This thesis presents a transmitter with digital baseband predistorter to improve linearity of power amplifier. The architecture adopts the look-up table predistorter base on a polar scheme, and realizes the digital processor using FPGA. The predistortion for AM/AM and AM/PM nonlinear relations in a 0.5£gm GaAs pHEMT class-AB power amplifier has been performed. One-tone, two-tone and multi-tone continuous waves generated by baseband signal are used for linearity test. The results demonstrate that the digital predistortion technique can effectively improve intermodulation distortion. With this technique, the power amplifier can operate in the higher power range to achieve a similar linearity and a higher efficiency.

Les météorites sont parmi les sources d’information les plus importantes sur la structure et l’évolution du système solaire. Cette thèse présente une étude des météorites d’Iran, en particulier celles retrouvées dans le désert de Lut et leur comparaisons avec celles des autres déserts chauds du monde. Les météorites de Lut sont étudiées en détail en vu de comprendre le potentiel de ce désert dans l’accommodation et la classification des météorites, les âges terrestres, la météorisation, distribution spatiale et ‘pairing’. Nous démontrons la présence de deux champs de strewnfields de météorites et mettons en évidence les conditions favorables à la conservation, accumulation et collection des météorites. Nos données révèlent les différences entre les effets chimiques et minéralogiques de le météorisation (l’altération) sur les météorites en provenance de différents déserts. Parmi les centaines de météorites classifiées des déserts chauds, nous présentons notre étude détaillée sur un chondrite non-classifié (El Médano 301). Cette météorite, pourrait représenter un nouveau sous-groupe des chondrites ordinaire (OCs) avec une composition chimique moins réduite par rapport aux OCs standards. Famenin et Moshampa, deux météorites tombées en été 2015 dans le nord-ouest d’Iran, sont également étudiées en détail. Famenin est un chondrite ordinaire de type 3 qui présente des charactéristiques intermédiaires entre les chondrites H et L. Enfin, nous présentons les résultats de notre étude sur la météorite de Moshampa qui est une chondrite brecciated de type LL5. / Meteorites are amongst the most important sources of information about the structure, formation, and evolution of the solar system. This thesis reports studies on the meteorites from Iran, in particular the Lut desert and their comparison with the meteorites from other hot deserts. Lut desert meteorites are studied in detail to understand the potential of this desert for hosting meteorites, meteorite classification, terrestrial ages, terrestrial weathering, spatial distribution and pairing. We shows the presence of two main meteorite strewnfields and evidence suitable conditions for preservation, accumulation and finding of meteorites. Meteorites from different hot deserts are studied in order to document meteorite abundances, classification, and their terrestrial alteration. Our data reveal differences between the chemical and mineralogical effects of terrestrial weathering on meteorites from different deserts. Among the hundreds of classified hot desert meteorites, we present a detailed study on an ungrouped chondrite (El Médano 301). This meteorite might be representative of a new grouplet of ordinary chondrites (OCs) showing more reduced compositions than standard OCs. Famenin and Moshampa, two meteorites fallen during summer 2015 in NW Iran, are studied in detail. Famenin is a type 3 ordinary chondrite showing characteristics intermediate between H and L chondrites. Together with similar intermediate meteorites, we suggest the existence of a separate ordinary chondrite grouplet for which a different designation (H^L) is proposed. Classification results of Moshampa brecciated LL5 chondrite are reported.

