Thesis (M.Tech.: Chiropractic)- Dept of Chiropractic, Durban Institute of Technology, 2005. xiii, 129 leaves :|bill. (some col.) ;|c30 cm / Research indicates the sacroiliac joint (prevalence of sacroiliac syndrome ranges from 19.3% and 47.9% (Toussaint et al., 1999)) as being the primary source of low-back pain in 22.5% of patients with back pain (Bernard et al., 1987:2107-2130). Treatment options that are available for the treatment of low-back pain include allopathic (Hellman and Stone, 2000), and manual therapies such as hydrotherapy and traction (Cull and Will, 1995). It has been found that allopathic interventions have been less effective than spinal manipulative therapy, even with spinal manipulative therapy having various modes of application (e.g. side posture and drop piece manipulations) (Gatterman et al., 2001). Drop table thrusting techniques were found to be effective for patients with neuromuskuloskeletal problems such as facet syndrome (Haldeman et al., 1993), however, it is still not known which specific drop piece technique is the most appropriate for sacroiliac syndrome. Thus it is important to ascertain the clinical effectiveness of the technique as certain conditions prevent the patient from being positioned in the conventional side posture for treatment of sacroiliac syndrome (White, 2003; Pooke, 2003; Hyde, 2003; Pretorius, 2003; Haldeman, 2003; Cramer, 2003; Engelbrecht, 2003). Therefore this study aims at determining the efficacy of a maintained contact drop piece manipulation technique.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / This paper considers the joint selection of the source code rate and channel code rate in an image telemetry system. Specifically considered is the JPEG2000 image coder and an LDPC code family. The goal is to determine the optimum apportioning of bits between the source and channel codes for a given channel signal-to-noise ratio and total bit rate, R(total). Optimality is in the sense of maximum peak image SNR and the tradeoff is between the JPEG2000 bit rate R(source) and the LDPC code rate R(channel). For comparison, results are included for the industry standard rate-1/2, memory-6 convolutional code.

There is substantial evidence that comprehenders predict language. In addition, dialogue partners seem to predict one another, as shown by well-timed turn-taking and by the fact that they can complete one another’s utterances. However, little is known about the mechanisms that (i) support the ability to form predictions of others’ utterances and (ii) allow such predictions to be integrated with representations of one’s own utterances. I propose (predictive) representations of others’ utterances are computed within a cognitive architecture that makes use of mechanisms routinely used in language production (i.e., for the representation of one’s own utterances). If this proposal is right, representing that another person is about to speak (and, possibly, representing what they are about to say) should affect the process of language production, as the two processes are based on overlapping mechanisms. I test this hypothesis in a series of novel joint language tasks. Psycholinguistic tasks (picture naming and picture description) that have traditionally been used to study individual language production are distributed across two participants, who either produce two utterances simultaneously or consecutively. In addition, solo versions of the same tasks (where only one participant speaks, while the other participant remains silent) are tested. Speech onset latencies and utterance duration measures are compared between the solo and the joint task. In a first set of experiments about simultaneous production, I show that participants take longer to name pictures when they believe that their partner is concurrently naming pictures than when they believe their partner is silent or is concurrently categorizing the pictures as being from the same or from different semantic categories. Second, I show that participants find it harder to stop speaking when they know that their partner is about to speak. These findings suggest that speakers are able to represent that another person is about to speak using some of the same mechanisms they use to produce language. However, in a third series of experiments, I show that participants do not routinely anticipate the content and timing of another person’s utterance in a way that affects concurrent production of utterances. In light of this evidence, I discuss the proposal that speakers use language production mechanisms to represent and anticipate their partner’s utterances and support coordination in dialogue.

The objective of this work is to investigate whether the game physics based modelling is accurate enough to be used in modelling the motion of the human body, in particular musculoskeletal motion. Hitherto, the implementation of game physics in the medical field focused only on anatomical representation for education and training purposes. Introducing gaming platforms and physics engines into orthopaedics applications will help to overcome several difficulties encountered in the modelling of articular joints. Implementing a physics engine (PhysX), which is mainly designed for video games, handles intensive computations in optimized ways at an interactive speed. In this study, the capabilities of the physics engine (PhysX) and gaming platform for modelling and simulating articular joints are evaluated. First, a preliminary validation is carried out for mechanical systems with analytical solutions, before constructing the musculoskeletal model to evaluate the consistency of gaming platforms. The developed musculoskeletal model deals with the human joint as an unconstrained system with 6 DOF which is not available with other joint modeller. The model articulation is driven by contact surfaces and the stiffness of surrounding tissues. A number of contributions, such as contact modelling and muscle wrapping, have been made in this research to overcome some existing challenges in joint modelling. Using muscle segmentation, the proposed technique effectively handles the problem of muscle wrapping, a major concern for many; thus the shortest path and line of action are no longer problematic. Collision behaviour has also shown a stable response for colliding as well as resting objects, provided that it is based on the principles of surface properties and the conservation of linear and angular momentums. The precision of collision detection and response are within an acceptable tolerance controllable by varying the mesh density. An image based analysis system is developed in this thesis, mainly in order to validate the proposed physics based modelling solution. This minimally invasive method is based on the analysis of marker positions located at bony positions with minimal skin movement. The image based system overcomes several challenges associated with the currently existing methods, such as inaccuracy, complication, impracticability and cost. The analysis part of this research has considered the elbow joint as a case study to investigate and validate the proposed physics based model. Beside the interactive 3D simulation, the obtained results are validated by comparing them with the image based system developed within the current research to investigate joint kinematics and laxity and also with published material, MJM and results from experiments performed at the Brunel Orthopaedic Research and Learning Centre. The proposed modelling shows the advantageous speed, reliability and flexibility of the proposed model. It is shown that the gaming platform and physics engine provide a viable solution to human musculoskeletal modelling. Finally, this thesis considers an extended implementation of the proposed platform for testing and assessing the design of custom-made implants, to enhance joint performance. The developed simulation software is expected to give indicative results as well as testing different types of prosthetic implant. Design parameterization and sensitivity analysis for geometrical features are discussed. Thus, an integrated environment is proposed to link the real-time simulation software with a manufacturing environment so as to assist the production of patient specific implants by rapid manufacturing.

published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy

published_or_final_version / Real Estate and Construction / Master / Master of Science in Construction Project Management

published_or_final_version / Business Administration / Master / Master of Business Administration

published_or_final_version / Business Administration / Master / Master of Business Administration

published_or_final_version / abstract / Real Estate and Construction / Doctoral / Doctor of Philosophy

published_or_final_version / Business Administration / Master / Master of Business Administration