O objetivo desse estudo foi investigar os efeitos de diferentes estruturas de prática no processo adaptativo da aprendizagem de uma tarefa de timing coincidente em função da idade. Crianças (n=40), adultos (n=47) e idosos (n=57) foram distribuídos em grupos de prática constante, aleatória, constante-aleatória e aleatória-constante. A tarefa consistiu em tocar certos alvos de forma seqüencial em integração a um estímulo visual. O delineamento envolveu duas fases de aprendizagem: estabilização e adaptação. Os dados foram analisados em relação aos erros absoluto, variável, constante e de execução. Os resultados mostraram que o processo adaptativo na aprendizagem de crianças, adultos e idosos de uma tarefa de timing coincidente foi beneficiado pela prática constante-aleatória / The objective of this study was to investigate the effects of different practice schedule on the adaptive process of the coincident timing task learning in function of age. Children (n=40), adults (n=47) and elderly (n=57) were distributed in constant, random, constant-random and random-constant practices group. The task consisted of touching response keys sequentially in conjunction with a visual stimulus. The experimental design involved two learning phases: stabilization and adaptation. The data were analyzed in terms of absolute, variable, constant and execution errors. The results showed that adaptive process in the learning of children, adults and elderly of a coincident timing task was beneficed by constant-random practice

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-11T13:06:57Z No. of bitstreams: 1 fabianobolpatoloures.pdf: 543019 bytes, checksum: 65a181a5df2e1bf7806b640db3cdbb35 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-20T18:35:51Z (GMT) No. of bitstreams: 1 fabianobolpatoloures.pdf: 543019 bytes, checksum: 65a181a5df2e1bf7806b640db3cdbb35 (MD5) / Made available in DSpace on 2016-06-20T18:35:51Z (GMT). No. of bitstreams: 1 fabianobolpatoloures.pdf: 543019 bytes, checksum: 65a181a5df2e1bf7806b640db3cdbb35 (MD5) Previous issue date: 2013-02-18 / A transição demográfica causa o aumento das doenças crônico-degenerativas, entre elas a osteoporose. Esta doença se caracteriza por diminuição da resistência dos ossos e consequentes fraturas. Entre essas, a fratura do quadril, nome dado às fraturas proximais do fêmur em idosos, sendo a mais devastadora. Alta mortalidade e morbidade associadas, além de custos elevados para os pacientes, a família e a sociedade dão relevância ao assunto. O tempo decorrido entre o trauma e a cirurgia, que é o tratamento ideal, tem influência nos resultados do tratamento. No Brasil, esse tempo é alargado. As evidências são conflitantes na literatura com relação à mortalidade. Os efeitos em qualidade de vida são importantes, uma vez que poucos pacientes retomam as atividades do período anterior à fratura. O objetivo deste trabalho foi analisar os efeitos do tempo decorrido entre o trauma e a cirurgia sobre os custos diretos médico-hospitalares do tratamento e da qualidade de vida em forma de utilidade, medida por meio do instrumento EuroQol-5D, um instrumento genérico de medição de qualidade de vida que se utiliza de cinco dimensões para isso e é transformado em utilidade através de normativas populacionais. A utilidade é um valor cardinal que reúne, em uma só medida, morbidade e mortalidade, variando de 0, morte, a 1, saúde perfeita. Foram criadas duas subamostras, separadas pelo tempo, em precoce, até 4 dias, e tardia, após 4 dias entre o trauma e a cirurgia. Uma árvore de decisão foi utilizada como modelo de análise, para compreender o evento e calcular as probabilidades de óbito intra-hospitalar, óbito durante a recuperação e o resultado em utilidade, além dos custos. O tempo médio entre a fratura e a cirurgia, nesta amostra de 115 pacientes, foi de 9,35 dias, com a permanência média de 13,45 dias. Os resultados, após controle por idade, gênero, tipo de fratura, tipo de tratamento e risco anestésico (ASA) demonstraram influência clinicamente significativa do tempo na mortalidade intra-hospitalar e estatisticamente significativa nos custos (p<0,001), sobretudo devido à diária de enfermaria (p<0,001). A permanência do paciente também foi estatisticamente aumentada no grupo da cirurgia tardia (p<0,001). O custo médio da amostra foi de R$ 5.132,31 (DP= 3.201,92). A razão custo-utilidade do modelo foi de R$ 9.854,34 por QALY para a estratégia da cirurgia precoce. Esta estratégia mostrou-se dominante no modelo e consistentemente dominante após análise de sensibilidade de extremos. O atraso na cirurgia, na nossa região, deveu-se, principalmente, ao atraso na transferência do hospital que recebe o paciente até aquele que tem complexidade para tratá-lo. As linhas-guia brasileiras devem incluir a cirurgia precoce como parte dos objetivos do tratamento por ser mais custo-efetiva. / The demographic transition causes the increase of chronic degenerative diseases, including osteoporosis. This disease is characterized by decreased bone strength and subsequent fractures. Among these, the hip fracture, the name given to the proximal femoral fractures in the elderly, is the most devastating. High mortality and morbidity, as well as high costs for patients, family and society, give relevance to the subject. The time elapsed between trauma and surgery, which is the ideal treatment, has influence on the results of treatment. In Brazil this time is extended. There are conflicting evidence in the literature regarding mortality. The effects on quality of life are important since few patients resume activities from before the fracture. The objective of this study was to analyze the effects of time elapsed between trauma and surgery on the direct costs of medical and hospital treatment and quality of life in the form of utility, measured by the instrument EuroQol-5D, a generic instrument for measuring quality of life that uses five dimensions and is transformed into utility through the population norms. The utility is a cardinal value that brings together measure morbidity and mortality ranges from 0, death, to 1, which is perfect health. Two subsamples were created. They were separated by time. One was Early, until 4 days between trauma and surgery and the other was Late, until four days after. A decision tree was used as a model for analysis, to understand the event and calculate the odds of in-hospital deaths, deaths during the recovery and result in utility, as well as the costs. The average time between fracture and surgery in this sample of 115 patients was 9.35 days, with the average hospital stay of 13.45 days. The results, after being managed by age, gender, type of fracture, type of treatment and anesthetic risk (ASA) demonstrated clinically meaningful influence of time on inhospital mortality and statistically significant on costs (p <0.001) mainly due to nursery daily rate (p<0.001).The patient's stay was also statistically increased in the late surgery group (p <0.001). The average cost of the sample was R$ 5,132.31 (DP= 3,201.92). The cost-utility ratio of the model was R $ 9,854.34 per QALY for the early surgery strategy. This strategy proved to be dominant in the model and consistently dominant after analyzing the sensitivity of extremes. The delay of the surgery in our region, is primarily due to the delay in the transfer from the hospital that receives the patient to the hospital that has the complexity to treat him. The Brazilian-guidelines should include early surgery as part of the treatment goals because they are more cost-effective.

In today’s world, embedded systems which have very large and highly configurable software systems, consisting of hundreds of tasks with huge lines of code and mostly with real-time constraints, has replaced the traditional systems. Generally in real-time systems, the WCET of a program is a crucial component, which is the longest execution time of a specified task. WCET is determined by WCET analysis techniques and the values produced should be tight and safe to ensure the proper timing behavior of a real-time system. Static WCET is one of the techniques to compute the upper bounds of the execution time of programs, without actually executing the programs but relying on mathematical models of the software and the hardware involved. Mathematical models can be used to generate timing estimations on source code level when the hardware is not yet fully accessible or the code is not yet ready to compile. In this thesis, the methods used to build timing models developed by WCET group in MDH have been assessed by evaluating the accuracy of the resulting timing models for a number of combinations of hardware architecture. Furthermore, the timing model identification is extended for various hardware platforms, like advanced architecture with cache and pipeline and also included floating-point instructions by selecting benchmarks that uses floating-points as well.

Title: Coordination changes in a selected remote part of the locomotor system when walking in straight shoes and high heels. Objective: The aim of the dissertation is to find out how walking on a high heel affects the coordination changes and timing of the beginning of muscle activation in a selected part of the musculoskeletal system in comparison with walking in shoes with straight soles. Methods: This research work has an empirical, comparative intra-individual character. Comparative analysis of coordination characteristics of the locomotor system with the experimental character of obtaining quantitative data. We used a portable electromyograph BIOMONITOR ME6000 (Mega Electronics Ltd., Finland) to monitor changes in the timing of muscle coordination during walking in flat-soled and high-heeled shoes on flat terrain and on a treadmill. We recorded the synchronized video on a Sony HDR-SR12 digital video camera (SONY Co., Japan). Motor units and their electrical potential were sensed by self-adhesive homologated hydrogels electrodes MEDICO LEAD-LOK (Medico Electrodes Int., India, ISO 13485: 2003). The research group consisted of 30 healthy women (age 25 ± 5 years, weight 57 ± 7 kg, height 16 ± 5 cm, BMI 21 ± 3), all respondents are occasional wearers of high-heeled shoes. Results: We confirmed the...

The prompt gamma-ray timing (PGT) method offers a relatively simple approach for range verification in proton therapy. Starting from the findings of previous experiments, several steps toward a clinical application of PGT have been performed in this work. First of all, several scintillation materials have been investigated in the context of PGT. The time resolution was determined at high photon energies in the MeV-region. In conclusion, the fast and bright scintillator CeBr3 is the material of choice in combination with a timing photomultiplier tube as light detector. A second study was conducted at Universitäts Protonen Therapie Dresden (UPTD) to characterize the proton bunch structure of a clinical beam concerning its time width and relative arrival time. The data is mandatory as input for simulation studies and to correct for phase drifts. The obtained data could furthermore be used for the first 2D imaging of a heterogeneous phantom based on prompt gamma-rays. In a last step, a PGT prototype system was designed using the findings from the first two studies. The prototype system is based on a newly developed digital spectrometer and a CeBr3 detector. The device is characterized at the ELBE bremsstrahlung beam. It was verified that the prototype operates within the specifications concerning time and resolution as well as throughput rate. Finally, for the first time the PGT system was used under clinical conditions in the treatment room of UPTD. Here, PGT data was obtained from the delivery of a three-dimensional treatment plan onto PMMA phantoms. The spot-by-spot analysis helped to investigate the performance of the prototype device under clinical conditions. As a result, range variations of 5 mm could be detected for the first time with an uncollimated system at clinically relevant doses. To summarize, the obtained results help to bring PGT closer to a clinical application.

Les translocations chromosomiques sont associées à un grand nombre de cancers. Les translocations chromosomiques sont impliquées dans la tumorigenèse par différents mécanismes : elles conduisent soit à une dérégulation d’un oncogène, soit à la formation d’un nouvel oncogène de fusion. Cependant, le lien direct entre l'apparition d'une translocation chromosomique et la formation d'une tumeur n'est pas totalement établi. Par exemple, plusieurs translocations associées au cancer ont été détectées dans le sang d’individus sains voire dans le sang de cordon des bébés avec une prévalence bien supérieure à celle de la maladie. Ceci suggère que la seule formation de la translocation ne suffit pas toujours à induire l’oncogenèse. La plupart des travaux de recherche antérieurs reposaient sur la surexpression de la protéine