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1
Pomierski, Wojciech. "Position signal filtering for hydraulic active heave compensation system." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71095.
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In the paper a new position signal filtering method with position prediction is presented along with test results using a simulation tool. The complete active heave compensation system performance with input signal filtering is also shown. The control system uses an input acceleration signal taken from the motion reference unit, which usually contains noise that is not acceptable for the position controller. Currently, a Kalman filter is used which is okay to use for certain conditions. The filter works similarly to how it is used for autonomous applications where two input positions are necessary, one from position sensors and another one taken from the model. The challenge is that there is no physical wave model available for the Kalman filter used for offshore position control and the waves are not predictable. It was found that a Kalman filter with a special signal prediction instead of the model input can be used. This position prediction helps to avoid system delays and the potential of missing the signal for a short period of the time.
2
Lischinsky, Pablo A. "Compensation de frottement et commande en position d'un robot hydraulique industriel." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0058.
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Bien que ce travail de these se soit concentre principalement sur la compensation de frottement, d'autres problemes en rapport avec la commande en position du robot, ont ete traites. La boucle la plus interne, qui commande en couple les actionneurs hydrauliques, est traitee d'abord. Le deuxieme niveau traite le probleme de la compensation de frottement et la commande en position. Une commande non-lineaire en couple qu'ameliore les performances de la boucle interne, a ete implantee sur le robot. Un schema de commande, avec variation de gains pre-calcules est proposee, qui presente l'avantage d'avoir une bande passante independante de la position. L'identification et compensation de frottement avec un nouveau modele dynamique, a ete aborde. Les parametres statiques et dynamiques associes au modele ont ete estimes. Pour les premiers, l'estimation a ete basee sur la reconstruction de la courbe statique de frottement-vitesse, basee sur des essais a vitesse constante. L'estimation des parametres dynamiques est basee sur la linearisation du modele de frottement, avec des essais avec des faibles deplacements. Trois methodes de compensation de frottement, avec parametres fixes et adaptatifs, ont ete presentes. Etant donne que les conditions de stabilite sont des conditions suffisantes, l'exigence de la propriete srp d'une fonction de transfert en boucle fermee s'est averee trop restrictive en pratique. La precision de positionnement du robot avec compensation de frottement est passee de 2-3 cm a 0. 5-1 cm. Finalement, une analyse de la commande pid en position, a montre la necessite de calculer en temps reel les termes diagonaux de la matrice d'inertie h(i,i), utilises dans la commande.
3
Ronquist, Anton, and Birger Winroth. "Estimation and Compensation of Load-Dependent Position Error in a Hybrid Stepper Motor." Thesis, Linköpings universitet, Reglerteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129554.
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Hybrid stepper motors are a common type of electric motor used throughout industry thanks to its low-cost, high torque at low speed and open loop positioning capabilities. However, a closed loop control is often required for industrial applications with high precision requirements. The closed loop control can also be used to lower the power consumption of the motor and ensure that stalls are avoided. It is quite common to utilise a large and costly position encoder or resolver to feedback the position signal to the control logic. This thesis has explored the possibility of using a low-cost position sensor based on Hall elements. Additionally, a sensorless estimation algorithm, using only stator winding measurements, has been investigated both as a competitive alternative and as a possible complement to the position sensor. The thesis work summarises and discusses previous research attempts to adequately measure or estimate and control the hybrid stepper motors position and load angle without using a typical encoder or resolver. Qualitative results have been produced through simulations prior to implementation and experimental testing. The readings from the position sensor is subject to noise, owing to its resolution and construction. The position signal has been successfully filtered, improving its accuracy from 0.56° to 0.25°. The output from the sensorless estimation algorithm is subject to non-linear errors caused by errors in phase voltage measurements and processing of velocity changes. However, the dynamics are reliable at constant speeds and could be used for position control.
4
Qin, Jinna. "Commande hybride position/force robuste d’un robot manipulateur utilisé en usinageet/ou en soudage." Thesis, Paris, ENSAM, 2013. http://www.theses.fr/2013ENAM0058/document.
