Spelling suggestions: "subject:"model amonitoring"" "subject:"model 19monitoring""
1 |
Ocean Colour Remote Sensing of Flood Plumes in the Great Barrier ReefAmetistova, Lioudmila January 2004 (has links)
The objective of the research reported in this thesis was to develop a technique to monitor the dynamics of sediments and nutrients entering the coastal ocean with river plumes associated with high intensity low frequency events (e.g. floods), using ocean colour remote sensing. To achieve this objective, an inverse bio-optical model was developed, based on analytical and empirical relationships between concentrations of optically significant substances and remote sensing of water-leaving radiance. The model determines concentrations of water-colouring substances such as chlorophyll, suspended sediments, and coloured dissolved organic matter, as well as the values of optical parameters using water-leaving radiances derived from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). To solve atmospheric correction in coastal waters, the aerosol type over clear waters is transferred to adjacent turbid water pixels. The vicinity of the Herbert River, central Great Barrier Reef zone, Australia, was used as a case study for the application of the algorithm developed. The satellite ocean colour technique was successfully validated using sea-truth measurements of water-colouring constituents acquired in the area during various seasons throughout 2002-2004. A high correlation between chlorophyll and dissolved organic matter was found in the coastal waters of the region, and when the bio-optical model was constrained to make chlorophyll a function of dissolved organic matter, the relationship between in situ and satellite-derived data was substantially improved. With reliable retrieval of the major water-colouring constituents, the technique was subsequently applied to study fluxes of particulate and dissolved organic and inorganic matter following a flood event in the Herbert River during the austral summer of 1999. Extensive field observations covering a seasonal flood in the Herbert River in February 2004 revealed high sediment and nutrient exports from the river to the adjacent coastal waters during the flood event. Due to rapid settling, the bulk of the sediment-rich influx was deposited close inshore, while the majority of nutrients exported from the river were consumed by phytoplankton in a relatively small area of the coastal ocean. With the help of ocean colour remote sensing, it was demonstrated that river-borne sediments and nutrients discharged by a typical flood in the Herbert River are mostly precipitated or consumed within the first 20 km from the coast and therefore are unlikely to reach and possibly affect the midshelf coral reefs of this section of the Great Barrier Reef lagoon.
|
2 |
Ocean Colour Remote Sensing of Flood Plumes in the Great Barrier ReefAmetistova, Lioudmila January 2004 (has links)
The objective of the research reported in this thesis was to develop a technique to monitor the dynamics of sediments and nutrients entering the coastal ocean with river plumes associated with high intensity low frequency events (e.g. floods), using ocean colour remote sensing. To achieve this objective, an inverse bio-optical model was developed, based on analytical and empirical relationships between concentrations of optically significant substances and remote sensing of water-leaving radiance. The model determines concentrations of water-colouring substances such as chlorophyll, suspended sediments, and coloured dissolved organic matter, as well as the values of optical parameters using water-leaving radiances derived from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). To solve atmospheric correction in coastal waters, the aerosol type over clear waters is transferred to adjacent turbid water pixels. The vicinity of the Herbert River, central Great Barrier Reef zone, Australia, was used as a case study for the application of the algorithm developed. The satellite ocean colour technique was successfully validated using sea-truth measurements of water-colouring constituents acquired in the area during various seasons throughout 2002-2004. A high correlation between chlorophyll and dissolved organic matter was found in the coastal waters of the region, and when the bio-optical model was constrained to make chlorophyll a function of dissolved organic matter, the relationship between in situ and satellite-derived data was substantially improved. With reliable retrieval of the major water-colouring constituents, the technique was subsequently applied to study fluxes of particulate and dissolved organic and inorganic matter following a flood event in the Herbert River during the austral summer of 1999. Extensive field observations covering a seasonal flood in the Herbert River in February 2004 revealed high sediment and nutrient exports from the river to the adjacent coastal waters during the flood event. Due to rapid settling, the bulk of the sediment-rich influx was deposited close inshore, while the majority of nutrients exported from the river were consumed by phytoplankton in a relatively small area of the coastal ocean. With the help of ocean colour remote sensing, it was demonstrated that river-borne sediments and nutrients discharged by a typical flood in the Herbert River are mostly precipitated or consumed within the first 20 km from the coast and therefore are unlikely to reach and possibly affect the midshelf coral reefs of this section of the Great Barrier Reef lagoon.
|
3 |
Implementace vybrané technologie pro ISP / Implementation of the Selected Technology for ISPDoležal, Martin January 2016 (has links)
The thesis focuses on implementation of selected technology within the company CPU-Kocourek, s.r.o, which provides varied internet services. Based on the theoretical part and the analysis of the current situation are proposed solutions suitable for the management of access network provider. The proposal part contains selection of the best proposal and its implementation into the routine mode of operation.
