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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.
281

STATISTICAL METHODS FOR CRITICAL PATHS SELECTION AND FAULT COVERAGE IN INTEGRATED CIRCUITS

Javvaji, Pavan Kumar 01 May 2019 (has links)
With advances in technology, modern integrated circuits have higher complexities and reduced transistor sizing. In deep sub-micron, the parameter variation-control is difficult and component delays vary from one manufactured chip to another. Therefore, the delays are not discrete values but are a statistical quantity, and statistical evaluation methods have gained traction. Furthermore, fault injection based gate-level fault coverage is non-scalable and statistical estimation methods are preferred. This dissertation focuses on scalable statistical methods to select critical paths in the presence of process variations, and to improve the defect coverage for complex integrated circuits. In particular, we investigate the sensitization probability of a path by a test pattern under statistical delays. Next, we investigate test pattern generation for improving the sensitization probability of a path, selecting critical paths that yield high defect coverage, and scalable method to estimate fault coverage of complex designs using machine learning techniques.
282

Influência litoestrutural na reorganização da drenagem e na retração erosiva de um escarpa: um registro de capturas fluviais no ribeirão das Laranjeiras (Juquitiba, Ibiúna, São Lourenço da Serra - SP) / Litho-structural influence in the rearrangement of drainage and erosive retraction of an escarpment: a record of stream piracies at Laranjeiras river (municipalities of Juquitiba, Ibiúna and São Lourenço da Serra - SP)

Silva, Katiúcia de Sousa 11 October 2013 (has links)
Este trabalho consiste no estudo da adaptação da rede de drenagem ao embasamento litológico e estrutural em uma área interplanáltica, mediada por uma faixa de escarpamento. A área-foco da pesquisa é a bacia do ribeirão das Laranjeiras, tributário do rio Juquiá-Guaçu e localizado no sopé da Serra de Paranapiacaba. O principal problema da pesquisa é a hipótese da ocorrência de uma captura fluvial do rio Sorocabuçu, situado em nível de base mais elevado, pelo ribeirão das Laranjeiras. A metodologia partiu do exame de Modelos Digitais de Elevação e mapeamentos topográficos e geológicos anteriores, posteriormente submetidos a cálculos morfométricos específicos. Os procedimentos consistiram da identificação de feições de relevo incidentes na bacia (por meio do traçado do Esboço Geomorfológico e do reconhecimento de lineamentos); da investigação sobre a retração da frente escarpada; e da análise das curvas hipsométricas, geometria e perfis longitudinais dos canais mais representativos da bacia. Em seguida, foram examinadas as prováveis ocorrências de rearranjos de drenagem na área, manifestas por capturas fluviais e decapitações, correlacionando-as com as evidências previamente obtidas no estudo morfométrico. Entre os resultados principais, foi demonstrado que a rede hidrográfica em questão é condicionada por diversos fatores de ordem litológica e estrutural, que terminam por orientar os canais afluentes, bem como o canal principal (o ribeirão das Laranjeiras). Estas estruturas são, em geral, sistemas de juntas e falhas do Paleozóico em direção NE-SW. Entretanto, a bacia é seccionada por uma possível falha mais recente, intitulada Falha de Itanhaém, transcorrente dextral e orientada a NW-SE, que atuou como zona de fraqueza e favoreceu a captura do rio Sorocabuçu pelo ribeirão das Laranjeiras. Por fim, discute-se o recuo erosivo da Serra de Paranapiacaba e sua relação com estas estruturas geológicas e a dinâmica da rede de drenagem local. / This research is a study of the adaptation of the drainage network to a geological and structural base in an interplateau area, which is mediated by a escarpment. The area-focus of the research is the Laranjeiras river basin, tributary of the Juquiá-Guaçu river and located at the footslope of the Paranapiacaba mountain range. The main problem of the research was the hypothesed ocurrence of river piracy of the Sorocabuçu River, located in highest base level, by the Laranjeiras river, on the lowest one. The methodology differed from the exam of Digital Elevation Models and topographic and geological maps, which was subsequently subjected to morphometric specific calculations. The procedures consisted of identifying the relief features in the basin (by tracing the Geomorphological Sketch and lineaments recognition), researching the retration of front scarp and analysing the hypsometric curves, geometry and longitudinal profiles of channels most representatives in the basin. Then, we examined the likely occurrence of rearrangements in the drainage, manifested by river piracies and beheadings, correlating them with the evidence previously obtained in the morphometric study. Among the main results, it was demonstrated that the hydrographic network in question is conditioned by several lithologic and structural factors, which ultimately guide channel tributaries and the main channel (Laranjeiras river). These structures are, in general, systems of joints and faults from Paleozoic, in the NE-SW direction. However, the basin is cut by a possible, recent fault, titled Itanhaém fault, rightlateral strike-slip, oriented to NW-SE. This acts as a zone of weakness and favors carving and capturing of the Sorocabuçu river by Laranjeiras river. Finally, we discuss the retraction of the Paranapiacaba mountain range and its relationship with these geological structures and the dynamics of the local drainage.
283

