In this thesis, we study weighted composition operatorsT(xn)=(£fnX£m(n)) between sequence spaces(c0,c,l1,lp), and more precisely, the sufficient and necessary condition that they are compact. First,we obtain some results of weighted composition operators beingcompact, weakly compact and completely continuous on c0 spaces. Then, we extend then to c,l1,and lp(1<p<¡Û) spaces. Finally, we obtain the condition that an operator from c0, c or lp into c0, c, or lq is compact, weakly compact or completely continuous.

The paper investigates problems of designing controllers to linear time-invariant continuous descriptor systems subject to norm-bounded structured uncertainty so that the closed-loop systems are admissible or D-admissible with their transfer matrices having H-infinite norm bounded by a prescribed value. The constant state feedback and the dynamic output feedback designs are addressed. In both design methods, sufficient LMI conditions are derived to guarantee achievement of the desired specifications, such as robust H-infinite norm and pole-clustering constraints. Finally, two numerical examples are shown for the illustration.

A novel on chip automatic tuning circuit for Gm ¡V C continuous time filter is presented. The circuit is composed of an integrator, a frequency tuning circuit, and a Q tuning circuit. A 4th order Chebyshev low pass filter is also designed with the tuning circuitry. All circuits are designed by using the parameters of TSMC 0.25um process. The power supplies are ¡Ó2.5V, and the cutoff frequency is 10MHz. The main LPF exhibits passband ripple below 4dB, and stopband attenuation over 70dB. The equilibrium time for tuning circuits is less than 3£gseconds.

This paper aims to first develop a model that analyzes how investors place orders in an order driven market. In this model, investors have different share evaluations and information is asymmetric. Private information is short-lived, and types of orders include a market order and a limit order. A market with or without bid-ask prices can influence investors¡¦ choices when submitting market orders. Hence, we discuss two kinds of market conditions in the first model. The first condition is a market with bid-ask prices, and the second is a market without bid-ask prices. Secondly, we develop an integrated model to analyze how an informed trader optimally chooses any combination of a market buy, market sell, limit buy and limit sell. In this model the informed trader observes the terminal value of a security. Then, the trader makes a choice of orders to submit under a market with bid-ask prices. As for the first model, there are some results in the first condition. At equilibrium, the optimal price of a limit order placed by an uninformed trader is related to the difference in share valuation and to adverse selection. The uninformed trader will request adverse selection risk premium, and the risk premium is related to the proportion of informed traders in the market and the value of private information. At this moment, informed traders get information benefits by submitting market orders. The information benefits are related to the difference in share valuation and the value of private information. On the other hand, we have found that informed traders will also experience adverse selection problem when placing limit orders and request risk premiums in limit prices. Informed traders¡¦ limit orders will be executed with the market orders of informed and uninformed traders who will be submitting next. The adverse selection risk of informed traders¡¦ limit orders is only related to private information value if uninformed traders don¡¦t place market orders. However, when uninformed traders submit only market orders, the adverse selection risk is related to the ratio of informed traders and private information value. From the first model, our results indicate the behaviors of informed traders who cannot submit market orders under a market with private information are short-lived like those of uninformed traders. However, we would like to know if an informed trader may submit a limit order. In the second model, in order to get information profit, the informed trader submits not only a market order, but also a limit order, even if the market has bid-ask prices and private information is not short-lived again. A combination of market-limit orders is more profitable than only a market order. In addition, limit orders enhance the profitability of market orders by reducing their losses in bad states. Finally, we obtain the result of price improvement for market orders.