|
4 |
Surface wave tomography and monitoring of time variations with ambient noise in NW-Bohemia/VogtlandFallahi, Mohammad Javad 25 August 2015 (has links)
In this study, ambient noise wavefield was used for the first time to image spatial and temporal upper crustal seismic structures in NW-Bohemia/Vogtland region. The data come from 111 stations and were collected from continuous recordings of the permanent station networks of Germany and Czech Academy of Sciences as well as temporary stations of the BOHEMA and PASSEQ experiments. Rayleigh and Love waves travelling between each station-pair are extracted by cross-correlating long time series of ambient noise data recorded at the stations. Group velocity dispersion curves are obtained by time-frequency analysis of cross-correlation functions between 0.1 and 1 Hz, and are tomographically inverted to provide 2-D group velocity maps. At shorter periods Rayleigh wave group velocity maps are in good agreement with surface geology where low velocity anomalies appear along Mariánské Lázně Fault and Eger rift. A low velocity zone is observed at the northern edge of Mariánské Lázně Fault which shifts slightly to the south with increasing period and correlates well with the main focal zone of the earthquake swarms at 5 s period. We invert the 2-D group velocity maps into a 3-D shear wave velocity model. In this step Love waves were excluded from further analysis because of their high level of misfit to modelled dispersion curves. Horizontal and vertical sections through the model reveal a clear low velocity zone above the Nový Kostel seismic focal zone which narrows towards the top of the seismic activity and ends above the shallowest hypocenters at 7 km depth.
We investigate temporal variation of seismic velocity within and around the Nový Kostel associated with 2008 and 2011 earthquake swarms by employing Passive Image Interferometry method using 7 continuous seismograms recorded by the WEBNET network. The results reveals stable seismic velocities without a clear post seismic velocity change during earthquake swarms in the Nový Kostel area.
|
5 |
Scalable Architecture for Automating Machine Learning Model Monitoringde la Rúa Martínez, Javier January 2020 (has links)
Last years, due to the advent of more sophisticated tools for exploratory data analysis, data management, Machine Learning (ML) model training and model serving into production, the concept of MLOps has gained more popularity. As an effort to bring DevOps processes to the ML lifecycle, MLOps aims at more automation in the execution of diverse and repetitive tasks along the cycle and at smoother interoperability between teams and tools involved. In this context, the main cloud providers have built their own ML platforms [4, 34, 61], offered as services in their cloud solutions. Moreover, multiple frameworks have emerged to solve concrete problems such as data testing, data labelling, distributed training or prediction interpretability, and new monitoring approaches have been proposed [32, 33, 65]. Among all the stages in the ML lifecycle, one of the most commonly overlooked although relevant is model monitoring. Recently, cloud providers have presented their own tools to use within their platforms [4, 61] while work is ongoing to integrate existent frameworks [72] into open-source model serving solutions [38]. Most of these frameworks are either built as an extension of an existent platform (i.e lack portability), follow a scheduled batch processing approach at a minimum rate of hours, or present limitations for certain outliers and drift algorithms due to the platform architecture design in which they are integrated. In this work, a scalable automated cloudnative architecture is designed and evaluated for ML model monitoring in a streaming approach. An experimentation conducted on a 7-node cluster with 250.000 requests at different concurrency rates shows maximum latencies of 5.9, 29.92 and 30.86 seconds after request time for 75% of distance-based outliers detection, windowed statistics and distribution-based data drift detection, respectively, using windows of 15 seconds length and 6 seconds of watermark delay. / Under de senaste åren har konceptet MLOps blivit alltmer populärt på grund av tillkomsten av mer sofistikerade verktyg för explorativ dataanalys, datahantering, modell-träning och model serving som tjänstgör i produktion. Som ett försök att föra DevOps processer till Machine Learning (ML)-livscykeln, siktar MLOps på mer automatisering i utförandet av mångfaldiga och repetitiva uppgifter längs cykeln samt på smidigare interoperabilitet mellan team och verktyg inblandade. I det här sammanhanget har de största molnleverantörerna byggt sina egna ML-plattformar [4, 34, 61], vilka erbjuds som tjänster i deras molnlösningar. Dessutom har flera ramar tagits fram för att lösa konkreta problem såsom datatestning, datamärkning, distribuerad träning eller tolkning av förutsägelse, och nya övervakningsmetoder har föreslagits [32, 33, 65]. Av alla stadier i ML-livscykeln förbises ofta modellövervakning trots att det är relevant. På senare tid har molnleverantörer presenterat sina egna verktyg att kunna användas inom sina plattformar [4, 61] medan arbetet pågår för att integrera befintliga ramverk [72] med lösningar för modellplatformer med öppen källkod [38]. De flesta av dessa ramverk är antingen byggda som ett tillägg till en befintlig plattform (dvs. saknar portabilitet), följer en schemalagd batchbearbetningsmetod med en lägsta hastighet av ett antal timmar, eller innebär begränsningar för vissa extremvärden och drivalgoritmer på grund av plattformsarkitekturens design där de är integrerade. I det här arbetet utformas och utvärderas en skalbar automatiserad molnbaserad arkitektur för MLmodellövervakning i en streaming-metod. Ett experiment som utförts på ett 7nodskluster med 250.000 förfrågningar vid olika samtidigheter visar maximala latenser på 5,9, 29,92 respektive 30,86 sekunder efter tid för förfrågningen för 75% av avståndsbaserad detektering av extremvärden, windowed statistics och distributionsbaserad datadriftdetektering, med hjälp av windows med 15 sekunders längd och 6 sekunders fördröjning av vattenstämpel.