Résistance des circuits cryptographiques aux attaques en faute / Resistance to fault attacks for cryptographic circuits

Bousselam, Kaouthar 25 September 2012 (has links)
Les blocs cryptographiques utilisés dans les circuits intégrés implémentent des algorithmes prouvés robustes contre la cryptanalyse. Toutefois des manipulations malveillantes contre le circuit lui-même peuvent permettre de retrouver les données secrètes. Entre autres, les attaques dites « en fautes » se sont révélés particulièrement efficaces. Leur principe consiste à injecter une faute dans le circuit (à l'aide d'un faisceau laser par exemple), ce qui produira un résultat erroné et à le comparer à un résultat correct. Il est donc essentiel de pouvoir détecter ces erreurs lors du fonctionnement du circuit.Les travaux de thèse présentées dans ce mémoire ont pour objet la détection concurrente d'erreurs dans les circuits cryptographique, en prenant comme support l'implantation du standard d'encryption symétrique l'Advanced Encryption standard « AES ». Nous analysons donc plusieurs schémas de détection d'erreur basés sur de la redondance d'information (code détecteur), certains issus de la littérature, d'autres originaux utilisant un double code de parité entrée-sortie permettant l'amélioration du taux de détection d'erreur dans ces circuits. Nous présentons aussi une étude montrant que le choix du type du code détecteur le plus approprié dépend, d'une part du type d'erreur exploitable pouvant être produite par un attaquant, et d'autre part du type d'implémentation du circuit à protéger. Les circuits cryptographiques sont également la cible d'autres attaques, et en particulier les attaques par analyse de consommation. Les contre mesures proposés jusqu'à lors pour un type d'attaques, se révèlent la plupart du temps néfastes sur la résistance du circuit face à d'autres types d'attaque. Nous proposons dans cette thèse une contre mesure conjointe qui protège le circuit à la fois contre les attaques en fautes et les attaques par analyse de consommation. / The cryptographic blocks used in the integrated circuits implement algorithms proved robust against cryptanalysis. However, malicious manipulation against the circuit itself can retrieve the secret data. Among known hardware attacks, attacks called "fault attacks" are proved particularly effective. Their principle is to inject a fault in the circuit (using for example a laser beam) that will produce an erroneous result and to compare it with a correct result. Therefore, it is essential to detect these errors during the circuit running.The work presented in this thesis concerns the concurrent detection of errors in cryptographic circuits, using as support the implementation of the Advanced Encryption Standard "AES". Thus, we analyze several error detection schemes based on the redundancy of information (detector code). We present a solution using dual code of parity to improve the rate of error detection in these circuits. We also present a study showing that the choice of the type of the detector code depends on one hand on the type of error that can be produced and be used by an attacker. On the other hand, it depends on type of the circuit implementation that we want to protect.The cryptographic circuits are also the target of further attacks, especially attacks by consumption analysis. The measures proposed against a type of attack, proved mostly negative against other types of attack. We propose in this work a joint measure that protects the circuit against both fault attacks and attacks by analysis of consumption.
284

