No description available.

As the use of digital systems continues to grow, there is an increasing need to convert analog information into the digital domain. Successive Approximation Register (SAR) analog-to-digital converters are used extensively in this regard due to their high resolution, small die area, and moderate conversion speeds. However, capacitor mismatch within the SAR converter is a limiting factor in its accuracy and resolution. Without some form of calibration, a SAR converter can only reasonably achieve an accuracy of 10 bits. The Split-ADC technique is a digital, deterministic, background self-calibration algorithm that can be applied to the SAR converter. This thesis describes the circuit design and physical implementation of a novel 16-bit 1MS/s SAR analog-to-digital converter for use with the Split-ADC calibration algorithm. The system was designed using the Jazz 0.18um CMOS process, successfully operates at 1MS/s, and consumes a die area of 1.2mm2. The calibration algorithm was applied, showing an improvement in the overall accuracy of the converter.

In the thesis, we propose an intelligent metamaterial to reduce the specific absorption rate (SAR) of cellular phone to phantom. We call our design intelligent metamaterial because it will not affect the antenna performance greatly. When the antenna is close to the phantom, the metamaterial acts like a stopband filter, thus reducing the SAR. We design a small metamaterial cell resonating at GSM 900 band, having 2 cm x 2cm x 0.4 cm in size. We use three cells to shield the PIFA antenna and the SAR is reduced by 29.12 % at a distance of 15 mm away from the phantom. Then we design a metamaterial cell having 1 cm x 1.95 cm x 0.4 cm in size,operating in GSM 1800 band. We use four cells to shield the PIFA antenna and the SAR reduced by 40.2 % at a distance of 15 mm away from the phantom. We also propose a dualband (GSM 900/1800) metamaterial having 2 cm x 4 cm x 0.8 cm in size. We use nine metamaterial cells to shield the dualband antenna and the ground¡Athe SAR reduced by 25 % at 900 MHz and 32.6 % at 1800 MHz at a distance of 15 mm away from the phantom.

In this thesis, an analysis of the various parameters derivable from polarimetric SAR measurements is reported. The theory related to polarimetry and the state of the art of its application to remote sensing of the Earth by means of SAR systems are thoroughly discussed. The experimental part of this work pursues the task of analyzing all the relevant polarimetric parameters. In the first part of the thesis, a systematic study of the different ways of examining polarimetric data has been performed. The main aim was to evaluate possible differences among the various polarimetric observables and the amount and usefulness of the information they contain. In this context, these observables have been compared by means of the accuracy estimates resulting from classification tests of real polarimetric SAR data. In the analysis proposed here, such accuracy estimates act as an objective measure of the “utility” of the observables. In the second part, some of the aforementioned polarimetric observables have been used for interferometric applications. The main objective was to determine if a characterization of volume scattering, one of the terms affecting the interferometric coherence, is possible. Once again a comparison of the selected parameters has been done in terms of their capability to reduce the effects of volume scattering in interferometric coherence images. Since this work is intended as a general survey of polarimetric observables, completeness has been an important goal, which the author hopes to have achieved. The twofold view of the investigations reported here, oriented both to classification and interferometry, contributes to a comprehensive understanding of the parameters under study. Keywords: Radar imaging, synthetic aperture radar (SAR), SAR polarimetry, SAR interferometry, polarimetric SAR interferometry, image classification. / In dieser Arbeit wird über die Analyse von unterschiedlichen Parametern, ermittelt vom polarimetrischen SAR, berichtet. Die Theorie der Polarimetrie und der Stand der Technik in der Radarfernerkundung der Erdoberfläche, die auf SAR-Systemen beruhe, ist gründlich dargestellt. Der experimentelle Anteil dieser Arbeit beinhaltet die Analyse von allen relevanten polarimetrischen Parametern. Der erste Teil ist eine systematische Untersuchung von polarimetrischen Daten, wobei unterschiedliche Wege analysiert werden. Die Hauptaufgabe besteht darin, sowohl die möglichen Unterschiede zwischen den verschiedenen Eingangsparametern als auch die Anzahl von Parametern und deren Nutzen zur Informationsgewinnung zu untersuchen. Demzufolge wurden die Eingangsparameter hinsichtlich ihrer Klassifikationsgenauigkeit auf vorhandene SAR Daten verglichen. In der vorgeschlagenen Untersuchung stellen die Genauigkeitsanalysen ein objektives Kriterium für den sogenannten “Nutzen” der Eingangsparameter dar. Im zweiten Teil wurden die zuvor genannten polarimetrischen Eingangsparameter für die interferometrische Anwendung eingesetzt. Im Vordergrund stand die Bestimmung der Volumenstreuung und deren Einfluss auf eines der Elemente der interferometrischen Kohärenz. Auch hier fand ein Vergleich der ausgesuchten Parameter in Bezug auf ihre Fähigkeit, den Effekt der Volumenstreuung in der interferonmetrischen Kohärenz zu reduzieren, statt. Diese Arbeit möchte eine allgemeine Erfassung von polarimetrischen Eingangsparametern geben, wobei ein wichtiger Punkt, vom Autor hoffentlich erreicht, die Vollständigkeit ist. Die doppelte Sicht der vorgestellten Untersuchungen, angelehnt an die Polarimetrie und Interferometrie, trägt zu einem umfassenden Verständnis der Parameter in dieser Arbeit bei. Stichworte: Abbildendes Radar, Synthetisches Apertur Radar (SAR), SAR-Polarimetrie, SAR-Interferometrie, Polarimetrische SAR-Interferometrie, Klassifikation.

SAR backscatter data contain both geometric and radiometric distortions due to underlying topography and the radar viewing geometry. Thus, applications using SAR backscatter data for deriving various scientific products (e.g. above ground biomass) require accurate absolute radiometric calibration. The calibration process involves estimation of the local radar scattering area through knowledge of the imaged terrain, which is often obtained through DEMs. High resolution UAVSAR data over a New Hampshire boreal forest test site was radiometrically calibrated using a low resolution SRTM DEM, and different calibration methods were tested and compared. Heteromorphic methods utilizing DEM integration are able to model scattering area better than homomorphic methods based on the local incidence or projection angle with a resultant backscatter calibration difference of less than 0.5 dB. Additionally, the impact of low DEM resolution on the calibration was investigated through a Fourier analysis of different topographic classes. Power spectra of high-resolution airborne lidar DEMs were used to characterize the topography of steep, moderate, and flat terrain. Thus, errors for a given low resolution DEM associated with a particular topographic class could be quantified through a comparison of its power spectrum with that from the lidar. These errors were validated by comparing DEM slope derived from SRTM and lidar DEMs. The impact of radiometric calibration on the biomass retrieval capabilities of UAVSAR data was investigated by fitting second-order polynomials to backscatter vs. biomass plots for the HH, HV, and VV polarizations. LVIS RH50 values were used to calculate biomass, and the process was repeated for both uncalibrated and area calibrated UAVSAR images. The calibration improved the $R^2$ values for the polynomial fits by 0.7-0.8 for all three polarizations but had little effect on the polynomial coefficients. The Fourier method for predicting DEM errors was used to predict biomass errors due to the calibration. It was revealed that the greatest errors occurred in the near range of the SAR image and on slopes facing towards the radar. / text

The aim of this thesis is to find method for flood monitoring from radar images. The thesis deals with flood in general and with organization of flood protection. There are described principles of radar sensors. There is also summary of satellites with their parameters. Next part of the thesis describes interaction between radar beam and different types of surface. Theoretical part is closed by overview of the existing methods for flood monitoring. In the practical part there is method for flood monitoring applied to areas affected by flood. The process is based on the classification of the radar image. Using classification and digital elevation model is drawn boundary of flooded area. The result boundaries are compared with the existing maximal flooded areas.

No description available.

