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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Real Time Telemetry Data Synthesis with the TMS320C25

Jun, Yao, Shi-yan, Liu 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / This paper presents the method of real time telemetry data synthesis for multi-beams and multi-receivers system in theory. For the practical implementation, we introduce a TMS320C25-based data synthesis board. Through a large number of simulating experiments, the satisfactory results are obtained, which obviously improve the performance of telemetry system. Therefore, all those technigues and results have the value of practical applications.
252

Visualizing effects : In stereoscopic images

Seefried, Kim January 2017 (has links)
This thesis explores and includes research on different impressions given in stereo rendering when creating a fire in three different manners.As technology progresses, stereoscopic rendering becomes increasingly more popular. Both movies and games are shown through VR to give users a more satisfying and lifelike interaction with a virtual environment.Three different versions of a fire were created in a game engine and then viewed with HTC Vive. Comparing mono and stereo rendering gave insights on how the different method looks when using stereoscopic rendering, and what impression the different methods gave the user.The different fires were tested with several users. Finally, this thesis concludes with an interview to one of the users and his different impressions of the fires. / Denna rapport undersöker och innehåller forskning om olika uppfattningar som uppkommer i stereo rendering när eld skapas på tre olika metoder.Allteftersom tekniken utvecklas blir stereo rendering allt mer populär. Både filmer och spel visas i VR för att ge användaren en mer tillfredsställande och verklighetstrogen upplevelse i en virtuell miljö.Tre olika versioner av eld skapades i en spelmotor och granskades sedan via en HTC Vive. Jämförandet av mono och stereo rendering gav en insikt i hur de olika metoderna uppvisas med användning av stereo rendering, och vilka uppfattningar de olika metoderna gav användaren.De olika eldarna testades av flera användare. Tillslut, avslutades denna tes med en intervju med en av användarna och hans uppfattningar av eldarna.
253

Identification de gènes impliqués à la fois dans le dépôt de gras dorsal et le contrôle de certains caractères de reproduction chez le porc

Lord, Étienne January 2005 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
254

Industrial robot motion control for joint tracking in laser welding

Gao, Jiaming January 2016 (has links)
Laser welding is used in modern industrial production due to its high welding speed and good welding performance comparing to more traditional arc welding. To improve the flex-ibility, robots can be used to mount the laser tool. However, laser welding has a high require-ment for the accuracy in positioning the laser tool. There are three main related variables which affect the laser welding accuracy: robot path accuracy, workpiece geometry and fixture repeatability. Thus, joint tracking is very important for laser welding to achieve high quality welds. There are many joint tracking systems which were proposed in recent years. After receiv-ing the joint information, a control system is necessary to control the robot motion in real-time. The open control system for the industrial robot is one trend for the future. A lot of methods and systems are proposed to control the robot motion. Some systems can achieve a high accuracy in the experiments. However, it is still hard to apply them in practical indus-trial production. Thus more commercial solutions appear to overcome the robot motion problem nowadays. They are very useful to realize practical applications. ABB EGM path correction module, a new function of Robotware, is one of the com-mercial solutions for robot motion control in real time. In the experiments presented in this work, a computer is used to simulate a sensor to create a path correction signal. To test its feasibility for the laser welding application, many experiments are conducted. One was to test the robot path repeatability when there is no correction message sent to the robot. Another was to test the level of accuracy EGM can achieve during the correction process. Different types of paths and three different speeds were separately carried out. The results showed that it is possible to use the EGM in the laser welding application. In the EGM feasibility test, there exists deviation in the z-direction. Since these deviations are less than 0.2mm, it will have a minor influence the laser welding performance, implying that the EGM path correction can be applied in practical production.
255

Implicit shape representation for 2D/3D tracking and reconstruction

Ren, Yuheng January 2014 (has links)
This thesis develops and describes methods for real-time tracking, segmentation and 3-dimensional (3D) model acquisition, in the context of developing games for stroke patients that are rehabilitating at home. Real-time tracking and reconstruction of a stroke patient's feet, hands and the control objects that they are touching can enable not only the graphical visualization of the virtual avatar in the rehabilitation games, but also permits measurement of the patient's performs. Depth or combined colour and depth imagery from a Kinect sensor is used as input data. The 3D signed distance function (SDF) is used as implicit shape representation, and a series of probabilistic graphical models are developed for the problem of model-based 3D tracking, simultaneous 3D tracking and reconstruction and 3D tracking of multiple objects with identical appearance. The work is based on the assumption that the observed imagery is generated jointly by the pose(s) and the shape(s). The depth of each pixel is randomly and independently sampled from the likelihood of the pose(s) and the shape(s). The pose(s) tracking and 3D shape reconstruction problems are then cast as the maximum likelihood (ML) or maximum a posterior (MAP) estimate of the pose(s) or 3D shape. This methodology first leads to a novel probabilistic model for tracking rigid 3D objects with only depth data. For a known 3D shape, optimization aims to find the optimal pose that back projects all object region pixels onto the zero level set of the 3D shape, thus effectively maximising the likelihood of the pose. The method is extended to consider colour information for more robust tracking in the presence of outliers and occlusions. Initialised with a coarse 3D model, the extended method is also able to simultaneously reconstruct and track an unknown 3D object in real time. Finally, the concept of `shape union' is introduced to solve the problem of tracking multiple 3D objects with identical appearance. This is formulated as the minimum value of all SDFs in camera coordinates, which (i) leads to a per-pixel soft membership weight for each object thus providing an elegant solution for the data association in multi-target tracking and (ii) it allows for probabilistic physical constraints that avoid collisions between objects to be naturally enforced. The thesis also explore the possibility of using implicit shape representation for online shape learning. We use the harmonics of 2D discrete cosine transform (DCT) to represent 2D shapes. High frequency harmonics are decoupled from low ones to represent the coarse information and the details of the 2D shape. A regression model is learnt online to model the relationship between the high and low frequency harmonics using Locally Weighted Projection Regression (LWPR). We have demonstrated that the learned regression model is able to detect occlusion and recover them to the complete shape.
256

Exploring Hybrid SPM-Cache Architectures to Improve Performance and Energy Efficiency for Real-time Computing

Wu, Lan 04 December 2013 (has links)
Real-time computing is not just fast computing but time-predictable computing. Many tasks in safety-critical embedded real-time systems have hard real-time characteristics. Failure to meet deadlines may result in the loss of life or in large damages. Known of Worst Case Execution Time (WCET) is important for reliability or correct functional behavior of the system. As multi-core processors are increasingly adopted in industry, it has become a great challenge to accurately bound the worst-case execution time (WCET) for real-time systems running on multi-core chips. This is particularly true because of the inter-thread interferences in accessing shared resources on multi-cores, such as shared L2 caches, which can significantly affect the performance but are very difficult to be estimate statically. We propose an approach to analyzing Worst Case Execution Time (WCET) for multi-core processors with shared L2 instruction caches by using a model checking based method. Our experiments indicate that compared to the static analysis technique based on extended ILP (Integer Linear Programming), our approach improves the tightness of WCET estimation more than 31.1% for the benchmarks we studied. However, due to the inherent complexity of multi-core timing analysis and the state explosion problem, the model checking based approach currently can only work with small real-time kernels for dual-core processors. At the same time, improving the average-case performance and energy efficiency has also been important for real-time systems. Recently, Hybrid SPM-Cache (HSC) architectures by combining caches and Scratch-Pad Memories (SPMs) have been increasingly used in commercial processors and research prototypes. Our research explores HSC architectures for real-time systems to reconcile time predictability, performance, and energy consumption. We study the energy dissipation of a number of hybrid on-chip memory architectures by combining both caches and Scratch-Pad Memories (SPM) without increasing the total on-chip memory size. Our experimental results indicate that with the equivalent total on-chip memory size, several hybrid SPM-Cache architectures are more energy-efficient than either pure software controlled SPMs or pure hardware-controlled caches. In particular, using the hybrid SPM-cache to store both instructions and data can achieve the best energy efficiency. However, the SPM allocation for the HSC architecture must be aware of the cache to harness the full potential of the HSC architecture. First, we propose and evaluate four SPM allocation strategies to reduce WCET for hybrid SPM-Caches with different complexities. These algorithms differ by whether or not they can cooperate with the cache or be aware of the WCET. Our evaluation shows that the cache aware and WCET-oriented SPM allocation can maximally reduce the WCET with minimum or even positive impact on the average-case execution time (ACET). Moreover, we explore four SPM allocation algorithms to maximize performance on the HSC architecture, including three heuristic-based algorithms, and an optimal algorithm based on model checking. Our experiments indicate that the Greedy Stack Distance based Allocation (GSDA) can run efficiently while achieving performance either the same as or close to the optimal results got by the Optimal Stack Distance based Allocation (OSDA). Last but not the least, we extend the two stack distance based allocation algorithms to GSDA-E and OSDA-E to minimize the energy consumption of the HSC architecture. Our experimental results show that the GSDA-E can also reduce the energy either the same as or close to the optimal results attained by the OSDA-E, while achieving performance close to the OSDA and GSDA.
257

WCET Optimizations and Architectural Support for Hard Real-Time Systems

Ding, Yiqiang 11 October 2012 (has links)
As time predictability is critical to hard real-time systems, it is not only necessary to accurately estimate the worst-case execution time (WCET) of the real-time tasks but also desirable to improve either the WCET of the tasks or time predictability of the system, because the real-time tasks with lower WCETs are easy to schedule and more likely to meat their deadlines. As a real-time system is an integration of software and hardware, the optimization can be achieved through two ways: software optimization and time-predictable architectural support. In terms of software optimization, we fi rst propose a loop-based instruction prefetching approach to further improve the WCET comparing with simple prefetching techniques such as Next-N-Line prefetching which can enhance both the average-case performance and the worst-case performance. Our prefetching approach can exploit the program controlow information to intelligently prefetch instructions that are most likely needed. Second, as inter-thread interferences in shared caches can signi cantly a ect the WCET of real-time tasks running on multicore processors, we study three multicore-aware code positioning methods to reduce the inter-core L2 cache interferences between co-running real-time threads. One strategy focuses on decreasing the longest WCET among the co-running threads, and two other methods aim at achieving fairness in terms of the amount or percentage of WCET reduction among co-running threads. In the aspect of time-predictable architectural support, we introduce the concept of architectural time predictability (ATP) to separate timing uncertainty concerns caused by hardware from software, which greatly facilitates the advancement of time-predictable processor design. We also propose a metric called Architectural Time-predictability Factor (ATF) to measure architectural time predictability quantitatively. Furthermore, while cache memories can generally improve average-case performance, they are harmful to time predictability and thus are not desirable for hard real-time and safety-critical systems. In contrast, Scratch-Pad Memories (SPMs) are time predictable, but they may lead to inferior performance. Guided by ATF, we propose and evaluate a variety of hybrid on-chip memory architectures to combine both caches and SPMs intelligently to achieve good time predictability and high performance. Detailed implementation and experimental results discussion are presented in this dissertation.
258

Real-time detection of wave profile changes

Tavakkol, Behnam January 1900 (has links)
Master of Science / Department of Industrial and Manufacturing Systems Engineering / Shing I. Chang / This research studies a few methodologies for real-time detection of wave profile changes. In regular profile monitoring, change detection takes place at the end of time period when a complete profile is available. In real-time change detection of profiles, a potential profile change takes place between the beginning and the end of the time period. The decision involves the identification whether a process is in control or out of control before the entire profile is generated. In this regard, five proposed methodologies were developed and tested in this thesis. Earthquake waves, manufacturing processes, and heart beat rate are a few examples of profiles with different natures that the proposed methodologies can be applied to. Water temperature profiles generated during a curing process are considered as an example in this study. Successful implementation of the proposed work on these profiles would cause saving great amounts of time and money. Five methods are studied for monitoring the water control process of a curing process. The first four proposed methodologies are based on an univariate approach where the statistic used for process monitoring is the enclosed area between the profiles and their fitted cutting lines. A multivariate approach is also proposed. A simulation study is also conducted when the best method is chosen based on it performance and simplicity of operations. Various types of acceptable and unacceptable profiles are simulated for the best proposed method identified in the preliminary study. The best method has a satisfactory performance in detecting the changes in the unacceptable profiles. In addition, the false alarm rate in identifying acceptable profiles as bad profiles is lower than 10%.
259

Prospektive Untersuchung zur Evaluation von Risikofaktoren und Inzidenzen invasiver Pilzinfektionen, sowie der konsekutiven antimykotischen Therapie bei Hochrisikopatienten mit akuter Leukämie und Langzeitaplasie nach Chemotherapie unter besonderer Berücksichtigung der Polymerasekettenreaktion zur Verbesserung der diagnostischen Optionen / Evaluation of risk factors, incidences of invasive fungal infections and antifungal treatment at high risk patients with acute leukaemia and high dose chemotherapy with following prolonged neutropenia considering polymerase chain reaction to improve the diagnostic options

Scheuermann, Sabine Verena January 2009 (has links) (PDF)
In der Hämatoonkologie nimmt die Inzidenz von Pilzinfektionen in den letzten 2 Jahrzehnten deutlich zu, wobei eine frühzeitige Diagnostik und adäquate Therapie hinsichtlich einer hohen Komplikationsrate wichtig ist. Umso deutlicher wird die Notwendigkeit einer Intensivierung und Verbesserung der Diagnostik, beispielsweise durch PCR. Es soll die Wertigkeit der routinemässigen PCR-Untersuchung als frühen Indikator einer Erkrankung in einer nicht durch Studiendiagnostik verfälschten klinischen Routine untersucht werden. Ein weiterer zentraler Punkt dieser Studie ist, ein Risikoprofil für neutropenische Patienten mit Chemotherapie bei Akuter Leukämie zu erstellen. Grundlegende Zusammenhänge zwischen individuellen wie auch generellen Risikofaktoren und Diagnosestellung einer IPI sollen durch die Untersuchung von 62 Patienten geklärt werden. Die PCR-Untersuchung ist ein schnelles und sensitives Verfahren zum Nachweis von Pilz-DNS. Es werden für die Sensitivität einer PCR, hinsichtlich der Diagnosestellung einer IPI im Zeitraum der Datenerhebung, ein Wert von 59,3 % und eine Spezifität von 71,4 % ermittelt. Betrachtet man den Zeitrahmen von 14 Tagen nach Beginn der Aplasie, so kann eine höhere Sensitivität von 72,7 % eruiert werden, wie auch ein hoher negativ prädiktiver Wert von 91,7. Eine invasive Mykose bei Patienten mit mehrfach negativem PCR-Nachweis kann somit als unwahrscheinlich angesehen werden. Besonderes Augenmerk wird in der Studie auch auf das Erstellen eines Risikoprofils für die Patienten hinsichtlich einer invasiven Mykose gelegt. In Hinblick auf die Chemotherapie-Protokolle und -Zyklen wird ein Trend zur frühen Chemotherapie deutlich. Bei der Überprüfung der epidemiologischen Verteilung für Deutschland kann erstmals eine signifikant unterschiedliche jahreszeitliche Verteilung an IPI nachgewiesen werden. So kommt es im Sommer signifikant seltener zu einer invasiven Mykose. Hingegen ist das Risiko der Krankheitsentstehung in den Monaten September, Oktober und November hochsignifikant gesteigert. Dieses sollte bei zukünftigen epidemiologischen Untersuchungen aber eventuell auch zur engmaschigen Diagnostik und Indikation prophylaktischer und empirischer Therapien berücksichtigt werden. / IFI are a life threatening complication in immunsupressed patients and have an increased incidence after chemotherapy for treatment of acute leukaemia (AL). Due its clinical implication as well as to difficulties in diagnosis and the isolation of causal organism, patients most often receive empirical and increasingly prophylactic antifungal therapy (AFT). The best choice of indication and also pharmacoeconomy depend on the local incidence and otherwise applied AFT. Therefore further characterisation of patients at risk and the knowledge influencing factors are essential for improving antifungal approaches. Little is known about climatic influence and seasonal distribution of fungal infections. Here we describe an epidemiological single center evaluation of AFT, clinical diagnosed IFI and its temporal distribution in AL patients. In a prospective evaluation during 2005 to 2006 patients diagnosed with AL and expected neutropenia for more than 9 days after chemotherapy were included and observed for up to 6 months. Underlying disease, patient characteristics, radiological evidence of pulmonary infiltrates, IFI as well as time point and indication of AFT have been collected. 62 patients with AL have been included in the evaluation. For 27 an IFI has been diagnosed clinically but only in a minority a causal pathogen could be detected. 42 patients received AFT. No correlation between the kind of chemotherapy and IFI could be found. There had been a relevant difference in the seasonal distribution of IFI. Especially for patients enrolled between September to November a significant higher incidence of 92% (p 0,002) could be detected. A further aim was to assess the performance of PCR in terms of diagnosing invasive aspergillosis, and we succeeded in supporting the value of a negative PCR result for ruling out IA and thereby helping to limit empirical therapy to those patients who are most likely to have a n invasive fungal infection. IFI is often a clinical indication for antimicrobial therapy in patients suffering from AL. In this evaluation only in a minority of patients the infection and its causal organism could be proven. In the majority of cases an empirical or preemptive therapy was initiated. This emphasis the necessity to intensify diagnostic efforts (e.g. galactomannan testing, BAL) and to improve tests (e.g. PCR). For the first time a seasonal influence on IFI in Germany could be demonstrated showing a significant higher rate in autumn. This should be taken into account in future epidemiological evaluations and might be helpful for the differentiation of prophylactic or empiric AFT.
260

A framework for a real-time knowledge based system.

Gebbie, Ian January 1993 (has links)
A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, in fulfilment of the requirements of the degree of Master of Science Engineering / A framework designed to contain and manage the use of knowledge in a real-time knowledge based system for high level control of an industrial process is presented. A prototype of the framework is designed and implemented on a static objectorientated shell. Knowledge is stored in objects and in forward chaining rules. The knowledge has a well defined structure, making it easy to create and manage. Rules are used to recognize conditions and propose control objectives. The framework uses the knowledge to determine variables that if altered will meet the objectives. Control actions are then found to implement changes to these variables The use of explicit control objectives makes it possible to determine if an action worked as intended and if its use is suitable for the present conditions. This enables a learning mechanism to be applied in the expert system. The prototype operated adequately, but the knowledge required to drive the. system was found to be very detailed and awkward to create. / Andrew Chakane 2018

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