Les progrès dans la fabrication des systèmes de calcul reconfigurables de type « Field Programmable Gate Arrays » (FPGA) s’appuient sur la technologie CMOS, ce qui engendre une consommation des puces élevée. Des nouveaux paradigmes de calcul sont désormais nécessaires pour remplacer les architectures de calcul traditionnel ayant une faible performance et une haute consommation énergétique. En particulier, optique intégré pourrait offrir des solutions intéressantes. Beaucoup de travail sont déjà adressées à l’utilisation d’interconnexion optique pour relaxer les contraintes intrinsèques d’interconnexion électronique. Dans ce contexte, nous proposons une nouvelle architecture de calcul reconfigurable optique, la « optical lookup table » (OLUT), qui est une implémentation optique de la lookup table (LUT). Elle améliore significativement la latence et la consommation énergétique par rapport aux architectures de calcul d’optique actuelles tel que RDL (« reconfigurable directed logic »), en utilisant le spectre de la lumière au travers de la technologie WDM. Nous proposons une méthodologie de conception multi-niveaux permettant l'explorer l’espace de conception et ainsi de réduire la consommation énergétique tout en garantissant une fiabilité élevée des calculs (BER~10-18). Les résultats indiquent que l’OLUT permet une consommation inférieure à 100fJ/opération logique, ce qui répondait en partie aux besoins d’un FPGA tout-optique à l’avenir. / Advances in the design of high performance silicon chips for reconfigurable computing, i.e. Field Programmable Gate Arrays (FPGAs), rely on CMOS technology and are essentially limited by energy dissipation. New design paradigms are mandatory to replace traditional, slow and power consuming, electronic computing architectures. Integrated optics, in particular, could offer attractive solutions. Many related works already addressed the use of optical on-chip interconnects to help overcome the technology limitations of electrical interconnects. Integrated silicon photonics also has the potential for realizing high performance computing architectures. In this context, we present an energy-efficient on-chip reconfigurable photonic logic architecture, the so-called OLUT, which is an optical core implementation of a lookup table. It offers significant improvement in latency and power consumption with respect to optical directed logic architectures, through allowing the use of wavelength division multiplexing (WDM) for computation parallelism. We proposed a multi-level modeling approach based on the design space exploration that elucidates the optical device characteristics needed to produce a computing architecture with high computation reliability (BER~10-18) and low energy dissipation. Analytical results demonstrate the potential of the resulting OLUT implementation to reach <100 fJ/bit per logic operation, which may meet future demands for on-chip optical FPGAs.

The Pixel Router was developed at the University of Kentucky with the intent of supporting multi-projector displays by combining the scalability of commercial software solutions with the flexibility of commercial hardware solutions. This custom hardware solution uses a Look Up Table for an arbitrary input to output pixel mapping, but suffers from high memory latencies due to random SDRAM accesses. In order for this device to achieve marketability, the image interpolation method needed improvement as well. The previous design used the nearest neighbor interpolation method, which produces poor looking results but requires the least amount of memory accesses. A cache was implemented to support bilinear interpolation to simultaneously increase the output frame rate and image quality. A number of software simulations were conducted to test and refine the cache design, and these results were verified by testing the implementation on hardware. The frame rate was improved by a factor of 6 versus bilinear interpolation on the previous design, and by as much as 50% versus nearest neighbor on the previous design. The Pixel Router was also certified for FCC conducted and radiated emissions compliance, and potential commercial market areas were explored.

abstract: Process migration is a heavily studied research area and has a number of applications in distributed systems. Process migration means transferring a process running on one machine to another such that it resumes execution from the point at which it was suspended. The conventional approach to implement process migration is to move the entire state information of the process (including hardware context, virtual memory, files etc.) from one machine to another. Copying all the state information is costly. This thesis proposes and demonstrates a new approach of migrating a process between two cores of Intel Single Chip Cloud (SCC), an experimental 48-core processor by Intel, with each core running a separate instance of the operating system. In this method the amount of process state to be transferred from one core's memory to another is reduced by making use of special registers called Lookup tables (LUTs) present on each core of SCC. Thus this new approach is faster than the conventional method. / Dissertation/Thesis / M.S. Computer Science 2013

Molecular Dynamics (MD) is a simulation technique widely used by computational chemists and biologists to simulate and observe the physical properties of a system of particles or molecules. The method provides invaluable three-dimensional structural and transport property data for macromolecules that can be used in applications such as the study of protein folding and drug design. The most time-consuming and inefficient routines in MD packages, particularly for large systems, are the ones involving the computation of intermolecular energy and forces for each molecule. Many fully atomistic systems such as CHARMM and NAMD have been refined over the years to improve their efficiency. But, simulating complex long-time events such as protein folding remains out reach for atomistic simulations. The consensus view amongst computational chemists and biologists is that the development of a coarse-grained (CG) MD package will make the long timescales required for protein folding simulations possible. The shortcoming of this method remains an inability to produce accurate dynamics and results that are comparable with atomistic simulations. It is the objective of this dissertation to develop a coarse-grained method that is computationally faster than atomistic simulations, while being dynamically accurate enough to produce structural and transport property data comparable to results from the latter. Firstly, the accuracy of the Gay-Berne potential in modelling liquid benzene in comparison to fully atomistic simulations was investigated. Following this, the speed of a course-grained condensed phase benzene simulation employing a Gay-Berne potential was compared with that of a fully atomistic simulation. While coarse-graining algorithmically reduces the total number of particles in consideration, the execution time and efficiency scales poorly for large systems. Both fully-atomistic and coarse-grained developers have accelerated packages using high-performance parallel computing platforms such as multi-core CPU clusters, Field Programmable Gate Arrays (FPGAs) and Graphics Processing Units (GPUs). GPUs have especially gained popularity in recent years due to their massively parallel architecture on a single chip, making them a cheaper alternative to a CPU cluster. Their relatively shorter development time also gives them an advantage over FPGAs. NAMD is perhaps the most popular MD package that employs efficient use of a single GPU or a multi-GPU cluster to conduct simulations. The Scientific Computing Research Unit’s in-house generalised CG code, the Free Energy Force Induced (FEFI) coarse-grained MD package, was accelerated using a GPU to investigate the achievable speed-up in comparison to the CPU algorithm. To achieve this, a parallel version of the sequential force routine, i.e. the computation of the energy, force and torque per molecule, was developed and implemented on a GPU. The GPU-accelerated FEFI package was then used to simulate benzene, which is almost exclusively governed by van der Waal’s forces (i.e. dispersion effects), using the parameters for the Gay-Berne potential from a study by Golubkov and Ren in their work “Generalized coarse-grained model based on point multipole and Gay-Berne potentials”. The coarse-grained condensed phase structural properties, such as the radial and orientational distribution functions, proved to be inaccurate. Further, the transport properties such as diffusion were significantly more unsatisfactory compared to a CHARMM simulation. From this, a conclusion was reached that the Gay-Berne potential was not able to model the subtle effects of dispersion as observed in liquid benzene. In place of the analytic Gay-Berne potential, a more accurate approach would be to use a multidimensional free energy-based potential. Using the Free Energy from Adaptive Reaction Coordinate Forces (FEARCF) method, a four-dimensional Free Energy Volume (FEV) for two interacting benzene molecules was computed for liquid benzene. The focal point of this dissertation was to use this FEV as the coarse-grained interaction potential in FEFI to conduct CG simulations of condensed phase liquid benzene. The FEV can act as a numerical potential or Look-Up Table (LUT) from which the interaction energy and four partial derivatives required to compute the forces and torques can be obtained via numerical methods at each step of the CG MD simulation. A significant component of this dissertation was the development and implementation of four-dimensional LUT routines to use the FEV for accurate condensed phase coarse-grained simulations. To compute the energy and partial derivatives between the grid points of the surface, an interpolation algorithm was required. A four-dimensional cubic B-spline interpolation was developed because of the method’s superior accuracy and resistance to oscillations compared with other polynomial interpolation methods. When The algorithm’s introduction into the FEFI CG MD package for CPUs exhausted the single-core CPU architecture with its large number of interpolations for each MD step. It was therefore impractical for the high throughput interpolation required for MD simulations. The 4D cubic B-spline algorithm and the LUT routine were then developed and implemented on a GPU. Following evaluation, the LUT was integrated into the FEFI MD simulation package. A FEFI CG simulation of liquid benzene was run using the 4D FEV for a benzene molecular pair as the numerical potential. The structural and transport properties outperformed the analytical Gay-Berne CG potential, more closely approximating the atomistic predicted properties. The work done in this dissertation demonstrates the feasibility of a coarse-grained simulation using a free energy volume as a numerical potential to accurately simulate dispersion effects, a key feature needed for protein folding.

The need for an efficient dimensionality reduction technique has remained a critical challenge for effective analysis of hyperspectral data for vegetation applications. Discrete wavelet transform (DWT), through multiresolution analysis, offers oppurtunities both to reduce dimension and convey information at multiple spectral scales. In this study, we investigated the utility of the Haar DWT for AVIRIS hyperspectral data analysis in three different applications (1) classification of three pine species (Pinus spp.), (2) estimation of leaf area index (LAI) using an empirically-based model, and (3) estimation of LAI using a physically-based model. For pine species classification, different sets of Haar wavelet features were compared to each other and to calibrated radiance. The Haar coefficients selected by stepwise discriminant analysis provided better classification accuracy (74.2%) than the original radiance (66.7%). For empirically-based LAI estimation, the models using the Haar coefficients explained the most variance in observed LAI for both deciduous plots (cross validation R² (CV-R²) = 0.79 for wavelet features vs. CV-R² = 0.69 for spectral bands) and all plots combined (CV R² = 0.71 for wavelet features vs. CV-R² = 0.50 for spectral bands). For physically-based LAI estimation, a look-up-table (LUT) was constructed by a radiative transfer model, DART, using a three-stage approach developed in this study. The approach involved comparison between preliminary LUT reflectances and image spectra to find the optimal set of parameter combinations and input increments. The LUT-based inversion was performed with three different datasets, the original reflectance bands, the full set of the wavelet extracted features, and the two wavelet subsets containing 99.99% and 99.0% of the cumulative energy of the original signal. The energy subset containing 99.99% of the cumulative signal energy provided better estimates of LAI (RMSE = 0.46, R² = 0.77) than the original spectral bands (RMSE = 0.69, R² = 0.42). This study has demonstrated that the application of the discrete wavelet transform can provide more accurate species discrimination within the same genus than the original hyperspectral bands and can improve the accuracy of LAI estimates from both empirically- and physically-based models. / Ph. D.