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La problématique traitée dans cette thèse concerne la commande de robots manipulateurs industriels légèrement flexibles utilisés pour la robotisation de procédés d'usinage et de soudage FSW. Le premier objectif est la modélisation des robots et des procédés. Les modèles développés concernant la cinématique et la dynamique de robots 6 axes à architecture série et à flexibilité localisées aux articulations. Les paramètres du modèle dynamique et les raideurs sont identifiés avec la méthode à erreur de sortie qui donne une bonne précision d'estimation. La norme relative du résidu du modèle après identification est de 3,2%. Le deuxième objectif est l'amélioration des performances de la robotisation des procédés. Un simulateur a été développé qui intègre le modèle dynamique du robot flexible, les modèles de procédés et le modèle du contrôleur de robot y compris les lois de commande en temps réel des axes et le générateur de trajectoires. Un observateur non-linéaire à grands gains est proposé pour estimer l'état complet du robot flexible ainsi que les efforts d'interaction. Ensuite, un compensateur basé sur l'observateur est proposé pour corriger les erreurs de positionnement en temps réel. La validation expérimentale sur un robot industriel Kuka, montre une très bonne estimation de l'état complet par l'observateur. Un soudage FSW précis grâce à la compensation en temps réel de la flexibilité du manipulateur a pu être effectué avec succèsThe problem addressed in this thesis concerns the control of industrial robot manipulators which are slightly flexible and used for machining and FSW processes. The first objective is to model the robots and processes. The developed models concern the kinematics and dynamics models of 6-axis robots with serial architecture and flexibility localized at joints. The dynamic model parameters and a part of the joint stiffnesses are identified with the approach of output error which gives a satisfy estimation accuracy. According to identification, the RMS residue of the model is 3.2%. The second objective is to improve the robotization performance of manufacturing processes. A simulator was developed that contains the dynamic model of the flexible robot, the process models and the model of the robot controller including control laws in real time of axes and the trajectory generator. A nonlinear high-gains observer is proposed to estimate the complete states of robot system as well as the operation wrenches. Then the observer-based compensator is proposed to correct the positioning errors in real time. The experimental validation of industrial robots shows a satisfactory estimating performance of the observer. A precise FSW welding owing to the real-time compensation for the flexibility of manipulator has been done successfully
5
Milner, Jill Robina. "Time of flight controller and stream position compensation system for the three dimensional printing process." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/11154.
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6
Herrera-Heras, Clemente. "Contribution à la commande numérique et à la compensation de l'asservissement de position angulaire d'un actionneur électrohydraulique." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376142870.
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7
Herrera, Clemente. "Contribution à la commande numérique et à la compensation de l'asservissement de position angulaire d'un actionneur électrohydrolique." Toulouse, INSA, 1988. http://www.theses.fr/1988ISAT0012.
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Asservissement numerique de position angulaire d'un actionneur electrohydraulique. Compensation par anticipation de l'inertie et des couples perturbantes. Stabilisation. Frottement. Commande numerique
8
Kilic, Ergin. "Novel Position Measurement And Estimation Methods For Cnc Machine Systems." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608762/index.pdf.
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Precision control of translational motion is vital for many CNC machine tools as the motion of the machinery affects the dimensional tolerance of the manufactured goods. However, the direct measurement along with the accurate motion control of machine usually requires relatively expensive sensors i.e. potentiometers, linear scales, laser interferometers. Hence, this study attempts to develop reference models utilizing low-cost sensors (i.e. rotary encoders) for accurate position estimation. First, an indirect measurement performance is investigated on a Timing Belt driven carriage by a DC Motor with a backlash included Gearbox head. An advanced interpolated technique is proposed to compensate the position errors while using indirect measurement to reduce the total cost. Then, a similar study was realized with a ball screw driven system. Next, a cable drum driven measurement technique is proposed to the machines which have long travel distance like plasma cutters. A test setup is proposed and manufactured to investigate the capstan drive systems. Finally, characteristics of Optical Mouse Sensors are investigated from different point of views and a test setup is proposed and manufactured to evaluate their performances in long terms. Beside all of these parts, motion control algorithms and motion control integrated circuits are designed and manufactured to realize experimental studies in a detailed manner.
9
Sharp, Phillip D. "ADVANCED TELEMETRY TRACKING SYSTEM DEVELOPMENT AT WHITE SANDS MISSILE RANGE." International Foundation for Telemetering, 1991. http://hdl.handle.net/10150/613057.
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International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, NevadaEarly in the 1980s White Sands Missile Range (WSMR) began studying the problem of updating the Telemetry Tracking Systems (TTS) used to support test range missions. The information and equipment available at that time indicated that very little technology advancement had occurred in the area of TTS. Because the TTS usually have a long service life, it was imperative that the new or updated systems be as good as the state-of-the-art in todays technology could produce. Because of the lack of technology advancements, it was evident that drastic measures would be required to achieve the objectives of the update effort. These findings resulted in a program called the Advanced Telemetry Tracking System Integration and Development (ATTSID). Its objective was to determine if it was possible to apply advanced computer technology to the solution of servosystem problems characteristic in most TTS. This paper and three related papers, The Advanced Telemetry Tracking Servosystem; An Automated Testing System for a Telemetry Tracking System; and The Microcomputer-based Digital Controller for the Advanced Telemetry Tracking System; document the objectives, design considerations, fabrication and evaluation of a prototype TTS. It utilizes a dedicated computer system to control, compensate the servo position loop, and provide automated testing of the servo and RF receiving systems. This computer system was installed and evaluated in one of the WSMR Transportable Telemetry Acquisition Systems (TTAS) for evaluation and refinement of the system. The results of this program will determine the evolution of TTS and extend the use of computer technology to providing more reliable and accurate telemetry tracking support of test range operations.
10
Khial, Karim. "Commande en position d'un servo-système incluant un réducteur harmonique avec mesure de couple et compensation de non-linéarités." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ65585.pdf.
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11
Day, Nathan McClain. "Tactile Sensing and Position Estimation Methods for Increased Proprioception of Soft-Robotic Platforms." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7004.
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Soft robots have the potential to transform the way robots interact with their environment. This is due to their low inertia and inherent ability to more safely interact with the world without damaging themselves or the people around them. However, existing sensing for soft robots has at least partially limited their ability to control interactions with their environment. Tactile sensors could enable soft robots to sense interaction, but most tactile sensors are made from rigid substrates and are not well suited to applications for soft robots that can deform. In addition, the benefit of being able to cheaply manufacture soft robots may be lost if the tactile sensors that cover them are expensive and their resolution does not scale well for manufacturability. Soft robots not only need to know their interaction forces due to contact with their environment, they also need to know where they are in Cartesian space. Because soft robots lack a rigid structure, traditional methods of joint estimation found in rigid robots cannot be employed on soft robotic platforms. This requires a different approach to soft robot pose estimation. This thesis will discuss both tactile force sensing and pose estimation methods for soft-robots. A method to make affordable, high-resolution, tactile sensor arrays (manufactured in rows and columns) that can be used for sensorizing soft robots and other soft bodies isReserved developed. However, the construction results in a sensor array that exhibits significant amounts of cross-talk when two taxels in the same row are compressed. Using the same fabric-based tactile sensor array construction design, two different methods for cross-talk compensation are presented. The first uses a mathematical model to calculate a change in resistance of each taxel directly. The second method introduces additional simple circuit components that enable us to isolate each taxel electrically and relate voltage to force directly. This thesis also discusses various approaches in soft robot pose estimation along with a method for characterizing sensors using machine learning. Particular emphasis is placed on the effectiveness of parameter-based learning versus parameter-free learning, in order to determine which method of machine learning is more appropriate and accurate for soft robot pose estimation. Various machine learning architectures, such as recursive neural networks and convolutional neural networks, are also tested to demonstrate the most effective architecture to use for characterizing soft-robot sensors.
12
Mišún, Filip. "Návrh automatického cyklu pro posuzování způsobilosti měření obrobkovou sondou na obráběcím centru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443252.
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This diploma thesis describes the procedures of individual electronic compensations for CNC machines used to increase the accuracy of machines. This part is followed by the determining tolerance of the measuring and the influence of individual electronic compensations based on measured data using touch probe and calibrated standards according to VDA 5 norm.
13
Kočiš, Petr. "Orientační ústrojí průmyslových robotů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231675.
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The diploma thesis deals with an orientation mechanism of industrial robots for mounting of pivots and screws into the mounting holes. In the first phase there is a research of inventions mainly realized in the United States Patent and Trademark Office database. Subsequently the conditions of the assembly are solved. On the base of the conditions the functional requirements are described. The diploma thesis includes seven conceptual variants, which are proposed as a 3D design. Using the basical multi-criteria method the best conceptual variant is specified. That is specified due to the accepted criterias. In the next part of the diploma thesis there is a calculation, that comprises this technically and economically most promising conceptual variant. The calculation consists of a statics, a kinematics and a dynamics of the propel, a stenght control of the mechanism and kinematics analysis of the whole mechanism. Results of the calculation are used by the detailed design of orientation mechanism, that also comprises technological production theory and a correct assembly. Economical analysis, which comprises cost of produce of this newly developed automation equipment, is worked up in the conclusion of the diploma thesis. The diploma thesis also comprises drawings. The variant solves a new conception, which can be patented as an utility model.
