In this study, the development and testing of a finite-difference model for wind-induced flow in shallow lakes, and, in particular, a new technique for improving the land--water boundary representation, are documented. The model solves nonlinear, as well as linear, versions of the two-dimensional depth-integrated shallow water equations. Finite-difference methods on rectangular grids are widely used in numerical models of environmental flows. In these models, land--water boundaries are usually approximated by a series of perpendicular line segments, which enable the impermeability condition to be easily implemented. A disadvantage of this approach is that the actual boundary is often poorly approximated, particularly in regions which have complicated coastlines, and, as a result, currents in these regions cannot be accurately predicted. A technique for improving the land--water boundary representation in finite-difference models is introduced. This technique permits the model boundary to contain diagonal line segments, in addition to the vertical and horizontal line segments used in traditional models. The new technique is based on a simple concept and can easily be included in existing finite-difference models. In order to test the new method, the linearised shallow water equations are solved numerically for oscillatory wind-driven flow in lakes with simple geometry. Predictions obtained using the new approach are compared with predictions from the traditional stepped boundary and known analytic solutions. A significant improvement in the accuracy of results is noticed when the new approach is used, particularly in currents close to shore. The increased accuracy obtained using the improved boundary representation can lead to a significant computational saving, when compared with running the rectangular grid model with smaller grid spacings. A second-order analytic solution to the nonlinear shallow water equations is developed for oscillatory wind-driven flow in a rectangular lake. Comparisons between this solution and numerical results, obtained using the traditional stepped boundary and the improved boundary, verify the finite-difference formulae used in these models, including the approximations used for the cross-advective terms close to shore. Once more, currents are predicted with greater accuracy when the new technique for representing the land--water boundary is implemented. The lake circulation model is applied to the Lower Murray Lakes, South Australia, and predicted water levels at Tauwitchere Barrage are shown to agree very well with observations. The model is then used to examine the effectiveness of two schemes that have been proposed to increase wind-induced circulation, and therefore potentially decrease salinity, in Lake Albert, demonstrating the model's use as an efficient and effective tool for analysing flow behaviour in lakes. / Thesis (Ph.D.)--Mathematical Sciences (Applied Mathematics), 2005.

<p>The aim of this paper is to analyse how subject, gender and sexuality is constructed in the book <i>Dårfinkar & dönickar </i>(1984), by Ulf Stark. In relation to this I have also analysed how the main character, Simone, develops from being a child into becoming a teenager.</p><p>Queertheory is the theoretical basis of this paper. Queer theory questions heteronormativity and aims to dissolve conceptions and notions that function in an excluding and limiting way. Queer theory also questions conceptions that seem obvious and/or natural, for example “woman”/”man” and “homo-/heterosexuality”.</p><p>I have chosen to focus the analysis on a number key events in the book and they are categorised according to Tiina Rosenberg`s three dramaturgic concepts: transformation, unveiling and restoration. I have also focused on how masculinities are constructed and to be able to this I have used R. W Connel`s theory. The result of my analysis is that the representation of gender in the book are constructed in accordance to the heterosexual matrix. It is also clear that Simone`s development from childhood to teenager follows Rosenberg`s three dramaturgic concepts.</p>

Iontophoresis is a method to enhance and regulate the transdermal drug delivery by application of an electric field to the skin. Application of small electric current (µ A) enhances transport of both charged and neutral molecules across the skin. Reverse of this process enables extraction of analytes across the skin for noninvasive sensing and diagnosis. Hence it is planned to conduct detailed studies on Reverse Iontophoresis. An invitro model is developed to study the extraction of glucose across the skin. Effects of magnitude of electric current, time of application, pH etc. on the extraction of glucose are studied. It is observed that extraction of glucose at the cathode is higher than at the anode. Advantage of invitro model is the possibility of varying parameters to an extent which is impossible invivo. Instrumentation suitable for continuous monitoring of reverse iontophoresis invivo in human subjects is developed. It supplies the required current and acquires the potential profile of the skin during reverse iontophoresis. Potential profiles showed that skin resistance decreases with the application of current. Experimental results revealed that the application of pulsed DC tends to make the reverse iontophoresis more effective by enhancing the flow of analytes which is proved by the fact that skin resistance decreases and stabilizes faster in comparison to the one with direct current reverse iontophoresis. Present work emphasizes the importance of selecting an appropriate duty cycle and frequency for reverse iontophoresis. Duty cycle around 95% and frequency of 250 mHz are good for low frequency reverse iontophoresis. Effect of reverse iontophoresis on the skin recovery is observed by monitoring the potential profiles at the end of the process. In all the reverse iontophoresis experiments, safety of the patient is ensured by fixing a compliance voltage level. Finally, Instrumentation to measure the capacitance of biosensors is developed based on frequency domain technique with a sinusoidal input. Accuracy in capacitance measurements is ±5%. Glucose measurement is demonstrated with the developed instrument using a capacitance type biosensor. The obtained results are in good agreement with the standard UV-Visible spectroscopic measurements based on phenol-sulphuric acid assay method.

