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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Contributions à la modélisation et la conception des systèmes de gestion de provenance à large échelle / [Contributions to the modelling and conception of large-scale provenance management systems]

Sakka, Mohamed Amin 28 September 2012 (has links)
Les avancées dans le monde des réseaux et des services informatiques ont révolutionné les modes d’échange, de partage et de stockage de l’information. Nous migrons de plus en plus vers des échanges numériques ce qui implique un gain en terme de rapidité de transfert, facilité de partage et d’accès ainsi qu’une efficacité d’organisation et de recherche de l’information. Malgré ses avantages, l’information numérique a l’inconvénient d’être volatile et modifiable ce qui introduit des problèmes liés à sa provenance, son intégrité et sa valeur probante. Dans ce contexte, la provenance apparait comme une méta-donnée cléqui peut servir pour juger la qualité de l’information et pour vérifier si elle répond à un ensemble d’exigences métier, techniques et légales. Aujourd’hui, une grande partie des applications et des services qui traitent, échangent et gèrent des documents électroniques sur le web ou dans des environnements Cloud génèrent des données de provenance hétérogènes, décentralisées et non interopérables. L’objectif principal de cette thèse est de proposer des solutions génériques et interopérables pour la modélisation de l’information de provenance et de concevoir des architectures de systèmes de gestion de provenance passant à l'échelle tant au niveau du stockage et que de l’exploitation(interrogation). Dans la première partie de la thèse, nous nous intéressons à la modélisation de la provenance. Afin de pallier à l’hétérogénéité syntaxique et sémantique qui existe entre les différents modèles de provenance, nous proposons une approche globale et cohérente pour la modélisation de la provenance basée sur les technologies du web sémantique. Notre approche repose sur un modèle de domaine minimal assurant un niveau d’interprétation minimal et commun pour n’importe quelle source de provenance. Ce modèle peut ensuite être spécialisé en plusieurs modèles de domaine pour modéliser des concepts et des propriétés métier différentes. Cette spécialisation assure l’interopérabilité sémantique souhaitée et permet par la suite de générer des vues métiers différentes sur les mêmes données de provenance. Dans la deuxième partie de la thèse, nous nous focalisons sur la conception des systèmes de gestion de provenance (ou PMS). Nous proposons tout d’abord une architecture logique de PMS indépendante des choix technologiques d’implémentation et de déploiement. Cette architecture détaille les modules assurant les fonctionnalités requises par notre approche de modélisation et sert comme architecture de référence pour la conception d’un PMS. Par la suite, et afin de préserver l’autonomie des sources de provenance, nous proposons une architecture distribuée de PMS à base de médiateur. Ce médiateur a une vision globale sur l’ensemble des sources et possède des capacités de distribution et de traitement de requêtes. Finalement la troisième partie de la thèse valide nos propositions. La validation de notre approche de modélisation a été réalisée dans un cadre industriel chez Novapost, une entreprise proposant des services SaaS pour l’archivage de documents à valeur probante. Ensuite, l’aspect passage à l’ échelle de notre architecture a été testé par l’implémentation de deux prototypes de PMS sur deux technologies de stockage différentes : un système RDF (Sesame) et un SGBD NoSQL (CouchDB). Les tests de montée en charge effectués sur les données de provenance Novapost ont montré les limites de Sesame tant pour le stockage que pour l’interrogation en utilisant le langage de requêtes SPARQL, alors que la version CouchDB associée à un langage de requêtes basé sur map/reduce a démontré sa capacité à suivre la charge de manière linéaire en augmentant le nombre de serveurs / Provenance is a key metadata for assessing electronic documents trustworthiness. It allows to prove the quality and the reliability of its content. With the maturation of service oriented technologies and Cloud computing, more and more data is exchanged electronically and dematerialization becomes one of the key concepts to cost reduction and efficiency improvement. Although most of the applications exchanging and processing documents on the Web or in the Cloud become provenance aware and provide heterogeneous, decentralized and not interoperable provenance data, most of Provenance Management Systems (PMSs) are either dedicated to a specific application (workflow, database, ...) or a specific data type. Those systems were not conceived to support provenance over distributed and heterogeneous sources. This implies that end-users are faced with different provenance models and different query languages. For these reasons, modeling, collecting and querying provenance across heterogeneous distributed sources is considered today as a challenging task. This is also the case for designing scalable PMSs providing these features. In the fist part of our thesis, we focus on provenance modelling. We present a new provenance modelling approach based on semantic Web technologies. Our approach allows to import provenance data from heterogeneous sources, to enrich it semantically to obtain high level representation of provenance. It provides syntactic interoperability between those sources based on a minimal domain model (MDM), supports the construction of rich domain models what allows high level representations of provenance while keeping the semantic interoperability. Our modelling approch supports also semantic correlation between different provenance sources and allows the use of a high level semantic query language. In the second part of our thesis, we focus on the design, implementation and scalability issues of provenance management systems. Based on our modelling approach, we propose a centralized logical architecture for PMSs. Then, we present a mediator based architecture for PMSs aiming to preserve provenance sources distribution. Within this architecture, the mediator has a global vision on all provenance sources and possesses query processing and distribution capabilities. The validation of our modelling approach was performed in a document archival context within Novapost, a company offering SaaS services for documents archiving. Also, we propose a non-functional validation aiming to test the scalability of our architecture. This validation is based on two implementation of our PMS : he first uses an RDF triple store (Sesame) and the second a NoSQL DBMS coupled with the map-reduce parallel model (CouchDB). The tests we performed show the limits of Sesame in storing and querying large amounts of provenance data. However, the PMS based on CouchDB showed a good performance and a linear scalability
12

Instrumental neutron activation analysis (INAA) characterization of pre-contact basalt quarries on the American Samoan Island of Tutuila

Johnson, Phillip Ray, II 25 April 2007 (has links)
This thesis presents a material-centered characterization of 120 geologic samples from four fine-grained basalt quarries on the Samoan Island of Tutuila. Previous unsuccessful attempts at definitive Tutuilan quarry differentiation have utilized x-ray fluorescence (XRF). In this study, clear differentiation of each analyzed quarry was achieved using instrumental neutron activation analysis (INAA). Biplots of canonical discriminant function scores for the INAA data illustrate clear separation based on the variation in chemical composition between each quarry. The samples analyzed not only define quarry separation, but also provide the "core group" for a preliminary baseline necessary for future artifact-centered provenance studies. Inclusion of these "core group" samples in the baseline was confirmed by stepwise discriminant analysis. These findings suggest the ability to determine quarry of origin on the island of Tutuila, which can elucidate the importance of individual Tutuilan quarries in the export and exchange of fine-grained basalts.
13

Semantic Provenance: Modeling, Querying, and Application in Scientific Discovery

Sahoo, Satya Sanket 27 October 2010 (has links)
No description available.
14

PALEOGEOGRAPHIC AND TECTONIC IMPLICATIONS OF THE LATE PALEOZOIC ALLEGHANIAN OROGEN DEVELOPED FROM ISOTOPIC SEDIMENTARY PROVENANCE PROXIES FROM THE APPALACHIAN FORELAND BASIN

Becker, Thomas Patrick 01 January 2005 (has links)
The Alleghanian orogeny was a collision between the Gondwanan and Laurentian continents that produced the Pangean supercontinent. Mechanical and kinematic models of collisional orogens are believed to follow a critical taper geometry, where the tectonic imbrication of continental crust begins nearest to the edge of continental plate and advances toward the craton in a break- forward sequence. Studies of shear zones within the Alleghanian collisional orogen, however, suggest that most of the early deformation was translational. Propagation of craton-directed thrusts into the foreland did not occur until the latest Pennsylvanian in the southern Appalachians, and the middle-late Permian in the central Appalachians. Radiometric sedimentary provenance proxies have been applied to the late Mississippian-early Permian strata within the Appalachian foreland basin to determine the crustal composition and structural evolution of the orogen during the continental collision. U-Pb ages of detrital zircons from the early to middle Pennsylvanian sandstones suggest that most of the detritus within the Appalachian basin was recycled from Mesoproterozoic basement and Paleozoic strata of the Laurentian margin. The presence of Archean and late Paleoproterozoic age detrital zircons is cited as evidence of recycling of the Laurentian syn-rift and passive-margin sandstones. Detrital zircon ages from early-middle Permian-age sandstones of the Dunkard Group do not contain any Archean or Paleoproterozoic detrital-zircon ages, implying a source of sediment with a much more restricted age population, possibly the igneous and metamorphic internides or middle Paleozoic sandstones from the Appalachian basin. The persistance of 360-400 Ma K/Ar ages of detrital white mica suggest that the sediment was supplied from a source that was exhumed during the Devonian Acadian orogeny. Detrital-zircon and detrital-white-mica ages from Pennsylvanian-age sandstones indicate that the late Paleozoic orogen did not incorporate any significant synorogenic juvenile crust. The 87Sr/86Sr ratios of middle Pennsylvanian-early Permian lacustrine limestones within the Appalachian basin show a slight enrichment through time, suggesting that labile 87Sr-rich minerals in the Alleghanian hinterland are being exposed. Stable isotopic data from the lacustrine limestones also corroborates that the Appalachian basin became much more arid through time.
15

Autenticitet i ett öppna data-sammanhang : Utmaningar och möjligheter ur ett arkivvetenskapligt perspektiv

Engvall, Tove January 2012 (has links)
By tradition, archival sciences has emerged in a context with defined information processes, with explicit information producers and custodians to which consumers make requests for the information. In this process, the archival science has developed methods and strategies to preserve authentic and reliable records and by that providing trustworthy information. In an online society, people are using the internet to get information for different purposes. Even though there is no legal obligation to guarantee the authenticity, it is of societal importance that the end users get trustworthy information. In this online context, open data is a trend that is growing fast over the world and it is interesting because its conditions raises many questions regarding authenticity. Since open data is free to reuse, link and combine with other information, and it is preferably in primary format it raises questions about how to maintain the integrity and identity of the information, which is the constituents of authenticity as it is used in this work. The idea in this essay is to discuss challenges with maintaining the authenticity for open data and also identify possible measures to promote authentic open data information on the web, so that the end users get the possibilities to assess its trustworthiness and fit for use. The essay is a qualitative text analyses, with the theoretical base in the InterPARES project results. Open Government Working groups 8 principles and Open Knowledge Foundations definition is discussed, as is also the discussion from other disciplines about provenance on the web, and ideas from digital records forensic. The results indicate that there are great challenges to maintain the authenticity of open data but there are also some solutions. Recorded provenance and traceability are key factors to enable the evaluation of the authenticity. But first the concept authenticity has to be interpreted in a wider sense. There is a need to maintain the authenticity of the parts, the data, in the information. Because the information is used in parts and if the new information created from it will be reliable, it need accurate data with established identity.
16

The Quaternary evolution of the Rio Alias southeast Spain, with emphasis on sediment provenance

Maher, Elizabeth January 2005 (has links)
This study aims to determine the late-Quaternary evolution of an ephemeral, transverse river system developed in southeast Spain, with particular reference to sediment provenance variation. The Rio Alias drains two inter-montane east-west orientated Neogene sedimentary basins; the Sorbas and Almeria basins. Pliocene to present transpressional tectonics has led to inversion of the sedimentary basins and incision of the developing fluvial system. Fluvial incision has led to the preservation of a suite of alluvial terraces recording the late-Quaternary development of the Rio Alias. Fluvial system inauguration began in the Plio-Pleistocene epoch. The primary fluvial system developed as a consequent river later becoming superimposed and transverse to structure. The drainage basin of the Rio Alias has been sub-divided into 4 sub-basins; The Lucainena, Polopos, Argamason and El Saltador sub-basins. Each basin is structurally controlled. The impact of climate, tectonics, river-capture and eustatic sea-level variation on the fluvial system evolution varies both spatially and temporally across the sub-basins of the Rio Alias. Across the region alluvial aggradation is thought to relate to global glacial periods and incision to interglacial periods. The Lucainena sub-basin is largely controlled by climatic variation related to glacial interglacial cycles with slight modification due to local small scale river-capture and regional epeirogenic uplift. The Polopos sub-basin is also largely controlled by climatic variation, however a major river-capture event c.70ka beheaded the Rio Alias of c.70% of its drainage area. Following the loss of drainage the beheaded Rio Alias system lost stream power, this is reflected in the decrease in size of bedform geometry and the reduced incisional capacity of the fluvial system of the post-capture terrace sequence. In the Argamason sub-basin the Rio Alias crosses the Carboneras Fault Zone, a left-lateral strike slip fault. Late-Quaternary tectonic activity has significantly modified the climatically generated signal. Large tortuous meanders developed in response to normal tectonic activity and continued tectonically driven base-level lowering led to abandonment of terraces and local incision. The El Saltador sub-basin is located at the seaward end of the system and the climate generated phases of aggradation and incision have been greatly complicated by eustatic sea-level variation related to glacial/interglacial cycles. The lowering of base-level due to sea-level regression initially led to pronounced incision along steep gradients and to the development of meander loops in the seaward end of the Rio Alias, during what regionally was a climate driven phase of aggradation. Analysis of the alluvial sediment using a combination of field based clast analysis and laboratory analysis (petrology, SEM, magnetic analysis) allows a detailed picture of sediment provenance variation to be established throughout the evolution of the Rio Alias. Provenance analysis provides information on the timing and extent of river-capture related loss of drainage area, the relative timing of local tectonic activity and also provides new information regarding sediment source area variation throughout the development of the fluvial system. Detailed analysis of the terrace sediments and the modern channel indicates that as the fluvial system incises, local input of sediment from the steepening valley sides grows increasingly dominant. The coupling between the hillslopes and the channel thus changes through time. Sediment provenance analysis has increased our understanding of the long-term fluvial evolution of the Rio Alias, identifying not only sediment provenance variation due to river-capture and changing geology but to fluvial system development.
17

The 'Consul Smith Palladio' at Virginia Commonwealth University and the American Renaissance

Barrett, Anne Rachelle 01 January 2006 (has links)
Among the finest books in the James Branch Cabell Library Special Collections is a recent acquisition (Fall 2005), the 1768 version of Palladia's Quattro Libri dell' architettura , published by Consul Joseph Smith in Venice. On the basis of present work, one can reconstruct Consul Smith's remarkable role in the history of international architecture. More than a century later, at least three major American Renaissance architectural firms owned no fewer than a total of four copies of the volume.This copy came from James Otis Post (1871-1951), son of the eminent George B. Post, who bought a copy of the Smith Palladio in Venice in 1896. Among other firms that owned the volume were Delano and Aldrich and Lawrence Hall Fowler, both important American Renaissance Firms in their own rights.
18

Prehispanic Obsidian Exploitation in the Department of Chinandega, Nicaragua

Unknown Date (has links)
This thesis examines the fabrication and provenance of 2,871 obsidian artifacts collected from twelve prehispanic archaeological sites in four physiographic zones throughout the Department of Chinandega, the northwesternmost department of Nicaragua. This research represents the first systematic study of obsidian artifacts in the region and focuses on two aspects of the obsidian artifacts. First, I present a macroscopic technical analysis of artifacts collected from twelve sites in the Department. The second part of the thesis presents a collaborative geochemical provenance study of obsidian procurement across these sites. Results indicate that most prehispanic sites participated in multiple sets of long-distance trade networks centered on obsidian as early as the Late Preclassic, up until the Late Postclassic, exploiting trade from four obsidian sources to the north. Analyses show that populations in the Department primarily, though not exclusively, utilized a core-flake industry that was worked on-site with material from the Güinope source in Honduras. A limited number of prismatic blades and a few other formal tools sourced from two additional further sources (La Esperanza in Honduras and Ixtepeque in Guatemala) appear almost exclusively as imported finished products more recently in the archaeological sequence. Additionally, the archaeological sites situated in the eastern coastal plains of the Department contained the largest variety of source material, followed by the sites of the northern foothills, a single site in the Nicaraguan depression, and lastly a single site in the Maribios volcanic front. Although ceramic analyses from the collection are partially complete and developing, this region is best understood as a cultural mosaic connected to the Mesoamerican populations in the north. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
19

Butterfly: A Model of Provenance

Tang, Yaobin 13 March 2009 (has links)
Semantically rich metadata is foreseen to be pervasive in tomorrow's cyber world. People are more willing to store metadata in the hope that such extra information will enable a wide range of novel business intelligent applications. Provenance is metadata which describes the derivation history of data. It is considered to have great potential for helping the reasoning, analyzing, validating, monitoring, integrating and reusing of data. Although there are a few application-specific systems equipped with some degree of provenance tracking functionality, few formal models of provenance are present. A general purpose, formal model of provenance is desirable not only to widely promote the storage and inventive usage of provenance, but also to prepare for the emergence of so called provenance management system. In this thesis, I propose Butterfly, a general purpose provenance model, which offers the capability to model, store, and query provenance. It consists of a semantic model for describing provenance, and an extensible algebraic query model for querying provenance. An initial implementation of the provenance model is also briefly discussed.
20

Active provenance for data intensive research

Spinuso, Alessandro January 2018 (has links)
The role of provenance information in data-intensive research is a significant topic of discussion among technical experts and scientists. Typical use cases addressing traceability, versioning and reproducibility of the research findings are extended with more interactive scenarios in support, for instance, of computational steering and results management. In this thesis we investigate the impact that lineage records can have on the early phases of the analysis, for instance performed through near-real-time systems and Virtual Research Environments (VREs) tailored to the requirements of a specific community. By positioning provenance at the centre of the computational research cycle, we highlight the importance of having mechanisms at the data-scientists' side that, by integrating with the abstractions offered by the processing technologies, such as scientific workflows and data-intensive tools, facilitate the experts' contribution to the lineage at runtime. Ultimately, by encouraging tuning and use of provenance for rapid feedback, the thesis aims at improving the synergy between different user groups to increase productivity and understanding of their processes. We present a model of provenance, called S-PROV, that uses and further extends PROV and ProvONE. The relationships and properties characterising the workflow's abstractions and their concrete executions are re-elaborated to include aspects related to delegation, distribution and steering of stateful streaming operators. The model is supported by the Active framework for tuneable and actionable lineage ensuring the user's engagement by fostering rapid exploitation. Here, concepts such as provenance types, configuration and explicit state management allow users to capture complex provenance scenarios and activate selective controls based on domain and user-defined metadata. We outline how the traces are recorded in a new comprehensive system, called S-ProvFlow, enabling different classes of consumers to explore the provenance data with services and tools for monitoring, in-depth validation and comprehensive visual-analytics. The work of this thesis will be discussed in the context of an existing computational framework and the experience matured in implementing provenance-aware tools for seismology and climate VREs. It will continue to evolve through newly funded projects, thereby providing generic and user-centred solutions for data-intensive research.

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