14
Dinelle, Katherine. "Implementation of a motion compensation system for high resolution brain positron emission tomography." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/32393.
Full textAbstract:
In this work we implement and validate a compensation method for subject
motion occurring during high resolution brain positron emission tomography
(PET). Head motion is acknowledged as a significant source of resolution
degradation in PET brain imaging; especially at the level of resolution, (2.5
mm)³ , available in the tomograph currently installed at our research centre.
Several methods have been developed which are able to partially correct for
this motion, however none provide the level of correction accuracy as the
method implemented here.
An infrared motion tracking system was installed to collect subject motion
information during PET scanning. In order to apply these measurements to the
PET data, a method for aligning the two reference frames both temporally and
spatially was developed. Installation of the motion tracking system allowed an
in-depth analysis of typical subject motions encountered during scanning. This
permitted us to motivate the need for motion correction, and to identify
activities causing head motion which may be limited prior to scanning.
Motion corrections based on the acquired data were incorporated into a
statistical reconstruction algorithm. First, the position and orientation of each
motion impacted event was corrected back to a common reference position.
Second, compensation was applied for variations in the relationship between
the location of an emission event and the sensitivity of the detectors that
measured it due to motion. The consideration of variations in tomograph
sensitivity separates this motion correction method from those attempted
previously. Experimental validation using phantom data revealed that the
motion correction was able to compensate for translations ranging from a few
millimeters to a few centimeters. When applied to human data, differences in the quantitative results for images reconstructed with and without motion
correction were on the order of those changes we are attempting to study.
The motion correction algorithm was developed by a previous student in our
group (A. Rahmim), while implementation and testing of the tracking system,
and validation of the motion correction algorithm with phantom and human
studies was completed as part of this work. Routine application of this motion
correction scheme will improve the effective resolution of the tomograph,
allowing improved quantification.Science, Faculty of
Physics and Astronomy, Department of
Graduate
15
Langner, Jens. "Event-Driven Motion Compensation in Positron Emission Tomography: Development of a Clinically Applicable Method." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-23509.
Full textAbstract:
Positron emission tomography (PET) is a well-established functional imaging method used in nuclear medicine. It allows for retrieving information about biochemical and physiological processes in vivo. The currently possible spatial resolution of PET is about 5 mm for brain acquisitions and about 8 mm for whole-body acquisitions, while recent improvements in image reconstruction point to a resolution of 2 mm in the near future. Typical acquisition times range from minutes to hours due to the low signal-to-noise ratio of the measuring principle, as well as due to the monitoring of the metabolism of the patient over a certain time. Therefore, patient motion increasingly limits the possible spatial resolution of PET. In addition, patient immobilisations are only of limited benefit in this context. Thus, patient motion leads to a relevant resolution degradation and incorrect quantification of metabolic parameters. The present work describes the utilisation of a novel motion compensation method for clinical brain PET acquisitions. By using an external motion tracking system, information about the head motion of a patient is continuously acquired during a PET acquisition. Based on the motion information, a newly developed event-based motion compensation algorithm performs spatial transformations of all registered coincidence events, thus utilising the raw data of a PET system - the so-called `list-mode´ data. For routine acquisition of this raw data, methods have been developed which allow for the first time to acquire list-mode data from an ECAT Exact HR+ PET scanner