Labor shortage has prompted researchers to develop robot platforms for agriculture field scouting tasks. Sensor-based automatic topographic mapping and scouting algorithms for rough and large unstructured environments were presented. It involves moving an image sensor to collect terrain and other information and concomitantly construct a terrain map in the working field. In this work, a triangular mesh map was first used to represent the rough field surface and plan exploring strategies. A 3D image sensor model was used to simulate collection of field elevation information.<p>A two-stage exploring policy was used to plan the next best viewpoint by considering both the distance and elevation change in the cost function. A greedy exploration algorithm based on the energy cost function was developed; the energy cost function not only considers the traveling distance, but also includes energy required to change elevation and the rolling resistance of the terrain. An information-based exploration policy was developed to choose the next best viewpoint to maximise the information gain and minimize the energy consumption. In a partially known environment, the information gain was estimated by applying the ray tracing algorithm. The two-part scouting algorithm was developed to address the field sampling problem; the coverage algorithm identifies a reasonable coverage path to traverse sampling points, while the dynamic path planning algorithm determines an optimal path between two adjacent sampling points.<p>The developed algorithms were validated in two agricultural fields and three virtual fields by simulation. Greedy exploration policy, based on energy consumption outperformed other pattern methods in energy, time, and travel distance in the first 80% of the exploration task. The exploration strategy, which incorporated the energy consumption and the information gain with a ray tracing algorithm using a coarse map, showed an advantage over other policies in terms of the total energy consumption and the path length by at least 6%. For scouting algorithms, line sweeping methods require less energy and a shorter distance than the potential function method.

The aim of this paper is to analyse how subject, gender and sexuality is constructed in the book Dårfinkar &amp; dönickar (1984), by Ulf Stark. In relation to this I have also analysed how the main character, Simone, develops from being a child into becoming a teenager. Queertheory is the theoretical basis of this paper. Queer theory questions heteronormativity and aims to dissolve conceptions and notions that function in an excluding and limiting way. Queer theory also questions conceptions that seem obvious and/or natural, for example “woman”/”man” and “homo-/heterosexuality”. I have chosen to focus the analysis on a number key events in the book and they are categorised according to Tiina Rosenberg`s three dramaturgic concepts: transformation, unveiling and restoration. I have also focused on how masculinities are constructed and to be able to this I have used R. W Connel`s theory. The result of my analysis is that the representation of gender in the book are constructed in accordance to the heterosexual matrix. It is also clear that Simone`s development from childhood to teenager follows Rosenberg`s three dramaturgic concepts.

Labor shortage has prompted researchers to develop robot platforms for agriculture field scouting tasks. Sensor-based automatic topographic mapping and scouting algorithms for rough and large unstructured environments were presented. It involves moving an image sensor to collect terrain and other information and concomitantly construct a terrain map in the working field. In this work, a triangular mesh map was first used to represent the rough field surface and plan exploring strategies. A 3D image sensor model was used to simulate collection of field elevation information.<p>A two-stage exploring policy was used to plan the next best viewpoint by considering both the distance and elevation change in the cost function. A greedy exploration algorithm based on the energy cost function was developed; the energy cost function not only considers the traveling distance, but also includes energy required to change elevation and the rolling resistance of the terrain. An information-based exploration policy was developed to choose the next best viewpoint to maximise the information gain and minimize the energy consumption. In a partially known environment, the information gain was estimated by applying the ray tracing algorithm. The two-part scouting algorithm was developed to address the field sampling problem; the coverage algorithm identifies a reasonable coverage path to traverse sampling points, while the dynamic path planning algorithm determines an optimal path between two adjacent sampling points.<p>The developed algorithms were validated in two agricultural fields and three virtual fields by simulation. Greedy exploration policy, based on energy consumption outperformed other pattern methods in energy, time, and travel distance in the first 80% of the exploration task. The exploration strategy, which incorporated the energy consumption and the information gain with a ray tracing algorithm using a coarse map, showed an advantage over other policies in terms of the total energy consumption and the path length by at least 6%. For scouting algorithms, line sweeping methods require less energy and a shorter distance than the potential function method.

