This thesis investigates the design of a local planning method for a reversing single joint tractor-trailer system that can be used in a sampling-based motion planner. The motion planner used is a Rapidly-exploring Random Tree (RRT) developed by Scania. The main objective of a local planning method is to generate a feasible path between two poses, which is needed when expanding the search tree in an RRT. The local planning method described in this thesis uses a set of curves, similar to Reeds-Shepp curves, feasible for a single joint tractor-trailer system. The curves are found by solving a constrained optimization problem that adheres to the kinematic model of the system. The reference for the tractor is generated by discretizing the path between curves. The reference for the trailer is generated by simulating the mission backwards where the curve radiuses are used as input. Simulating the mission backwards circumvents the instability of the system when reversing. The generated references are then compared to references generated by a lattice-based motion planner. The length of the references generated by the RRT are smaller than those generated by the lattice-based motion planner in simple open environments. The RRT had issues finding a path in cases where the environment was complex while the lattice-based motion planner found a path in every scenario. The computational time was significantly lower for the RRT in all simulations. The RRT generates all references between any two given poses while the lattice-based motion planner approximate the start and goal poses to the closest vertex in the search-space.  The references generated by the RRT did not perform optimally when small turns were needed along the curves due to the distance needed for maneuvering the tractor. Therefore, a new optimization problem has to be defined for which the small turns are considered.

Magister Curationis / Background: A preceptor is defined as a specialized tutor who gives practical training to the student in the practice settings. Preceptors are frequently used to orientate nursing students to prepare them for their duties as professional nurses. In the Western Cape Province professional nurses attend a training programme to prepare them for the role of preceptor. Following the training it is unclear how the trained nurse preceptors' perceive their preparation for the role. The perceptions of preceptors may also influence their commitment to their role. Aims and Objectives: The purpose of this study was to explore the interrelationships among preceptors' perceptions of benefits and rewards of, support for and commitment to the role. A conceptual framework guided the study which replicated previous studies that explored nurse preceptors' perceptions. Research Methodology: A descriptive, correlational design was used in this study to address the research questions. A quantitative approach was used to establish the perceptions of nurse preceptors' benefits, support and commitment to the role. The convenience sample was drawn from the preceptors (n=60) who completed the preceptor training programme at the University of the Western Cape. Instrumentation for the study included the following scales: Preceptor's Perceptions of Benefits and Rewards Scale, the Preceptor's Perceptions of Support Scale and the Commitment to the Preceptor Role Scale. Data analysis was performed through SPSS 20.0 to produce both descriptive and inferential statistics and to establish the relationships between the variables. Results and Recommendations: Statistical significance was examined and correlation between variables were analysed. The findings indicated that nurse preceptors were committed to their role: the workload of nurse preceptors needs to be refined and in-service training should be given to the nursing staff in relation to the goals of the nurse preceptor in the clinical and education units. The findings of this study will add to what is known about preceptors' perceptions and may assist in guiding the evaluation of the preceptorship programme. In addition, the results may inform nurse managers about the perceived benefits, rewards and support required by preceptors, thus adding to the body of knowledge about clinical teaching and learning. Ethical Considerations: Ethical clearance was sought from the Ethics Committee of the University of the Western Cape and informed consent was obtained from the participants. iv