within an acceptable time frame. Furthermore, methods for acquiring the patient motion in clinical routine and methods for an automatic analysis of the registered motion have been developed. For the clinical integration of the aforementioned motion compensation approach, the development of additional methods (e.g. graphical user interfaces) was also part of this work. After development, optimisation and integration of the event-based motion compensation in clinical use, analyses with example data sets have been performed. Noticeable changes could be demonstrated by analysis of the qualitative and quantitative effects after the motion compensation. From a qualitative point of view, image artefacts have been eliminated, while quantitatively, the results of a tracer kinetics analysis of a FDOPA acquisition showed relevant changes in the R0k3 rates of an irreversible reference tissue two compartment model. Thus, it could be shown that an integration of a motion compensation method which is based on the utilisation of the raw data of a PET scanner, as well as the use of an external motion tracking system, is not only reasonable and possible for clinical use, but also shows relevant qualitative and quantitative improvement in PET imagingDie Positronen-Emissions-Tomographie (PET) ist ein in der Nuklearmedizin etabliertes funktionelles Schnittbildverfahren, das es erlaubt Informationen über biochemische und physiologische Prozesse in vivo zu erhalten. Die derzeit erreichbare räumliche Auflösung des Verfahrens beträgt etwa 5 mm für Hirnaufnahmen und etwa 8 mm für Ganzkörperaufnahmen, wobei erste verbesserte Bildrekonstruktionsverfahren eine Machbarkeit von 2 mm Auflösung in Zukunft möglich erscheinen lassen. Durch das geringe Signal/Rausch-Verhältnis des Messverfahrens, aber auch durch die Tatsache, dass der Stoffwechsel des Patienten über einen längeren Zeitraum betrachtet wird, betragen typische PET-Aufnahmezeiten mehrere Minuten bis Stunden. Dies hat zur Folge, dass Patientenbewegungen zunehmend die erreichbare räumliche Auflösung dieses Schnittbildverfahrens limitieren. Eine Immobilisierung des Patienten zur Reduzierung dieser Effekte ist hierbei nur bedingt hilfreich. Es kommt daher zu einer relevanten Auflösungsverschlechterung sowie zu einer Verfälschung der quantifizierten Stoffwechselparameter. Die vorliegende Arbeit beschreibt die Nutzbarmachung eines neuartigen Bewegungskorrekturverfahrens für klinische PET-Hirnaufnahmen. Mittels eines externen Bewegungsverfolgungssystems wird während einer PET-Untersuchung kontinuierlich die Kopfbewegung des Patienten registriert. Anhand dieser Bewegungsdaten führt ein neu entwickelter event-basierter Bewegungskorrekturalgorithmus eine räumliche Korrektur aller registrierten Koinzidenzereignisse aus und nutzt somit die als "List-Mode" bekannten Rohdaten eines PET Systems. Für die Akquisition dieser Daten wurden eigens Methoden entwickelt, die es erstmals erlauben, diese Rohdaten von einem ECAT Exact HR+ PET Scanner innerhalb eines akzeptablen Zeitraumes zu erhalten. Des Weiteren wurden Methoden für die klinische Akquisition der Bewegungsdaten sowie für die automatische Auswertung dieser Daten entwickelt. Ebenfalls Teil der Arbeit waren die Entwicklung von Methoden zur Integration in die klinische Routine (z.B. graphische Nutzeroberflächen). Nach der Entwicklung, Optimierung und Integration der event-basierten Bewegungskorrektur für die klinische Nutzung wurden Analysen anhand von Beispieldatensätzen vorgenommen. Es zeigten sich bei der Auswertung sowohl der qualitativen als auch der quantitativen Effekte deutliche Änderungen. In qualitativer Hinsicht wurden Bildartefakte eliminiert; bei der quantitativen Auswertung einer FDOPA Messung zeigte sich eine revelante Änderung der R0k3 Einstromraten eines irreversiblen Zweikompartment-Modells mit Referenzgewebe. Es konnte somit gezeigt werden, dass eine Integration einer Bewegungskorrektur unter Zuhilfenahme der Rohdaten eines PET Systems sowie unter Nutzung eines externen Verfolgungssystems nicht nur sinnvoll und in der klinischen Routine machbar ist, sondern auch zu maßgeblichen qualitativen und quantitativen Verbesserungen in der PET-Bildgebung beitragen kann
16
Langner, Jens. "Event-Driven Motion Compensation in Positron Emission Tomography: Development of a Clinically Applicable Method." Doctoral thesis, Forschungszentrum Dresden-Rossendorf e.V, 2008. https://tud.qucosa.de/id/qucosa%3A25077.
Full textAbstract:
Positron emission tomography (PET) is a well-established functional imaging method used in nuclear medicine. It allows for retrieving information about biochemical and physiological processes in vivo. The currently possible spatial resolution of PET is about 5 mm for brain acquisitions and about 8 mm for whole-body acquisitions, while recent improvements in image reconstruction point to a resolution of 2 mm in the near future. Typical acquisition times range from minutes to hours due to the low signal-to-noise ratio of the measuring principle, as well as due to the monitoring of the metabolism of the patient over a certain time. Therefore, patient motion increasingly limits the possible spatial resolution of PET. In addition, patient immobilisations are only of limited benefit in this context. Thus, patient motion leads to a relevant resolution degradation and incorrect quantification of metabolic parameters.
The present work describes the utilisation of a novel motion compensation method for clinical brain PET acquisitions. By using an external motion tracking system, information about the head motion of a patient is continuously acquired during a PET acquisition. Based on the motion information, a newly developed event-based motion compensation algorithm performs spatial transformations of all registered coincidence events, thus utilising the raw data of a PET system - the so-called `list-mode´ data. For routine acquisition of this raw data, methods have been developed which allow for the first time to acquire list-mode data from an ECAT Exact HR+ PET scanner within an acceptable time frame. Furthermore, methods for acquiring the patient motion in clinical routine and methods for an automatic analysis of the registered motion have been developed. For the clinical integration of the aforementioned motion compensation approach, the development of additional methods (e.g. graphical user interfaces) was also part of this work.
After development, optimisation and integration of the event-based motion compensation in clinical use, analyses with example data sets have been performed. Noticeable changes could be demonstrated by analysis of the qualitative and quantitative effects after the motion compensation. From a qualitative point of view, image artefacts have been eliminated, while quantitatively, the results of a tracer kinetics analysis of a FDOPA acquisition showed relevant changes in the R0k3 rates of an irreversible reference tissue two compartment model. Thus, it could be shown that an integration of a motion compensation method which is based on the utilisation of the raw data of a PET scanner, as well as the use of an external motion tracking system, is not only reasonable and possible for clinical use, but also shows relevant qualitative and quantitative improvement in PET imaging.Die Positronen-Emissions-Tomographie (PET) ist ein in der Nuklearmedizin etabliertes funktionelles Schnittbildverfahren, das es erlaubt Informationen über biochemische und physiologische Prozesse in vivo zu erhalten. Die derzeit erreichbare räumliche Auflösung des Verfahrens beträgt etwa 5 mm für Hirnaufnahmen und etwa 8 mm für Ganzkörperaufnahmen, wobei erste verbesserte Bildrekonstruktionsverfahren eine Machbarkeit von 2 mm Auflösung in Zukunft möglich erscheinen lassen. Durch das geringe Signal/Rausch-Verhältnis des Messverfahrens, aber auch durch die Tatsache, dass der Stoffwechsel des Patienten über einen längeren Zeitraum betrachtet wird, betragen typische PET-Aufnahmezeiten mehrere Minuten bis Stunden. Dies hat zur Folge, dass Patientenbewegungen zunehmend die erreichbare räumliche Auflösung dieses Schnittbildverfahrens limitieren. Eine Immobilisierung des Patienten zur Reduzierung dieser Effekte ist hierbei nur bedingt hilfreich. Es kommt daher zu einer relevanten Auflösungsverschlechterung sowie zu einer Verfälschung der quantifizierten Stoffwechselparameter. Die vorliegende Arbeit beschreibt die Nutzbarmachung eines neuartigen Bewegungskorrekturverfahrens für klinische PET-Hirnaufnahmen. Mittels eines externen Bewegungsverfolgungssystems wird während einer PET-Untersuchung kontinuierlich die Kopfbewegung des Patienten registriert. Anhand dieser Bewegungsdaten führt ein neu entwickelter event-basierter Bewegungskorrekturalgorithmus eine räumliche Korrektur aller registrierten Koinzidenzereignisse aus und nutzt somit die als "List-Mode" bekannten Rohdaten eines PET Systems. Für die Akquisition dieser Daten wurden eigens Methoden entwickelt, die es erstmals erlauben, diese Rohdaten von einem ECAT Exact HR+ PET Scanner innerhalb eines akzeptablen Zeitraumes zu erhalten. Des Weiteren wurden Methoden für die klinische Akquisition der Bewegungsdaten sowie für die automatische Auswertung dieser Daten entwickelt. Ebenfalls Teil der Arbeit waren die Entwicklung von Methoden zur Integration in die klinische Routine (z.B. graphische Nutzeroberflächen). Nach der Entwicklung, Optimierung und Integration der event-basierten Bewegungskorrektur für die klinische Nutzung wurden Analysen anhand von Beispieldatensätzen vorgenommen. Es zeigten sich bei der Auswertung sowohl der qualitativen als auch der quantitativen Effekte deutliche Änderungen. In qualitativer Hinsicht wurden Bildartefakte eliminiert; bei der quantitativen Auswertung einer FDOPA Messung zeigte sich eine revelante Änderung der R0k3 Einstromraten eines irreversiblen Zweikompartment-Modells mit Referenzgewebe. Es konnte somit gezeigt werden, dass eine Integration einer Bewegungskorrektur unter Zuhilfenahme der Rohdaten eines PET Systems sowie unter Nutzung eines externen Verfolgungssystems nicht nur sinnvoll und in der klinischen Routine machbar ist, sondern auch zu maßgeblichen qualitativen und quantitativen Verbesserungen in der PET-Bildgebung beitragen kann.