Évaluation de méthodes faible consommation contre les attaques matérielles / Evaluation of low power methods against hardware attacks

Ordas, Sébastien 30 November 2015 (has links)
La consommation des circuits intégrés n'a cessé d'augmenter cette dernière décennie. Avec l'augmentation du prix de l'énergie et la démocratisation des systèmes embarqués, des méthodes permettant de gérer le compromis consommation performance, comme la gestion dynamique de la fréquence et de la tension d'alimentation ou encore du potentiel de substrat, ont été élaborées. Ces méthodes, qui sont de plus en plus couramment mises en œuvre dans les systèmes intégrés, permettent de diminuer la consommation de ceux-ci, et mieux de gérer le compromis consommation performance. Certains de ces circuits, embarquant ces méthodes peuvent avoir à effectuer des opérations traitant des informations confidentielles. Il est donc nécessaire de s'interroger sur l'éventuel impact de ces sur la sécurité des systèmes intégrés. Dans ce contexte, les travaux de thèse reportés dans le présent document, ont eu pour objectif d'analyser la compatibilité de ces méthodes de gestion de la consommation avec la conception de circuits robustes aux attaques matérielles. Plus particulièrement, l'objectif a été de déterminer si ces techniques de conception faible consommation, constituent des obstacles réels ou bien facilitent les attaques matérielles par observation et perturbation exploitant le canal électromagnétique. Dans un premier temps, une étude sur l'efficacité des attaques par observation en présence de gestion aléatoire de la tension, de la fréquence et de la polarisation de substrat a été conduite. Dans un deuxième temps, l'impact de la gestion dynamique des tensions d'alimentation et de substrat sur la capacité à injecter des fautes par médium électromagnétique a été étudié. Ce document présente l'ensemble des résultats de ces analyses.Mots-clés : Attaques Matérielles, Attaques par Canaux Auxiliaires, Attaques par fautes, Canal électromagnétique, DVFS, Body-Biasing. / The consumption of integrated circuits has been increasing over the last decade. With the increase of energy prices and the democratization of embedded systems, methods to manage the consumption performance compromise, such as the dynamic management of the frequency and the supply voltage or the substrate potential, were developed. These methods, which are becoming more commonly implemented in integrated systems, allow to reduce the consumption of those latter, and to better manage the tradeoff between consumption and performance.Some of these circuits, embedding these methods, may have to perform some operations with confidential information. It is therefore necessary to consider the possible impact of these methods on the safety of the integrated systems. In this context, the work reported in this thesis aimed to analyze the compatibility of these methods of power management with the design of robust circuits to physical attacks.Specifically, the objective was to determine whether these low-power techniques constitute real obstacles or facilitate the attacks by observation or perturbation exploiting the electromagnetic channel. Initially, a study on the effectiveness of attacks by observation in the presence of random management of voltage, frequency and substrate polarization was done. Secondly, the impact of the dynamic management of supply voltages and substrate polarization on the ability to inject faults by electromagnetic medium was studied. This document presents the overall results of these analyzes. Keyword : Hardware Attacks, Side Channel Attacks, Faults Attacks, Electromagnetic canal, DVFS, Body-biasing
285

Afundamentos de tensão em consumidores industriais : uma análise baseada no fator de impacto e na severidade dos eventos considerando os efeitos de faltas elétricas em sistemas de potência