de fusion, oncogène supposé. Ces approches présentent de nombreuses limites, la translocation chromosomique est alors absente de même que le contexte chromosomique natif du gène de fusion (promoteur endogène, statut de la chromatine, etc.) ou les éventuels effets d’haplo-insuffisance qui ne sont pas récapitulés. La molécule d’ADN étant organisée de manière non aléatoire dans le noyau, les réarrangements chromosomiques sont également susceptibles d’affecter le statut épigénétique, la réplication et la transcription du chromosome dérivatif entier, en plus des segments d’ADN nouvellement juxtaposés. Or la technologie CRISPR/Cas9, permet de reproduire la translocation chromosomique in situ, après avoir induit deux cassures double-brin simultanées. Ce travail de thèse a porté spécifiquement sur la translocation t(2,5) (p23, q35) qui induit l’expression de la protéine de fusion NPM1-ALK fréquemment rencontrée dans le lymphome anaplasique à grandes cellules (ALCL). Nous avons reproduit la t(2,5) à la fois dans des lignées cellulaires mais aussi dans des cellules T primaires à la fin de ma thèse. Nous avons pu montrer des modifications significatives du timing de réplication des cellules qui portent la translocation en comparaison des cellules isogéniques de départ (par la méthode du Répli-seq) pouvant avoir un impact sur l’homéostasie des cellules tumorales. En parallèle, nous avons mis en évidence la formation d'ARN circulaires de fusion spécifiques, exprimés à partir du gène de fusion, spécifiques des lignées tumorales. Ces ARN circulaires pourraient donner naissance à de nouveaux biomarqueurs diagnostic/pronostic dans le futur. Ces travaux permettront de mieux comprendre les conséquences des translocations chromosomiques oncogéniques dans les cellules humaines et pourraient mener vers de nouvelles orientations thérapeutiques à l’avenir. / Chromosomal translocations are associated with a wide range of cancers. These chromosomal rearrangements are implicated in tumorigenesis by different mechanisms: either they lead to oncogene upregulation or tumor suppressor downregulation. However, the direct link between the appearance of one chromosomal translocation and tumor formation is not always clear. For example, several cancer translocations have been found in PBMCs or in cord blood cells from healthy individuals, suggesting that translocation formation alone is not always sufficient to drive oncogenesis. Most of previous research works on cancer translocation relied on studies using overexpression of the fusion protein. These approaches do not reproduce the chromosome arm translocation nor the chromosomal context of the fusion gene (endogenous promotor, chromatin status etc…) or do not recapitulate a potential haplo-insufficiency of the translocated cells. Because the DNA molecule is organized non-randomly in the nucleus, chromosomal rearrangements are also likely to impact the epigenetic, replication and transcriptional status of the whole rearranged chromosome in addition to the newly juxtaposed gene segments. Using CRISPR/Cas9 technology, we can recapitulate chromosomal translocation in situ, after inducing 2 concurrent double-strand breaks. In this work, we focus on t(2,5)(p23,q35) leading to NPM1-ALK fusion protein frequently found in Anaplasic Large Cell Lymphoma (ALCL). We could recapitulate t(2;5) in cell lines but more importantly in human primary T cells from healthy donors. We showed significant modifications on Replication Timing in model cell lines compare to isogenic non-translocated cells (using Repli-seq analysis). Importantly, these changes might have a direct impact on tumor cell homeostasis. In parallel, we also highlighted the formation of specific fusion circular RNAs expressed from the fusion gene also found in tumor cells. These circular RNAs could give rise to new diagnostic/prognostic biomarkers in the future. This work will lead to a better understanding of the consequences of cancer translocation in human cells and could give new directions for therapeutics in future.

