Fuzzy logic control of automated guided vehicle

This thesis describes the fuzzy logic based control system for an automated guided vehicle ( AGV ) designed to navigate from one position and orientation to another while avoiding obstacles. A vehicle with an onboard computer system and a beacon based location system has been used to provide experimental confirmation of the methods proposed during this research. A simulation package has been written and used to test control techniques designed for the vehicle. A series of navigation rules based upon the vehicle's current position relative to its goal produce a fuzzy fit vector, the entries in which represent the relative importance of sets defined over all the possible output steering angles. This fuzzy fit vector is operated on by a new technique called rule spreading which ensures that all possible outputs have some activation. An obstacle avoidance controller operates from information about obstacles near to the vehicle. A method has been devised for generating obstacle avoidance sets depending on the size, shape and steering mechanism of a vehicle to enable their definition to accurately reflect the geometry and dynamic performance of the vehicle. Using a set of inhibitive rules the obstacle avoidance system compiles a mask vector which indicates the potential for a collision if each one of the possible output sets is chosen. The fuzzy fit vector is multiplied with the mask vector to produce a combined fit vector representing the relative importance of the output sets considering the demands of both navigation and obstacle avoidance. This is operated on by a newly developed windowing technique which prevents any conflicts produced by this combination leading to an undesirable output. The final fit vector is then defuzzified to give a demand steering angle for the vehicle. A separate fuzzy controller produces a demand velocity. In tests carried out in simulation and on the research vehicle it has been shown that the control system provides a successful guidance and obstacle avoidance scheme for an automated vehicle

Geochemistry of mineral dust in the McMurdo Dry Valleys Region, Antarctica

The transport and deposition of windblown materials are major processes in the ice-free areas of polar regions. The deposition of aeolian material provides connectivity within the ecosystems of these regions and is integral in understanding geochemical balances and exchanges between landscape units. We have analyzed materials deposited on glacier and permanent lake-ice surfaces as well as geomorphological features formed by aeolian processes in the largest ice-free area in Antarctica, the McMurdo Dry Valleys (~78 °S) in order to determine the source of this sediment. This presentation will focus on the materials collected from the glacier and lake surfaces. The bulk of sediment movement occurs during foehn events in the austral winter that redistribute material throughout the region. The majority of these samples were sand size (\u3e80 %) by weight. Samples containing the highest silt size were from the glaciers in the eastern portion of the Taylor Valley which is the most downwind position. Major rock-forming elements were analyzed using Standard XRF techniques. The alkali metals were depleted with respect to the Upper Continental Crust (UCC), in both the sand and silt fractions, while the alkaline earths were enriched. The TiO2, Fe2O3 and Al2O3 in the sands are similar to UCC values. The major element geochemistry of the aeolian material suggests that it is a mix of the four major rock types in the Valley itself: PreCambrian basement complex, Beacon Sandstone, Ferrar Dolerite and McMurdo Volcanics. Sr isotopic measurements of the fine grained materials from the glacier surfaces indicate the material is similar to the soils from their respective glacier/lake basins. Nd isotope values of this material lie intermediate to the rock values, indicating multiple sources of the aeolian material. The Sr and Nd isotopic data do not plot within the fields of dust from either Vostok or Dome C ice cores which has been interpreted as coming primarily from South America. All of our data suggest a local source of the majority of aeolian material deposited with Taylor Valle

Personal Finance Skills Among Health Professionals: Piloting A Student-Led Finance Curriculum And A Review Of The Current Landscape

Introduction Despite high costs of education, extended lengths of training, and rapidly increasing student debt, personal finance is an often-overlooked topic within professional school curricula. Due to the combination of high debt burden and poor financial literacy, professional students report low confidence and high stress regarding their personal finances. While some medical schools have begun to integrate financial education into their formal training, others provide little to no resources to combat this growing issue. Methods To address this gap and provide financial education opportunities, the Financial Development Club (FDC) was founded by students at the University of Nebraska Medical Center. The FDC aimed to fill gaps in financial knowledge through four, one-hour seminars on topics identified by students as being particularly relevant. Following implementation of this seminar series, surveys assessing student attitudes towards the presented financial topics were distributed to all students on campus, and results were stratified by attendance and non-attendance at the seminars. Results Students who attended the seminars rated themselves as significantly more comfortable with all four financial topics (e.g. debt management, budgeting, investing, and retirement) compared to their peers who did not attend (p\u3c0.05). Conclusions These findings demonstrate the efficacy of a small scale, student-run initiative to increase financial literacy on a single campus. Not only are these results a promising indication of the utility of a single club, they also offer a scaffold on which to build a formal personal and health care finance curriculum

'Committed, motivated and joyful?'Job satisfaction and organisational commitment of managers at a South African public utility