Oliveira, Roger Alves de January 2018 (has links)
The present work deals with a comparative analysis of IEEE 1564 standardization and Module 8 of Distribution Procedures of the Brazilian Agency of Electrical Regulation, within the scope of voltage sags. For such comparison, a case study of monitoring is performed on an industrial consumer sensitive to the disturbance during 24 months. Additionally, since the main causes of the voltage sags are the electrical faults of the system to which the industry is inserted, the relations between both events are analyzed. From the simultaneity of these contingencies, a unique set of data was obtained through MATLAB R , which allowed the clustering of variables with K-means algorithm through WEKA software. Simultaneous events were also convenient for the validation of a simulation model in ANAFAS software. The results obtained with the application of such methodology allowed to know the impact of the events, to analyze the vulnerability area, to propose mitigations in the power system under study, as well as to validate a simulation model of sags with relative error less than 10 % to more than 70 % of cases.
286

Geologia estrutural aplicada a mineração subterrânea de carvão: Mina D, Araranguá, SC

Petry, Thales Sebben January 2017 (has links)
A mineração subterrânea na região carbonífera de Santa Catarina possui forte controle estrutural. A área de pesquisa da Mina D situa-se na porção NE do município de Araranguá. Este trabalho definiu o comportamento estrutural das rochas sedimentares e da camada de carvão Barro Branco na área de pesquisa através da avaliação integrada de imagens de satélite e dados de 100 furos de sondagem. As principais direções dos lineamentos identificadas nas imagens de satélite são N30º-60ºW, N60º-80ºE e N30º-60ºE. O mapa de contorno estrutural da camada de carvão e as seções geológicas mostram que a área é afetada por falhas normais de direção N30°-60°W, N50°-70°E, N10°-20°W e E-W. As falhas normais de direção NE apresentam extensão regional e exercem significativa influência no arranjo estrutural da área. Nesses casos os rejeitos são expressivos (>100 metros) e inviabilizam a recuperação econômica do carvão em algumas porções da área. A orientação das galerias deve ser de modo paralelo a estas falhas nas suas proximidades. As falhas normais de direção NW são as mais frequentes e possuem extensão e rejeitos menores (<30 metros). O planejamento da lavra deve considerar esse sistema de falhas, evitando o cruzamento das mesmas. As falhas normais de direção N-S foram identificadas na área e apresentam rejeitos expressivos (>70 metros). Ocorrem ainda falhas inversas associadas ao soerguimento ocasionado por intrusões de diabásio. Próximo a estas áreas podem ocorrer zonas de acúmulo de tensões, geralmente associadas a problemas de instabilidade de teto e levantamento de piso. A metodologia aplicada demonstrou ser eficiente na determinação prévia das estruturas tectônicas e na avaliação preliminar da sua influência na mineração subterrânea de carvão. / The underground coal mining in the carboniferous region of Santa Catarina state has a great structural control. The Mina D research area is located in the NE portion of the Araranguá city. This study has defined the structural bearing of the sedimentary rocks and the Barro Branco coal seam in the research area through the integrated evaluation of satellite images and 100 boreholes data. The major lineaments identified in the satellite images have N30º-60ºW, N60º-80ºE and N30º-60ºE directions. The coal seam structural contour map and the geological sections presents that the area is affected by normal faults which have N30°- 60°W, N50°-70°E, N10°-20°W and E-W directions. The NE direction normal faults have regional extension and are the most influent in the structural arrangement of the area. This faults have expressive tailings (>100 meters) and prevent the economic recover of the coal in some portions of the area. The galleries should be oriented parallel to it. The normal faults with NW direction is the most frequent and have minor extension and tailings (<30 meters). The mining plan should consider it in order to avoid have to cross it. The N-S direction normal faults were identified in the area and presents expressive tailings (>70 meters). Inverse faults occur associated with the uplift related to diabase sills intrusion. Close to this area may occur stress accumulation zones usually related to roof instability and floor heaving problems. The applied methods proved to be efficient in the determination of tectonic structures and in the preliminary evaluation of their influence on underground coal mining.
287

