published_or_final_version / abstract / toc / Computer Science and Information Systems / Master / Master of Philosophy

The incidence of lumbar spinal stenosis (LSS) is steadily rising, mostly because of a noticeably older age structure. In Sweden, LSS surgery has increased continuously over the years and is presently the most common argument to undergo spine surgery. The purpose of the surgery is to decompress the neural elements in the stenotic spinal canal. To avoid instability, there has been a tradition to do the decompression with a complementary fusion, especially if degenerative spondylolisthesis is present preoperatively. The overall aims of this thesis were to evaluate which method of surgery that generally can be considered to give sufficiently good clinical results with least cost to society and risk of complications and to determine whether there is a difference in outcome between smokers and non-smokers. The Swespine Register was used to collect data on clinical outcome after LSS surgery. In two of the studies, large cohorts were observed prospectively with follow-up after 2 years. Data were analysed in a multivariate model and logistic regression. In a randomised controlled trial (RCT, the Swedish Spinal Stenosis Study), 233 patients were randomised to either decompression with fusion or decompression alone and then followed for 2 years. The consequence of preoperative degenerative spondylolisthesis on the results was analysed and a health economic evaluation performed. The three-dimensional CT technique was used in a radiologic biomechanical pilot study to evaluate the stabilising role of the segmental midline structures in LSS with preoperative degenerative spondylolisthesis by comparing laminectomy with bilateral laminotomies. Smokers, in comparison with non-smokers, showed less improvement after surgery for LSS. Decompression with fusion did not lead to better results compared with decompression alone, no matter if degenerative spondylolisthesis was present preoperatively or not; nor was decompression with fusion found to be more cost-effective than decomression alone. The instability caused by a decompression proved to be minimal and removal of the midline structures by laminectomy did not result in increased instability compared with the preservation of these structures by bilateral laminotomies. In LSS surgery, decompression without fusion should generally be the treatment of choice, regardless of whether preoperative degenerative spondylolisthesis is present or not. Special efforts should be targeted towards smoking cessation prior to surgery.

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Working within the morphosyntactic framework of Distributed Morphology (DM, Halle and Marantz 1993, 1994) within the Minimalist Program (Chomsky 1995), this dissertation proposes a new economy constraint on the grammar, MINIMIZE EXPONENCE, which selects the derivation that realizes all its interpretable features with the fewest morphemes. The purpose of this proposal is to capture the conflicting needs of the grammar to be both maximally contrastive and maximally efficient.I show that the constraint MINIMIZE EXPONENCE has a number of effects on analyses of morphosyntactic phenomena. I propose that, in order to satisfy MINIMIZE EXPONENCE, the roots in a derivation fuse with the functional heads projected above them, resulting in a simplex head that contains both a root and interpretable features. Following the tenets of DM, this head is now a target for the process of Vocabulary insertion. Since the target node contains both content and functional information, so too can Vocabulary Items (VIs) be specified for both types of information. This allows VIs such as eat and ate to compete with each other. This competition of forms linked to the same root allows for a new model of root allomorphy within the framework of DM. In this model of root allomorphy, following proposals by Pfau (2000), VIs that realize roots participate in competition in the same was as do VIs that realize abstract morphemes. Since root VIs are participating in competition and are specified for both content and formal features, the need for licensing through secondary exponence as proposed by Harley and Noyer (2000) is removed from the framework. Further, since eat and ate in this model are different VIs with different specifications that compete with each other for insertion, this model of root allomorphy also eliminates the need for readjustment rules as proposed by Halle and Marantz (1993, 1994) and elaborated on by Marantz (1997). This new model of root allomorphy allows for an account of the blocking of regular inflection in English nominal compounds (e.g. *rats-catcher), which was problematic for theorists working with DM, given the tenets of the framework.I also show that the fusion of roots and functional elements driven by MINIMIZE EXPONENCE allows for a new account of subcategorization. The model of subcategorization presented here falls out of the following facts: 1) arguments are introduced by functional heads; 2) those heads fuse with the root they are projected above, resulting in the node containing both the root and the features of the functional heads; 3) since the root now contains both the root and the formal features, the corresponding VI can be specified for both; 4) VIs that realize roots can also be specified for compatibility or incompatibility of the features of the functional heads that license argument structure. The result here is an underspecification model of subcategorization that predicts a number of behaviors of verbs with respect to their argument structure that it is difficult for a full specification model to account for. Those include polysemy (I ran the ball to Mary) and structural coercion (I thought the book to Mary).

The molecular mechanisms involved in the regulation of protease (PR) activity and human immunodeficiency virus type 1 (HIV-1) viral maturation are incompletely elucidated. To better understand the importance of the cleavage event between HIV-1 PR and reverse transcriptase (RT), we have selectively mutagenized specific residues at the junction between these genes to produce a PR-RT fusion protein in the context of a full-length proviral construct. Mutant viruses derived from COS-7 cells transfected with this construct were analyzed in regard to each of viral replication, maturation, and infectivity. Immunoblot analysis revealed that the mutation prevented cleavage between the PR and RT proteins and that both existed as a PR:RT fusion protein in each of cellular and viral lysates. Interestingly, intracellular PR that existed within the PR-RT fusion protein not only remained functionally active, bid also processed HIV-1 precursor proteins with slightly increased efficiency as shown in time-course experiments in transfected COS-7 cells. In contrast, the RT component of the fusion protein was active at wild-type levels in in vitro and endogenous RT assays. Electron microscopy revealed that mutant viruses containing the cleavage site mutation between PR and RT possessed wild-type morphology. These viruses also displayed wild-type sensitivities to inhibitors of each of HIV-1 PR and RT activities. However, viruses containing the PR-RT fusion protein were 20-times less infectious than Wild-type viruses. This defect was further pronounced when mutated Gag-Pol proteins were overexpressed as a consequence of an additional mutation that interfered with frameshifting. Thus, unlike cleavage site mutations at the N-terminus of PR, a cleavage site mutation between PR and RT did not prevent proteolytic processing and abolish infectivity; rather, viruses containing PRAT fusion proteins were viable, in agreement with the notion that C-terminal liberation of PR is not as critical for

Fault detection and diagnosis is quite important in engineering systems, and deserves further attention in view of the increasing complexity of modern machinery. Traditional single-sensor methods of fault monitoring and diagnosis may find it difficult to meet modern industrial requirements because there is usually no direct way to measure and accurately correlate a machine fault to a single sensor output. Fusion of information from multiple sensors can overcome this shortcoming. In this thesis, a neural-fuzzy approach of multi-sensor fusion is developed for a network-enabled remote fault diagnosis system. The approach is validated by applying it to an industrial machine called the Iron Butcher, which is a machine used in the fish processing industry for the removal of the head in fish prior to further processing for canning. An important characteristic of the fault diagnosis approach developed in this thesis is to make an accurate decision of the machine condition by fusing information from different sensors. First, sound, vibration and vision signals are acquired from the machine using a microphone, an accelerometer and a digital CCD camera, respectively. Second, the sound and vibration signals are transformed into the frequency domain using fast Fourier transformation (FFT). A feature vector from the FFT frequency spectra is defined and extracted from the acquired information. Also, a feature based vision tracking approach—the Scale Invariant Feature Transform (SIFT)—is applied to the vision data to track the object of interest (fish) in a robust manner. Third, Sound, vibration and vision feature vectors are provided as inputs to a neuro-fuzzy network for fault detection and diagnosis. A four-layer neural network including a fuzzy hidden layer is developed in the thesis to analyze and diagnose existing faults. By training the neural network with sample data for typical faults, faults of five crucial components in the fish cutting machine are detected with high reliability and robustness. Alarms to warn about impending faults may be generated as well during the machine operation. A network-based remote monitoring architecture is developed as well in the thesis, which will facilitate engineers to monitor the machine condition in a more flexible manner from a remote site. Developed multi-sensor approaches are validated using computer simulations and physical experimentation with the industrial machine, and compared with a single-sensor approach.

In this thesis, seven multi-sensor data fusion based estimation techniques are investigated. All methods are compared in terms of their ability to fuse data from loop detectors and Bluetooth tracked probe vehicles to accurately estimate freeway traffic speed. In the first case study, data generated from a microsimulation model are used to assess how data fusion might perform with present day conditions, having few probe vehicles, and what sort of improvement might result from an increased proportion of vehicles carrying Bluetooth-enabled devices in the future. In the second case study, data collected from the real-world Bluetooth traffic monitoring system are fused with corresponding loop detector data and the results are compared against GPS collected probe vehicle data, demonstrating the feasibility of implementing data fusion for real-time traffic monitoring today. This research constitutes the most comprehensive evaluation of data fusion techniques for traffic speed estimation known to the author.

In this thesis, seven multi-sensor data fusion based estimation techniques are investigated. All methods are compared in terms of their ability to fuse data from loop detectors and Bluetooth tracked probe vehicles to accurately estimate freeway traffic speed. In the first case study, data generated from a microsimulation model are used to assess how data fusion might perform with present day conditions, having few probe vehicles, and what sort of improvement might result from an increased proportion of vehicles carrying Bluetooth-enabled devices in the future. In the second case study, data collected from the real-world Bluetooth traffic monitoring system are fused with corresponding loop detector data and the results are compared against GPS collected probe vehicle data, demonstrating the feasibility of implementing data fusion for real-time traffic monitoring today. This research constitutes the most comprehensive evaluation of data fusion techniques for traffic speed estimation known to the author.

The main objectives of the project are: Exploit the opportunity for internationalization offered by the sale of stocks, in which there is no direct competition on the Internet either in Spain or in Europe. Find an outlet for Spanish products by marketing them in other countries and vice versa, in order to maintain the image of the brand name in the country of origin, among other reasons. Automate the process whereby an offer or demand originating in Spain can interact with an offer or demand in another country, which was previously unimaginable. We call this multi-language and multi-currency. Develop new applications to improve the handling of stocks both on the SOLOSTOCKS platform itself and in the internal management processes of client firms, which can acquire software in ASP format.

Orthopaedic reconstruction often involves the surgical introduction of structural implants that provide for rigid fixation, skeletal stabilization, and bone integration. The high stresses incurred by these implanted devices have historically limited material choices to metallic and select polymeric formulations. While mechanical requirements are achieved, these non-degradable materials do not participate actively in the remodeling of the skeleton and present the possibility of long-term failure or rejection. This is particularly relevant in cervical fusion, an orthopaedic procedure to treat damaged, degenerative or diseased intervertebral discs. A significant improvement on the available synthetic bone replacement/regeneration options for implants to treat these conditions in the cervical spine may be achieved with the development of primarily mineral biocomposites comprised of a bioactive ceramic matrix reinforced with a biodegradable polymer. Such a biocomposite may be engineered to possess the clinically required mechanical properties of a particular application, while maintaining the ability to be remodeled completely by the body. A biocomposite of Si-doped calcium phosphate (Si-CaP) and poly(ε-caprolactone) (PCL) was developed for application as such a synthetic bone material for potential use as a fusion device in the cervical spine. In this thesis, a method by which high mineral content Si-CaP/PCL biocomposites with interpenetrating matrices of mineral and polymer phases may be prepared will be demonstrated, in addition to the effects of the various preparation parameters on the biocomposite density, porosity and mechanical properties. This new technique by which dense, primarily ceramic Si-CaP/PCL biocomposites were prepared, allowed for the incorporation of mineral contents ranging between 45-97vol%. Polymer infiltration, accomplished solely by passive capillary uptake over several days, was found to be capable of fully infiltrating the microporosity of the sintered calcium phosphate ceramic. After infiltration, these biocomposite materials demonstrated an increase in compressive strength, flexural strength and Young’s modulus with increasing ceramic content and met design targets for use as a cervical fusion prosthesis. The biocomposite was amenable to shaping and drilling and was found to maintain its strength after 30 days immersion in Earle’s Balanced Salt. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2009-11-24 16:18:16.461