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Ontologies et web sémantique pour une construction évolutive d'applications dédiées à la logistique / Ontologies and semantic web for an evolutive development of logistic applicationsHendi, Hayder 04 December 2017 (has links)
Le domaine de la logistique implique souvent la résolution de problèmes combinatoires complexes. Ces derniers font également implicitement référence à des processus, acteurs, activités et méthodes concernant divers aspects qu'il faut considérer. Ainsi, un même problème peut faire intervenir des processus de vente/achat, transport/livraison et gestion de stock. Ces processus sont tellement divers et interconnectés qu'il est difficile pour un logisticien de tous les maîtriser. Dans cette thèse, nous proposons l'explicitation, par le biais d'ontologies, de connaissances conceptuelles et sémantiques concernant les processus logistiques. Ces connaissances explicites sont alors mises à contribution pour construire un système à base de connaissances permettant de guider les logisticiens dans la construction, de façon incrémentale et semi-automatique, de solutions informatiques à un problème qui leur est posé à un moment donné. Nous mettons en oeuvre une ontologie concernant le domaine de la logistique connectée à une ontologie associée à la problématique de l'optimisation. Nous établissons ainsi un lien sémantique explicite entre le domaine de la logistique et celui de l'optimisation. Cela permet aux logisticiens d'identifier de façon précise et sans ambigüité le problème logistique auquel il est confronté et les problèmes d'optimisation associés. L'identification des problèmes conduit alors à un processus de choix des solutions allant du choix du processus logistique précis à mettre en oeuvre à celui de la méthode de résolution du problème combinatoire et cela jusqu'à la découverte du composant informatique à invoquer et qui est matérialisé par un service web. L'approche que nous avons adoptée et mise en oeuvre a été expérimentée avec les problèmes de routage de véhicules, le problème de transport ferroviaire de passagers et le problème de terminaux de conteneurs. / Logistics problems are often complex combinatorial problems. These may also implicitly refer to the processes, actors, activities, and methods concerning various aspects that need to be considered. Thus the same process may involve the processes of sale/purchase, transport/delivery, and stock management. These processes are so diverse and interconnected that it is difficult for a logistic expert to compete all of them. In this thesis, we propose the explications with the help of ontologies of conceptual ans semantic knowledge concerning the logistic processes. This explicit knowledge is then used to develop a reasoning system to guide the logistic expert for an incremental and semi-automatic construction of a software solution to an instantly posed problem. We define an ontology concerning the inter-connected logistics and associated optimization problem. We, henceforth, establish an explicit semantic link between the domains of logistics and the optimization. It may allow the logistic expert to identify precisely and unambiguously the confronted logistic problem and the associated optimization problem. The identification of the problems then leads to a process to choose the solutions ranging from the choice of the precise logistic process to be implemented to that of the method to solve the combinatorial problem until the discovery of the software component to be invoked and which is implemented by a web service. The approach we have adopted and implemented has been experimented with the "Vehicle Routing Problems", the "Passenger Train Problem" and the "Container Terminal problems".
