Power distribution networks (PDNs) are conducting structures employed in semiconductor systems with the aim of providing circuits with reliable and constant operating voltage. This network has non-neglible electrical parasitics. Consequently, when digital circuits inside the chip switch, the supply voltage delivered to them does not remain ideal and exhibits spatial and temporal voltage fluctuations. These fluctuations in the supply voltage, known as the power-supply noise (PSN), can affect the functionality and the performance of modern microprocessors. The design of this PDN in the chip is an important part in ensuring power integrity. Modeling and simulation of the PSN in on-chip PDNs is important to reduce the cost of processors. These PDNs have irregular geometries, which affect the PSN. As a result, they have to be modeled. The problem sizes encountered in this simulation are usually large (on the order of millions), necessitating computationally efficient simulation approaches. Existing approaches for this simulation do not guarantee at least one of the following three required properties: computationally efficiency, accuracy, and numerically robustness. Therefore, there is a need to develop accurate, numerically robust, and efficient algorithms for this simulation. For many interconnects (e.g., transmission lines, board connectors, package PDNs), only their frequency responses and SPICE circuits (e.g., nonlinear switching drivers, equivalent circuits of interconnects) terminating them are known. These frequency responses are usually available only up to a certain maximum frequency. Simulating the electrical behavior of these systems is important for the reliable design of microprocessors and for their faster time-to-market. Because terminations can be nonlinear, a transient simulation is required. There is a need for a transient simulation of band-limited frequency-domain data characterizing a multiport passive system with SPICE circuits. The number of ports can be large (greater than or equal to 100 ports). In this simulation, unlike in traditional circuit simulators, normal properties like stability and causality of transient results are not automatically met and have to be ensured. Existing techniques for this simulation do not guarantee at least one of the following three required properties: computationally efficiency for a large number of ports, causality, and accuracy. Therefore, there is a need to develop accurate and efficient time-domain techniques for this simulation that also ensure causality. The objectives of this Ph.D. research are twofold: 1) To develop accurate, numerically robust, and computationally efficient time-domain algorithms to compute PSN in on-chip PDNs with irregular geometries. 2) To develop accurate and computationally efficient time-domain algorithms for the causal cosimulation of band-limited frequency-domain data with SPICE circuits.

The purpose of this thesis is to create a high school digital photography curriculum that is relevant to real world application and would enable high school students to enter the work force with marketable skills or go on to post secondary education with advanced knowledge in the field of digital imaging.

Produto de uma pesquisa teórica e empírica, esta dissertação aborda um campo conceitual comum entre a área de projeto pertencente à arquitetura e ao design, a formação escolar básica e as tecnologias digitais de modelagem e fabricação. Tal temática pauta-se na contemporaneidade, na medida em que se inserem novos meios de apoio ao ensino e aprendizado na formação escolar básica. Desse modo, o computador até então utilizado como processador de texto e imagens, alia-se à modelagem, à fabricação digital e à comunicação em rede. Como abordado nessa dissertação, o termo \"design\" é empregado com distintos enfoques no campo da formação escolar básica, o primeiro deles de caráter mais vinculado ao campo das artes, enquanto o segundo insere-se no campo das tecnologias de fabricação e no estudo da cultura material da sociedade contemporânea. Tendo em vista o campo comum dessas ações permeando as áreas de projeto, formação básica escolar e tecnologias digitais, esta investigação considera a partir uma base teórica, um grupo de dezoito pontos de convergência que subsidiou os trabalhos de campo. Esses trabalhos foram estruturados a partir de quatro tipos de oficinas realizadas na periferia da cidade de Guarulhos, região metropolitana de São Paulo, organizadas em um ambiente de livre acesso e que foram detalhadas nesse trabalho. Essa formulação teórico-prática visa traçar considerações acerca do campo comum estudado em que, tecnologias digitais de modelagem e fabricação têm auxiliado no desenvolvimento de linguagens e habilidades mentais em um público inserido na formação escolar básica. Pretende-se assim avançar no debate sobre a formação do indivíduo na atualidade. / The product of a theoretical and empiric research, this paper discusses a common conceptual ground among the project area -which includes the architecture and the design-, basic education, and digital modelling and manufacturing technologies. Its subject is based on the contemporaneity, to the extent that it introduces new means of support for learning and teaching in basic education. In this way, the computer -to that moment used exclusively for text and image processing- allies with modelling, digital manufacturing, and network communication. As herein discussed, the word \"design\" is used with different meanings in the field of basic education, the first of which has a stronger relation with the field of arts, whereas the second one lies within the field of manufacturing technologies and the studies on the material culture of the contemporary society. Considering the common ground of said activities, which permeate the fields of design, basic education and digital technology, this research take into account a group of eighteen common points of agreement from a theoretical basis that subsided the field studies. Those studies were structured from four types of workshop held in the outskirts of Guarulhos, in the metropolitan region of São Paulo, organized in a free-access environment, and which are herein detailed. This theoretical and practical formulation has as purpose to address the considerations resulting from the studied common ground, insofar as digital modelling and manufacturing technologies has helped the development of languages and mental skills of such a young audience still in basic education. The aim is to advance the debate on the formation of the individual nowadays.

<p>A Monte Carlo simulation of the Neutron Wall detector system has been performed using Geant4, in order to define optimum conditions for the detection and identification of multiple neutrons. Emphasis was put on studying the scattering of neutrons between different detectors, which is the main source of the apparent increase of the number of detected neutrons. The simulation has been compared with experimental data. The quality of neutron gated γ-ray spectra was improved for both two- and three-neutron evaporation channels. The influence of small amounts of γ rays mis-interpreted as neutrons was investigated. It was found that such γ rays dramatically reduce the quality of neutron gated γ-ray spectra.</p><p>The interaction properties of fast neutrons in a closed-end coaxial and a planar high-purity germanium detector (HPGe) were studied. Digitised waveforms of HPGe preamplifier signals were recorded for time-of-flight separated neutrons and γ rays, emitted by a ²⁵²Cf source. The experimental waveforms from the detectors were compared to simulated pulse shapes. In the analysis, special emphasis was given to the detection of elastically scattered neutrons, which may be an important effect to take into account in future spectrometers based on γ-ray tracking. No differences between neutron and γ-ray induced pulse shapes were found in this work.</p><p>A Monte Carlo simulation of the interactions of fast neutrons in the future 4π γ-ray spectrometer AGATA was also performed, in order to study the influence of neutrons on γ-ray tracking. It was shown that although there is a large probability of detecting neutrons in AGATA, the neutrons decrease the photo-peak efficiency of AGATA by only about 1% for each neutron emitted in coincidence with γ rays. The peak-to-background ratios in γ-ray spectra are, however, reduced to a much larger extent. The possibility of using AGATA as a neutron detector system was also investigated.</p>

A Monte Carlo simulation of the Neutron Wall detector system has been performed using Geant4, in order to define optimum conditions for the detection and identification of multiple neutrons. Emphasis was put on studying the scattering of neutrons between different detectors, which is the main source of the apparent increase of the number of detected neutrons. The simulation has been compared with experimental data. The quality of neutron gated γ-ray spectra was improved for both two- and three-neutron evaporation channels. The influence of small amounts of γ rays mis-interpreted as neutrons was investigated. It was found that such γ rays dramatically reduce the quality of neutron gated γ-ray spectra. The interaction properties of fast neutrons in a closed-end coaxial and a planar high-purity germanium detector (HPGe) were studied. Digitised waveforms of HPGe preamplifier signals were recorded for time-of-flight separated neutrons and γ rays, emitted by a 252Cf source. The experimental waveforms from the detectors were compared to simulated pulse shapes. In the analysis, special emphasis was given to the detection of elastically scattered neutrons, which may be an important effect to take into account in future spectrometers based on γ-ray tracking. No differences between neutron and γ-ray induced pulse shapes were found in this work. A Monte Carlo simulation of the interactions of fast neutrons in the future 4π γ-ray spectrometer AGATA was also performed, in order to study the influence of neutrons on γ-ray tracking. It was shown that although there is a large probability of detecting neutrons in AGATA, the neutrons decrease the photo-peak efficiency of AGATA by only about 1% for each neutron emitted in coincidence with γ rays. The peak-to-background ratios in γ-ray spectra are, however, reduced to a much larger extent. The possibility of using AGATA as a neutron detector system was also investigated.

Analog-to-digital converter (ADC) is the main workhorse in a digital waveform recorder. Strictly speaking, an ADC is supposed to perform uniformly, irrespective of the characteristics of the signal to be acquired. However, because of certain hardware related inconsistencies, its performance declines, particularly, when acquiring non-repetitive, fast-rising, high frequency signals. The error and distortion contributed due to its declining performance, for the entire range of signals, can be comprehensively characterized by the static and dynamic nonlinearities. Actual testing of ADCs is the only way of estimating these indices. These characteristics reveal information at the microscopic level, such as bit-level aberrations, code transitions, response and settling trends, etc. These tests attain greater significance, when the digitizer is part of a reference measuring or a calibration system, because, the levels of accuracies to be achieved in such a setup may become comparable to the error introduced by the ADC. Hence, testing ADCs is a priority. International and national standards exist for testing digital waveform recorders and ADCs. For several years, the matter related to reducing static test time of high-resolution ADCs was highlighted through many publications. A critical examination of the literature indicates the major schools-of-thought pursued so far, are, (i) refinements to ramp/triangular signal based static testing, (ii) proposals for use of alternative methods and/or test signals for static test, (iii) innovative ways of achieving a relaxation in signal source requirements and, (iv) efforts to combine static and dynamic test into a single test with an appropriate test signal. As a consequence of the literature review, objectives of the thesis were formulated. They attempt to resolve- (i) Conceive a suitable test signal for simultaneous estimation of static and dynamic nonlinearity through a single test (ii) Explore possibility of employing a low-linearity ramp signal to estimate static nonlinearity (iii) Estimating static nonlinearity by exploiting linearity property of a sine signal • In the first part of the thesis, a method is proposed for the concurrent estimation of static and dynamic nonlinearity characteristics of an ADC, with the application of a single test signal. The novelty arises from the fact that the test signal proposed is new, and so is the concept of extracting the static and dynamic nonlinearity from the ADC output. This was achieved by conceiving a test signal, comprising of a high frequency sinusoid (which addresses the dynamic requirement), modulated by a low frequency ramp (which addresses the static requirement). • Static characteristics of an ADC can be determined directly from the histogram-based quasi-static approach by measuring the ADC output, when excited by an ideal ramp/triangular signal of sufficiently low frequency. This approach requires only a fraction of time compared to the conventional DC test, is straightforward, easy to implement, and, in principle is an accepted method as per the revised IEEE-1057. However, the only drawback is that ramp signal sources are not ideal. Thus, nonlinearity present in the ramp signal gets superimposed on the measured ADC characteristics, which renders them, as such, unusable. The second part of the work describes a proposal to get rid of the ramp signal nonlinearity, before it is applied to the ADC. A simple method is presented which employs a low-linearity ramp signal, but yet causes only a fraction of influence on the measured ADC static characteristics. • The third part of the thesis describes a novel method to estimate the actual static characteristics of an ADC using a low frequency sine signal, say, less than 10 Hz, by employing the histogram-based approach. It is based on the well known fact that variation of sine signal is ‘reasonably linear,’ when the angle is small. In the proposed method, the ADC under test has to be ‘fed’ with this ‘linear’ portion of the sine wave. Due to harmonics and offset in input excitation, this ‘linear’ part of the sine signal is marginally different, compared to an ideal ramp signal of equal amplitude. However, since it is a sinusoid, this difference can be accurately determined and later compensated from the measured ADC output. Thus, the corrected ADC output will correspond to the true ADC static nonlinearity. The proposed approach successfully addresses all the three concerns while estimating static linearity, i.e. it is time-efficient, excites all the ADC code-bins reasonably uniformly and tackles the source linearity issue quite nicely. These proposals are novel, simple, easy to implement, time-efficient and importantly static nonlinearity characteristics determined from them are in good agreement with that estimated by the original DC-based technique. Implementation of each method is discussed along with experimental results, for two 8-bit digital oscilloscopes and a 10-bit real time digitizer. Further details are presented in the thesis.

Este trabalho apresenta uma arquitetura para simulação de circuitos de lógica com binacional de topologia arbitrária, visando interfaceamento com algoritmos evolutivos para fins de geração de hardware. A implementação é em FPGA utilizando a técnica VRC. O simulador permite circuitos compostos por LUTs de número de entradas parametrizável. A livre interconectividade entre as LUTs permite a construção de circuitos cíclicos. A arquitetura é modular e de interfaceamento simples. Alta performance é obtida através do uso de múltiplos módulos de simulação em paralelo, trazendo resultados que ultrapassam os obtidos em outros trabalhos utilizando DPR. / This work presents an architecture for simulation of combinational logic circuits of arbitrary topology, meant to be interfaced with evolutionary algorithms for hardware generation. It was implemented in FPGA using the VRC technique. The simulator allows for circuits composed of LUTs of parametrizable number of imputs. The free interconectivity between LUTs allows the construction of cyclic circuits. The architecture is modular and of simple interfacing. High performance is obtained by the use of multiple simulation modules in parallel, bringing results that surpass the ones obtained from other works based on DPR.