Dans le cadre de la certification de ses moteurs d'hélicoptères, Safran Helicopter Engines réalise des essais en fonctionnement lors desquels les réponses vibratoires de turbomachines (compresseurs et turbines) sont mesurées. Les réponses vibratoires contiennent des modes (ou raies spectrales) dont les fréquences et amplitudes doivent être caractérisées. Les mesures sont réalisées par la technologie tip-timing qui permet d'observer les vibrations de toutes les pales d'un aubage en rotation.Cependant, la technologie tip-timing présente deux spécificités importantes. Premièrement, l'échantillonnage des signaux de vibrations est irrégulier quasi-périodique. Deuxièmement, l'ordre de grandeur des fréquences de vibration est généralement supérieur à la fréquence d'échantillonnage équivalente. Ces deux caractéristiques donnent lieu à des artefacts des composantes fréquentielles sur les spectres des signaux de vibrations. Ceux-ci gênent alors fortement l'identification du contenu spectral et perturbent donc l'interprétation du comportement vibratoire des pales.La nouvelle méthode d'analyse spectrale proposée s'appuie sur une modélisation parcimonieuse des signaux tip-timing et prend en compte les variations de la fréquence de rotation. L'analyse spectrale des signaux est alors réalisée par la minimisation d'un critère des moindres carrés linéaires régularisé par une pénalisation de "norme-l0" par l'algorithme Block-OMP.À l'aide de résultats numériques sur signaux synthétiques, il est démontré que cette méthode fournit de bonnes performances d'estimations des composantes spectrales et réalise une réduction importante de leurs artefacts. La prise en compte des variations de la fréquence de rotation permet en effet de tirer profit de l'utilisation de longues durées d'observation afin de réduire significativement les artefacts des composantes fréquentielles contenus dans les spectres. Par ailleurs, avec des performances légèrement meilleures à celles de l'ESMV (méthode reconnue pour l'analyse spectrale des signaux tip-timing), la méthode proposée est environ cent fois plus rapide.Deux cas de données réelles sont étudiés. À travers une détection de crique de pale, le premier cas d'étude montre que la méthode proposée est pertinente et réalise des estimations comparables aux méthodes industrielles. Le second cas d'étude présente plusieurs vibrations synchrones et asynchrones simultanées. Cela met en avant la capacité de réduction des artefacts des composantes fréquentielles de la méthode développée afin de faciliter l'interprétation du contenu vibratoire complexe de ce signal.L'optimisation du placement des sondes tip-timing est également étudiée pour faciliter l'identification des composantes synchrones. À partir de résultats numériques, il est démontré qu'éloigner les capteurs améliore l'estimation des amplitudes ce type de composantes. / As part of the certification of its helicopter engines, Safran Helicopter Engines performs operational tests in which the vibrations responses of turbomachines (compressors and turbines) are measured. The vibratory responses contain modes (or spectral lines) whose frequencies and amplitudes must be characterized. The measurements are provided by the tip-timing technology which can observe the vibrations of all the blades while rotating.However, tip-timing technology has two important features. Firstly, the sampling of the vibrating signals is irregular quasi-periodic. Secondly, the vibrating frequencies are generally higher than the equivalent sampling frequency. These two characteristics generate frequency components artefacts onto the vibrating signals spectrum. As a consequence, they strongly hinder the identification of the spectral content and thus disturb the interpretation of the blades vibratory behaviour.The proposed new spectral analysis method relies on sparse modelling of the tip-timing signals and considers the variations of the rotational frequency. The spectral analysis of the signals is then performed by the minimization of a linear least squares criterion regularized by a penalty of "norm-l0" by the Block-OMP algorithm.Using numerical results from synthetic signals, it is shown that this method provides good spectral component estimation performances and achieves a significant reduction of their artefacts. Considering the variations of the rotational frequency allows to take advantage of the use of long observation periods in order to significantly reduce the frequency components artefacts contained in the spectrum. In addition, with slightly better performances than the ESMV (acknowledged method for the tip-timing signals spectral analysis), the proposed method is about a hundred times faster.Two cases of real data are studied. Through a detection of a blade crack, the first studied case shows that the proposed method is relevant and makes equivalent estimates with respect to industrial methods. The second studied case presents several simultaneous synchronous and asynchronous vibrations. That highlights the ability to reduce the frequency components artefacts of the developed method in order to simplify the interpretation of the complex vibratory content of this signal.The optimization of the positioning of the tip-timing probes is also studied in order to simplify the identification of synchronous components. From numerical results, it is demonstrated that moving away the probes improves the amplitudes estimation of this type of components.