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A Cloud-based business continuity framework for container terminal operations: A South African case studyKutame, Felix Nyadzani January 2020 (has links)
PhD (Business Management) / Department of Business Management / Contemporary cloud-based computing is crucial for the efficient delivery of ICT systems to users, as well as for versatile disaster recovery and business continuity management (BCM) platforms. Based on the need for efficient and fault-tolerant port operations, this study proposes a cloud-based business continuity framework (BCM) for the container terminal operations (CTO) in South Africa. The study examined the impact of ICT systems and services on Container Terminal Operations (CTO); determined Critical Business Functions in operations that must stay operational and analysed the impact of the unavailability of ICT systems and services on critical operations. This empirical study employed both quantitative and qualitative research designs and collecting data through self-constructed and self-administered questionnaires and interviews. Quantitative data was analysed using the IBM Statistical Package of Social Science (SPSS) Version 23 while qualitative data was analysed through thematic analysis of interviews. Results show that to realize effective organizational resilience using BCM, three insights, as underlying mechanisms for assimilating cloud computing in BCM can be inferred: the first is that a digitalized BCM architecture ‘fits’ the cloud computing model. The specific BCM characteristics that befits cloud computing are continuous data processing; continuous data access and delivery; multi-platform data access; always – on ICT Services; and better decision making. Secondly, the cloud computing model is a ‘viable’ model that can contribute to managing complex organizations characterized by business units that are highly differentiated in terms of size, structure, ICT and investment levels. For such complex organizations, viability is visible in terms of how the multi-units can harness collective intelligence (CI) for more effective BCM. Collective intelligence, as a form of universally distributed intelligence that is constantly enhanced, coordinated in real time, and which results in effective mobilization of organizational competence, is a core organizing metaphor for achieving BCM in a complex organization. Lastly, to realize BCM, underpinned by greater digitalization of BCM and harnessing of CI; there is need for rethinking strategy towards adoption of an ‘Intelliport strategy’ or ‘smart’ BCM for ports, currently intertwined with the notion of the 4IR. That the ‘smart’ nature of BCM require the assimilation of 4IR technologies that enable ubiquitous presence and real time information regarding organizational processes. Adopting an ‘Intelliport strategy’ is likely to have two main implications for BCM and practice: the first is linked to the development of a circular economy, in which aggregation of BCM activities can enhance sustainable development of the seaports; and secondly, adoption of a cloud computing model that can result in the enhancement of business growth of the units promote collaborative problem solving and decision making in BCM. / NRF
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Prüfung von Flexitanksystemen mittels Bahnauflaufversuchen unter Berücksichtigung des SchockantwortspektrumsHartwig, Peter 11 November 2013 (has links)
Die vorliegende Arbeit befasst sich mit der Weiterentwicklung eines Prüfregelwerks für Flexitanksysteme hinsichtlich des durchzuführenden Bahnauflaufstoßes. Während eines solchen Versuchs wird das Flexitanksystem, bestehend aus einem herkömmlichen Seefrachtcontainer und beladen mit einem wassergefüllten Folientank sowie einiger Zusatzeinrichtungen, auf einem Tragwagen verankert und anschließend einer intensiven Stoßbelastung ausgesetzt. Der Nachweis der Dichtigkeit des Tanks und die Einhaltung diverser Verformungsgrenzwerte am Container entscheiden über den Ausgang des Versuchs. Während die Arbeit auch diese Punkte aufgreift, liegt der eigentliche Schwerpunkt in der Auseinandersetzung mit derjenigen Beurteilungsgröße, welche die Erfüllung der Prüfanforderungen bestimmt.
Derzeit wird dieses Prüfkriterium über eine Beschleunigungsamplitude definiert, was allerdings eine gewisse Unschärfe mit sich bringt. Die Prüfmethodik und ihre Entwicklungsgeschichte, sowie die damit einhergehenden Nachteile werden im Detail erläutert und eine Möglichkeit der Erweiterung des Kriteriums mithilfe des Schockantwortspektrums geboten. Als Beurteilungsgröße für die dynamische Prüfung von Tankcontainern bereits fest etabliert, wird dieses mathematische Analysewerkzeug in allen Einzelheiten vorgestellt und dessen Eignung für die Anwendung im Bahnauflaufstoß für Flexitanksysteme untersucht. Zu diesem Zweck wird ein Simulationsmodell entwickelt, mit dessen Hilfe eine ausführliche Parameteranalyse durchgeführt und deren Ergebnisse Versuchsmessungen gegenübergestellt werden. Die Schlussfolgerungen münden in einem dem Flexitanksystem angepassten Prüfkriterium auf Basis des Schockantwort-spektrums, welches in Form eines Regelwerksentwurfs den entscheidungsberechtigten Gremien vorgeschlagen wird.
Die Inhalte der drei Hauptkapitel der Dissertation können in folgenden Punkten zusammengefasst werden:
Das Flexitanksystem wird vorgestellt, der Auflaufversuch erläutert und diskutiert sowie Versuchsergebnisse präsentiert und nach verschiedenen Gesichtspunkten analysiert.
Das Schockantwortspektrum wird hergeleitet, dessen Charakteristika herausgestellt und deren Anwendung an praktischen Beispielen demonstriert.
Die Eignung des Schockantwortspektrums zur Beurteilung von Auflaufstößen mit Flexitanksystem wird überprüft, die Einflussfaktoren in einer Parameteranalyse durchleuchtet und die Ergebnisse in die Definition eines neuen Prüfkriteriums eingeflochten.
Die Dissertation entstand im Rahmen eines Fördermittelprojekts des Europäischen Sozialfonds und in Kooperation mit der Prüfanlage der TÜV SÜD Rail GmbH in Görlitz.
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Exponering av luftföroreningar : -vid arbete i hamnmagasin / Occupational exposure to air pollution : -at port warehouseNordgren, Susanne January 2015 (has links)
Syftet med examensarbetet var att översiktligt undersöka vilka hälsofarliga luftföroreningarsom medarbetarna vid hamnmagasinen eventuellt exponeras föroch huruvida något hygieniskt gränsvärde riskerade att överskridas samt att seom de skyddsåtgärder som vidtagits kan förbättras. Resultatet från studien visaratt det finns vissa exponeringsrisker för de som arbetar vid hamnen både frångods, dieselavgaser samt rester av gasbehandlingsmedel i containrar.Arbetsmomenten där truckföraren befinner sig inne i trucken bedöms somrelativt skyddat både från partiklar och gaser, men det finns andra arbetsuppgifterdär arbetaren inte är lika skyddad. Mätningarna av kvävedioxid visadeatt exponeringen av dieselavgaser för den medarbetare som öppnadecontainrarna inte översteg några hygieniska gränsvärden, under de dagar sommätningarna genomfördes, men var något högre än för truckföraren som satt ihytten. Huruvida exponeringen av damm från gods riskerar att utvecklas tillhälsoproblem är omöjligt att avgöra utan en grundlig riskbedömning, därdammätningar kan ge en fingervisning om hur riskfylld situationen är för desom eventuellt exponeras.Organisationen bör implementera säkrare rutiner och genomföra åtgärder sommotiverar medarbetarna att använda befintlig skyddsutrustning. Det gäller intebara för exponering av dieselavgaser och damm från lossning och lastning avgods utan även vid öppnandet av containrar där rester av gasbehandlingsmedelkan finnas kvar i containern och där några ämnen misstänkts varacancerframkallande.Slutsatser: Genomföra en grundlig riskbedömning och kartlägga möjliga hälsoriskerkring luftföroreningar. Upprätta skriftliga arbetsbeskrivningar där eventuella risker föreligger. Installera ventilation i magasinen som styrs av halten kvävedioxid för attsäkerställa att höga halter av dieselavgaser inte uppstår. Behov av motivationshöjande insatser kring säkerhetskultur ochanvändningen av skyddsutrustning. Implementera fungerande rutiner som följer lagstiftningen förhanteringen av damm och gaser som gäller för cancerframkallandeämnen. / The purpose of this thesis was to examine the risk of hazardous air pollutantsthat employees at the harbor may be exposed to and assess whether anyexposure limits might be exceeded, and to review if the security measures taken,can be improved. The results of the study show that there is some risk ofexposure for those working in the harbor from both the cargo, diesel exhaustand residues from fumigants in the containers. The operations when the truckdriver is inside the forklift is considered relatively protected from both particlesand gases, but there are other tasks where the worker is not as protected.Measurements of nitrogen dioxide showed that exposure to diesel exhaust forthe employee who opened the containers during the days that the measurementswere performed did not exceed some critical values, but was slightly higherthan for the driver who was sitting in the forklift. Whether the exposure to dust,from the cargo, constitutes a risk for health effects is impossible to determinewithout a thorough risk assessment, where measurements of dust can give anindication of how risky the situation is for the exposed workers.The organization should implement safer practices and implementing measuresthat motivates employees to use existing protective equipment. This applies notonly for exposure to diesel exhaust and dust from loading and unloading ofgoods, but also at the opening the doors on the containers in which residues offumigants, in which some are suspected to be carcinogenic, can remain in thecontainer.Conclusions: Conduct a thorough risk assessment and identify potential health riskswith air pollution. Establish written work instructions where potential hazards exist. Install ventilation in the warehouses, which is controlled by the levels ofnitrogen dioxide, to ensure that high levels of diesel exhaust does notoccur. Need to increase motivation for safety and the use of protectiveequipment. Implement procedures to comply with the legislation for the managementof dust and gases that applies to carcinogens substances.
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Containertransport till sjöss : En studie av containerkrisen 2020-202X / Containertransport at sea : A study of the containercrisis 2020-202XMassini, Hashem, Papaioannou, Dominique Audrey Natalia January 2022 (has links)
Krisen i den globala leveranskedjan för containrar blev tydligt synlig 2020 och pågår fortfarande. Ett betydande avtryck har lämnats, inte bara på marknaden för containertransporter utan också på världsekonomin som helhet. Det kan därför vara fördelaktigt att få en djupare förståelse för de drivande faktorerna i denna kris för att kunna hantera bättre eller förhindra liknande utmaningar i framtiden. Syftet med denna studie var att identifiera och beskriva en kedja av händelser med deras bidragande faktorer och konsekvenser som leder till att containerkrisen börjar år 2020. Följande forskningsfrågor ställs: 1.Vilka är de mest bidragande faktorerna som störde balansen i containertransporter? 2.Hur påverkas sjöcontainertransporten och vilken roll har den händelsekedjan som resulterade i containerkrisen 2020-202X? En kvalitativ litteraturgenomgång genomfördes för denna studie. Dessutom bestod den datainsamlingsmetoden som användes för denna studie av sekundärt vetenskapligt material, men även icke-vetenskapliga artiklar, inklusive nyhetsdatabaser och maritima databaser. Studien identifierade de viktigaste bidragande faktorerna till containerkrisen att vara Covid-19 och Suezkanal incidenten. Vidare föreslås det även att handelskriget mellan Kina och USA har varit en bakomliggande orsak för denna kris. Konsekvenserna som fastställdes var bristen på tomma containrar, förändringar i efterfrågan av varor före och under pandemin och störningar i leveranskedjan där förseningar, överbelastning i hamnar och ekonomiska följder spelade roll i den globala handeln, särskilt containertransporter. / The crisis in the global container supply chain clearly became visible in 2020 and is still ongoing. An imprint has indeed been left not only on the markets of container shipping transport but also on the world economy as a whole. Therefore, it may be beneficial to gain an in-depth understanding of the driving factors of this crisis, that in order to be able to deal better or even prevent similar future challenges. The purpose of this study was therefore to identify and describe a chain of events with their contributing factors and consequences that lead to the start of the container crisis in 2020. This study’s research questions were: 1.What are the most important contributing factors that disrupted the balance in container transport? 2.How is maritime containertransport affected and what is the role of the chain of events that resulted in the container crisis 2020-202X? A qualitative literature review was conducted for this study. Moreover, the data collection method used for this paper consisted of secondary academic material, but also non-scientific articles, including news databases and maritime databases. This study has identified that the main contributing factors to the container crisis were the Covid-19 and the Suez channel. However, it is also suggested that the trade war between USA and China has also served as the backbone of this crisis. Moreover, the identified concequences were shortage in containers, changes in the demand of goods during and prior to the pandemic and in further, disruptions in the supply chain, including schedule delays, congestions in ports and financial consequences in the global trade, specifically that of container transport.