17
El-Sayed, Nader Mahmoud. "An examination of executive directors' remuneration in FTSE 350 companies." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/14025.
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Issues as to the suitability of executive compensation packages have obtained an ever increasing profile in recent years. Whilst there has been quite extensive empirical investigation of pay-performance sensitivity, the framework of performance-pay has received less attention in the literature and examination to date. Besides this - whilst there has been a quantum of investigation of relationships between compensation and performance, there has been less focus on case study based analysis. In this context, the current study makes a twofold contribution to the examination of executive directors’ remuneration in FTSE 350 companies. First, this research aims to empirically investigate linkages between the nature and amount of compensation packages and company performance with a particular focus on examining the extent of interrelationships between pay and performance over a ten year period from 1999 to 2008. Within the scope of a variety of theoretical perspectives, this deductive study puts a focus on addressing the question of whether managerial compensation is the greater influence on firm performance or whether it is the latter which has the greater influence on the former. Second, this study seeks to qualitatively add to the relevant literature by means of a longitudinal case study of remuneration at UK based major multi-national company, BP, over a ten year period from 2001 till 2010. Within the context of a variety of theoretical and institutional perspectives, this inductive study explores, by means of investigation of BP’s Directors Remuneration Reports, the role of the BP remuneration committee in setting the mechanisms and structures which determine the nature and extent of executive remuneration packages at BP and considers the wider generalisability of the findings therefrom. Overall the current study utilises a mixed methods approach via a combination both quantitative and qualitative modes of analysis – an approach which is relatively rare in the discipline of research into corporate governance and related issues. The outcomes from the empirical work show evidence of the presence of dual positive associations between executive compensation and company performance. However, the results do indicate that executive compensation is more influential in its effect on firm performance than the framework of performance-related pay. This finding is interpreted as lending support to the stewardship and/or tournament theories as to underlying drivers of executive remuneration in comparison with agency theory, represented by agent-principal or managerial hegemony perspectives, as an explanatory of the construction of executive remuneration and the link with firm performance. Similar to prior literature, the empirical findings indicate that equity-based compensation is more robust in the linkage with firm performance than cash pay dominated packages. However, the results showed that the existence of remuneration committees in general reveals insignificant and negatively related to total CEO/executive remuneration. This finding highlights therefore the need to put a focus on the actual role of compensation committee in setting the type and extent of executive pay packages in a large UK company. The outcomes from the archival case study also suggest that it is difficult to find significant support for a pure agency theory approach whereby shareholders seek to align their interests directly with those of their managers as a driver of executive compensation packages. There is more evidence suggestive of a managerial power/hegemony perspective which is heavily mediated by the presence of powerful non-executive directors and the institutional presence of the remuneration committee. Perhaps the most significant aspects to emerge from the case study are the importance of personal relationships and power at boardroom level. Beyond this the inferences of the supplementary content analysis conducted specifically on the Directors Remuneration Reports are suggestive of a focus on overall BP performance rather than on the specific activities and achievements of individual executive directors. In conclusion, the findings of the present study provide a wealth of detail both quantitative and qualitative as to the manner in which executive remuneration has been set in the UK in recent years and as to linkages both with corporate performance and underlying theories of the determinants of executive remuneration. As such it sheds light on an area of importance and one of continued private and public concern and may be of interest to those responsible for governance within firms and to wider public and regulatory interest as well as future researchers in the field.