Testarbetets svåra val / The hard choice of testing

Jakupovic, Dennis, Makdessi, Jade, Vennberg, Robert January 2010 (has links)
När det talas om test pratas det på ett sätt som om det vore ett nytt fenomen, men i själva verket kan rötterna spåras tillbaks till 1978. Det är först på senare år som test har börjat etablera sig mer och mer och nyttan med test bland systemutvecklingsorganisationer respektive testorganisationer. Människan omges ständigt av information vare sig det är av elektronisk, fysiskt eller annan form. Det är därför inte så konstigt att tidsåldern människan befinner sig i kallas för ”informationsåldern”. Successivt har människan mer och mer etablerat ett beroende av verktygen för att ge stöd för informationen människan omges av i sin vardag. En del människor använder enkla mjukvarusystem medan en del använder mer komplexa mjukvarusystem och ibland till och med kritiska system som måste fungera felfritt. Om mjukvarusystemet har ett fel som hindrar mjukvarans funktionalitet kommer det att medföra konsekvenser beroende på vad konsekvensen medför och innebär för användaren. Det kan vara allt ifrån en personlig ekonomisk förlust till en livshotande konsekvens. Orsaken till konsekvensen kan exempelvis leda till felanvändning av mjukvaran, men oftast så ligger felet inte hos användaren utan att mjukvaran har en defekt och anledningen till det är förmodligen att mjukvaran inte testats tillräckligt. Det är därför av yttersta vikt att mjukvaran testas eftersom den annars skulle förlora sitt syfte i och med att den inte längre fyller en funktion. Test sträcker sig dock längre än att bara testa för att säkerställa att mjukvaran är felfri. Genom test kan mjukvarans kvalitet säkras, det kan generera lägre kostnader i längden genom att fel hittas innan den leverats till slutanvändaren, test medför även en kontroll av uppfyllnadsgraden av kravspecifikationerna som formulerats av kund. I dagens läge genomförs därför test alltmer agilt i systemutvecklingen och är därmed en procedur i systemutvecklingen till skillnad från den traditionella vattenfallsmodellen där test genomförs i slutfaserna av systemutvecklingen. Test utförs antingen av en systemutvecklingsorganisation eller en separat test organisation. I denna studie har därför ett antal delfrågor formulerats för att sedan på en mera detaljerad nivå belysa för- respektive nackdelar med hur test bedrivs i de respektive organisationerna och ett antal har identifierats. Bland många som identifierats så utmärks en särskild fördel och nackdel när en separat testorganisation samt när en systemutvecklingsorganisation bedriver test. Nämligen att test tar tid ifall en separat testorganisation bedriver test, men fördelen med det är att det medför att en mjukvara testats grundligt medan i en systemutvecklings-organisation så bedrivs test mer utifrån premisserna huruvida det ryms inom ramen för budgeten även om enhetstester och systemtester alltid utförs. Nackdelen med test inom systemutvecklingsorganisationen är att test tar mycket tid.
288

A Structural and 40Ar/39Ar Geochronological Re-Evaluation of Low-Angle Normal Faults in Southeastern Idaho