During the past decade, publications and conferences on management in African organisations (Kamoche 2011a; 2011b) and in global contexts (Mangaliso 2001; Jackson 2004)1 have increased steadily. In various African contexts and organisations, job satisfaction (JS) (Walumbwa et al. 2005) and organisational commitment (OC) (Gbadamosi 2003; Wasti 2003; Nyengane 2007; Pillay 2008) have been researched. Most of the previous research is quantitative in nature. Although quantititative research provides insights into the relationships between variables, it does not necessarily provide in-depth meaningful conclusions on micro-psychological levels (e.g. Sempane, Rieger & Roodt 2002; Buitendach & De Witte 2005)

What future subordinates will value in their leaders

Leaders should not randomly choose a leadership style. To be effective, leaders need to ensure that their leadership style is congruent with what subordinates value. The focus of this study is on what the future South African graduate workforce will value in a leader. The female and male respondents in this study emphasise similar leadership values, indicating that there is no distinct set of competencies that will be valued separately by males and females. The same was found for respondents of different cultures, namely African, Coloured, Indian, White and other. With respect to both gender and culture, the respondents emphasise a mixture of African and Western leadership values. This supports the idea that to be effective in South Africa, leaders need to understand the prevailing national cultural values before simply applying ''foreign'' leadership models and theories based upon cultural values found in the West. This research finds that irrespective of gender and culture in the South African workplace, to be effective, leaders need to be loyal and inspirational, have vision and integrity and must be open and honest with their subordinates. Leaders should avoid being autocratic, strict, religious, ritualistic and traditional. They should also avoid using consensus and perceived external control

Employee performance, leadership style and emotional intelligence

Purpose: The purpose of this research is to explore the relationship between employee performance, leadership style and emotional intelligence in the context of a South African parastatal. Problem Investigated: There is a lack of literature and empirical research on the type of leadership required to achieve high levels of employee performance within South African parastatals. Methodology: The Multifactor Leadership Questionnaire (MLQ) was used to determine leadership style, while the Emotional Competency Profiler (ECP) was used to determine the emotional intelligence of the sample of leaders. Employee performance data was provided by the parastatal, based on their performance management system. Data was analysed using correlation analysis, multiple regression analysis, the standard regression ANOVA/F-test, t-tests and Cronbach alpha reliability coefficient. Findings: The findings of the research show that the ECP is a reliable measure of emotional intelligence and that while the MLQ is a reliable measure of transformational leadership, it is not a reliable measure of transactional leadership. The results of the correlation analysis show a positive significant relationship between emotional intelligence and transformational leadership and a negative significant relationship between employee performance and emotional intelligence. The results of regressing employee performance on emotional intelligence and transformational leadership show that emotional intelligence and transformational leadership have no significant effect on employee performance. The results of the regression models of the research could be biased by the lack of variance in employee performance data. Value of the Research: The value of the research lies in it confirming the MLQ as a reliable measure of transformational leadership and the ECP as a reliable measure of emotional intelligence. The finding of a positive significant relationship between emotional intelligence and transformational leadership is a valuable contribution to the literature. Conclusion: Although a positive significant relationship between emotional intelligence and transformational leadership was found, there is a need for further research to determine the type of leadership best suited to achieve high levels of employee performance within the parastatal

On the density of polyharmonic splines

This article treats the question of fundamentality of the translates of a polyharmonic spline kernel (also known as a surface spline) in the space of continuous functions on a compact set \Omega\subset \RR^d when the translates are restricted to $\Omega$. Fundamentality is not hard to demonstrate when a low degree polynomial may be added or when translates are permitted to lie outside of $\Omega$; the challenge of this problem stems from the presence of the boundary, for which all successful approximation schemes require an added polynomial. When $\Omega$ is the unit ball, we demonstrate that translates of polyharmonic splines are fundamental by considering two related problems: the fundamentality in the space of functions vanishing at the boundary and fundamentality of the restricted kernel in the space of continuous function on the sphere. This gives rise to a new approximation scheme composed of two parts: one which approximates purely on $\partial \Omega$, and a second part involving a shift invariant approximant of a function vanishing outside of a neighborhood $\Omega$.Comment: 17 page

Livestock Raiding Among the Pastoral Turkana of Kenya:

Summaries The long?persisting and erroneous conception of famine among the pastoral Turkana of Kenya as an essentially ‘drought?driven’ event has given way to growing recognition today of the key role which livestock raiding plays in the breakdown of coping strategies. However, this article argues that the phenomenon of cattle raids per se is not the problem. Rather it is the fashion in which raiding has been transformed over the years, from a quasi?cultural practice with important livelihood?enhancing functions, into more predatory forms driven by an economic logic and modern forms of violence. This article seeks to understand predatory raiding and its effects in terms of the changing functions which raiding serves within pastoral society and, increasingly, outside it. The article uses a model of armed conflict and livelihood vulnerability to illustrate how violence and the threat of violence interact with drought to undermine the coping strategies of herders