The wideband channel has been analyzed at the University of Gävle by using millimeter-wave (mm-Wave) frequency for improving the fifth-generation (5G) in Radio-frequency (RF) characterization. The proposed mm-Wave frequency is 24GHz, which is carried out from measurement testbed at the Robotics Lab. To explore the channel behaviors of the ISM band and mobile radio, three typically environments have been created inside of the Robotics Lab at the University of Gävle in which are Higher reflection (HR), natural reflection (NR), and Ultra reflection (UR). The relative motion of the transmitter (Tx) is carried out by adjoining the omnidirectional antenna to a KUKA robot's arm inside the Robotics lab at the University of Gävle, Sweden. The radio channel behavior is observed at different circumstances with two different movements of KUKA’s arm e.g., higher speed (2m/s) and slower speed (1m/s) for the Line of sight (LOS) and Non-Line of sight (NLOS) condition. We then achieve the time-varying power delay profile (PDP) and frequency-varying Doppler spectral density (DSD) from scattering components of the experiment environment. The Wide-band channel characteristics have been based on the (PDP) and (DSD), we analyze the root-mean-square of the (RMS) delay spread, RMS Doppler spread, Coherence time, Coherence bandwidth, and mean delay, Doppler shift from 24 different scenarios for behaviors of the mobile radio channels and indoor wireless application. / <p>Actually, My thesis title is '' A Study of Multipath Propagation and Doppler Effect at 24GHz ISM band''. I have generated mm-wave frequency from my testbed which is 24GHz. For better analysis, i was designed and created a Multipath environment inside of the  Robotics Lab at University of Gävle, I also used KUKA Robot and designed two diffrient motion for the Transmitter,such as ''C'' type and '' inverse ''type .</p>

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1980. / MICROFICHE COPY AVALABLE IN ARCHIVES AND SCIENCE. / Vita. / Includes bibliographical references. / by Edmond Joseph Murphy, Jr. / Ph.D.

Precise velocity and acceleration information is required for many real time applications. A standalone GPS receiver can be used to derive such information; however, there are many unsolved problems in this regard. This thesis establishes the theoretical basis for precise velocity and acceleration determination using a standalone GPS receiver in real time. An intensive investigation has been conducted into the Doppler effect in GPS. A highly accurate Doppler shift one-way observation equation is developed based on a comprehensive error analysis of each contributing factor including relativistic effects. Various error mitigation/elimination methods have been developed to improve the measurement accuracy of both the Doppler and Doppler-rate. Algorithms and formulae are presented to obtain real-time satellite velocity and acceleration in the ECEF system from the broadcast ephemeris. Low order IIR differentiators are designed to derive Doppler and Doppler-rate measurements from the raw GPS data for real-time applications. Abnormalities and their corresponding treatments in real-time operations are also discussed. In addition to the velocity and acceleration determination, this thesis offers a good tool for GPS measurement modelling and for design of interpolators, differentiators, as well as Kalman filters. The relativistic terms presented by this thesis suggest that it is possible to measure the geopotential directly using Doppler shift measurements. This may lead to a foundation for the development of a next generation satellite system for geodesy in the future.

This thesis presents theoretical studies of several x-ray spectroscopies - x-ray absorption, x-ray photoelectron emission, radiative and non-radiative resonant Raman scattering spectroscopy. The main focus point is investigating the influence of nuclear dynamics on these spectra for a variety of small molecules - naphthalene, biphenyl, ethylene, the water dimer, HCl, CO. The theoretical tools used consist of the basic equations of the relevant x-ray spectroscopy. Wave packet methods are also used. The molecular parameters needed for our simulations are obtained through suitable quantum chemical calculations, based on either wave function or density functional methods. Our simulations are compared to experimental data, where available. Simulations of x-ray absorption and x-ray photoionization spectra for naphthalene and biphenyl show that the spectral shapes are heavily influenced by the joint effect of two factors -- chemical shifts and excitations of vibrational progression. Comparison between the two molecules and also comparison to a reference case -- benzene, provides useful insight into the molecular behavior under core excitation. In a further step, we consider the O1s x-ray photoelectron spectrum of the water dimer. A substantial broadening of the two bands originating from the donor and the acceptor oxygen is found. It is caused by excitations of soft intermolecular vibrational modes, associated with the hydrogen bond. Another strong influence of the nuclear dynamics is clearly seen in the resonant x-ray Raman scattering of HCl. Vibrational collapse is observed experimentally and confirmed theoretically for distinctive situations. This effect allows to eliminate completely the vibrational broadening, and hence, considerably increase the spectral resolution. We considered also the vibrational dynamics in resonant soft x-ray Raman scattering from ethylene. The importance of vibronic coupling and symmetry effects is discussed and emphasized. We obtained excellent agreement with the experimental data. We predict an interference effect in the resonant Auger scattering from fixed-in-space molecules. By exciting a molecule to a dissociative state and measuring the angular distribution of the Auger electrons in coincidence with the molecular ion, one can observe this effect. The interference pattern can be used after Fourier transformation for extracting structural data about the studied system. We have found that two-center interference leads to an enhancement of the recoil effect. Finally, it is shown that core excitation to doubly-excited dissociative Pi state is accompanied by Doppler splitting of the atomic peak in resonant Auger scattering from carbon monoxide. / QC 20100910

The rapid growth in the number of large wind farms has raised serious concerns about their effects on existing radar systems. The large size and rotational movement of the turbine blades can give rise to significant Doppler clutters, which interfere with the detection of moving targets such as aircraft and storms. A previous Air Force study has collected and analyzed the time-varying radar cross section resulting from the blade rotation of a single 1.5 MW turbine. However, multiple interactions taking place in a turbine were not studied in detail. Multiple interactions could play an important role in the propagation of radar signals through wind farms. This thesis sets out to more closely examine the various Doppler features resulting from the scattering due to a single turbine. Backscattered and forward scattered data are measured at Ku-band from various wind turbine models using a motorized turntable in the laboratory. The tested models include a 1:160 scale model turbine, a 3-arm wire model turbine, and a small wind turbine from Bergey Windpower with 2’ blades. The data are processed based on the short-time Fourier transform in order to relate the resulting time-varying Doppler features to various scattering mechanisms. The experimental findings are corroborated by simulations performed using the Numerical Electromagnetics Code (NEC). Furthermore, we propose a post-processing general method to reduce the intensity of the turbine scattered data. This method is applied to filter out simulated Doppler clutter from two different simulation techniques. First, the method is applied to remove the simulated Doppler clutter from the point scatterer model. Next, the algorithm is applied to simulated backscattered data generated using a high-frequency ray tracing code, Ahilo. / text

In meteor-burst communications systems, the channel is bursty with a continuously fluctuating signal-to-noise ratio. Adaptive data rate systems attempt to use the channel more optimally by varying the bit rate. Current adaptive rate systems use a method of closed-loop decision-feedback to control the transmitted data rate. It is proposed that an open-loop adaptive data rate system without a decision feedback path may be possible using implicit channel information carried in the first few milliseconds of the link establishment probe signal. The system would have primary application in low-cost half-duplex telemetry systems. It is shown that the key elements in such a system would be channel predictors. The development of these predictors is the focus of this research. Two novel methods of predicting channel parameters are developed. The first utilises early fast Doppler information that precedes many long duration, large signal-to-noise-ratio overdense trails. The presence of early fast Doppler at the trail commencement is used as a toggle to operate at a higher data rate. Factors influencing the use of early fast Doppler for this purpose are also presented. The second method uses artificial neural networks. Data measured during trail formation is processed and presented to the neural networks for prediction of trail parameters. Several successful neural networks are presented which predict trail type, underdense or overdense, and peak trail amplitude from the first 50ms of the trail's lifetime. This method allows better estimation of the developing trail. This fact can be used to implement a multi-rate open-loop adaptive data rate system. / Thesis (Ph.D.)-University of Natal, Durban, 1994.

This thesis describes an experimental investigation of high frequency acoustic wave scattering from turbulent premixed flames. The objective of this work was to characterize the scattered incoherent acoustic field and determine its parametric dependence on frequency, flame brush thickness, incident and measurement angles, mean velocity and flame speed. The experimental facility consists of a slot burner with a flat flame sheet that is approximately 15 cm wide and 12 cm tall. The baseline cold flow characteristics and flame sheet statistics were extensively characterized. Studies were performed over a wide range of frequencies (1-24 kHz) in order to characterize the role of the incident acoustic wave length. The spectrum of the scattered acoustic field showed distinct incoherent spectral sidebands on either side of the driving frequency. The scattered incoherent field was characterized in terms of the incoherent field strength and spectral bandwidth and related to the theoretical predictions. The role of the flame front wrinkling scale, i.e., flame brush thickness, was also studied. Flame brush thickness was varied independent of the mean velocity and flame speed by using a variable turbulence generator. Results are reported for five flame brush thickness cases, ranging from 1.2 mm to 5.2 mm. Some dependence of scattered field characteristics on flame brush thickness was observed, but the magnitude of the effect was much smaller than expected from theoretical considerations. The spatial dependence of the scattered field was investigated by measuring the scattered field at four measurement angles and exciting the flame at four incident angles. Theory predicts that these variations influence the spatial scale of the acoustic wave normal to the flame, a result confirmed by the measurements. Measurements were performed for multiple combinations of mean velocities and flame speeds. The scattered field was observed to depend strongly on the flame speed. Further analysis suggested that the change in orientation angle distribution with flame speed had a large influence on the scattered field. The scattered field characteristics did not show any appreciable change with mean velocity. This result was expected since flame brush thickness characteristics themselves exhibit a weak velocity dependence.