Vankeuren, Marc Anthony January 2015 (has links)
The development of gently inclined faults with large stratigraphic separation has long been enigmatic in the corridor of southeastern Idaho. Recent interpretations have culled examples from across the Basin and Range to suggest that these faults originated at a low dip and represent a regional scale low-angle normal fault system. In contrast, others cite extensive studies from fault mechanics and seismological data that cast doubt on whether these extensional structures could have formed at low inclination in the upper crust. This dissertation reviews the evidence and timing of the proposed Bannock detachment system in the Bannock Range of southeastern Idaho and puts forth a re-evaluation of the styles of extension in the region and a regional framework in which to place them. Chapter 1 re-evaluates gently dipping normal faults in the southern Bannock Range of southeastern Idaho that have previously been interpreted as evidence for a regional detachment system originating and slipping at a low inclination. Previous work was based on geometrical relations between faults and bedding in lacustrine sediments of the upper Miocene to lower Pliocene Salt Lake Formation. The detachment argument was underpinned by three locations on the Oxford Mountain at which Salt Lake Formation was inferred to have been cut by low-angle normal faults. These locations have been re-evaluated. Two of the locations were found to preserve bedding-to-fault geometries that are well explained by offset from a fault of moderately dipping inclination. The third example is re-interpreted as an unconformable contact, not a fault, an observation that by itself precludes the existence of a detachment at that location. Chapter 2 presents a test of tephronchronology by the 40Ar/39Ar isotopic method. This study compares ages obtained by the geochronologic method of tephrochronology to ages obtained by 40Ar/39Ar single grain laser fusion of feldspars. The results of this study suggest certain considerations must be made when employing the method of tephrochronology for chronological work. Chapter 3 presents a regional synthesis for the tectonics of southeastern Idaho expanding on the new data presented in chapters 1 and 2. 40Ar/39Ar ages obtained from the Salt Lake Formation show evidence that extension in this region was underway > 15 Ma. Bedding-to-fault cutoff angles for the low-angle faults with the largest stratigraphic separations in the region suggest that the now gently inclined normal faults developed with moderate to steep dips, then tilted to lower inclination during continued extension. A splay of the Paris thrust is interpreted to account for both geometric relations between Paleozoic age rocks and the Neoproterozoic Pocatello Formation, as well as an unconformable contact between Pocatello Formation and late Miocene to Pliocene lake deposits of the Salt Lake Formation. This dissertation focuses on one example of a detachment system. However, it has implications for low-angle faults in general – particularly in regions like the Basin and Range that have had a protracted deformation history. The examples we have studied are important because they involve strata as young as Pliocene and they provide strong support for the role of tilting in accounting for the present-day attitude of large-offset normal faults, eliminating the need for the well-known mechanical paradox of low-angle normal fault formation.
289

Directional Comparison Bus Protection Using Superimposed Partial Operating Current Characteristics

Baral, Bishwas 23 May 2019 (has links)
Various directional comparison bus protection methods including widely used superimposed directional element method need to have both voltages and currents from all feeders connected to the zone of protection to find the direction of current for detecting a bus fault or a line fault. The purpose of the thesis is to present a new technique for directional comparison bus protection to discriminate a bus fault from line fault and normal condition. The new technique, which is implementing superimposed directional element method to modify partial operating current characteristics (POC) method to superimposed POC (SPOC) method, does not use voltages from feeders, hence capacitor voltage transformers (CVTs) are no longer needed in the zone of protection. The proposed technique was implemented in 4-bus and IEEE 14-bus test system and was tested using different fault cases including CT saturation and high impedance fault. The proposed technique, SPOC method was compared with POC method with both methods implemented in same test systems and tested with same fault cases. The results show that the proposed technique is successful to detect bus faults with high accuracy and high speed.
290

Middle Miocene to Holocene History of the Delacroix Island Fault System

Levesh, Jarrett Leigh 23 May 2019 (has links)
An in-depth field study of the Delacroix Island producing field illustrates the evolution of the east-trending Delacroix Island Fault during the last 13 My. Well log correlations and 3-D seismic interpretation of 22 subsurface bio-stratigraphic horizons across the fault reveal variable stratigraphic thicknesses and displacement. Wells, with well log curve data as shallow as 31 m (100 ft) below the surface, were used to calculate interval thicknesses, expansion indices, sediment accumulation rates, burial history and magnitudes of displacement. Through these analyses, a correlation was found between the positioning of ancient Miocene depocenters over Delacroix Island and a period of increased fault activity. Historic satellite imagery (last 34 yrs) of the field depicts a lineation on the modern marsh surface coincident with the upward projected fault plane. Continuous wetland loss on the downthrown side of the fault trace suggests that recent and continued fault movement may be contributing to marsh submergence.

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