The fundamental nature of the research question for this study was centred on the functions of internal communication. It was within this context that functionalism as theoretical approach was selected for the study of internal communication within the Government Communication and Information System (GCIS) in South Africa. Functionalism’s interest in the structure and function of communication is evident in its major assumption, namely that the phenomenon of mass communication is a system that is a whole consisting of several interrelated and interdependent parts. In addition two related theories, systems theory and classical management theory, were employed as departure for the study. Related literature on internal communication bears evidence that the flow of internal communication differs from one environment to the other. This depends on the type of information that has been communicated and the type of organisation in which the internal communication occurs. Managing employees effectively requires communication and the quality of communication amongst the people that comprise an organisation is a crucial variable in determining organisational success. This requires a common understanding of the role and structure of communication and its functions. Internal communication is the strength of any organisation. Communication scholars such as Verwey and Du Plooy (2003), Kitchen and Daly (2002), Gibson and Hodgetts (1991), Murabe (1990) and numerous others already demonstrated the overwhelming importance of internal communication in today’s business environment. Internal communication creates a platform for participative decision making, employees’ interaction, information sharing, creativity and innovation, as well as an environment that fosters productivity and creates a sense of organisational ownership.A comprehensive internal communication system is required to unambiguously translate the vision, mission and strategic objectives of any organisation into reality. Furthermore effective internal communication has a potential to build and sustain social interaction within the organisation and most importantly to drive a service delivery message to all employees. Effective communication and service delivery have recently become issue of exceptional importance in government departments in South Africa, particularly in government agencies. Factors such as organisational culture and leadership style have an influence on internal communication. Organisational culture defines and describes what the organisation stands for. Leadership is very critical for internal communication as it informs the organisation’s vision. If the leadership is negatively inclined, there is no way in which the internal communication will thrive. It is always advisable to strike a balance between organisational culture, leadership and internal communication. The findings of this study indicate that management and employees of the GCIS perceive the function of internal communication differently; that both management and employees have inadequate general understanding of the communication channels and communication structure within the GCIS and reveal that though there are numerous communication channels available, only few are used and preferred within the GCIS. The selection and the understanding of communication channels within the organisation are critical elements for internal communication. Therefore, the communication department or division should ensure broader consultation with all key stakeholders within the organisation. It is regrettable to have communication channels within the organisation that are not understood by the majority of employees and to discover that out of the twenty that are implemented, only five are mainly used and two preferred by most of the management and the employees. / Dissertation (MPhil)--University of Pretoria, 2013. / hb2013 / Marketing Management / unrestricted

Robot path planning and dynamic obstacle avoidance are defined as a problem that robots plan a feasible path from a given starting point to a destination point in a nonlinear dynamic environment, and safely bypass dynamic obstacles to the destination with minimal deviation from the trajectory. Path planning is a typical sequential decision-making problem. Dynamic local observable environment requires real-time and adaptive decision-making systems. It is an innovation for the robot to learn the policy directly from demonstration trajectories to adapt to similar state spaces that may appear in the future. We aim to develop a method for directly learning navigation behavior from demonstration trajectories without defining the environment and attention models, by using the concepts of Generative Adversarial Imitation Learning (GAIL) and Sequence Generative Adversarial Network (SeqGAN). The proposed SeqGAIL model in this thesis allows the robot to reproduce the desired behavior in different situations. In which, an adversarial net is established, and the Feature Counts Errors reduction is utilized as the forcing objective for the Generator. The refinement measure is taken to solve the instability problem. In addition, we proposed to use the Rapidly-exploring Random Tree* (RRT*) with pre-trained weights to generate adequate demonstration trajectories in dynamic environment as the training data, and this idea can effectively overcome the difficulty of acquiring huge training data.

No description available.

In this thesis, I explore various techniques for achieving greater melodicism with the drumset. My approach centers primarily through different arranging methods. The basis of this work is four of my own compositions, specifically arranged in order to enable melodic playing with the drumset. Within the Jazz tradition certain instruments have specific roles. For example, the drums usually have an accompanying role behind the soloists and melody presentation. This is key within the context of the music however, in this project I try to discover the other musical roles primarily melodic and soloistic expression, with the drumset. This work could be of value to any jazz musician wanting to learn more about how different musical roles can influence improvisation and their general playing, and especially for those drummers wishing to develop their melodic playing. Keywords: Exploring different musical roles, compositions, drums, arranging, melodic playing / <p><strong><em>På konsersten framfördes fyra original kompositioner ut av mig:</em></strong></p><p><em>Aqua, På Väg, Framför Brasan &amp; The Last Dance</em></p><p><strong>Medverkande:</strong></p><p>Melker Annas - Trombon</p><p>Eskil Larsson - Tenorsax</p><p>Maja Svantesson - Sång</p><p>Anton Brodin - Gitarr</p><p>Jakob Ulmestrand - Bas</p><p>Ryan Ward - Trumset &amp; kompositioner</p>

Many of the applications that have been proposed for future small unmanned aerial vehicles (UAVs) are at low altitude in areas with many obstacles. A vital component for successful navigation in such environments is a path planner that can find collision free paths for the UAV. Two popular path planning algorithms are the probabilistic roadmap algorithm (PRM) and the rapidly-exploring random tree algorithm (RRT). Adaptations of these algorithms to an unmanned autonomous helicopter are presented in this thesis, together with a number of extensions for handling constraints at different stages of the planning process. The result of this work is twofold: First, the described planners and extensions have been implemented and integrated into the software architecture of a UAV. A number of flight tests with these algorithms have been performed on a physical helicopter and the results from some of them are presented in this thesis. Second, an empirical study has been conducted, comparing the performance of the different algorithms and extensions in this planning domain. It is shown that with the environment known in advance, the PRM algorithm generally performs better than the RRT algorithm due to its precompiled roadmaps, but that the latter is also usable as long as the environment is not too complex. The study also shows that simple geometric constraints can be added in the runtime phase of the PRM algorithm, without a big impact on performance. It is also shown that postponing the motion constraints to the runtime phase can improve the performance of the planner in some cases. / <p>Report code: LiU–Tek–Lic–2006:10.</p>

This research examined the usefulness of art making in exploring sexuality. Specifically, women participating in partners of sex addicts groups and the LGBTQ online community were invited to take an online survey, exploring both visually and verbally discuss how they view their sexuality and how they think others view their sexuality. The data was then analyzed within and between categories to produce three overarching themes: (1) Expressing sexuality: the tension between the self and others (2) The usefulness of art making to explore sexuality, and (3) Limitations and challenges of the study. Through the discussion of the themes, researchers found a dichotomy between how participants see their sexuality and how others see it. Art was found to be a useful device for exploring the emotionality and complexity of sexuality.

Unmanned air vehicles (UAVs) have become an important area of research. UAVs are used in many environments which may have previously unknown obstacles or sources of danger. This research addresses the problem of obstacle mapping and path planning while the UAV is in flight. Online obstacle mapping is achieved through the use of a multi-resolution map. As sensor information is received, a quadtree is built up to hold the information based upon the uncertainty associated with the measurement. Once a quadtree map of obstacles is built up, we desire online path re-planning to occur as quickly as possible. We introduce the idea of a quadtree rapidly-exploring random tree (RRT), which will be used as the online path re-planning algorithm. This approach implements a variable sized step instead of the fixed-step size usually used in the RRT algorithm. This variable step uses the structure of the quadtree to determine the step size. The step size grows larger or smaller based upon the size of the area represented by the quadtree it passes through. Finally this approach is tested in a simulation environment. The results show that the quadtree RRT requires fewer steps on average than a standard RRT to find a path through an area. It also has a smaller variance in the number of steps taken by the path planning algorithm in comparison to the standard RRT.

Exploring the Planets (http://explanet.info) is a free online college textbook covering thebasic concepts of planetary science emphasizing the character and evolution of the planetarybodies in the Solar System. The latest edition (3rd edition) was published online in 2007 by EricH Christiansen. Since the release of the third edition, two important planetary missions havebeen completed: MESSENGER (to Mercury) and New Horizons (to Pluto). These missionsprovided new information and fundamental insights into these planetary bodies, which have notyet been included in Exploring the Planets. The modern results based on recent investigations ofMercury and Pluto are critical for our understanding of the nature and history of these bodies andthe Solar System and build upon the previous information on Mercury and Pluto gained fromMariner 10 (1974-1975) and the Hubble Space Telescope, respectively. These two planetarybodies are end members in a spectrum of objects in the Solar System. Mercury is small, hot,dense, and a silicate metal rich end member of the planets, helping scientists understand thethermal and accretionary evolution of the terrestrial planets. Pluto is cold, icy, distant from theSun, and a representative object of the vast Kuiper Belt, and is thus another end member amongplanetary bodies. These two bodies refine models of how different planets will evolve over time,and how our Solar System has evolved. For these reasons, it is important to update Exploring thePlanets to summarize the current understanding of the geology of Mercury and Pluto. This way,students can better understand their formation and evolution and the implications for theevolution of our Solar System.