From the viewpoint of the adaptive solution of partial differential equations a finit e element method on hierarchical triangular meshes is developed permitting hanging nodes arising from nonuniform hierarchical refinement. Construction, extension and restriction of the nonuniform hierarchical basis and the accompanying mesh are described by graphs. The corresponding FE basis is generated by hierarchical transformation. The characteristic feature of the generalizable concept is the combination of the conforming hierarchical basis for easily defining and changing the FE space with an accompanying nonconforming FE basis for the easy assembly of a FE equations system. For an elliptic model the conforming FEM problem is solved by an iterative method applied to this nonconforming FEM equations system and modified by projection into the subspace of conforming basis functions. The iterative method used is the Yserentant- or BPX-preconditioned conjugate gradient algorithm. On a MIMD computer system the parallelization by domain decomposition is easy and efficient to organize both for the generation and solution of the equations system and for the change of basis and mesh.

Over the last decade, researchers have attempted to show how efficient the markets are by using Fama’s Efficiency Market Hypothesis (EMH). The theory states that an investor cannot increase his returns without taking additional risk. The markets can be efficient in different forms depending on the information included in the traded asset. It is quoted that: "There ain't no such thing as a free lunch". However, the topic still remains disputable since researchers have introduced controversial findings after investigating different markets. Overall, emerging markets have been characterized with higher volatility which consequently declares for market imperfections. Commonly, these market inefficiencies are quickly captured by the eye of the investors who are lurking for potential benefits through exploiting them. These are the so called arbitrage opportunities which exist on different level of impact, depending on the attitude of the market. The existence of arbitrage is clear evidence against Fama’s theory and it has been documented in numerous studies. Unfortunately those events occur rarely and disappear in a matter of seconds, thus; is highly competitive to capitalize. Over the last decade high frequency trading (HFT) became popular on different markets and it allowed traders to make decisions and execute transactions in a matter of milliseconds using algorithms. The market we are interested in is the Forex market which is a decentralized market where currencies from all over the world are traded. Main participants include multinational banks which rely heavily on HFT. The method used to benefit from inefficiency is called triangular arbitrage and it involves selling and buying 3 sets of currency pairs in times when a parity is violated. The goal of this study is to answer the following research question, “Is there a difference in triangular arbitrage opportunities between emerging markets and developed ones?” The main objective of this research is to examine how the number of arbitrage occurrences varies considering different market characteristics. Furthermore, the originality of the research stems from the comparison between strategies using currencies from developed economies and emerging ones. Moreover, the additional academic value comes from the analysis of a new dataset that has not yet been examined. Lastly, our results make an empirical contribution into a country’s economy by reducing market inefficiencies and increasing economic stability. Our sample consists of quantitative data totaling to 2.4 million observations per quotation taken from 2011 and 2013 for currencies picked using a non-probability convenience method based on their property to be converted to EUR and USD currency and availability of information. The research revealed that differences between the two types of market exist, and indicates that the “early” markets possess higher arbitrage activity in contrast to the mature economies. These results should boost the potential for a better trading management and upgrade the profit growth.

All heat pump cycles have one common feature that connects them to one another; this feature is the presence of a heat exchanger. There are even some heat–driven cycles that are completely composed of heat exchangers, every heat exchanger fulfilling a different, though critical role. The need therefore exists to optimize heat exchangers, more specifically Compact Heat Exchangers (CHE). This study deals with the optimization of such a CHE by determining an optimal hydraulic diameter of the micro–channels in a CHE, for minimal hydraulic losses. Two Computational Fluid Dynamics (CFD) models were developed for a single micro–channel that is present in a CHE. The first model had a semi–circular cross–section, the second a triangular cross–section. The results were verified by comparing it with existing experimental data. Following the verification of the results, the micro–channel was optimized by implementing an optimum diameter for the lowest pressure drop over the micro–channel. This was done for both the semi–circular and triangular micro–channel cross–sections. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.

All heat pump cycles have one common feature that connects them to one another; this feature is the presence of a heat exchanger. There are even some heat–driven cycles that are completely composed of heat exchangers, every heat exchanger fulfilling a different, though critical role. The need therefore exists to optimize heat exchangers, more specifically Compact Heat Exchangers (CHE). This study deals with the optimization of such a CHE by determining an optimal hydraulic diameter of the micro–channels in a CHE, for minimal hydraulic losses. Two Computational Fluid Dynamics (CFD) models were developed for a single micro–channel that is present in a CHE. The first model had a semi–circular cross–section, the second a triangular cross–section. The results were verified by comparing it with existing experimental data. Following the verification of the results, the micro–channel was optimized by implementing an optimum diameter for the lowest pressure drop over the micro–channel. This was done for both the semi–circular and triangular micro–channel cross–sections. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.