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Large-Eddy Simulation Modelling for Urban ScaleKönig, Marcel 07 April 2014 (has links)
In this work the model ASAM is enriched with new eddy viscosity based dynamic Smagorinsky subgrid-scale models. Therefore the model is more physically based to study atmospheric flow configurations at several atmospheric scales with main focus to urban scale flow with building-resolved resolution.
The implemented dynamic procedures work well and showed good agreement to literature data. In a convective atmospheric boundary layer (ABL) the dynamic Smagorinsky coefficient reaches maximum values of 0.15 and decreases towards the surface or in stable stratified flow regimes. Vertical profiles of the Smagorinsky coefficient in a diurnal cycle of ABL depict typical behaviour of the dynamic Smagorinsky coefficient in near surface flow, free-stream, or stable stratified flow.
Furthermore a modified inflow generation approach is proposed to produce fully turbulent flow fields. To modify a mean flow turbulent fluctuations are generated by superposition of sinusoidal and cosinesoidal modes. Due to the implementation of this inflow method the model ASAM has the ability to reproduce a given wind field with information from its mean wind speed and their fluctuation energy spectrum.
The model configuration developed in this work is able to reproduce flow structure in a complex urban geometry. The Mock Urban Setting Test (MUST) experiment represent an urban roughness geometry by placing 120 shipping containers ordinary arranged in an array. The used building-resolved resolution is able to capture dynamic flow structures like specific wake flow, recirculation regions or eddy detachment. The dynamic fluctuating behaviour of the wind velocity components is reproduced by the model with regard to peak magnitudes and their temporal occurrence. Satisfying agreement is found between tracer gas dispersion field measurements and the model results by capturing the fluctuating concentration magnitude and in some extend the mean values.:1 Introduction 1
2 Fundamentals of Large-Eddy Simulation in atmospheric boundary layers 7
2.1 The atmospheric boundary layer . . . . . . . . . . . . . . . . . . . . . 7
2.2 Atmospheric turbulence . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Basic equations of LES . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3 Subgrid-scale modelling 15
3.1 Eddy viscosity subgrid-scale models . . . . . . . . . . . . . . . . . . . 15
3.1.1 Smagorinsky subgrid-scale model . . . . . . . . . . . . . . . . 16
3.1.2 Dynamic Smagorinsky subgrid-scale model . . . . . . . . . . . 18
3.1.3 Scale-dependent dynamic Smagorinsky subgrid-scale model . . 23
3.2 Implementation in the All Scale Atmospheric Model (ASAM) . . . . . 26
3.2.1 General description of ASAM . . . . . . . . . . . . . . . . . . 26
3.2.2 Subgrid-scale modelling in ASAM . . . . . . . . . . . . . . . . 27
3.3 Applications to meteorological situations . . . . . . . . . . . . . . . . 37
3.3.1 Stable and unstable stratified atmospheric boundary layers . . 37
3.3.2 Flow over periodic sinusoidal hill . . . . . . . . . . . . . . . . 49
4 Generation of turbulent inflow conditions 51
4.1 The necessity of turbulent inflow . . . . . . . . . . . . . . . . . . . . 51
4.2 Synthetic turbulent inflow generation method . . . . . . . . . . . . . 53
4.3 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.4 2D simulation results . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5 Mock Urban Setting Test Experiment (MUST) 65
5.1 Micro-scale urban simulation . . . . . . . . . . . . . . . . . . . . . . . 65
5.2 Description of the experiment . . . . . . . . . . . . . . . . . . . . . . 68
5.3 Wind tunnel measurenments of MUST . . . . . . . . . . . . . . . . . 70
5.4 Numerical MUST simulation with ASAM . . . . . . . . . . . . . . . . 72
5.4.1 Choice of initial condition . . . . . . . . . . . . . . . . . . . . 75
5.4.2 Results of simulating case 2682353 . . . . . . . . . . . . . . . 81
5.4.3 Results of simulating case 2681829 . . . . . . . . . . . . . . . 98
