The marine boundary layer (MBL) is the region where energy, momentum and masses are exchanged between the ocean surface and the free troposphere. The lack of observations with high vertical resolution over the ocean significantly restricts the understanding of the complex physical processes that occur inside the MBL. The relatively short vertical extent of the MBL (average about 1~2 km) and the frequent cloudiness at its top make probing the MBL extremely difficult from the space. Several features of the Global Positioning System (GPS) radio occultation (RO) technique suggest that it has a great potential for sensing the MBL. These features include global coverage, high vertical resolution, and the ability of GPS signals to penetrate clouds.Over moist marine areas, a large negative moisture gradient often exists across the thermal inversion capping the MBL, which can cause super-refraction (SR) or ducting. A large number of high-resolution soundings have shown that SR occurs about 90% of the time in a year over the subtropical and tropical oceans and even 50% at high-latitudes during the summer. In the presence of SR, the reconstruction of refractivity from RO data becomes an ill-posed inverse problem, i.e., a given RO bending angle profile is consistent with a continuum (an infinite number) of refractivity profiles. The standard Abel retrieval gives the minimum refractivity solution of the continuum and thus produces the largest negative bias, consistent with a negative bias that is often present in the retrieved refractivity profiles in the moist lower troposphere. Simulation studies indicate a large variation of the negative refractivity biases (could be over -15%). The impact of diffraction effects and the open-loop receiver tracking on the bending angle and refractivity retrievals are assessed. A novel approach is developed and tested to reconstruct the vertical refractivity structure within and below the SR layer, which yields a much-improved retrieval, especially below the SR layer (less than 0.5% error). Such a reconstruction method should greatly enhance our ability to measure the MBL globally using the GPS RO technique as well as to improve the MBL parameterizations used in weather and climate models.

It is an important step in clinical practice to discriminate real diseased patients from healthy persons. It would be great to get such discrimination from some common information like personal information, life style, and the contact with diseased patient. In this study, a score is calculated for each patient based on a survey through generalized linear model, and then the diseased status is decided according to previous sexually transmitted diseases (STDs) records. This study will facilitate clinics in grouping patients into real diseased or healthy, which in turn will affect the method clinics take to screen patients: complete screening for possible diseased patient and some common screening for potentially healthy persons.

The Herschel Space Observatory (Herschel), a flagship mission of the European Space Agency (ESA), is comprised of three cryogenically cooled instruments commissioned to explore the far-infrared/submillimetre universe. Herschel's remote orbit at the second Lagrangian point (L2) of the Sun-Earth system, and its cryogenic payload, impose a need for thorough instrument characterization and rigorous testing as there will be no possibility for any servicing after launch. The Spectral and Photometric Imaging Receiver (SPIRE) is one of the instrument payloads aboard Herschel and consists of a three band imaging photometer and a two band imaging spectrometer. The imaging spectrometer on SPIRE consists of a Mach-Zehnder (MZ)-Fourier transform spectrometer (FTS) coupled with bolometric detector arrays to form an imaging FTS (IFTS). This thesis presents experiments conducted to verify the performance of an IFTS system from a space based platform, i.e. the use of the SPIRE IFTS within the Herschel space observatory. Prior to launch, the SPIRE instrument has undergone a series of performance verification tests conducted at the Rutherford Appleton Laboratory (RAL) near Oxford, UK. Canada is involved in the SPIRE project through provision of instrument development hardware and software, mission flight software, and support personnel. Through this thesis project I have been stationed at RAL for a period spanning fifteen months to participate in the development, performance verification, and characterization of both the SPIRE FTS and photometer instruments. This thesis discusses Fourier transform spectroscopy and related FTS data process ing (Chapter 2). Detailed discussions are included on the spectral phase related to the FTS beamsplitter (Chapter 3), the imaging aspects of the SPIRE IFTS instrument (Chapter 4), and the noise characteristics of the SPIRE bolometer detector arrays as measured using the SPIRE IFTS (Chapter 5). This thesis presents results from experiments performed both on site at the RAL Space Science and Technology Department (SSTD) Assembly Integration Verification (AIV) instrument test facility as well as from the Astronomical Instrumentation Group (AIG) research laboratories within the Department of Physics & Astronomy at the University of Lethbridge. / xxiii, 243 leaves : ill. (some col.) ; 29 cm

The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments on the European Space Agency's (ESA's) Herschel Space Observatory (HSO). The medium resolution spectroscopic capabilities of SPIRE are provided by an imaging Fourier transform spectrometer (IFTS). A software simulator of the SPIRE IFTS was written to generate realistic data products, making use of available qualification and test data. We present the design and implementation of the simulator. Component and end-to-end simulations were compared to results from the first SPIRE instrument proto-flight model (PFMI) test campaign conducted at the Rutherford Appleton Laboratory (RAL) in Oxford, England in 2005. Final characterization of the simulator involved the determination of astronomical quantities from the synthetic data products of a simple molecular cloud. / xix, 213 leaves : ill. (some col.) ; 29 cm.

