Abstract The interrelationship between variables involved in focusing schlieren systems is fairly well understood, however how changing the variables affects the resultant images is not. In addition, modified grids and arrangements, such as two dimensional, colour and retroreflective systems have never been directly compared to a standard system. The existing theory is developed from first principles to its current state. An apparatus was specifically designed to test grid and arrangement issues while keeping the system geometry, optical components and the test object identical. Source grid line spacing and clear line width to dark line width ratio were varied to investigate the limits of diffraction and banding and to find an optimum grid for this apparatus. Two dimensional, colour, retroreflective and a novel projected arrangement were then compared to this optimum case. In conclusion, the diffraction limit is accurately modelled by the mathematical equations. The banding limit is slightly less well modelled as additional factors seem to affect the final image. Inherent problems with the two dimensional and colour systems indicate that while they can be useful, they are not worth developing further though chromatism in the system meant that colour systems were not fully investigated. The retroreflective and projected systems have the most potential for large scale use and should be developed further.

This dissertation uses multiple tools to investigate tropical anvil, i.e., thick, non-precipitating cloud associated with deep convection with the main objectives to provide a climatology of tropics-wide anvil properties and a better understanding of anvil formation, and to provide a more realistic assessment of the radiative impact of tropical anvil on the large-scale circulation. Based on 10 years (1998-2007) of observations, anvil observed by the Tropical Rainfall Measuring Mission (TRMM) Precipitation (PR) shows significant geographical variations, which can be linked to variations in the parent convection. Strong upper level wind shear appears to assist the generation of anvil and may further explain the different anvil statistics over land and ocean. Variations in the large-scale environment appear to play a more important role in anvil production in regions where convection regularly attains heights greater than 7 km. For regions where convection is less deep, variations in the depth of the convection and the large-scale environment likely contribute more equally to anvil generation. Anvil radiative heating profiles are estimated by extrapolating millimeter cloud radar (MMCR) radiative properties from Manus to the 10-year TRMM PR record. When the unconditional anvil areal coverage is taken into account, the anvil radiative heating becomes quite weak, increasing the PR latent heating profile by less than 1 percent at mid and upper levels. Stratiform rain and cirrus radiative heating contributions increase the upper level latent heating by 12 percent. This tropical radiative heating only slightly enhances the latent heating driven model response throughout the tropics, but more significantly over the East Pacific. These modest circulation changes suggest that previous studies may have overemphasized the importance of radiative heating in terms of Walker and Hadley circulation variations. Further, the relationship of cloud radiative heating to latent heating needs to be taken into account for more realistic studies of cloud radiative forcing on the large-scale circulation.

A novel design methodology of a decentralized adaptive sliding mode control scheme for a class of large-scale systems with mismatched disturbances and uncertainties in each subsystem and interconnections is proposed in this thesis. The main idea of this new method is that the design of the switching surface of each subsystem is through the design of a pseudo-feedback controller which can stabilize the dynamics when system is in the sliding mode. The feedback gain of the pseudo controller then becomes a important parameter of switching surface. The proposed controllers of each subsystem contain three parts. The first part is measurable feedback signals, and the second part is an adaptive control mechanism, which is used for overcoming the disturbances and uncertainties of each subsystem and interconnections among subsystems. The information of upper bound of those disturbances and uncertainties are not required. The third part of the decentralized controllers is used for adjusting the convergent rate of state variables of the controlled system. The asymptotical stability is guaranteed for each subsystem even if the mismatched perturbations exist when employing the proposed control scheme. An example is demonstrated for showing the feasibility of the proposed methodology.

A methodology of designing a novel sliding surface for a class of large-scale systems with matched and mismatched perturbations is proposed in this thesis. The main idea is that some adaptive mechanisms are embedded both in the sliding surface function and in the controllers, so that not only the mismatched perturbations are suppressed during the sliding mode, but also the information of upper bound of perturbation is not required except the upper bound of perturbation from input channel. The proposed controller of each subsystem contains two parts. The first part is measurable feedback signals, and the second part is an adaptive control mechanism, which is used for overcoming the perturbation of each subsystem as well as interconnections among subsystems. The dynamics of the controlled system can be driven into the sliding surface in a finite time, and the property of asymptotical stability of each subsystem is guaranteed. Two numerical examples are given to demonstrate the feasibility of the proposed methodology.

Based on the Lyapunov stability theorem, a methodology of designing a decentralized multi-surface adaptive sliding mode control scheme is proposed in this thesis for a class of large-scale nonlinear systems with mismatched perturbations and interconnections. By utilizing the sliding mode control technique, the designed decentralized robust controller with adaptive mechanisms embedded enable the output of each subsystem to track its own desired output signal, and stabilize the whole large-scale system as well as each subsystem at the same time. In addition, the accuracy of output tracking can be adjusted through the designed parameter embedded in the controller. The purpose of the adaptive mechanisms included in the controller is to adapt the unknown upper bounds of perturbations and interconnections. Finally, two illustrative examples are given to demonstrate the feasibility of the proposed methodology.