5.4.4 Case resume . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6 Summary and outlook 111
6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
6.2 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
7 Bibliography 117
List of Figures 127
List of Tables 135
Acronyms 137
Nomenclature 139
Acknowledgement 143
List of Publications 145
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Container Orchestration : the Migration Path to KubernetesAndersson, Johan, Norrman, Fredrik January 2020 (has links)
As IT platforms grow larger and more complex, so does the underlying infrastructure. Virtualization is an essential factor for more efficient resource allocation, improving both the management and environmental impact. It allows more robust solutions and facilitates the use of IaC (infrastructure ascode). Many systems developed today consist of containerized microservices. Considered the standard of container orchestration, Kubernetes is the natural next step for many companies. But how do we move on from previous solutions to a Kubernetes cluster? We found that there are not a lot of detailed enough guidelines available, and set out to gain more knowledge by diving into the subject - implementing prototypes that would act as a foundation for a resulting guideline of how it can be done.
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Understanding The Impact Of Market demand For Paper And Paperboard On Swedish Ports : A scenario planning approachPersson, Hanna, Bodiroga, Dejan January 2023 (has links)
Background: The global marketplace is characterized by rapid and constantchange, resulting in complex logistics systems. The port industry, which is a crucial link in the supply chain, seeks to understand the complexity of market dynamics. Ports should understand the changing market dynamics to better meet the market demand and have a competitive advantage. One representative from the port industry is Swedish ports and the Port of Gothenburg, which will be the focus of this thesis. The market demand for paper and paperboard has been a significant driver of shipping activities in Swedish ports. The market demand for bulk and container shipping is also relevant due to its influence on the port’s operation. Furthermore, itis essential for port authorities to understand the demand-oriented infrastructure to develop strategies to meet the market dynamics. Purpose: This thesis has been undertaken on behalf of the PoG. The purpose of the thesis is to provide a clearer understanding of how the current and future market demand of paper and paperboard influence Swedish ports with scenario planning. Based on the future market demand for paper and paperboard, additional information of the future market demand for bulk and container will be included in the scenarios. By using the scenarios, recommendations will be given regarding investments the port authority at PoG needs to implement as a response to future paper and paperboard market demand. Methodology: The thesis has a qualitative case study with Port of Gothenburg as the study object. Data collection has been conducted through semi- and unstructuredinterviews from the Swedish forest industry, three forest companies and port authority at Port of Gothenburg. Additionally, scenario planning will be the main analysis method in this thesis. Conclusion: The current market demand for paper and paperboard indicates that demand for paper is decreasing, while demand for paperboard is increasing. The future market demand for paper and paperboard can develop in several ways. The authors of this thesis believe that the market demand for paper will have a structural fall with an exception for special paper. While paperboard will have a continuous increase. Furthermore, there is currently an increase of bulk and container shipping in the Port of Gothenburg. The authors believe that future market demand for bulk will be stable, while container will have an increased trend. However, as the market demand is hard to predict, the thesis presents