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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.
211

Datové sklady - principy, metody návrhu, nástroje, aplikace, návrh konkrétního řešení / Data warehouses -- main principles, concepts and methods, tools, applications, design and building of data warehouse solution in real company

Mašek, Martin January 2007 (has links)
The main goal of this thesis is to summarize and introduce general theoretical concepts of Data Warehousing by using the systems approach. The thesis defines Data Warehousing and its main areas and delimitates Data Warehousing area in terms of higher-level area called Business Intelligence. It also describes the history of Data Warehousing & Business Intelligence, focuses on key principals of Data Warehouse building and explains the practical applications of this solution. The aim of the practical part is to perform the evaluation of theoretical concepts. Based on that, design and build Data Warehouse in environment of an existing company. The final solution shall include Data Warehouse design, hardware and software platform selection, loading with real data by using ETL services and building of end users reports. The objective of the practical part is also to demonstrate the power of this technology and shall contribute to business decision-making process in this company.
212

Compiling Unit Clauses for the Warren Abstract Machine

Herbert, George D. 01 January 1987 (has links)
This thesis describes the design, development, and installation of a computer program which compiles unit clauses generated in a Prolog-based environment at Argonne National Laboratories into Warren Abstract Machine (WAM) code. The program enhances the capabilities of the environment by providing rapid unification and subsumption tests for the very significant class of unit clauses. This should improve performance substantially for large programs that generate and use many unit clauses.
213

Vem ser dig? : En fallstudie kring kameraövervakning och integritet på universitet. / Who sees you?

Karabas, Emre, Gullin, Petter January 2021 (has links)
The aim of this study is to examine how students and personnel at universities perceive camera surveillance and the handling of the data gathered by it. This is done through a qualitative research approach where the research strategy is a case study with interviews as a data collection method. The study is based on two perspectives - students and employees. The purpose of the study is to investigate how camera surveillance and management of the data collected is handled at a university, with Uppsala University as a case study. (The focus in the study is on awareness of and attitudes towards camera surveillance - to identify and gain a deeper understanding of university employees and students' attitudes towards camera surveillance and the management of the data that the university collects). The reason for camera surveillance at the University, perceived advantages and disadvantages as well as how the experience and importance of personal integrity, are affected by various factors such as the handling and use of surveillance data. Another issue is the respondents' knowledge of GDPR and the rights they have regarding camera surveillance. The survey is limited to people at Uppsala University. Other monitoring systems such as access systems and logging as well as the handling of this data are delimited from the study and excluded from the survey. / Uppsatsen avser undersöka studenters och universitetsanställdas inställning till kameraövervakning och hanteringen av de data som kan samlas in. Det görs genom en kvalitativ forskningsansats där forskningsstrategin är fallstudie med intervjuer som datainsamlingsmetod. Studien utgår från två perspektiv - studenter och anställda. Syftet med denna studie är att undersöka hur kameraövervakning och hantering av de data som samlas in fungerar på ett universitet, med Uppsala universitet som fallstudie. (Fokus i studien ligger på medvetenhet om och inställning till kameraövervakning - att identifiera och få en djupare förståelse för universitetsanställda och studenters inställning till kameraövervakning och hanteringen av de data som universitetet samlar in). Vad som motiverar (är anledningen till) kameraövervakning på Universitetet, upplevda för- och nackdelar samt hur upplevelsen och vikten av den personliga integriteten, påverkas av olika faktorer som til lexempel hanteringen och användandet av övervakningsdata. En annan frågeställning är respondenternas kunskaper kring GDPR och de rättigheter de har vid kameraövervakning. Undersökningen är avgränsad till personer vid Uppsala universitet. Andra övervakningssystem som till exempel inpasseringssystem och loggning liksom hantering av dessa data är avgränsade från studien och exkluderas från undersökningen.
214