In 2002, Baker and Wurgler posited that capital structure is the cumulative outcome of past attempts to time the equity market. Due to this theory´s recent introduction it has not been subjected to the same comprehensive testing as other financing theories. Most importantly, this theory lacks extensive industry and country specific testing that is required to truly understand its explanatory power. Thus, the purpose of this thesis is to evaluate the applicability of the market timing theory on a country and industry specific level. Given these constraints, the study measured the market timing effects on Swedish real estate firms by performing a panel data regression with yearly financial data from 1991 through 2021. In addition, due to the time-varying nature of capital structure, the data was further divided into three sub periods. First, the study controls for short-term effects by regressing market-to-book with three components of leverage. The results suggest a positive relationship between equity issues and market-to-book values, indicating support for short-term market timing effects. Next, the study implements the external financed weighted-average market-to-book variable to measure if the market timing effects are indeed persistent over the long run. Opposing the market timing theory, the results do not find any support for long-term effects. Instead, the findings imply that firms likely rebalance their capital structure shortly after equity market timing attempts. / År 2002 påstod Baker och Wurgler att ett företags kapitalstruktur är det kumulativa resultatet av historiska försök att tajma aktiemarknaden. Då denna teori är relativt ny så har den inte utsatts för samma rigorösa prövning som äldre finansieringsteorier. Med andra ord så saknar teorin i synnerhet omfattande bransch-och-nationsspecifika tester. Syftet med denna avhandling är därmed att undersöka Market-timing-teorins applicerbarhet på svenska fastighetsföretag genom att utföra en paneldataregression med årliga finansiella data mellan 1991 och 2021. På grund av kapitalstrukturens tidsvarierande karaktär delades studiens data upp i tre tidsintervall. Först kontrollerade studien för kortsiktiga effekter genom regression av market-to-book med tre komponenter av skuldsättningsgraden. Resultaten tyder på ett positivt samband mellan aktieemissioner och market-to-book, vilket indikerar stöd för kortsiktiga effekter av market-timing. Därefter implementerar studien External Finance Weighted-Average Market-to-book variabeln för att mäta om market-timing-effekterna verkligen är ihållande på lång sikt. I motsats till market-timing-teorin finner resultaten inte något stöd för långsiktiga effekter. I stället antyder resultaten att företag sannolikt balanserar om sin kapitalstruktur kort efter försök av market-timing.

Os recentes avanços experimentados pela tecnologia CMOS tem permitido a fabricação de transistores em dimensões submicrônicas, possibilitando a integração de dezenas de milhões de dispositivos numa única pastilha de silício, os quais podem ser usados na implementação de sistemas eletrônicos muito complexos. Este grande aumento na complexidade dos projetos fez surgir uma demanda por ferramentas de verificação eficientes e sobretudo que incorporassem modelos físicos e computacionais mais adequados. A verificação de timing objetiva determinar se as restrições temporais impostas ao projeto podem ou não ser satisfeitas quando de sua fabricação. Ela pode ser levada a cabo por meio de simulação ou por análise de timing. Apesar da simulação oferecer estimativas mais precisas, ela apresenta a desvantagem de ser dependente de estímulos. Assim, para se assegurar que a situação crítica é considerada, é necessário simularem-se todas as possibilidades de padrões de entrada. Obviamente, isto não é factível para os projetos atuais, dada a alta complexidade que os mesmos apresentam. Para contornar este problema, os projetistas devem lançar mão da análise de timing. A análise de timing é uma abordagem independente de vetor de entrada que modela cada bloco combinacional do circuito como um grafo acíclico direto, o qual é utilizado para estimar o atraso do circuito. As primeiras ferramentas de análise de timing utilizavam apenas a topologia do circuito para estimar