four scenarios of different futureoutcomes of market demand for paper, paperboard, bulk- and container shipping. There are several investments needed for the Port of Gothenburg to respond to theestablished demand scenarios. Investments that will benefit Port of Gothenburg themost are Port Community System (PCS), Integrated Warehouse ManagementSystem (IWMS), Real-Time Location System (RTLS), development of port quays,larger quay cranes and floating islands, and cold ironing and renewable energy. Key words: Paper, Paperboard, forest industry, bulk, container, cargo shipping,seaport, Port of Gothenburg, scenario planning, port investments
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Intelligent autoscaling in Kubernetes : the impact of container performance indicators in model-free DRL methods / Intelligent autoscaling in Kubernetes : påverkan av containerprestanda-indikatorer i modellfria DRL-metoderPraturlon, Tommaso January 2023 (has links)
A key challenge in the field of cloud computing is to automatically scale software containers in a way that accurately matches the demand for the services they run. To manage such components, container orchestrator tools such as Kubernetes are employed, and in the past few years, researchers have attempted to optimise its autoscaling mechanism with different approaches. Recent studies have showcased the potential of Actor-Critic Deep Reinforcement Learning (DRL) methods in container orchestration, demonstrating their effectiveness in various use cases. However, despite the availability of solutions that integrate multiple container performance metrics to evaluate autoscaling decisions, a critical gap exists in understanding how model-free DRL algorithms interact with a state space based on those metrics. Thus, the primary objective of this thesis is to investigate the impact of the state space definition on the performance of model-free DRL methods in the context of horizontal autoscaling within Kubernetes clusters. In particular, our findings reveal distinct behaviours associated with various sets of metrics. Notably, those sets that exclusively incorporate parameters present in the reward function demonstrate superior effectiveness. Furthermore, our results provide valuable insights when compared to related works, as our experiments demonstrate that a careful metric selection can lead to remarkable Service Level Agreement (SLA) compliance, with as low as 0.55% violations and even surpassing baseline performance in certain scenarios. / En viktig utmaning inom området molnberäkning är att automatiskt skala programvarubehållare på ett sätt som exakt matchar efterfrågan för de tjänster de driver. För att hantera sådana komponenter, container orkestratorverktyg som Kubernetes används, och i det förflutna några år har forskare försökt optimera dess autoskalning mekanism med olika tillvägagångssätt. Nyligen genomförda studier har visat potentialen hos Actor-Critic Deep Reinforcement Learning (DRL) metoder i containerorkestrering, som visar deras effektivitet i olika användningsfall. Men trots tillgången på lösningar som integrerar flera behållarprestandamått att utvärdera autoskalningsbeslut finns det ett kritiskt gap när det gäller att förstå hur modellfria DRLalgoritmer interagerar med ett tillståndsutrymme baserat på dessa mätvärden. Det primära syftet med denna avhandling är alltså att undersöka vilken inverkan statens rymddefinition har på prestandan av modellfria DRL-metoder i samband med horisontell autoskalning inom Kubernetes-kluster. I synnerhet visar våra resultat distinkta beteenden associerade med olika uppsättningar mätvärden. Särskilt de set som uteslutande innehåller parametrar som finns i belöningen funktion visar överlägsen effektivitet. Dessutom våra resultat ge värdefulla insikter jämfört med relaterade verk, som vår experiment visar att ett noggrant urval av mätvärden kan leda till anmärkningsvärt Service Level Agreement (SLA) efterlevnad, med så låg som 0, 55% överträdelser och till och med överträffande baslinjeprestanda i vissa scenarier.