Distributed P2P Data Backup System / Distributed P2P Data Backup System

Mészáros, István January 2013 (has links)
Tato diplomová práce představuje model a prototyp kooperativního distributivního systému zálohování dat založeném na P2P komunikační síti. Návrh systému umožňuje uživatelům přispět svým lokálním volným místem na disku do systému výměnou za spolehlivé úložiště jejich dat u jiných uživatelů. Představené řešení se snaží splnit požadavky uživatelů na ukládání dat, zároveň však také řeší, jak se vypořádat s mírou nepředvídatelnosti uživatelů  ohledně poskytování volného místa. To je prováděno dvěma způsoby - využitím Reed - Solomon kódů a zároveň také tím, že poskytuje možnost nastavení parametrů dostupnosti. Jedním z těchto parametrů je časový rozvrh, který značí, kdy uživatel může nabídnout předvídatelný přínos do systému. Druhý parametr se týká spolehlivosti konkrétního uživatele v rámci jeho slíbeného časového úseku. Systém je schopen najít synchronizaci ukládaných dat na základě těchto parametrů. Práce se zaměřuje rovněž na řešení zabezpečení systému proti širšímu spektru možných útoků. Hlavním cílem je publikovat koncept a prototyp. Jelikož se jedná o relativně nové řešení, je důležitá také zpětná vazba od široké veřejnosti, která může produkt používat. Právě jejich komentáře a připomínky jsou podnětem pro další vývoj systému.
215

Cloud data storage security based on cryptographic mechanisms / La sécurité des données stockées dans un environnement cloud, basée sur des mécanismes cryptographiques

Kaaniche, Nesrine 15 December 2014 (has links)
Au cours de la dernière décennie, avec la standardisation d’Internet, le développement des réseaux à haut débit, le paiement à l’usage et la quête sociétale de la mobilité, le monde informatique a vu se populariser un nouveau paradigme, le Cloud. Le recours au cloud est de plus en plus remarquable compte tenu de plusieurs facteurs, notamment ses architectures rentables, prenant en charge la transmission, le stockage et le calcul intensif de données. Cependant, ces services de stockage prometteurs soulèvent la question de la protection des données et de la conformité aux réglementations, considérablement due à la perte de maîtrise et de gouvernance. Cette dissertation vise à surmonter ce dilemme, tout en tenant compte de deux préoccupations de sécurité des données, à savoir la confidentialité des données et l’intégrité des données. En premier lieu, nous nous concentrons sur la confidentialité des données, un enjeu assez considérable étant donné le partage de données flexible au sein d’un groupe dynamique d’utilisateurs. Cet enjeu exige, par conséquence, un partage efficace des clés entre les membres du groupe. Pour répondre à cette préoccupation, nous avons, d’une part, proposé une nouvelle méthode reposant sur l’utilisation de la cryptographie basée sur l’identité (IBC), où chaque client agit comme une entité génératrice de clés privées. Ainsi, il génère ses propres éléments publics et s’en sert pour le calcul de sa clé privée correspondante. Grâce aux propriétés d’IBC, cette contribution a démontré sa résistance face aux accès non autorisés aux données au cours du processus de partage, tout en tenant compte de deux modèles de sécurité, à savoir un serveur de stockage honnête mais curieux et un utilisateur malveillant. D’autre part, nous définissons CloudaSec, une solution à base de clé publique, qui propose la séparation de la gestion des clés et les techniques de chiffrement, sur deux couches. En effet, CloudaSec permet un déploiement flexible d’un scénario de partage de données ainsi que des garanties de sécurité solides pour les données externalisées sur les serveurs du cloud. Les résultats expérimentaux, sous OpenStack Swift, ont prouvé l’efficacité de CloudaSec, en tenant compte de l’impact des opérations cryptographiques sur le terminal du client. En deuxième lieu, nous abordons la problématique de la preuve de possession de données (PDP). En fait, le client du cloud doit avoir un moyen efficace lui permettant d’effectuer des vérifications périodiques d’intégrité à distance, sans garder les données localement. La preuve de possession se base sur trois aspects : le niveau de sécurité, la vérification publique, et les performances. Cet enjeu est amplifié par des contraintes de stockage et de calcul du terminal client et de la taille des données externalisées. Afin de satisfaire à cette exigence de sécurité, nous définissons d’abord un nouveau protocole PDP, sans apport de connaissance, qui fournit des garanties déterministes de vérification d’intégrité, en s’appuyant sur l’unicité de la division euclidienne. Ces garanties sont considérées comme intéressantes par rapport à plusieurs schémas proposés, présentant des approches probabilistes. Ensuite, nous proposons SHoPS, un protocole de preuve de possession de données capable de traiter les trois relations d’ensembles homomorphiques. SHoPS permet ainsi au client non seulement d’obtenir une preuve de la possession du serveur distant, mais aussi de vérifier que le fichier, en question, est bien réparti sur plusieurs périphériques de stockage permettant d’atteindre un certain niveau de la tolérance aux pannes. En effet, nous présentons l’ensemble des propriétés homomorphiques, qui étend la malléabilité du procédé aux propriétés d’union, intersection et inclusion / Recent technological advances have given rise to the popularity and success of cloud. This new paradigm is gaining an expanding interest, since it provides cost efficient architectures that support the transmission, storage, and intensive computing of data. However, these promising storage services bring many challenging design issues, considerably due to the loss of data control. These challenges, namely data confidentiality and data integrity, have significant influence on the security and performances of the cloud system. This thesis aims at overcoming this trade-off, while considering two data security concerns. On one hand, we focus on data confidentiality preservation which becomes more complex with flexible data sharing among a dynamic group of users. It requires the secrecy of outsourced data and an efficient sharing of decrypting keys between different authorized users. For this purpose, we, first, proposed a new method relying on the use of ID-Based Cryptography (IBC), where each client acts as a Private Key Generator (PKG). That is, he generates his own public elements and derives his corresponding private key using a secret. Thanks to IBC properties, this contribution is shown to support data privacy and confidentiality, and to be resistant to unauthorized access to data during the sharing process, while considering two realistic threat models, namely an honest but curious server and a malicious user adversary. Second, we define CloudaSec, a public key based solution, which proposes the separation of subscription-based key management and confidentiality-oriented asymmetric encryption policies. That is, CloudaSec enables flexible and scalable deployment of the solution as well as strong security guarantees for outsourced data in cloud servers. Experimental results, under OpenStack Swift, have proven the efficiency of CloudaSec in scalable data sharing, while considering the impact of the cryptographic operations at the client side. On the other hand, we address the Proof of Data Possession (PDP) concern. In fact, the cloud customer should have an efficient way to perform periodical remote integrity verifications, without keeping the data locally, following three substantial aspects : security level, public verifiability, and performance. This concern is magnified by the client’s constrained storage and computation capabilities and the large size of outsourced data. In order to fulfill this security requirement, we first define a new zero-knowledge PDP proto- col that provides deterministic integrity verification guarantees, relying on the uniqueness of the Euclidean Division. These guarantees are considered as interesting, compared to several proposed schemes, presenting probabilistic approaches. Then, we propose SHoPS, a Set-Homomorphic Proof of Data Possession scheme, supporting the 3 levels of data verification. SHoPS enables the cloud client not only to obtain a proof of possession from the remote server, but also to verify that a given data file is distributed across multiple storage devices to achieve a certain desired level of fault tolerance. Indeed, we present the set homomorphism property, which extends malleability to set operations properties, such as union, intersection and inclusion. SHoPS presents high security level and low processing complexity. For instance, SHoPS saves energy within the cloud provider by distributing the computation over multiple nodes. Each node provides proofs of local data block sets. This is to make applicable, a resulting proof over sets of data blocks, satisfying several needs, such as, proofs aggregation
216