Este trabalho apresenta uma arquitetura para simulação de circuitos de lógica com binacional de topologia arbitrária, visando interfaceamento com algoritmos evolutivos para fins de geração de hardware. A implementação é em FPGA utilizando a técnica VRC. O simulador permite circuitos compostos por LUTs de número de entradas parametrizável. A livre interconectividade entre as LUTs permite a construção de circuitos cíclicos. A arquitetura é modular e de interfaceamento simples. Alta performance é obtida através do uso de múltiplos módulos de simulação em paralelo, trazendo resultados que ultrapassam os obtidos em outros trabalhos utilizando DPR. / This work presents an architecture for simulation of combinational logic circuits of arbitrary topology, meant to be interfaced with evolutionary algorithms for hardware generation. It was implemented in FPGA using the VRC technique. The simulator allows for circuits composed of LUTs of parametrizable number of imputs. The free interconectivity between LUTs allows the construction of cyclic circuits. The architecture is modular and of simple interfacing. High performance is obtained by the use of multiple simulation modules in parallel, bringing results that surpass the ones obtained from other works based on DPR.

Produto de uma pesquisa teórica e empírica, esta dissertação aborda um campo conceitual comum entre a área de projeto pertencente à arquitetura e ao design, a formação escolar básica e as tecnologias digitais de modelagem e fabricação. Tal temática pauta-se na contemporaneidade, na medida em que se inserem novos meios de apoio ao ensino e aprendizado na formação escolar básica. Desse modo, o computador até então utilizado como processador de texto e imagens, alia-se à modelagem, à fabricação digital e à comunicação em rede. Como abordado nessa dissertação, o termo \"design\" é empregado com distintos enfoques no campo da formação escolar básica, o primeiro deles de caráter mais vinculado ao campo das artes, enquanto o segundo insere-se no campo das tecnologias de fabricação e no estudo da cultura material da sociedade contemporânea. Tendo em vista o campo comum dessas ações permeando as áreas de projeto, formação básica escolar e tecnologias digitais, esta investigação considera a partir uma base teórica, um grupo de dezoito pontos de convergência que subsidiou os trabalhos de campo. Esses trabalhos foram estruturados a partir de quatro tipos de oficinas realizadas na periferia da cidade de Guarulhos, região metropolitana de São Paulo, organizadas em um ambiente de livre acesso e que foram detalhadas nesse trabalho. Essa formulação teórico-prática visa traçar considerações acerca do campo comum estudado em que, tecnologias digitais de modelagem e fabricação têm auxiliado no desenvolvimento de linguagens e habilidades mentais em um público inserido na formação escolar básica. Pretende-se assim avançar no debate sobre a formação do indivíduo na atualidade. / The product of a theoretical and empiric research, this paper discusses a common conceptual ground among the project area -which includes the architecture and the design-, basic education, and digital modelling and manufacturing technologies. Its subject is based on the contemporaneity, to the extent that it introduces new means of support for learning and teaching in basic education. In this way, the computer -to that moment used exclusively for text and image processing- allies with modelling, digital manufacturing, and network communication. As herein discussed, the word \"design\" is used with different meanings in the field of basic education, the first of which has a stronger relation with the field of arts, whereas the second one lies within the field of manufacturing technologies and the studies on the material culture of the contemporary society. Considering the common ground of said activities, which permeate the fields of design, basic education and digital technology, this research take into account a group of eighteen common points of agreement from a theoretical basis that subsided the field studies. Those studies were structured from four types of workshop held in the outskirts of Guarulhos, in the metropolitan region of São Paulo, organized in a free-access environment, and which are herein detailed. This theoretical and practical formulation has as purpose to address the considerations resulting from the studied common ground, insofar as digital modelling and manufacturing technologies has helped the development of languages and mental skills of such a young audience still in basic education. The aim is to advance the debate on the formation of the individual nowadays.