Made available in DSpace on 2014-10-09T12:47:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:10Z (GMT). No. of bitstreams: 1 08989.pdf: 4487879 bytes, checksum: e80261387f79b3fc70c007567515777d (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo

Made available in DSpace on 2014-10-09T12:47:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:10Z (GMT). No. of bitstreams: 1 08989.pdf: 4487879 bytes, checksum: e80261387f79b3fc70c007567515777d (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo

Orientador: Anibal Faundes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-08T03:02:55Z (GMT). No. of bitstreams: 1 FerreiraNeto_PedroPires_D.pdf: 756822 bytes, checksum: 391b94a37ae61d1eb12c2c4f4b8aeacb (MD5) Previous issue date: 2006 / Resumo: Objetivo: Avaliar a capacidade dos índices de pulsatilidade das artérias umbilical e cerebral média e a relação do índice de pulsatilidade umbilico-cerebral em fetos de gestantes hipertensas de predizer risco de resultados perinatais adversos de acordo com a idade gestacional. Métodos: No período de janeiro de 2000 a agosto de 2004 foi realizada a avaliação dopplervelocimétrica dos índices de pulsatilidade da artéria umbilical (IPAU), da artéria cerebral média (IPACM) e da relação do índice de pulsatilidade umbilical/cerebral (IPAU/IPACM) de 289 gestantes com hipertensão artérial, com idade gestacional entre 24 a 41 semanas de gestação. Os resultados doplervelocimétricos que apresentaram IPAU acima do percentil 95 ou fluxo diastólico ausente ou reverso, IPACM abaixo do percentil 5 e relação IPAU/IPACM acima do percentil 95, foram avaliados quanto à capacidade de prever resultados perinatais adversos (Apgar do 5º minuto < 7, recém-nascido pequeno para a idade gestacional (RN PIG), ocorrência da doença da síndrome do desconforto respiratório (SDR), ocorrência da síndrome hipóxico-isquêmica (SHI) e óbito perinatal. Estes resultados foram comparados entre si sem ajuste e com ajuste pela idade gestacional no parto. Resultados: Os resultados alterados da dopplervelocimetria não estiveram associados ao risco de Apgar do 5º minuto < 7, antes de ajustar por idade gestacional. Com o ajuste, o risco aumentou. Entretanto, apenas a associação com alteração do IPAU alcançou significação estatística. O risco de ocorrência de recém-nascido PIG aumentou entre cinco e sete vezes na análise sem ajuste e em torno de três vezes na análise ajustada, e foi estatisticamente significativa para todos os parâmetros da dopplervelocimetria estudados. O risco de SHI aumentou entre duas e cinco vezes antes do ajuste. O aumento do risco ajustado foi significativo apenas para IPAU e relação IPAU/IPACM. Quanto ao risco da SDR houve aumento de duas a seis vezes na análise sem ajuste, mas na análise ajustada não houve aumento. Na análise da mortalidade perinatal o risco não ajustado foi entre três e dez vezes maior, nos casos com alteração do IPAU, IPACM e na relação IPAU/IPACM. Na análise ajustada apenas o IPAU alterado apresentou associação com risco quase três vezes maior e foi estatisticamente significativo. Conclusão: Neste grupo selecionado de gestantes hipertensas, a análise isolada do IPAU apresentou melhor correlação com os resultados perinatais do que a análise do IPACM ou da relação IPAU/IPACM, particularmente quando a análise foi feita com o ajuste da idade gestacional / Abstract: Objetive: To evaluate the capacity of the pulsatility Index of the umbilical artery and of the median cerebral artery and of the umbilical/cerebral ratio to predict adverse perinatla outcomes. Métodos: Dopplervelocimetric evaluation of the pulsatility Index of the umbilical artery (IPAU) and of the Median cerebral artery (IPACM) and of the umbilical/cerebral ratio (IPAU/IPACM) was carried out 289 pregnant women with hypertension at 24 through 41 weeks of gestation. Abscent or reverse diastolic flux and, IPAU above the 95 percentil, IPACM below percentil 10 and IPAU/IPACM ratio over the 95 percentil were evaluated in relation to its associasaion with adverse perinatal outcomes (5 minutes Apgar score < 7, small for gestational age (PIG), hialine membrane disease (DMH), hipoxic ischemic syndrome (SHI) and perinatal death. These results were compare before and after adjustment by gestational age at birth. Results: Abnormal Doppler results were not associated with the risk of 5 minutes Apgar score < 7 before adjustment by gestational age. After adjustment the risk increased, but only adnormal IPAU was significantly associated with. 5 minutes Apgar score < 7. The risk of PIG was 5 to 7 times higher before adjustment and arround 3 times and significantly higher after adjustment in cases with alterations in any of the three Doppler indicators studied. The risk of SHI was increased between 2 and 5 times before adjustment, but after adjustment the risk was significantly higher when the IPAU and the IPAU/IPACM ratio were adnormal. The risk DMH appeared to be between 2 and 6 times higher before adjustment, but became insignificant for the three indicators after adjustment. The risk of perinatal death before adjustment was between 3 and 10 times higher in cases with alteration in the IPAU, IPACM and the IPAU/IPACM ratio. After adjustment, only adnormal IPAU was associated with a three folds increase risk, that was statistiocally significant. Conclusion: In this selected group of preganat women with hypertension the isolated analysys of IPAU showed the best correlation with adverse perinatal outcomes, particularly after adjustment by gestational age / Doutorado / Tocoginecologia / Doutor em Tocoginecologia