Cette thèse se consacre à l'étude de décodeurs itératifs, pour des codes correcteurd'erreurs binaires et non-binaires à faible densité (LDPC). Notre objectif est de modéliserdes décodeurs de complexité faibles et de faible latence tout en garantissantde bonne performances dans la région des très faibles taux d'erreur (error floor).Dans la première partie de cette thèse, nous étudions des décodeurs itératifssur des alphabets finis (Finite Alphabet iterative decoders, FAIDs) qui ont étérécemment proposés dans la littérature. En utilisant un grand nombre de décodeursFAIDs, nous proposons un nouvel algorithme de décodage qui améliore la capacité decorrections d'erreur des codes LDPC de degré dv = 3 sur canal binaire symétrique.La diversité des décodeurs permet de garantir une correction d'erreur minimale sousdécodage itératif, au-delà de la pseudo-distance des codes LDPC. Nous donnonsdans cette thèse un exemple detailé d'un ensemble de décodeur FAIDs, qui corrigetous les évènements d'erreur de poids inférieur ou égal à 7 avec un LDPC de petitetaille (N=155,K=64,Dmin=20). Cette approche permet de corriger des évènementsd'erreur que les décodeurs traditionnels (BP, min-sum) ne parviennent pas à corriger.Enfin, nous interprétons les décodeurs FAIDs comme des systèmes dynamiques etnous analysons les comportements de ces décodeurs sur des évènements d'erreur lesplus problématiques. En nous basant sur l'observation des trajectoires périodiquespour ces cas d'étude, nous proposons un algorithme qui combine la diversité dudécodage avec des sauts aléatoires dans l'espace d'état du décodeur itératif. Nousmontrons par simulations que cette technique permet de s'approcher des performancesd'un décodage optimal au sens du maximum de vraisemblance, et ce pourplusieurs codes.Dans la deuxième partie de cette thèse, nous proposons un nouvel algorithmede décodage à complexité réduite pour les codes LDPC non-binaires. Nous avonsappellé cet algorithme Trellis-Extended Min-Sum (T-EMS). En transformant le domainede message en un domaine appelée domaine delta, nous sommes capable dechoisir les déviations ligne par ligne par rapport à la configuration la plus fiable,tandis que les décodeurs habituels comme le décodeur EMS choisissent les déviationscolonne par colonne. Cette technique de sélection des déviations ligne parligne nous permet de réduire la complexité du décodage sans perte de performancepar rapport aux approches du type EMS. Nous proposons également d'ajouter une colonne supplémentaire à la représentation en treillis des messages, ce qui résoudle problème de latence des décodeurs existants. La colonne supplémentaire permetde calculer tous les messages extrinséque en parallèle, avec une implémentationmatérielle dédiée. Nous présentons dans ce manuscrit, aussi bien les architecturesmatérielles parallèle que les architectures matérielles série pour l'exécution de notrealgorithme T-EMS. L'analyse de la complexité montre que l'approche T-EMS estparticulièrement adapté pour les codes LDPC non-binaires sur des corps finis deGalois de petite et moyenne dimensions. / This thesis is dedicated to the study of iterative decoders, both for binary and non-binary low density parity check (LDPC) codes. The objective is to design low complexity and low latency decoders which have good performance in the error floor region.In the first part of the thesis, we study the recently introduced finite alphabet iterative decoders (FAIDs). Using the large number of FAIDs, we propose a decoding diversity algorithm to improve the error correction capability for binary LDPC codes with variable node degree 3 over binary symmetric channel. The decoder diversity framework allows to solve the problem of guaranteed error correction with iterative decoding, beyond the pseudo-distance of the LDPC codes. We give a detailed example of a set of FAIDs which corrects all error patterns of weight 7 or less on a (N=155,K=64,Dmin=20) short structured LDPC, while traditional decoders (BP, min-sum) fail on 5-error patterns. Then by viewing the FAIDs as dynamic systems, we analyze the behaviors of FAID decoders on chosen problematic error patterns. Based on the observation of approximate periodic trajectories for the most harmful error patterns, we propose an algorithm which combines decoding diversity with random jumps in the state-space of the iterative decoder. We show by simulations that this technique can approach the performance of Maximum LikelihoodDecoding for several codes.In the second part of the thesis, we propose a new complexity-reduced decoding algorithm for non-binary LDPC codes called trellis extended min sum (T-EMS). By transforming the message domain to the so-called delta domain, we are able to choose row-wise deviations from the most reliable configuration, while usual EMS-like decoders choose the deviations column-wise. This feature of selecting the deviations row-wise enables us to reduce the decoding complexity without any performance loss compared to EMS. We also propose to add an extra column to the trellis representation of the messages, which solves the latency issue of existing decoders. The extra column allows to compute all extrinsic messages in parallel, with a proper hardware implementation. Both the parallel and the serial hardware architectures for T-EMS are discussed. The complexity analysis shows that the T-EMS is especially suitable for high ratenon-binary LDPC codes on small and moderate fields.

L'utilisation du LiDAR en télédétection permet une description précise de l'architecture du couvert végétal. L'objet de cette thèse est le développement des approches d'inversion de mesures LiDAR à l'aide d'une modélisation physique et statistique du signal dans le but d'estimer des propriétés biophysiques de cultures dominantes (blé, maïs) du Sud-Ouest de la France et d'un couvert forestier en Chine. Le travail a tout d'abord porté sur l'estimation du LAI et la hauteur des cultures par inversion de formes d'onde LiDAR à faible empreinte. Une base de données de simulations de formes d'onde réalistes des cultures est réalisée à l'aide du modèle de transfert radiatif (MTR) DART. L'inversion consiste à utiliser la technique de table de correspondance qui consiste à chercher la simulation la plus proche de l'observation réelle. Le travail a ensuite porté sur l'estimation du profil de LAI des arbres de la forêt. Une approche variationnelle d'estimation du profil de LAI par inversion de formes d'ondes est proposée. Elle repose sur un MTR simplifié et une technique de lissage du profil de LAI s'appuyant sur les chaines de Markov. La formulation bayésienne du problème, nous amène à une fonction de coût non-linéaire. Elle est minimisée à l'aide d'une nouvelle technique de gradient multi-échelle. Les approches développées montrent bien leurs performances en les appliquant sur des données réelles de cultures (maïs et blé) et de milieu forestier. / The use of LiDAR in remote sensing allows a precise description of the vegetation cover architecture. The aim of this thesis is the development of LiDAR data inversion approaches using physical and statistical signal modeling in order to estimate the biophysical properties of dominant crops (wheat, maize) of the South-West of France and a forest cover in China. The work firstly focused on estimating LAI and crop height by small footprint LiDAR waveforms inversion. A realistic crop waveform simulations database is performed using the Radiative Transfer Model (MTR) DART. The inversion consists in using the Look up Table technique which consists of looking for the closest simulation to the actual observation. The second inversion approach focused on LAI profile estimation of the forest trees. A variational approach to estimate LAI by waveform inversion is proposed. It relies on a simplified MTR and LAI profile smoothing technique based on Markov chains. The Bayesian formulation of the problem leads us to a non-linear cost function. It is minimized using a new multi-scale gradient technique. The developed approaches show clearly their performance by applying them to real crop data (corn and wheat) and forest.

The debate around the issue of homosexuals in Isl m has recently gained momentum globally. New arguments surfaced which were not discussed previously by the jurists. Some have argued that homosexuality is genetic and others believe it is caused by a hormonal imbalance. Isl m has given Muslims a comprehensive social system in which to operate. It has reserved explicit judgment on many pertinent issues and allowed research to address contemporary challenges by means of Ijtih d (personal reasoning). The Islamic judicial system states unequivocally and unambiguously that it expects from its followers to respect the judicial process. This thesis aims to address the most recent arguments by Muslim homosexuals. I will employ Qiy s (analogical deduction) to assess these latest claims and formulate an Islamic judgment regarding them. The formulation of this judgment, though, will take place sketching a legal and historical background of homosexuality in Isl m.