Paclitaxel is a natural occurring diterpene alkaloid originally isolated from the bark of Taxus brevifolia. It is now one of the most important chemotherapeutic agents for clinical treatment of ovarian and breast cancers. Recent clinical trials have also shown paclitaxel's potential for the treatment of non-small-cell lung cancer, head and neck cancer, and other types of cancers. While tremendous chemical research efforts have been made in the past years, which established the fundamental structure-activity relationships of the paclitaxel molecule, and provided analogs for biochemical studies to elucidate the precise mechanism of action and for the development of second-generation agents, many areas remain to be explored. In continuation of our efforts in the structure-activity relationships study of A-norpaclitaxel, five new analogs modified at the C-1 substituent and analogs with expanded B-ring or contracted C-ring have now been prepared. Preliminary biological studies indicated that the volume rather than functionality at the C-1 position plays a role in determining the anticancer activity by controlling the relative position of the tetracyclic ring system, which in turn controls the positions of the most critical functionalities such as the C-2 benzoyl, the C-4 acetate, and the C-13 side chain. The optimum conformation could possibly be modulated by ring contraction or expansion, as suggested by the improved activity of a B-lactone-A-norpaclitaxel analog. Chemical investigations were also carried out in the C-6 and C-7 positions and led to the synthesis of five new analogs. Of particular importance, 6a-hydroxy-paclitaxel, the major human metabolite of paclitaxel, was synthesized for the first time through a C-7 epimerization reaction. The availability of the major human metabolite through synthesis makes it possible to perform in vivo biological investigations on the metabolite, and it also offers an important opportunity for the production of standard HPLC samples of the metabolites which could be useful in the clinical monitoring of paclitaxel's disposition in human patients. Previous modifications at the C-4 position suggested that analogs with an acyl group other than an acetate at C-4 may exert similar activity to paclitaxel. Little was known, however, on the conformation-activity relationships of the C-4 position. In order to further explore the C-4 chemistry, a mild C-4 acylation method using acid as the acyl source was successfully developed. The new method was exemplified by the synthesis of water-soluble paclitaxel analogs with hydrophilic functional groups at the terminal of the C-4 acyl moiety. This method should be applicable to a variety of similar carboxylic acids and offer an alternative or even better approach for the preparation of C-4 modified paclitaxel analogs. Lastly, in addition to the extension of paclitaxel analog library, specially designed analogs have been sought to probe the active conformation of paclitaxel. An analog that has a bridge to tie up the C-4 acyl group with an inert position would be useful for this purpose. With successful demonstration of the above C-4 acylation method, combined with the well established C-6 chemistry, the synthesis of such a novel C-4 and C-6 bridged paclitaxel analog was completed. / Ph. D.

No / In the past fifty years it has been clearly identified that the presence of biological tissues effect the performance of the antenna and considerable effort has been made to improve the characteristics of the mobile phone antenna's but very less effort has been put in to evaluate the effects of the radio frequency and energy absorption by the biological organisms and their effect. In this work as part of a bigger work package we have evaluated the effects of the handset orientation on the values of SAR and radiation efficiency as well as the effect of the distance upon these values. The study has produced some very interesting results showing that the most common way of holding the mobile phone i.e. microphone close to the mouth produces the highest SAR values.

Los Radares de Apertura Sintética, o sistemas SAR, representan el mejorejemplo de sistemas activos de teledetección por microondas. Debido a su naturaleza coherente, un sistema SAR es capaz de adquirir información dedispersión electromagnética con una alta resolución espacial, pero por otro lado, esta naturaleza coherente provoca también la aparición de speckle.A pesar de que el speckle es una medida electromagnética, sólo puede ser analizada como una componente de ruido debido a la complejidad asociadacon el proceso de dispersión electromagnética.Para eliminar los efectos del ruido speckle adecuadamente, es necesario un modelo de ruido, capaz de identificar las fuentes de ruido y como éstasdegradan la información útil. Mientras que este modelo existe para sistemasSAR unidimensionales, conocido como modelo de ruido speckle multiplicativo,éste no existe en el caso de sistemas SAR multidimensionales.El trabajo presentado en esta tesis presenta la definición y completa validación de nuevos modelos de ruido speckle para sistemas SAR multidimensionales,junto con su aplicación para la reducción de ruido speckle y la extracción de información.En esta tesis, los datos SAR multidimensionales, se consideran bajo una formulación basada en la matriz de covarianza, ya que permite el análisisde datos sobre la base del producto complejo Hermítico de pares de imágenesSAR. Debido a que el mantenimiento de la resolución especial es un aspectoimportante del procesado de imágenes SAR, la reducción de ruido speckleestá basada, en este trabajo, en la teoría de análisis wavelet.