Integration gedruckter Elektronik in Kunststoffe durch Folienhinterspritzen

Weigelt, Karin 29 May 2013 (has links)
Ausgehend von der Anwendung von Folienhinterspritzprozessen für dekorative Zwecke wurde deren Nutzung für die Integration elektronischer Strukturen in Kunststoffbauteile untersucht. Die Herstellung der elektronischen Bauelemente erfolgte mittels verschiedener Druckverfahren mit elektrisch leitfähigen und dielektrischen Materialien auf Polycarbonatfolien. Im Fokus standen zum einen kapazitiv auslesbare Speicherstrukturen und zum anderen Elektrolumineszenzleuchten. Nach dem Druck wurden die bedruckten Folien z. T. verformt und hinterspritzt. In der Arbeit wird auf die Auswirkungen der Verform- und Hinterspritzprozesse eingegangen. Schwerpunktmäßig wird die elektronische bzw. optische Funktionalität der Bauelemente, die Beeinflussung durch Klimaveränderungen und die Haftfestigkeit der Folien betrachtet. Im Ergebnis konnten erstmals die Realisierbarkeit hinterspritzter elektronischer Bauelemente nachgewiesen sowie verschiedene Einflussfaktoren auf deren Funktionalität identifiziert werden. / Based on the application of film insert molding for graphic purposes, the utilization of this process for the integration of electronic devices into plastic components was examined. The manufacturing of the electronic devices was realized by applying electrical conductive and dielectric inks on polycarbonate foil by various printing processes. Capacitive data storage patterns and electroluminescent lamps are the main applications. The production sequence included the printing process, forming of the foil where required and back injection molding. The impact of forming and film insert molding was investigated. The electronic and/or optical functionality of the devices, the influence of ambient conditions like temperature or humidity and the adhesion strength of the foils were in the focus of the evaluation. As a result, the feasibility of film insert molded electronic devices could be verified and various impact factors could be identified for the first time.
217