o atraso, sendo assim referenciadas como analisadores de timing topológicos. Entretanto, tal aproximação pode resultar em estimativas demasiadamente pessimistas, uma vez que os caminhos mais longos do grafo podem não ser capazes de propagar transições, i.e., podem ser falsos. A análise de timing funcional, por sua vez, considera não apenas a topologia do circuito, mas também as relações temporais e funcionais entre seus elementos. As ferramentas de análise de timing funcional podem diferir por três aspectos: o conjunto de condições necessárias para se declarar um caminho como sensibilizável (i.e., o chamado critério de sensibilização), o número de caminhos simultaneamente tratados e o método usado para determinar se as condições de sensibilização são solúveis ou não. Atualmente, as duas classes de soluções mais eficientes testam simultaneamente a sensibilização de conjuntos inteiros de caminhos: uma baseia-se em técnicas de geração automática de padrões de teste (ATPG) enquanto que a outra transforma o problema de análise de timing em um problema de solvabilidade (SAT). Apesar da análise de timing ter sido exaustivamente estudada nos últimos quinze anos, alguns tópicos específicos não têm recebido a devida atenção. Um tal tópico é a aplicabilidade dos algoritmos de análise de timing funcional para circuitos contendo portas complexas. Este constitui o objeto básico desta tese de doutorado. Além deste objetivo, e como condição sine qua non para o desenvolvimento do trabalho, é apresentado um estudo sistemático e detalhado sobre análise de timing funcional. / The recent advances in CMOS technology have allowed for the fabrication of transistors with submicronic dimensions, making possible the integration of tens of millions devices in a single chip that can be used to build very complex electronic systems. Such increase in complexity of designs has originated a need for more efficient verification tools that could incorporate more appropriate physical and computational models. Timing verification targets at determining whether the timing constraints imposed to the design may be satisfied or not. It can be performed by using circuit simulation or by timing analysis. Although simulation tends to furnish the most accurate estimates, it presents the drawback of being stimuli dependent. Hence, in order to ensure that the critical situation is taken into account, one must exercise all possible input patterns. Obviously, this is not possible to accomplish due to the high complexity of current designs. To circumvent this problem, designers must rely on timing analysis. Timing analysis is an input-independent verification approach that models each combinational block of a circuit as a direct acyclic graph, which is used to estimate the critical delay. First timing analysis tools used only the circuit topology information to estimate circuit delay, thus being referred to as topological timing analyzers. However, such method may result in too pessimistic delay estimates, since the longest paths in the graph may not be able to propagate a transition, that is, may be false. Functional timing analysis, in turn, considers not only circuit topology, but also the temporal and functional relations between circuit elements. Functional timing analysis tools may differ by three aspects: the set of sensitization conditions necessary to declare a path as sensitizable (i.e., the so-called path sensitization criterion), the number of paths simultaneously handled and the method used to determine whether sensitization conditions are satisfiable or not. Currently, the two most efficient approaches test the sensitizability of entire sets of paths at a time: one is based on automatic test pattern generation (ATPG) techniques and the other translates the timing analysis problem into a satisfiability (SAT) problem. Although timing analysis has been exhaustively studied in the last fifteen years, some specific topics have not received the required attention yet. One such topic is the applicability of functional timing analysis to circuits containing complex gates. This is the basic concern of this thesis. In addition, and as a necessary step to settle the scenario, a detailed and systematic study on functional timing analysis is also presented.

