Sharif Digital Repository

In this paper, after introduction of symmetric multi- frequency signal, it will be presented how to estimate Doppler frequency from estimated frequency tones of returned echo. After that, three methods of Pisarenko, Prony and MUSIC for frequency estimation will be introduced, and then these methods are applied to estimate tone frequencies of a multi-carrier signal. It will be shown that estimation of Doppler frequency by multi-frequency signal transmission leads to less rms error than single-frequency signal, in the condition of equal SNR. Infact it will be suggested that distribution of the power of signal in spectrum instead of adding up all the power in one point, leads to less Doppler... 

In this work, two important opioid antagonists, naltrexone and oxycodone, were prepared from thebaine and were characterized by IR, 1H NMR and 13C NMR spectroscopy. Moreover, computational NMR and IR parameters were obtained using density functional theory (DFT) at B3LYP/6-311++G* * level of theory. Complete NMR and vibrational assignment were carried out using the observed and calculated spectra. The IR frequencies and NMR chemical shifts, determined experimentally, were compared with those obtained theoretically from DFT calculations, showed good agreements. The RMS errors observed between experimental and calculated data for the IR absorptions are 85 and 105 cm-1, for the 1H NMR peaks are... 

In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency. The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear musclelike- actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organlike sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex...