial isolation among critical and non-critical vehicle services in different domains on the same machine. Time- and safety-critical vehicle functions are implemented in a sandboxed Real-time Operating System (OS) domain, and non-critical software is developed in a sandboxed general-purpose OS (e.g., Linux, Android) domain. To leverage the advantages of model-driven vehicle function development, DriveOS provides a multi-domain application framework in Simulink. This thesis also presents a real-time task pipeline scheduling algorithm in multiprocessors for communication between connected vehicle services with end-to-end guarantees. The benefits and performance of the overall automotive system framework are demonstrated with hardware-in-the-loop testing using real-world applications, car datasets and simulated benchmarks, and with an early-stage deployment in a production-grade luxury electric vehicle

    Effects of the COVID-19 Pandemic on Manufacturing Companies' Supply Chain Management in Finland

    Get PDF
    The COVID-19 outbreak shocked the whole world in 2020. As the pandemic quickly spread across the globe, only during its first year, over 75 million positive cases and 1,6 million deaths were reported worldwide, and in November 2022, the same numbers were over 634 million and 6,6 million. The world’s economic system and global markets were greatly affected, and many countries tried to counter the pandemic’s spread by implementing strict lockdowns, which further caused turbulence on the markets. Countless manufacturing companies across the globe were faced with massive global supply chain disruptions, and they were felt even in companies operating in Finland. Managers and scholars alike have been working very hard for the past three years to find out what were (and are) the best countermeasures to combat the pandemic’s effects and disruptions, but a consensus of an answer is still missing. This thesis aims to investigate the effects of the COVID-19 pandemic on manufacturing companies operating in Finland, and to examine what kind of ways or methods these companies adopted to counter the COVID-19 pandemic in Finland compared to the rest of the world. These two topics form the two main research questions of this thesis, and they are answered from the basis of a qualitative systematic literature review and a mostly qualitative semi-structured interview study to which interviewees from six different manufacturing companies take part in. The literature review consists of supply chain management theory and a look into the effects of the COVID-19 pandemic on manufacturing companies operating outside of Finland. The literature review is also used to build a theoretical framework, which is used in the end to analyse the results of the interview study and compare them to the findings of the literature review. The results of this thesis offer insight into the differences of the COVID-19 pandemic’s impacts on the supply chain management of manufacturing companies operating in Finland and outside of Finland, and the different supply chain management related countermeasures taken by these companies. From the literature review, it was discovered that global supply shortages, large-scale fluctuations in demand, consumption shocks, and increases in material prices and lead times were some of the most recognizable effects of the COVID-19 pandemic on the manufacturing companies operating outside of Finland, often affecting directly to their operations and Tier 1 suppliers. The interview results reflected similar results, only the companies operating in Finland mostly experienced the pandemic’s effects through their suppliers’ suppliers’ problems, which were usually operating outside of Finland. Also, the companies that were located in countries that went into lockdowns had their own challenges as well. To counter the global supply chain disruptions, both the interview study and the literature review provided similar findings: the realization of the necessity of evolving the existing supply chain management from lean thinking to a more agile and resilient system became evident for those that hadn’t already done so. Differences in the ways of attempting to accomplish this were found, but the goal was still very similar for most of the companies

    Rethink Digital Health Innovation: Understanding Socio-Technical Interoperability as Guiding Concept

