<p>Using more than just on antenna can significantly speed up the data rate in a wireless communication system. These systems are commonly referred to as Diversity- and MIMO-systems. Due to tight volume restriction for the antennas, e.g. in a mobile phone, electromagnetic coupling between the antennas will degrade the capacity of the wireless system and lower the coverage.</p><p><p>In the proposed thesis, a thorough study of Ethertronics’ standard antennas will be established in which the antennas will be used in a multiport system, e.g. MIMO. The thesis will be strongly related to Ethertronics’ engagement in Chase and therefore also dependent on the latest progresses on MPA (Multiport Analyzer) developed in Chase. The thesis will result in a working methodology how to use MPA plus design-, location- and orientation rules for the standard antennas used in a multiport system.</p></p>

Cardiac output (Q) is an important determinant of the cardiovascular system‟s ability to meet the oxygen needs of the body. This dissertation addresses the non-invasive measurement of Q, in healthy children and those with heart and lung disease. 1) The correction factors for collision broadening, downstream difference and end tidal CO2 (PetCO2), used in the CO2 rebreathe (equilibrium) method, were evaluated. In lung disease, one is unable to assume a normal dead space to estimate arterial CO2 (PaCO2), and the use of any of these correction factors alone should be used with caution as they each exert a profound effect on the Q measurement. 2) A new equation to predict PaCO2 from PetCO2 in patients with CF was derived via multiple regression analysis, taking into account disease severity. 3) The validity and reliability of Q measures via the inert gas rebreathing technique (InnocorTM device) were evaluated. The highest intraclass correlation coefficients were attained during exercise (0.7-0.98), indicating excellent reliability of the device. Comparisons of Q measures from the InnocorTM (QInn) to the AMIS mass spectrometer system (QAmis) were made to assess validity. The bias (QInn-QAmis) and limits of agreement (±2SD) were 0.45 ± 1.9 L.min-1 and 0.27 ± 2.1 for children with congenital heart disease and healthy controls respectively, with no systematic differences between the two methods. 4) Assessment of cardiac output in Fontan patients demonstrated that an individualized, atrioventricular (AV) delay optimization was required. Moreover, there was a small but significant improvement in heart function with AV synchronized pacing (DDI) versus ventricular pacing (VVI), suggesting that further study with a larger sample of patients is warranted. The limitations and strengths of the measurement of non-invasive cardiac output in children, primarily via respiratory gas analysis, were delineated and recommendations were made for their use.

Cardiac output (Q) is an important determinant of the cardiovascular system‟s ability to meet the oxygen needs of the body. This dissertation addresses the non-invasive measurement of Q, in healthy children and those with heart and lung disease. 1) The correction factors for collision broadening, downstream difference and end tidal CO2 (PetCO2), used in the CO2 rebreathe (equilibrium) method, were evaluated. In lung disease, one is unable to assume a normal dead space to estimate arterial CO2 (PaCO2), and the use of any of these correction factors alone should be used with caution as they each exert a profound effect on the Q measurement. 2) A new equation to predict PaCO2 from PetCO2 in patients with CF was derived via multiple regression analysis, taking into account disease severity. 3) The validity and reliability of Q measures via the inert gas rebreathing technique (InnocorTM device) were evaluated. The highest intraclass correlation coefficients were attained during exercise (0.7-0.98), indicating excellent reliability of the device. Comparisons of Q measures from the InnocorTM (QInn) to the AMIS mass spectrometer system (QAmis) were made to assess validity. The bias (QInn-QAmis) and limits of agreement (±2SD) were 0.45 ± 1.9 L.min-1 and 0.27 ± 2.1 for children with congenital heart disease and healthy controls respectively, with no systematic differences between the two methods. 4) Assessment of cardiac output in Fontan patients demonstrated that an individualized, atrioventricular (AV) delay optimization was required. Moreover, there was a small but significant improvement in heart function with AV synchronized pacing (DDI) versus ventricular pacing (VVI), suggesting that further study with a larger sample of patients is warranted. The limitations and strengths of the measurement of non-invasive cardiac output in children, primarily via respiratory gas analysis, were delineated and recommendations were made for their use.

Using more than just on antenna can significantly speed up the data rate in a wireless communication system. These systems are commonly referred to as Diversity- and MIMO-systems. Due to tight volume restriction for the antennas, e.g. in a mobile phone, electromagnetic coupling between the antennas will degrade the capacity of the wireless system and lower the coverage. In the proposed thesis, a thorough study of Ethertronics’ standard antennas will be established in which the antennas will be used in a multiport system, e.g. MIMO. The thesis will be strongly related to Ethertronics’ engagement in Chase and therefore also dependent on the latest progresses on MPA (Multiport Analyzer) developed in Chase. The thesis will result in a working methodology how to use MPA plus design-, location- and orientation rules for the standard antennas used in a multiport system.

The aim of this thesis is to design a controllable DC-link output voltage for isolated slotless tubular linear generators (STLG), which is capable of directly harnessing wave and solar thermal energies. For supplying stable DC-link voltage to load, a suitable voltage regulation circuit is designed based on the integrate system performance assessment. Electrical and mechanical parameters in this refined STLG design are involved to analyze the operational behaviors through magnetic equivalent circuit analysis at different operating modes. From the theoretical modeling and experimental results, both the AC-side and DC-side properties of generator outputs can then be thoroughly investigated. Finally, based on the performance of controllable rectifier model, a three-phase PWM rectifier has been established, and then the regulated DC-link voltage can be implemented using a DSP-based controller combined with required peripheral circuits.

The ubiquity of circadian systems has allowed their characterization in a broad range of model systems, which has greatly improved knowledge of how these systems are organized and the vast range of cellular and organismal processes under circadian control. Most of the advances, however, have come in describing the central oscillators of these systems, and, in some cases, the input pathways used to coordinate these oscillators to external time. Very little progress has been made in understanding the output pathways that allow circadian systems to regulate the breadth of processes shown to be clock-controlled. A genetic selection was designed to obtain mutations in genes involved in circadianregulated expression of the Neurospora crassa ccg-1 and ccg-2 genes. Some, but not all, of the strains obtained display altered regulation of more than one ccg as well as an ‘Easlike’ appearance on solid media, and altered circadian period on race tubes. The data suggest a model in which output from the clock to these two genes is through a single, bifurcated pathway. The cloning of the gene mutated (rrg-1) in one of the strains from the above selection led to the first molecular description of a circadian output pathway in Neurospora, the HOG MAP kinase pathway. The HOG pathway has been previously described with regard to its role in the osmotic-stress response. The discovery of the involvement of rrg-1 in circadian regulation of ccg-1 and ccg-2 led to the discovery of regulation of the HOG pathway by the circadian clock. The data indicate that osmotic stress information and time-of-day information are transduced through the HOG pathway and implicate a role for the clock in preparing the organism for daily occurrences of hyperosmotic stress associated with sun exposure. The genetic selection, and the description of the HOG pathway with regard to circadian output, provide a basis for further characterization of circadian output in Neurospora. The ubiquity of MAP kinase pathways, such as the HOG pathway, and the observed similarities in the mechanisms of circadian clock function across multiple phyla, indicate that these findings may well be applicable to other model systems.

Input¬output approximation of spacecraft motion is convenient and necessary in many situations. For a rigid¬body spacecraft, this process is simple because the system is governed by a set of equations that is linear in the system parameters. However, the combination of a flexible appendage and a rigid hub adds complexity by increasing the degrees of freedom and by introducing nonlinear coupling between the hub and appendage. Assumed Modes is one technique for modeling flexible body motion. Traditional Assumed Modes uses a set of linear assumed modes, but when dealing with rotating flexible systems, a modification of this method allows for the use of quadratic assumed modes. The quadratic assumed model provides an increased level of sophistication, but the derivation still neglects a set of higher¬order terms. This work develops the nonlinear equations of motion that arise from retaining these nonlinear, higher¬order terms. Simulation results reveal that the inclusion of these terms noticeably changes the motion of the system. Once the equations of motion have been developed, focus turns to the input¬output mapping of a system that is simulated using this set of equations. Approxi¬mating linear systems is straightforward, and many methods exist that can success¬fully perform this function. On the other hand, few approximation methods exist for nonlinear systems. Researchers at Texas A&M University recently developed one such method that obtains a linear estimation and then uses an adaptive polynomial estimation method to compensate for the disparity between that estimate and the true measurements. This research includes an in¬depth investigation of this nonlinear approximation technique. Finally, these two major research thrusts are combined, and input¬output approx¬imation is performed on the nonlinear rotational spacecraft model developed herein. The results of this simulation show that the nonlinear method holds a significant advantage over a traditional linear method in certain situations. Specifically, the nonlinear algorithm provides superior approximation for systems with nonzero natu¬ral frequencies. For the algorithm to be successful when rigid¬body modes are present, the system motion must be persistently exciting. This research is an important first step toward developing a nonlinear parameter identification algorithm.

In this thesis, LMI approach is employed to design a static output feedback controller so that all poles of the considered closed-loop continuous-time system are located within a prescribed LMI region, named D region. Based on the coordinate transformation, an analysis about the derived LMI-based sufficient condition is also established. The result is, moreover, extended to treat pole placement in the generalized LMI region, denoted by DR region. In addition to the requirement on pole location, two commonly exploited system performances in robust control, i.e. the H2 and Hinf designs, are also considered so that the multiobjective control by static output feedback is investigated in this thesis. To address robustness issue of the designed controllers, three different uncertainty descriptions, i.e. norm bounded uncertainty, positive real uncertainty, and polytopic uncertainty, are considered and LMI conditions for quadratic D stabilization by static output feedback have been derived. The bounded realness and positive realness with respect to an LMI D region are studied as well. Numerical examples are provided in the end of chapters 3, 4, and 5 to illustrate the obtained results there.

Based on the Lyapunov stability theorem, a methodology of designing an adaptive sliding mode control (ASMC) scheme is proposed in this thesis for a class of linear dynamic systems with matched and mismatched perturbations. Firstly, by utilizing a pseudo control input in the design of a novel sliding surface function, one can not only suppress the mismatched perturbations in the sliding mode, but also achieve the objective of output tracking. In addition, the accuracy of output tracking can be adjusted through the designed parameter embedded in this pseudo controller. Then, a sliding mode controller is derived to guarantee the existence of the sliding mode in a finite time by using adaptive mechanism, which is used to overcome the lumped perturbations so that the upper bound of perturbations is not required. Finally, two illustrative examples are given to demonstrate the validity of the results.

A novel power-saving and small-area digital output cell is proposed in the first topic of this thesis. The new output cell dramatically reduces the output power consumption by filtering pre-defined spikes, which have been considered as one of the major power dissipation sources of the whole chip, with little sacrifice of speed or delay. The bound of the spikes to be removed can be pre-defined either dynamically by digital selection signals or permanently by fuses to be burned. The maximum operating clock is 200 MHz given a 10 pF off-chip load based on testing result of the testkey chip with an almost 28 % power reduction at all PVT corners. The second topic presents a design of a 19-T (19 transistors) full adder with high impedance circuit and conflict circuit. The transistor count is dramatically reduced such that the power dissipation as well as the area on chip is very small .