The analysis of the large-scale international multi-sports event and city development¡Ðtaking the 2009 World Games pre-events as examples. Since winning the right to host the 2009 World Games in June 2004, Taiwan has been making numerous preparations for the big event. During the preparation period, intense preparations and the support of human resource as well as material resource are essential. However, Taiwan is currently lacking of experienced organizations on hosting large-scale international sports events and un-unified affair right. The promotion of the central policy rarely takes into account the diverse local public opinion over an extended period of time, which causes the inappropriate resource allocation for local development. The preparation is full of difficulties because the central and local resources could not bring out the full beneficial result. This research aims to analyze the 2009 World Games pre-events by using the data and literature review analysis. It does not only improve the hardware and software of city¡¦s structure. It also offers the opportunity for citizens to interact with various cultures. The most important thing is increasing the centripetal force of the people in a short time and promoting Taiwan into the international stage. The key factor is the marketing tactics brought out by the sports event, which expresses concretely the cultural integration, united harmony and state consciousness of Taiwan. The marketing tactics brought out by sports event pushes the rapid development of the city appearance, creative and artistic livelihood, and sustainable environment and tourism industries. We hope to drive the economic development by hosting large-scale sports event. Our goal is to promote the city and show the vitality of entire city. The global participative sports event will bring the long-term benefit for the city economy. Kaohsiung should work harder in the future, striving actively for the right to host international event which helps internationalize the city, expand commercial possibilities, and gain people recognition.

To make progress in the face of failures, long-running parallel applications need to save their state, known as a checkpoint. Unfortunately, current checkpointing techniques are becoming untenable on large-scale supercomputers. Many applications checkpoint all processes simultaneously--a technique that is easy to implement but often saturates the network and file system, causing a significant increase in checkpoint overhead. This thesis introduces compiler-assisted staggered checkpointing, where processes checkpoint at different places in the application text, thereby reducing contention for the network and file system. This checkpointing technique is algorithmically challenging since the number of possible solutions is enormous and the number of desirable solutions is small, but we have developed a compiler algorithm that both places staggered checkpoints in an application and ensures that the solution is desirable. This algorithm successfully places staggered checkpoints in parallel applications configured to use tens of thousands of processes. For our benchmarks, this algorithm successfully finds and places useful recovery lines that are up to 37% faster for all configurations than recovery lines where all processes write their data at approximately the same time. We also analyze the success of staggered checkpointing by investigating sets of application and system characteristics for which it reduces network and file system contention. We find that for many configurations, staggered checkpointing reduces both checkpointing time and overall execution time. To perform these analyses, we develop an event-driven simulator for large-scale systems that estimates the behavior of the network, global file system, and local hardware using predictive models. Our simulator allows us to accurately study applications that have thousands of processes; it on average predicts execution times as 83% of their measured value. / text

As more applications rely on distributed systems (peer-to-peer services, content distribution networks, cloud services), it becomes necessary to identify hosts that return content to the user with minimal delay. A large scale map of delays would aid in solving this problem. Existing methods, which deploy devices to every region of the Internet or use of a single vantage point have yet to create such a map. While services such as PlanetLab offer a distributed network for measurements, they only cover 0.3% of the Internet. The focus of our research is to increase the speed of the single vantage point approach so that it becomes a feasible solution. We evaluate the feasibility of performing large scale measurements by performing an experiment using more hosts than any previous study. First, an efficient scanning algorithm is developed to perform the measurement scan. We then find that a custom Windows network driver is required to overcome bottlenecks in the operating system. After developing a custom driver, we perform a measurement scan larger than any previous study. Analysis of the results reveals previously unidentified drawbacks to the existing architectures and measurement methodologies. We propose novel meth- ods for increasing the speed of experiments, improving the accuracy of measurement results, and reducing the amount of traffic generated by the scan. Finally, we present architectures for performing an Internet scale measurement scan. We found that with custom drivers, the Windows operating system is a capable platform for performing large scale measurements. Scan results showed that in the eleven years since the original measurement technique was developed, the response patterns it relied upon had changed from what was expected. With our suggested improvements to the measurement algorithm and proposed scanning architectures, it may be possible to perform Internet scale measurement studies in the future.

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Results from large-scale assessments of academic achievement are key sources of evidence in the development of education policy and reform. The increasing influence of these assessments underscores the need for the results to be valid and reliable. This study investigates possible threats to the validity of reading proficiency assessments by examining the influence of two motivational variables: the interest attributed to the texts students read, and the amount of effort that students invest in undertaking the reading assessment. Using data from Australian pilot assessments and the Programme for International Student Achievement (PISA) this study explores the influence of interest and effort on reading proficiency outcomes and on the conclusions that can be drawn from these assessments.