    Get PDF
    Diese Dissertation sucht nach einem theoretischem GrundgerĂŒst, um komplexe, digitale Gesundheitsinnovationen so zu entwickeln, dass sie bessere Erfolgsaussichten haben, auch in der alltĂ€glichen Versorgungspraxis anzukommen. Denn obwohl es weder am Bedarf von noch an Ideen fĂŒr digitale Gesundheitsinnovationen mangelt, bleibt die Flut an erfolgreich in der Praxis etablierten Lösungen leider aus. Dieser unzureichende Diffusionserfolg einer entwickelten Lösung - gern auch als Pilotitis pathologisiert - offenbart sich insbesondere dann, wenn die geplante Innovation mit grĂ¶ĂŸeren Ambitionen und KomplexitĂ€t verbunden ist. Dem geĂŒbten Kritiker werden sofort ketzerische Gegenfragen in den Sinn kommen. Beispielsweise was denn unter komplexen, digitalen Gesundheitsinnovationen verstanden werden soll und ob es ĂŒberhaupt möglich ist, eine universale Lösungsformel zu finden, die eine erfolgreiche Diffusion digitaler Gesundheitsinnovationen garantieren kann. Beide Fragen sind nicht nur berechtigt, sondern mĂŒnden letztlich auch in zwei ForschungsstrĂ€nge, welchen ich mich in dieser Dissertation explizit widme. In einem ersten Block erarbeite ich eine Abgrenzung jener digitalen Gesundheitsinnovationen, welche derzeit in Literatur und Praxis besondere Aufmerksamkeit aufgrund ihres hohen Potentials zur Versorgungsverbesserung und ihrer resultierenden KomplexitĂ€t gewidmet ist. Genauer gesagt untersuche ich dominante Zielstellungen und welche Herausforderung mit ihnen einhergehen. Innerhalb der Arbeiten in diesem Forschungsstrang kristallisieren sich vier Zielstellungen heraus: 1. die UnterstĂŒtzung kontinuierlicher, gemeinschaftlicher Versorgungsprozesse ĂŒber diverse Leistungserbringer (auch als inter-organisationale Versorgungspfade bekannt); 2. die aktive Einbeziehung der Patient:innen in ihre Versorgungsprozesse (auch als Patient Empowerment oder Patient Engagement bekannt); 3. die StĂ€rkung der sektoren-ĂŒbergreifenden Zusammenarbeit zwischen Wissenschaft und Versorgungpraxis bis hin zu lernenden Gesundheitssystemen und 4. die Etablierung daten-zentrierter Wertschöpfung fĂŒr das Gesundheitswesen aufgrund steigender bzgl. VerfĂŒgbarkeit valider Daten, neuen Verarbeitungsmethoden (Stichwort KĂŒnstliche Intelligenz) sowie den zahlreichen Nutzungsmöglichkeiten. Im Fokus dieser Dissertation stehen daher weniger die autarken, klar abgrenzbaren Innovationen (bspw. eine Symptomtagebuch-App zur Beschwerdedokumentation). Vielmehr adressiert diese Doktorarbeit jene Innovationsvorhaben, welche eine oder mehrere der o.g. Zielstellung verfolgen, ein weiteres technologisches Puzzleteil in komplexe Informationssystemlandschaften hinzufĂŒgen und somit im Zusammenspiel mit diversen weiteren IT-Systemen zur Verbesserung der Gesundheitsversorgung und/ oder ihrer Organisation beitragen. In der Auseinandersetzung mit diesen Zielstellungen und verbundenen Herausforderungen der Systementwicklung rĂŒckte das Problem fragmentierter IT-Systemlandschaften des Gesundheitswesens in den Mittelpunkt. Darunter wird der unerfreuliche Zustand verstanden, dass unterschiedliche Informations- und Anwendungssysteme nicht wie gewĂŒnscht miteinander interagieren können. So kommt es zu Unterbrechungen von InformationsflĂŒssen und Versorgungsprozessen, welche anderweitig durch fehleranfĂ€llige ZusatzaufwĂ€nde (bspw. Doppeldokumentation) aufgefangen werden mĂŒssen. Um diesen EinschrĂ€nkungen der EffektivitĂ€t und Effizienz zu begegnen, mĂŒssen eben jene IT-System-Silos abgebaut werden. Alle o.g. Zielstellungen ordnen sich dieser defragmentierenden Wirkung unter, in dem sie 1. verschiedene Leistungserbringer, 2. Versorgungsteams und Patient:innen, 3. Wissenschaft und Versorgung oder 4. diverse Datenquellen und moderne Auswertungstechnologien zusammenfĂŒhren wollen. Doch nun kommt es zu einem komplexen Ringschluss. Einerseits suchen die in dieser Arbeit thematisierten digitalen Gesundheitsinnovationen Wege zur Defragmentierung der Informationssystemlandschaften. Andererseits ist ihre eingeschrĂ€nkte Erfolgsquote u.a. in eben jener bestehenden Fragmentierung begrĂŒndet, die sie aufzulösen suchen. Mit diesem Erkenntnisgewinn eröffnet sich der zweite Forschungsstrang dieser Arbeit, der sich mit der Eigenschaft der 'InteroperabilitĂ€t' intensiv auseinandersetzt. Er untersucht, wie diese Eigenschaft eine zentrale Rolle fĂŒr Innovationsvorhaben in der Digital Health DomĂ€ne einnehmen soll. Denn InteroperabilitĂ€t beschreibt, vereinfacht ausgedrĂŒckt, die FĂ€higkeit von zwei oder mehreren Systemen miteinander gemeinsame Aufgaben zu erfĂŒllen. Sie reprĂ€sentiert somit das Kernanliegen der identifizierten Zielstellungen und ist Dreh- und Angelpunkt, wenn eine entwickelte Lösung in eine konkrete Zielumgebung integriert werden soll. Von einem technisch-dominierten Blickwinkel aus betrachtet, geht es hierbei um die GewĂ€hrleistung von validen, performanten und sicheren Kommunikationsszenarien, sodass die o.g. InformationsflussbrĂŒche zwischen technischen Teilsystemen abgebaut werden. Ein rein technisches InteroperabilitĂ€tsverstĂ€ndnis genĂŒgt jedoch nicht, um die Vielfalt an Diffusionsbarrieren von digitalen Gesundheitsinnovationen zu umfassen. Denn beispielsweise das Fehlen adĂ€quater VergĂŒtungsoptionen innerhalb der gesetzlichen Rahmenbedingungen oder eine mangelhafte PassfĂ€higkeit fĂŒr den bestimmten Versorgungsprozess sind keine rein technischen Probleme. Vielmehr kommt hier eine Grundhaltung der Wirtschaftsinformatik zum Tragen, die Informationssysteme - auch die des Gesundheitswesens - als sozio-technische Systeme begreift und dabei Technologie stets im Zusammenhang mit Menschen, die sie nutzen, von ihr beeinflusst werden oder sie organisieren, betrachtet. Soll eine digitale Gesundheitsinnovation, die einen Mehrwert gemĂ€ĂŸ der o.g. Zielstellungen verspricht, in eine existierende Informationssystemlandschaft der Gesundheitsversorgung integriert werden, so muss sie aus technischen sowie nicht-technischen Gesichtspunkten 'interoperabel' sein. Zwar ist die Notwendigkeit von InteroperabilitĂ€t in der Wissenschaft, Politik und Praxis bekannt und auch positive Bewegungen der DomĂ€ne hin zu mehr InteroperabilitĂ€t sind zu verspĂŒren. Jedoch dominiert dabei einerseits ein technisches VerstĂ€ndnis und andererseits bleibt das Potential dieser Eigenschaft als Leitmotiv fĂŒr das Innovationsmanagement bislang weitestgehend ungenutzt. An genau dieser Stelle knĂŒpft nun der Hauptbeitrag dieser Doktorarbeit an, in dem sie eine sozio-technische Konzeptualisierung und Kontextualisierung von InteroperabilitĂ€t fĂŒr kĂŒnftige digitale Gesundheitsinnovationen vorschlĂ€gt. Literatur- und expertenbasiert wird ein Rahmenwerk erarbeitet - das Digital Health Innovation Interoperability Framework - das insbesondere Innovatoren und Innovationsfördernde dabei unterstĂŒtzen soll, die Diffusionswahrscheinlichkeit in die Praxis zu erhöhen. Nun sind mit diesem Framework viele Erkenntnisse und Botschaften verbunden, die ich fĂŒr diesen Prolog wie folgt zusammenfassen möchte: 1. Um die Entwicklung digitaler Gesundheitsinnovationen bestmöglich auf eine erfolgreiche Integration in eine bestimmte Zielumgebung auszurichten, sind die Realisierung eines neuartigen Wertversprechens sowie die GewĂ€hrleistung sozio-technischer InteroperabilitĂ€t die zwei zusammenhĂ€ngenden Hauptaufgaben eines Innovationsprozesses. 2. Die GewĂ€hrleistung von InteroperabilitĂ€t ist eine aktiv zu verantwortende Managementaufgabe und wird durch projektspezifische Bedingungen sowie von externen und internen Dynamiken beeinflusst. 3. Sozio-technische InteroperabilitĂ€t im Kontext digitaler Gesundheitsinnovationen kann ĂŒber sieben, interdependente Ebenen definiert werden: Politische und regulatorische Bedingungen; Vertragsbedingungen; Versorgungs- und GeschĂ€ftsprozesse; Nutzung; Information; Anwendungen; IT-Infrastruktur. 4. Um InteroperabilitĂ€t auf jeder dieser Ebenen zu gewĂ€hrleisten, sind Strategien differenziert zu definieren, welche auf einem Kontinuum zwischen KompatibilitĂ€tsanforderungen aufseiten der Innovation und der Motivation von Anpassungen aufseiten der Zielumgebung verortet werden können. 5. Das Streben nach mehr InteroperabilitĂ€t fördert sowohl den nachhaltigen Erfolg der einzelnen digitalen Gesundheitsinnovation als auch die Defragmentierung existierender Informationssystemlandschaften und trĂ€gt somit zur Verbesserung des Gesundheitswesens bei. Zugegeben: die letzte dieser fĂŒnf Botschaften trĂ€gt eher die FĂ€rbung einer Überzeugung, als dass sie ein Ergebnis wissenschaftlicher BeweisfĂŒhrung ist. Dennoch empfinde ich diese, wenn auch persönliche Erkenntnis als Maxim der DomĂ€ne, der ich mich zugehörig fĂŒhle - der IT-Systementwicklung des Gesundheitswesens

    Firefighters\u27 Perceptions and Experiences of Seeking Mental Health Treatment Services

    Get PDF
    Firefighters are repeatedly exposed to trauma on the job, which could result in the need for mental health services; however, many firefighters experience barriers that impede their access to available resources. Additional research is needed from a qualitative lens on firefighters\u27 help-seeking behaviors to inform the development of treatment interventions. The purpose of this study was to explore firefighters’ perceptions and experiences of seeking professional mental health treatment services. A generic qualitative approach and interpretive lens were used for the investigation. Twelve active U.S. firefighters with a minimum of 2 years on the job participated in semistructured interviews. Thematic analysis yielded five themes: (a) trauma exposure, (b) fire service culture, (c) perceptions of available resources, (d) financial burden, and (e) the role of interpersonal relationships in seeking help. Participants reported various barriers to seeking help: their perceptions of support, stigma, access to treatment, availability of services, and financial costs. Additionally, participants had mixed views on employee assistance programs, specifically in regard to confidentiality protections and availability of competent clinicians. Understanding the perceptions and experiences of firefighters related to seeking mental health treatment may empower firefighters by giving them a platform to have their voices heard, inform clinicians on how to tailor treatment, and alert policy makers about the need to make resources available to this population. Positive social change implications include improved access to resources and decreased stigma
    • 

    corecore