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Detecting latency spikes in network quality measurements caused by hypervisor pausing virtual environment execution. : Finding ways to detect hypervisor-induced latency spikes during an execution in a virtual environment from the virtual environment.Bouaddi, Hilaire January 2022 (has links)
Virtual Environments have transformed over the years the way software is built and distributed. The recent growth of services such as Amazon EC2 or Google Cloud is representative of this trend and encourages developers to build software intended for virtual environments like virtual machines or containers. Despite all the benefits that virtualization brings (isolation, security, energy efficiency, stability, portability, etc.), the extra layer of software between the virtual environment and the hardware, called the hypervisor, increases the complexity of a system and the interpretation of its metrics. In this paper, we explore the situation of software performing latency measurements from a virtual environment. This is an example of a use-case where latency from the hypervisor could lead to measurable noise on the virtual environment if the hypervisor makes our environment wait for resources for milliseconds. To solve this problem, we propose an algorithm that will filter out this noise from computed metrics from the virtual environment. This algorithm was developed studying correlation between those metrics and hypervisor-induced latency spikes. We also try to be hypervisor agnostic which means that this work stays relevant whether a virtual environment is deployed locally or on a Cloud Service with different (and constantly evolving) hypervisor technologies. This research gives an overview of hypervisor technologies and how latency can appear when executing processes on virtual environments. As we will see, computing the metric and running the algorithm make network quality measurements from virtual environments more reliable and can explain unexpected latencies. / Virtuella miljöer(virtual environments) har under åren förändrat hur mjukvara(software) byggs och distribueras. Den senaste tidens tillväxt av tjänster som Amazon EC2 eller Google Cloud är representativ för denna trend och uppmuntrar utvecklare att bygga programvara avsedd för virtuella miljöer som virtuella maskiner eller behållare. Trots alla fördelar som virtualisering ger (isolering, säkerhet, energieffektivitet, stabilitet, portabilitet, etc.), ökar det extra lagret av mjukvara mellan den virtuella miljön och hårdvaran, kallad hypervisor, komplexiteten hos ett system och tolkning av dessa måtvärden. I denna artikel utforskar vi situationen för programvara som utför latensmätningar från en virtuell miljö. Detta är ett exempel på ett användningsfall där latens från hypervisorn kan leda till mätbart brus i den virtuella miljön om hypervisorn får vår miljö att vänta på resurser i millisekunder. För att lösa detta problem föreslår vi en algoritm som kommer att filtrera bort detta brus från beräknade mätvärden från den virtuella miljön. Denna algoritm utvecklades för att studera korrelationen mellan dessa mätvärden och hypervisor-inducerade latensspikar. Vi försöker också vara hypervisoragnostiska vilket innebär att detta arbete förblir relevant oavsett om en virtuell miljö distribueras lokalt eller på en molntjänst med olika (och ständigt utvecklande) hypervisorteknologier. Denna forskning ger en översikt över hypervisorteknologier och hur latens kan uppstå när processer körs i virtuella miljöer. Som vi kommer att se gör beräkning av måtten och körning av algoritmen mätningar av nätverkskvalitet från virtuella miljöer mer tillförlitliga och kan förklara oväntade latenser. / Les environments virtuels transforment depuis des années la manière de développer et distribuer du logiciel. La récente croissance de services comme Amazon EC2 ou Google Cloud reflète bien cette tendance et encourage les développeurs à construire du logiciel déployable sur des environnements virtuels comme des machines virtuels ou des conteneurs. Malgré tous les bénéfices que la virtualisation apporte (isolation, sécurité, efficacité énergétique, stabilité, portabilité, etc.), la couche logiciel supplémentaire entre l’environnement virtuel et le hardware, appelée hyperviseur, augmente la complexité d’un système et l’interprétation de ces métriques. Dans ce mémoire de projet de fin d’études, nous explorons la situation où un logiciel effectue des tests de latence depuis un envirronnement virtuel. Cette situation est un exemple d’un cas d’utilisation où la latence introduite par un hyperviseur peut mener à un bruit mesurable si l’hyperviseur fait attendre notre environnement dans l’ordre de grandeur de la milliseconde. Pour résoudre ce problème, nous proposons un algorithme qui filtre ce bruit à partir de métriques calculées directement depuis l’environnement virtuel. Cet algorithme est dévelopé en étudiant la corrélation entre nos métriques et une latence dite "hypervisor-induced". Cette approche permet donc une grande flexibilité dans la technologie sous-jacente de l’hôte puisque celui-ci peut utiliser des hyperviseurs différents ou même faire partie d’un service Cloud sans que notre solution en soit impactée. Ce mémoire donne aussi un aperçu de la technologie derrière un hyperviseur et comment de la latence peut s’introduire dans l’exécution d’un processus dans un environnement virtuel.
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