of the Thesis

We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution simulation of cosmic reionization. The simulation involving 24 billion dark matter particles utilizes a hybrid code with a particle-mesh N-body algorithm for dark matter and prescriptions for baryons a...

In analytical placement, one seeks locations of circuit modules that optimize an objective function, but allows module overlaps. Our work introduces a novel minimization of maximal path delay that improves upon previously known algorithms for timing-driven placement. Our placement algorithms have provable properties and are fast in practice.

In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface, separated by a fixed angular distance are crosscorrelated, and this leads to a wave packet signal. Accurately measuring the travel times of these wave packets is crucial for inferring the sub-surface properties in the Sun. The observed signal is quite noisy, and to improve the signal-tonoise ...

This study presents a full-duplex Radio-over-Fiber (RoF) system providing the users' wireless access with a bit rate of 10 Gbps over 40 GHz radio carrier. This system can be used in a centralized radio access network (C-RAN) architecture because we provide a fully analog front haul link between central station and base station. We can consider it as infrastructure between remote radio heads (RR...

The 2D Quaternionic Fourier Transform (QFT), applied to a real 2D image, produces an invertible quaternionic spectrum. If we conserve uniquely the first quadrant of this spectrum, it is possible, after inverse transformation, to obtain, not the original image, but a 2D quaternion image, which generalize in 2D the classical notion of 1D analytical image. From this quaternion image, we compute th...

The analytical signal method for seismic attenuation (Q) estimation is reviewed and investigated using a 1D surface data model and field VSP data. The error in Q-factor recovery from modelled data using the analytical signal method is better than 7 percent over a range of Q-factors from 25 to 100. The method is applied to the enhanced downgoing P-wave of an offset VSP-survey from Ross Lake, Sas...

An analytical model for the read back signal is derived for perpendicular and longitudinal magnetic recording. The model captures the contribution of a single bit rather than the contribution of a bit transition which makes it applicable to patterned media as well as continuous media. It is based on the law of Biot–Savart and separates the contribution of the magnetic media from the head sensit...

Among previous analyses of the steady-state free-precession (SSFP) signal in rapid MRI, one treatment resulted in equations that require the evaluation of infinite binomial series. Here, an analytical solution is derived by a transformation into the power series expansion of the derivative of the inverse sine function, which is essentially a root. The treatment is extended to include higher-ord...