Cloud Computing Pricing and Deployment Efforts : Navigating Cloud Computing Pricing and Deployment Efforts: Exploring the Public-Private Landscape / Prissättning och Implementeringsinsatser för Molntjänster : Att Navigera Molntjänsters Prissättning och Implementeringsinsatser: Utforska det Offentlig-Privata Landskapet

Kristiansson, Casper, Lundström, Fredrik January 2023 (has links)
The expanding adoption of cloud computing services by businesses has transformed IT infrastructure and data management in the computing space. Cloud computing offers advantages such as availability, scalability, and cost-effectiveness, making it a favored choice for businesses of all sizes. The aim of this thesis is to compare private and public cloud computing services in terms of pricing and implementation effort as well as comparing the cloud providers to each other. The top three cloud providers that will be examined are Google GCP, Microsoft Azure, and Amazon AWS. The study examines different pricing models and evaluates their effectiveness in different business scenarios. In addition, the thesis also discusses the challenges associated with building and maintaining private infrastructure and the deployment of applications to cloud computing service are examined. The research methodology involves data collection, analysis, and a case study of developing and deploying a ticketing system application on different cloud platforms. The ticket system helps to provide a realistic example and investigation of the cloud providers. The findings will help companies make informed decisions regarding the selection of the most appropriate cloud computing service based on pricing models and implementation efforts. The thesis provides valuable information on private and public cloud computing and recommends appropriate pricing models for different scenarios. This study adds to existing knowledge by analyzing current pricing models and deployment concepts in cloud computing. The thesis does not propose new solutions but follows a structured format compiling information on private, and public cloud computing and a comprehensive review of cloud computing pricing models and marketing efforts. / Den växande adoptionen av molntjänster inom företag har förändrat IT-infrastrukturen och datahanteringen inom datorområdet. Molntjänster erbjuder fördelar såsom tillgänglighet, skalbarhet och kostnadseffektivitet, vilket gör det till ett populärt val för företag i alla storlekar. Syftet med denna avhandling är att jämföra privata och offentliga molntjänster med avseende på prissättning och implementeringsinsatser samt att jämföra molnleverantörerna med varandra. De tre främsta molnleverantörerna som kommer att undersökas är Google GCP, Microsoft Azure och Amazon AWS. Studien undersöker olika prismodeller och utvärderar deras effektivitet i olika affärsscenarier. Dessutom diskuterar avhandlingen också utmaningarna med att bygga och underhålla privat infrastruktur samt implementeringen av applikationer till molntjänster. Forskningsmetodologin omfattar datainsamling, analys och en fallstudie av utveckling och implementering av ett support system på olika molnplattformar. Supportsystemet hjälper till att ge ett realistiskt exempel och undersökning av molnleverantörerna. Resultaten kommer att hjälpa företag att fatta informerade beslut när det gäller valet av lämpligaste molntjänst baserat på prismodeller och implementeringsinsatser. Avhandlingen tillhandahåller värdefull information om privat och offentlig molntjänst och rekommenderar lämpliga prismodeller för olika scenarier. Denna studie bidrar till befintlig kunskap genom att analysera nuvarande prismodeller och implementeringskoncept inom molntjänster. Avhandlingen föreslår inga nya lösningar, men följer en strukturerad format genom att sammanställa information om privat och offentlig molntjänst samt en omfattande översikt av prismodeller och marknadsinsatser inom molntjänster.
218

Cloud Computing and the GLAM sector : A case study of the new Digital Archive Project of Åland Maritime Museum.