Bandpass sigma-delta modulators combine oversampling and noise shaping to get very high resolution in a limited bandwidth. They are widely used in applications that require narrowband high-resolution conversion at high frequencies. In recent years interests have been seen in wireless system and software radio using sigma-delta modulators to digitize signals near the front end of radio receivers. Such applications necessitate clocking the modulators at a high frequency (MHz or above). Therefore a loop filter is required in continuous-time circuits (e.g., using transconductors and integrators) rather than discretetime circuits (e.g., using switched capacitors) where the maximum clocking rate is limited by the bandwidth of Opamp, switch’s speed and settling-time of the circuitry. In this work, the design of a CMOS fourth-order bandpass sigma-delta modulator clocking at 500 MHz for direct conversion of narrowband signals at 125 MHz is presented. A new calibration scheme is proposed for the best signal-to-noise-distortion-ratio (SNDR) of the modulator. The continuous-time loop filter is based on Gm-C resonators. A novel transconductance amplifier has been developed with high linearity at high frequency. Qfactor of filter is enhanced by tunable negative impedance which cancels the finite output impendence of OTA. The fourth-order modulator is implemented using 0.35 mm triplemetal standard analog CMOS technology. Postlayout simulation in CADENCE demonstrates that the modulator achieves a SNDR of 50 dB (~8 bit) performance over a 1 MHz bandwidth. The modulator’s power consumption is 302 mW from supply power of ± 1.65V.

This thesis research investigated the predictive performance of pavement marking retroreflectivity measured under various conditions of continuous wetting. The researcher compared nighttime detection distance of pavement markings in simulated rain conditions and the retroreflectivity of the same pavement markings in several continuous wetting conditions. Correlation analyses quantified the predictive performance of the resulting retroreflectivity values from the continuous wetting conditions. The researcher measured the retroreflectivity of 18 pavement marking samples under 14 different conditions. The American Society for Testing and Materials (ASTM) has three standards for measuring the retroreflectivity of pavement markings under: dry (E-1710), recovery (E-2177), and continuous wetting conditions (E-2176). Using three ASTM standard conditions resulted in three sets of retroreflectivity data, and variations of the continuous wetting standard produced an additional 11 sets of continuous wetting condition data. The researcher also incorporated detection distance values measured for the same 18 pavement marking samples under three different simulated rainfall conditions at night. The three conditions included: high (0.87 in/hr), medium (0.52 in/hr), and low (0.28 in/hr) flow rates, these rates were to simulate typical rainfall rates in the state of Texas. The correlation analyses measures the linear relationship as well as the logarithmic relationship between the detection distance and the retroreflectivity of the pavement markings. A pavement markings' retroreflectivity is typically used as a detection distance performance indicator, therefore a high degree of correlation between retroreflectivity and detection distance would be desired. A high degree of correlation would indicate that a measured retroreflectivity value of a pavement marking would provide a good indication of the expected detection distance. The researcher conducted analyses for several subgroups of the pavement markings based on the markings type or characteristics. Dry, recovery, and all the continuous wetting retroreflectivity data were correlated to the detection distances. Correlation values found during this thesis research did not show a high degree of correlation for most of the subgroups analyzed. This indicates that measured retroreflectivity would not provide very good predictive performance of the pavement markings detection distance in rainy conditions.

<p>The main goal with the master thesis has been to do a status evaluation of the chain machinery with its start chain and wire to secure the production on a short basis due to that a reconstruction is not planned at this time. An evaluation of the condition of the start chain and the rollers in the chain depository has been done. An offer has been requested for a new start chain and the evaluation of the start chains may be a basis for the decision taking. The production has been able to go on, although it has arisen some problems which have been difficult to find the causes for. There is no gathered “picture” of the machinery status and a mapping of each machinery has been compiled of comprehensive logs. Observations and measurements have also been done to prove and elucidate the biggest problems.</p><p>After the compilation a concentration has been done of the two most frequently problems during the last years, that is to say, 2006 to 2008. The work has finally fallen into suggestions for improvements of routines and suggestions for concepts for construction changes to keep a continuous stable production until a bigger reconstruction will be made.</p><p>The two problems which have been focused on were the “limit-switches” for the wires and the heat-radiation-shields situated under the tilt bridges. The arrangement for the wire problem shown to be quite simple to implement and its cause was due to that the friction was to big in the shackle, which function is to be pressed down by the wire, and thereby didn’t trigger an alarm on the computer screens.</p><p>To prevent this, lubrication was done for respective shackle to sustain the production for a short period of time. Although there have been done some concepts to sustain the production for a longer period of time.</p><p>The problems concerning the heat-radiation-shields under the tilt bridges can be solved mainly by changed maintenance routines, which have been attached in the list which has been formed.</p>

Thesis (Ph. D.)--Open University.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 65-68). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 65-68). Also available on the Internet.