A débit de données élevé, typiquement supérieur à 10 Gsymboles/s, les lignes de<p>télécommunication optique à fibre monomode souffrent de façon accrue des distorsions<p>inhérentes à la fibre et à l’architecture de transmission. Nous pouvons classer les<p>effets de fibre en plusieurs catégories:<p>– Les effets linéaires. La dispersion chromatique est entraînée par la dépendance en<p>fréquence de l’indice de réfraction de la fibre. Il en résulte un élargissement des<p>bits optiques. La dispersion des modes de polarisation prend son origine dans<p>la biréfringence de la fibre. La modélisation de cet effet est compliquée par son<p>caractère stochastique et variable dans le temps.<p>– Les effets non linéaires prennent leur origine dans un indice de réfraction de<p>fibre qui dépend du champ optique. Ces effets peuvent être classés en deux<p>catégories. Premièrement, les effets intérieurs à un canal dont le plus influant<p>est l’automodulation de phase qui découle de l’effet Kerr optique :l’intensité<p>d’une impulsion lumineuse influence sa propre propagation. Deuxièmement, il<p>existe des conséquences de l’effet Kerr par lesquelles les différents canaux, se<p>propageant au sein de la même fibre, s’influencent mutuellement. Le phénomène<p>le plus influent parmi ces derniers est la modulation de phase croisée :l’intensité<p>d’un canal influence la propagation dans un canal voisin.<p>– Les pertes par diffusion Rayleigh sont compensées par les amplificateurs distribués<p>le long de la ligne de transmission. L’amplification optique par l’intermédiaire<p>d’émission stimulée dans des dispositifs dopés aux ions Erbium est<p>accompagnée d’émission spontanée amplifiée. Ceci entraîne la présence d’un<p>bruit blanc gaussien se superposant au signal à transmettre.<p>– La gestion des canaux dans le réseau optique implique la présence dans les noeuds<p>du réseau de filtres de sélection, des multiplexeurs et démultiplexeurs.<p>Nous examinerons aussi les effets de ligne non inhérents à la fibre mais à l’architecture<p>de transmission. Les modèles de l’émetteur et du récepteur représentent les imperfections<p>d’implémentation des composants optiques et électroniques.<p>Un premier objectif est de définir et évaluer un format de modulation robuste aux<p>imperfections introduites sur le signal par la fibre optique et par l’émetteur/récepteur.<p>Deux caractéristiques fondamentales du format de modulation, determinants pour la<p>performance du système, sont étudiés dans ce travail :<p>– La forme d’ onde. Les symboles complexes d’information sont mis en forme par<p>un filtre passe-bas dont le profil influence la robustesse du signal vis-à-vis des<p>effets de ligne.<p>– La distribution des fréquences porteuses. Les canaux de communication sont<p>disposés sur une grille fréquentielle qui peut être définie de manière électronique<p>par traitement de signal, de manière optique ou dans une configuration hybride.<p>Lorsque des porteuses optiques sont utilisées, le bruit de phase relatif entre lasers<p>entraîne des effets d’ influence croisée entre canaux. En revanche, les limites des<p>implémentations électroniques sont données par la puissance des architectures<p>numériques.<p>Le deuxième objectif est de concevoir des techniques de traitement numérique du<p>signal implémentées après échantillonnage au récepteur afin de retrouver l’information<p>transmise. Les fonctions suivantes seront implémentées au récepteur :<p>– Les techniques d’estimation et d’égalisation des effets linéaires introduits par la<p>fibre optique et par l’émetteur et le récepteur. Le principe de l’égalisation dans<p>le domaine fréquentiel est de transformer le canal convolutif dans le domaine<p>temporel en un canal multiplicatif qui peut dès lors être compensé à une faible<p>complexité de calcul par des multiplications scalaires. Les blocs de symboles<p>émis doivent être rendus cycliques par l’ajout de redondance sous la forme d’un<p>préfixe cyclique ou d’une séquence d’apprentissage. Les techniques d’égalisation<p>seront comparées en termes de performance (taux d’erreurs binaires, efficacité<p>spectrale) et en termes de complexité de calcul. Ce dernier aspect est particulièrement<p>crucial en vue de l’optimisation de la consommation énergétique du<p>système conçu.<p>– Les techniques de synchronisation des signaux en temps/fréquence. Avant de<p>pouvoir égaliser les effets linéaires introduits dans la fibre, le signal reçu devra<p>être synchronisé en temps et en fréquence sur le signal envoyé. La synchronisation<p>est généralement accomplie en deux étapes principales :l’acquisition réalisée<p>avant de recevoir les symboles d’information don’t l’objectif est une première<p>estimation/compensation des effets de manière "grossière", le tracking réalisé en<p>parallèle à l’estimation des symboles d’information dont l’objectif est l’estimation<p>/compensation des effets de manière "fine". Les algorithmes d’acquisition et<p>de tracking peuvent nécessiter l’envoi d’informations connues du récepteur.<p>– Les techniques d’estimation et de compensation des imperfections de fonctionnement<p>de l’émetteur et du récepteur. Une structure de compensation des effets<p>introduits par les composants optiques et électroniques sera développée afin de<p>relâcher les contraintes d’implémentation de l’émetteur et du récepteur.<p>Etant donné la très haute cadence à laquelle les échantillons du signal sont produits<p>(plusieurs dizaines de Gech/s), une attention particulière est portée à la complexité de<p>calcul des algorithmes proposés. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished