Today's radio frequency receivers for digital wireless communication are getting more and more complex. A single receiver unit should support multiple bands, have a wide bandwidth, be flexible and show good performance. To fulfil these requirements, new receiver architectures have to be developed and used. One possible alternative is the RF undersampling architecture. This thesis evaluates the RF undersampling architecture, which make use of an undersampling track-and-hold circuit with very wide bandwidth to perform direct sampling of the RF carrier before the analogue-to-digital converter. The architecture’s main advantages and drawbacks are identified and analyzed. Also, techniques and improvements to solve or reduce the main problems of the RF undersampling receiver are proposed.

The basis for this thesis involved a four month Accelerate Canada internship at the Grand River Hospital Emergency Department in Kitchener, Ontario. The Emergency Department (ED) Process Committee sought insight into strategies that could potentially reduce patient length of stay in the ED, thereby reducing wait times for emergency patients. This thesis uses discrete event simulation to model the overall system and to analyze the effect of various operational strategies within the fast track area of the emergency department. It discusses the design and development process for the simulation model, proposes various operational strategies to reduce patient wait times, and analyzes the different scenarios for an optimal fast track strategy. The main contribution of this thesis is the use of simulation to determine an optimal fast track strategy that reduces patient length of stay, thereby reducing patient wait times. Wait times were most significantly reduced when there was an increased physician presence/availability towards the fast track system. This had the greatest impact on the total time spent in the ED and also on queue length. The second most significant reduction to the performance measures occurred when an additional emergency nurse practitioner was supplemented to the fast track system. Accordingly, the nurse practitioner’s percent utilization increased. There was only one two-way interaction effect that was statistically significant in reducing the primary performance measure of wait times; however, the effect did not change the queue length, a secondary performance measure, by a significant amount. Finally, the implementation of a See-and-treat model variant for fast track had a negligible effect on both the average length of stay and queue length.

Population estimation is an important task in all wildlife conservation. Such estimations are often difficult in low-density species such as big carnivores. The painted dog (Lycaon pictus) is an endangered species and the first aim of IUCNs action plan is to assess the size and the distribution of the remaining population. This study is the first step towards a quantitative method to distinguish painted dog footprints from footprints of feral domestic dogs and hyaenas. Footprint photographs were collected and digitally processed and total pad area and angles between the digits and backpad of the paw were measured. Both the pad area and the angles show a statistically significant difference between the species. However, further analysis shows that there is no significant difference in pad area between painted dog females and domestic dog males. Size of the pads alone is therefore not suitable as a measure to determine the species from an unknown footprint. The angles between backpad and digits seem to be more suitable to distinguish between species. Therefore, a combination of pad size and the angle between backpad and digits might be useful to estimate the species from an unknown footprint in the field.

The basic principle in SAS is to use an array which is small in length to create a long synthetic array thus the better resolution is achieved through the use of signal processing. Additionally, the resolution that is independent of range and signal frequency, makes SAS a advantageous tool for applications. Although the origin of SAS comes from SAR, SAS still needs to overcome all constraints for real-world application. In a previous study by Sung and prof. Liu, published results of the along track resolution experiments which were well done however there was still much room in range resolution, the purpose of this research is to achieve high range resolution at any ranges. Indeed there are many existing factors affecting the capability of resolution which including characteristic of the target, certain arrangements of targets, bandwidth, waveforms and pulse duration and etc. High range resolution is obtained using pulse compression techniques. The experiments were carried out using the transducers of AST MK VI 192 kHz which were employed to transmit and receive signals, scanned various copper balls at anechoic water tank(4 m ¡Ñ 3.5 m ¡Ñ 2 m) in NSYSU. From the equipment we have now results were evaluated based on both simulated and real data: for the range resolution the pulse length is very important the shortest pulse length on an object would be 2L/c theoretically, the measured range resolution is about 7.5 cm for the 20-kHz bandwidth signals and 5 cm for along track resolution. As all the experiments have been successful in the Water Tank, we intent to launch further investigation of this research to the real world application of SAS i.e. in Sizihwan Bay Marine Test Field.

When we probe into how on-line games affect the interaction between teenagers and their families, we find that the parents¡¦ teaching attitude is the key factor of affecting the children¡¦s behavior in the games. If the parents and the children have a better interaction, or even they can play the games together, then the development of the children are comparatively healthier and better. From the analysis of this study, we see that on-line games did not bring about bad effects to the children, on the contrary, under the guidance of the parents, the children can successfully go in and out the world of on-line games. Such an unharmed result is just what most of the parents like to see: not to indulge, not to be deceived, not to contract bad habits from bad friends and so on. However, comparatively, the children¡¦s experience in on-line games could lack spirit of adventure. No matter in a fictitious or a concrete society, the grownups have a higher capacity of awakening after all. The guidance of the parents can inspire unlimited possibilities in the children, and they can ward off the chance of getting hurt under the parents¡¦ protection. ¡§Defeat is the motivation of growth; deception is the turning point of development!¡¨ Don¡¦t forget to reserve the room for defeat during the process of children guidance and assistance. When the grownups shake off the self-centered and subjective viewpoints, they are conscious of a transformation of a hero. In the fictitious world, making a mistake is a rare chance to launch an unexpected discovery, and life starts to liaise the unknown power. Regardless of old or young, and which life stage you are at, conjuration can always unveil the overture of mythic transformation. When you fulfill a spiritual trial and ritual, it is like you are experiencing a circle of death and resurrection. Experiences are past concepts and modes of thinking in a familiar living domain which are applicative no more, and it is time to cross the threshold. After returning I hope to provide some corresponded and balanced viewpoints to the past one-way discourse, and let the teenagers to show more distinctive features of themselves.

Detection and tracking of signals used in sonar applications in noisy environment is the focus of this thesis. We have concentrated on the low Signal-to-Noise Ratio (SNR) case where the conventional detection methods are not applicable. Furthermore, it is assumed that the duty cycle is relatively low. In the problem that is of concern the carrier frequency, pulse repetition interval (PRI) and the existence of the signal are not known. The unknown character of PRI makes the problem challenging since it means that the signal exists at some unknown intervals. A recursive, Bayesian track-before-detect (TBD) filter using particle filter based methods is proposed to solve the concerned problem. The data used by the particle filter is the magnitude of a complex spectrum in complex Gaussian noise. The existence variable is added in the design of the filter to determine the existence of the signal. The evolution of the signal state is modeled by a linear stochastic process. The filter estimates the signal state including the carrier frequency and PRI. Simulations are done under different scenarios where the carrier frequency, PRI and the existence of the signal varies. The results demonstrate that the algorithm presented in this thesis can detect signals which cannot be detected by conventional methods. Besides detection, the tracking performance of the filter is satisfying.

In this study Track Before Detect (TBD) approach will be analysed for tracking of dim moving targets. First, a radar setup is presented in order to introduce the radar range equation and signal models. Then, preliminary information is given about particle filters. As the main algorithm of this thesis, a multi-model particle filter method is developed in order to solve the non-linear non-Gaussian Bayesian estimation problem. Probability of target existence and RMS estimation accuracy are defined as the performance parameters of the algorithm for very low SNR targets. Simulation results are provided and performance analysis is presented as a conclusion.

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Factors of very rapidly rising oil prices, the running out time limits on continued use of fossil fuels, as well as elements of the Kyoto Protocol, have greatly arouses the increasing emphasis on natural and renewable energy sources. 40 minutes of total solar radiation on earth could provide enough power to meet the energy needs of all human beings for approximately one year. The potential of solar energy is virtually limitedless. Moreover, by means of solar powered batteries, solar energy can be directly converted to electric power. Since it neither pollutes the environment or ecology, solar is an extremely clean source of energy. The life-span of solar cell is very long, possibly 20 years or more. The capability of solar batteries to provide energy is approximately proportional to the intensity of the sunlight. This thesis proposes the use of Artificial intelligence for "Sun Track Solar Energy System". This system employs Fuzzy Logic Control Theory, combined with Grey Relational Analysis, for tracking the angle of the sun, and further control the motor to adjust the angle for tracking, so direct sunlight could be acquired to increase power output. As a result of the experiment, comparing the electricity generated from the fix angle solar battery with the AI-based Sun Track Solar Energy System, the latter one has an efficiency increase up to 23% for the same amount of sunlight.

<p>Carbody tilting is today a mature and inexpensive technology allowing higher speeds in curves and thus reduced travel time. The technology is accepted by most train operators, but a limited set of issues still holding back the full potential of tilting trains. The present study identifies and report on these issues in the first of two parts in this thesis. The second part is dedicated to analysis of some of the identified issues. The first part contains Chapters 2 to 5 and the second Chapters 6 to 12 where also the conclusions of the present study are given.</p><p>Chapters 2 and 3 are related to the tilting train and the interaction between track and vehicle. Cross-wind stability is identified as critical for high-speed tilting trains. Limitation of the permissible speed in curves at high speed may be needed, reducing the benefit of tilting trains at very high speed. Track shift forces can also be safety critical for tilting vehicles at high speed. An improved track standard must be considered for high speed curving.</p><p>Chapters 4 and 5 cover motion sickness knowledge, which may be important for the competitiveness of tilting trains. However, reduced risk of motion sickness may be contradictory to comfort in a traditional sense, one aspect can not be considered without also considering the other. One pure motion is not the likely cause to the motion sickness experienced in motion trains. A combination of motions is much more provocative and much more likely the cause. It is also likely that head rotations contribute as these may be performed at much higher motion amplitudes than performed by the train.</p><p>Chapter 6 deals with services suitable for tilting trains. An analysis shows relations between cant deficiency, top speed, tractive performance and running times for a tilting train. About 9% running time may be gained on the Swedish line Stockholm – Gothenburg (457 km) if cant deficiency, top speed and tractive performance are improved compared with existing tilting trains. One interesting conclusion is that a non-tilting very high-speed train (280 km/h) will have longer running times than a tilting train with today’s maximum speed and tractive power. This statement is independent of top speed and tractive power of the non-tilting vehicle.</p><p>Chapters 7 to 9 describe motion sickness tests made on-track within the EU-funded research project<i> Fast And Comfortable Trains (FACT).</i> An analysis is made showing correlation between vertical acceleration and motion sickness. However, vertical acceleration could not be pointed out as the cause to motion sickness as the correlation between vertical acceleration and several other motions are strong.</p><p>Chapter 10 reports on design of track geometry. Guidelines for design of track cant are given optimising the counteracting requirements on comfort in non-tilting trains and risk of motion sickness in tilting trains. The guidelines are finally compared with the applied track cant on the Swedish line Stockholm – Gothenburg. Also transition curves and vertical track geometry are shortly discussed.</p><p>Chapters 11 and 12 discusses the analysis, draws conclusions on the findings and gives proposals of further research within the present area.</p>