The European Space Agency's Herschel Space Observatory is comprised of three cryogenically cooled instruments commissioned to explore the far infrared/submillimetre universe. The Spectral and Photometric Imaging REceiver (SPIRE) is one of Herschel's instruments and consists of a three band imaging photometer and a two band imaging spectrometer. Canada is involved in the SPIRE project through provision of instrument development hardware and software, mission flight software, and support personnel. This thesis discusses Fourier transform spectroscopy (FTS) and FTS data processing. A detailed discussion is included on FTS phase correction, with results presented from the optimization of an enhanced Forman phase correction routine developed for this work. This thesis discusses the design, verification, and use of the hardware and software provided by Dr. Naylor's group as it relates to SPIRE verification testing. Results of the photometer characterization are presented. The current status of SPIRE and its future schedule is also discussed. / xvii, 239 leaves : ill. (some col.) ; 28 cm.

This thesis examines the design of high speed transimpedance amplifiers (TIAs) in low cost complimentary metal oxide semiconductor (CMOS) technology. Due to aggressive scaling, CMOS has become an attractive technology for high speed analog circuits. Besides the cost advantage, CMOS offers the potential for higher levels of integration since the analog circuits can be integrated with digital electronics on the same substrate. A 2.5 Gbps transimpedance amplifier fabricated using 0.18 um CMOS technology is presented. The TIA uses a shunt-shunt feedback topology with a cascode gain stage. Measurements of the transimpedance gain, group delay, and common mode rejection ratio are presented for the TIA and show a good match to simulated results. The noise of the TIA was characterized by measuring the noise parameters of the TIA. The noise parameters are then used to determine the input referred noise current spectral density. A 10 Gbps transimpedance amplifier fabricated using 0.18 um CMOS technology is also presented. This TIA uses a shunt-shunt feedback topology with a common source gain stage. In order to achieve the required bandwidth, the TIA uses a bandwidth extension technique called shunt-series inductive peaking. A discussion of the different methods of bandwidth extension using inductive peaking is included, and the optimal configurations for maximally flat responses are shown for shunt inductive peaking,series inductive peaking, and shunt-series inductive peaking. The TIA circuit topology is optimized using a novel noise analysis that uses a high frequency noise model for the transistor. The optimum transistor size and bias current are determined to minimize the amplifier noise. Unfortunately differential measured results are not available due to a stability problem in the amplifier. The cause of this instability is further explored and modifications to solve the problem are discussed. Single-ended results are presented and show reasonable agreement with simulated results. Differences in the results are attributed to poor modelling of the on-chip spiral inductors. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-07-16 13:34:41.46

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In modern day communication systems, there is a constant demand for increase in transmission rates. This is however limited by the bandwidth limitation of the channel. Inter symbol interference (ISI) imposes a great threat to increasing data rates by degrading the signal quality. Equalizers are used at the receiver to compensate for the losses in the channel and thereby greatly mitigate ISI. Further, an adaptive equalizer is desired which can be used over a channel whose response is unknown or is time-varying. A low power equalizing solution in a moderately attenuated channel is an analog peaking filter which boosts the signal high frequency components. Such conventional continuous time linear equalizers (CTLE) provide a single degree of controllability over the high frequency boost. A more complex CTLE has been designed which has two degrees of freedom by controlling the high frequency boost as well as the range of frequencies over which the boost is applied. This extra degree of controllability over the equalizer response is desired to better adapt to the varying channel response and result in an equalized signal with a wider eye opening. A robust adaptation technique is necessary to tune the equalizer characteristics. Some of the commonly used techniques for adaptation of CTLEs are based on energy comparison criterion in the frequency domain. But the adaptation achieved using these techniques might not be optimal especially for an equalizer with two degrees of controllability. In such cases an eye opening monitor (EOM) could be used which evaluates the actual signal quality in time domain. The EOM gives an estimate on the signal quality by measuring the eye opening of the equalized signal in horizontal and vertical domain. In this thesis work a CTLE with two degrees of freedom with an EOM based adaptation system has been implemented.

Syftet med föreliggande kvalitativa studie var att undersöka hur sändares kommunikation av återkoppling till mottagare upplevdes av sändare respektive mottagare. Undersökningsgruppen bestod av åtta deltagare tillhörande två undergrupper, fyra sändare och fyra mottagare där varje sändare hade en arbetsmässig koppling till en av mottagarna. Fokus låg på deltagarnas subjektiva upplevelser av återkopplingssituationer i arbetet och utgick från tre teoretiska teman; kanal, innehåll och tydlighet. Det insamlade materialet analyserades genom en hybrid av deduktiv och induktiv tematisk analys. Resultatet visade att både sändare och mottagare av återkopplingen upplevde den fysiskt närvarande kanalen som den starkaste, effektivaste och mest förekommande. Sändarna upplevde att de gav en mer innehållsrik och frekvent förekommande återkoppling än vad mottagarna upplevde att de fick. Mottagarna upplevde återkopplingen som tydligast när sändarna använde sig av ett beskrivande underlag. / The objective of this qualitative study was to examine the experience of the transmitter and the receiver of the given communicated feedback from transmitter to receiver. The interview participants consisted of eight participants belonging in two subgroups, four transmitters and four receivers where each transmitter had a workwise connection to one of the receivers. The focus of this study was on the participants subjective experiences in feedback situations at work and based on three theoretical themes; channel, content and clarity. The results were analyzed by a hybrid model of deductive and inductive thematic analysis. The result showed that both the transmitter and the receiver experience the physical presence as the strongest, most effective and most occurring channel. The transmitters felt that they provided a more comprehensive and a more frequent feedback than the recipients felt that they got. The receivers perceived feedback as most clear when the transmitters used a descriptive foundation during feedback situations.