|
6 |
The control system in formal language theory and the model monitoring approach for reliability and safety / Systèmes de contrôle dans la théorie des langages et approche par monitoring des modèles pour la sécuritéChen, Zhe 09 July 2010 (has links)
Cette thèse contribue à l’étude de la fiabilité et de la sécurité-innocuité des systèmes informatisés, modélisés par des systèmes à événements discrets. Les principales contributions concernent la théorie des Systèmes de Contrôle (notés C Systems) et l’approche par Monitoring des modèles.Dans la première partie de la thèse, nous étudions la théorie des Systèmes de Contrôle qui combine et étend de façon significative, les systèmes de réécriture de la théorie des langages et le contrôle supervisé. Un système de contrôle est une structure générique qui contient deux composants : le composant contrôlé et le composant contrôlant qui restreint le comportement du composant contrôlé. Les deux composants sont exprimés en utilisant le même formalisme comme des automates ou des grammaires. Nous considérons différentes classes de systèmes de contrôle basés sur différents formalismes comme, par exemple, les automates, les grammaires, ainsi que leurs versions infinies et concurrentes. Ensuite, une application de cette théorie est présentée. Les systèmes de contrôle basés sur les automates de Büchi sont utilisés pour vérifier par model-checking, des propriétés définissant la correction sur des traces d’exécution spécifiées par une assertion de type nevertrace.Dans la seconde partie de la thèse, nous investiguons l’approche de monitoring des modèles dont la théorie des systèmes de contrôle constitue les fondations formelles. Le principe pivot de cette approche est la «spécification de propriétés comme contrôleur». En d’autres termes, pour un système, les exigences fonctionnelles, d’une part, et des propriétés, d’autre part, sont modélisées et implantées séparément, les propriétés spécifiées contrôlant le comportement issu des exigences fonctionnelles. De cette approche découle ainsi deux techniques alternatives, respectivement nommées monitoring de modèle et génération de modèle. Cette approche peut être utilisée de diverses manières pour améliorer la fiabilité et la sécurité-innocuité de divers types de systèmes. Nous présentons quelques applications qui montrent l’intérêt pratique de cette contribution théorique. Tout d’abord, cette approche aide à prendre en compte les évolutions des spécifications des propriétés. En second lieu, elle fournit une base théorique à la sécurité fonctionnelle, popularisée par la norme IEC 61508. En troisième lieu, l’approche peut être utilisée pour formaliser et vérifier l’application de guides de bonnes pratiques ou des règles de modélisation appliquées par exemple pour des modèles UML.Ces résultats constituent les bases pour des études futures de dispositifs plus perfectionnés, et fournissent une nouvelle voie pour s’assurer de la fiabilité et de la sécurité-innocuité des systèmes / This thesis contributes to the study of reliability and safety of computer and software systems which are modeled as discrete event systems. The major contributions include the theory of Control Systems (C Systems) and the model monitoring approach.In the first part of the thesis, we study the theory of control systems which combines and significantly extends regulated rewriting in formal languages theory and supervisory control. The control system is a generic framework, and contains two components: the controlled component and the controlling component that restricts the behavior of the controlled component. The two components are expressed using the same formalism, e.g., automata or grammars. We consider various classes of control systems based on different formalisms, for example, automaton control systems, grammar control systems, and their infinite versions and concurrent variants. After that, an application of the theory is presented. The Büchi automata based control system is used to model and check correctness properties on execution traces specified by nevertrace claims.In the second part of the thesis, we investigate the model monitoring approach whose theoretical foundation is the theory of control systems. The key principle of the approach is “property specifications as controllers”. In other words, the functional requirements and property specification of a system are separately modeled and implemented, and the latter one controls the behavior of the former one. The model monitoring approach contains two alternative techniques, namely model monitoring and model generating. The approach can be applied in several ways to improve reliability and safety of various classes of systems. We present some typical applications to show its strong power. First, the approach provides better support for the change and evolution of property specifications. Second, it provides the theoretical foundation of safety-related systems in the standard IEC 61508 for ensuring the functional validity. Third, it is used to formalize and check guidelines and consistency rules of UML.These results lay out the foundations for further study of more advanced control mechanisms, and provide a new way for ensuring reliability and safety
|
Page generated in 0.5506 seconds