Os recentes avanços experimentados pela tecnologia CMOS tem permitido a fabricação de transistores em dimensões submicrônicas, possibilitando a integração de dezenas de milhões de dispositivos numa única pastilha de silício, os quais podem ser usados na implementação de sistemas eletrônicos muito complexos. Este grande aumento na complexidade dos projetos fez surgir uma demanda por ferramentas de verificação eficientes e sobretudo que incorporassem modelos físicos e computacionais mais adequados. A verificação de timing objetiva determinar se as restrições temporais impostas ao projeto podem ou não ser satisfeitas quando de sua fabricação. Ela pode ser levada a cabo por meio de simulação ou por análise de timing. Apesar da simulação oferecer estimativas mais precisas, ela apresenta a desvantagem de ser dependente de estímulos. Assim, para se assegurar que a situação crítica é considerada, é necessário simularem-se todas as possibilidades de padrões de entrada. Obviamente, isto não é factível para os projetos atuais, dada a alta complexidade que os mesmos apresentam. Para contornar este problema, os projetistas devem lançar mão da análise de timing. A análise de timing é uma abordagem independente de vetor de entrada que modela cada bloco combinacional do circuito como um grafo acíclico direto, o qual é utilizado para estimar o atraso do circuito. As primeiras ferramentas de análise de timing utilizavam apenas a topologia do circuito para estimar o atraso, sendo assim referenciadas como analisadores de timing topológicos. Entretanto, tal aproximação pode resultar em estimativas demasiadamente pessimistas, uma vez que os caminhos mais longos do grafo podem não ser capazes de propagar transições, i.e., podem ser falsos. A análise de timing funcional, por sua vez, considera não apenas a topologia do circuito, mas também as relações temporais e funcionais entre seus elementos. As ferramentas de análise de timing funcional podem diferir por três aspectos: o conjunto de condições necessárias para se declarar um caminho como sensibilizável (i.e., o chamado critério de sensibilização), o número de caminhos simultaneamente tratados e o método usado para determinar se as condições de sensibilização são solúveis ou não. Atualmente, as duas classes de soluções mais eficientes testam simultaneamente a sensibilização de conjuntos inteiros de caminhos: uma baseia-se em técnicas de geração automática de padrões de teste (ATPG) enquanto que a outra transforma o problema de análise de timing em um problema de solvabilidade (SAT). Apesar da análise de timing ter sido exaustivamente estudada nos últimos quinze anos, alguns tópicos específicos não têm recebido a devida atenção. Um tal tópico é a aplicabilidade dos algoritmos de análise de timing funcional para circuitos contendo portas complexas. Este constitui o objeto básico desta tese de doutorado. Além deste objetivo, e como condição sine qua non para o desenvolvimento do trabalho, é apresentado um estudo sistemático e detalhado sobre análise de timing funcional. / The recent advances in CMOS technology have allowed for the fabrication of transistors with submicronic dimensions, making possible the integration of tens of millions devices in a single chip that can be used to build very complex electronic systems. Such increase in complexity of designs has originated a need for more efficient verification tools that could incorporate more appropriate physical and computational models. Timing verification targets at determining whether the timing constraints imposed to the design may be satisfied or not. It can be performed by using circuit simulation or by timing analysis. Although simulation tends to furnish the most accurate estimates, it presents the drawback of being stimuli dependent. Hence, in order to ensure that the critical situation is taken into account, one must exercise all possible input patterns. Obviously, this is not possible to accomplish due to the high complexity of current designs. To circumvent this problem, designers must rely on timing analysis. Timing analysis is an input-independent verification approach that models each combinational block of a circuit as a direct acyclic graph, which is used to estimate the critical delay. First timing analysis tools used only the circuit topology information to estimate circuit delay, thus being referred to as topological timing analyzers. However, such method may result in too pessimistic delay estimates, since the longest paths in the graph may not be able to propagate a transition, that is, may be false. Functional timing analysis, in turn, considers not only circuit topology, but also the temporal and functional relations between circuit elements. Functional timing analysis tools may differ by three aspects: the set of sensitization conditions necessary to declare a path as sensitizable (i.e., the so-called path sensitization criterion), the number of paths simultaneously handled and the method used to determine whether sensitization conditions are satisfiable or not. Currently, the two most efficient approaches test the sensitizability of entire sets of paths at a time: one is based on automatic test pattern generation (ATPG) techniques and the other translates the timing analysis problem into a satisfiability (SAT) problem. Although timing analysis has been exhaustively studied in the last fifteen years, some specific topics have not received the required attention yet. One such topic is the applicability of functional timing analysis to circuits containing complex gates. This is the basic concern of this thesis. In addition, and as a necessary step to settle the scenario, a detailed and systematic study on functional timing analysis is also presented.