Faruqi, Ubaid Ali January 2023 (has links)
This thesis examines the benefits and drawbacks of cloud computing technology within the GLAM (Galleries, Libraries, Archives, and Museums) sector of Sweden and Finland. It employs the case study of the recently developed and launched Digital Archive Project at Åland Maritime Museum which leveraged the Amazon Web Services (AWS) technology stack to provide a cloud-based digital platform for the museum's archival materials. The primary objective of this study is to understand the interaction, usage, and suitability of cloud computing technologies and the impact of User Experience (UX) (primary users being the GLAM professionals) on digitalization efforts. This study analyzes eight GLAM institutions in Sweden and Finland using semi-structured interviews and compares the trust and readiness of adapting to private cloud service providers. The findings reveal that Finland has a more ‘aggressive’ and experimental approach to newer technologies such as cloud computing tools, compared to Sweden. In Sweden, there is an appreciation for pleasant UX and methods to make heritage material more accessible, but there is also a lot of hesitation due to the data privacy regulations in the aftermath of the Schrems II Judgment and the invalidation of the EU-U.S. Privacy Shield Agreement. The study concludes that AWS as a cloud provider is difficult to incorporate in the public sector GLAM institutions compared to the private sector. The study also provides practical recommendations for GLAM institutions and professionals and calls for further interdisciplinary research with Digital Humanists at the center of it.
219

Development of a continuous condition monitoring system based on probabilistic modelling of partial discharge data for polymeric insulation cables

Ahmed, Zeeshan 09 August 2019 (has links)
Partial discharge (PD) measurements have been widely accepted as an efficient online insulation condition assessment method in high voltage equipment. Two sets of experimental PD measuring setups were established with the aim to study the variations in the partial discharge characteristics over the insulation degradation in terms of the physical phenomena taking place in PD sources, up to the point of failure. Probabilistic lifetime modeling techniques based on classification, regression and multivariate time series analysis were performed for a system of PD response variables, i.e. average charge, pulse repetition rate, average charge current, and largest repetitive discharge magnitude over the data acquisition period. Experimental lifelong PD data obtained from samples subjected to accelerated degradation was used to study the dynamic trends and relationships among those aforementioned response variables. Distinguishable data clusters detected by the T-Stochastics Neighborhood Embedding (tSNE) algorithm allows for the examination of the state-of-the-art modeling techniques over PD data. The response behavior of trained models allows for distinguishing the different stages of the insulation degradation. An alternative approach utilizing a multivariate time series analysis was performed in parallel with Classification and Regression models for the purpose of forecasting PD activity (PD response variables corresponding to insulation degradation). True observed data and forecasted data mean values lie within the 95th percentile confidence interval responses for a definite horizon period, which demonstrates the soundness and accuracy of models. A life-predicting model based on the cointegrated relations between the multiple response variables, trained model responses correlated with experimentally evaluated time-to-breakdown values and well-known physical discharge mechanisms, can be used to set an emergent alarming trigger and as a step towards establishing long-term continuous monitoring of partial discharge activity. Furthermore, this dissertation also proposes an effective PD monitoring system based on wavelet and deflation compression techniques required for an optimal data acquisition as well as an algorithm for high-scale, big data reduction to minimize PD data size and account only for the useful PD information. This historically recorded useful information can thus be used for, not only postault diagnostics, but also for the purpose of improving the performance of modelling algorithms as well as for an accurate threshold detection.
220

Nanolithography on thin films using heated atomic force microscope cantilevers

Saxena, Shubham 01 November 2006 (has links)
Nanotechnology is expected to play a major role in many technology areas including electronics, materials, and defense. One of the most popular tools for nanoscale surface analysis is the atomic force microscope (AFM). AFM can be used for surface manipulation along with surface imaging. The primary motivation for this research is to demonstrate AFM-based lithography on thin films using cantilevers with integrated heaters. These thermal cantilevers can control the temperature at the end of the tip, and hence they can be used for local in-situ thermal analysis. This research directly addresses applications like nanoscale electrical circuit fabrication/repair and thermal analysis of thin-films. In this study, an investigation was performed on two thin-film materials. One of them is co-polycarbonate, a variant of a polymer named polycarbonate, and the other is an energetic material called pentaerythritol tetranitrate (PETN). Experimental methods involved in the lithography process are discussed, and the results of lithographic experiments performed on co-polycarbonate and PETN are reported. Effects of dominant parameters during lithography experiments like time, temperature, and force are investigated. Results of simulation of the interface temperature between thermal cantilever tip and thin film surface, at the beginning of the lithography process, are also reported.

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