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Cícha, Tadeáš. "Implementace svařovacího automatu do výroby armatur." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-379011.
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The Diploma Thesis is focused on the implementation of FCAW welding technology to the manufacturing process of a mechanical engineering company. One part of implementation is partial automation of manufacturing process with positioner machine which is connected to the welding source. Practical part of Diploma Thesis includes the verification of the weldability of used materials and assigning of pWPS for subsequent qualification of the welding process WPQR with the welding technology FCAW.
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Kapidou, Alexandra. "Application for Wind Farm Integration Complying with the Grid Code by Designing an Outer Control Strategy for the Converter." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187686.
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The continuously increasing energy penetration from wind farms into the grid raises concerns regarding power quality and the stable operation of the power system. The Grid Code´s requirements give strict guidelines for a wind farm´s behaviour under faulty or abnormal operating conditions.The primary purpose of this project is the application of a STATCOM for wind farm integration complying with the Grid Code. Towards that, an outer control strategy for the converter is designed so as to regulate the voltage at the point of common coupling by providing reactive power compensation. Thus the safe operation of the grid will be ensured since the wind farm will follow the Grid Code´s standards.The existing Grid Code requires only a positive sequence current controller. This study attempts to investigate whether this is sufficient or not and to examine the possibility of extending the Grid Code requirements so as to incorporate a negative sequence current controller as well. The results support the latter suggestion. Also, the use of SiC devices was also considered in this project.Den ständigt ökande penetrationen av vindenergi i elnätet väcker farhågor om elkvalitet och stabil drift av kraftsystemet. Nätkoden (Grid Code) ger strikta riktlinjer för en vindkraftsparks beteende i felfall och under onormala driftsförhållanden.Huvudsyftet med detta projekt är att använda en STATCOM för integration av vindkraftsparker så att nätkoden uppfylls. I detta projekt utformas en yttre reglerstrategi för omriktaren för att reglera spänningen vid anslutningspunkten för vindkraftsparken genom att tillhandahålla reaktiv effektkompensering. Därigenom uppnås en säker drift av nätet eftersom vindkraftparken kommer att följa nätkoden.Den befintliga nätkoden kräver endast styrning av plusföljdskomponenten av strömmen. Denna studie försöker undersöka om detta är tillräckligt samt undersöka möjligheten för att utvidga nätkoden genom att införa ett krav på styrning av negativ-sekvens ström. Resultaten stöder det sistnämnda förslaget. Även användningen av halvledarkomponenter av kiselkarbid-SiC studerades i detta projekt.
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Althabity, Mohammad M. "Enforceability of arbitral awards containing interest : a comparative study between Sharia law and positive laws." Thesis, University of Stirling, 2016. http://hdl.handle.net/1893/23090.
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The dynamics of our globalised world open the way for international trade and transactions between different countries; this may lead to conflicts in laws where transactions and trade may be subject to different legal systems. One of the biggest issues in international commercial law is disputes over the charging of interest, for example with regard to late payment, interest-based loans, or compensation for damages. Interest disputes are considered to be a complex area of law and even more complex in the international field. At the international level, interest claims may be connected to many areas of commerce and thus governed by various laws, which are different from one country to another; moreover, each country has its own interest rate and such rates are changeable according to the nature of law and economics under some jurisdictions. Furthermore, the concept of interest itself is affected by influences such as religious beliefs and economic, political and cultural trends. Interest can be treated as a substantive or a procedural matter. The settlement of these disputes therefore faces difficulties. Arbitration, as a method for settlement of disputes, is characterised by special features that assist in resolving these issues; but it faces some obstructions, especially in international commercial arbitration. The practices of arbitral tribunals and national courts in this regard are different. The results of different interpretations, approaches, and theories with regard to arbitration, at the pre-arbitration, during arbitration and post-arbitration stages, may also differ widely due to the diversity of financial and legal systems such as Common Law, Civil Law and the Islamic legal system – Sharia Law – across different countries. Each legal system has a different methodology and theories, even within an individual country under one legal system, and a state within a federal system has its own laws, which may have different interpretations in this respect. The New York Convention of 1958 on enforcing foreign arbitral awards was established in favour of arbitral awards and for the purpose of unifying international rules of arbitration. This Convention provides some procedural and substantive rules for the enforcement of foreign arbitral awards, but also provides some grounds for refusal. These rules have been affected by different interpretations under different jurisdictions and legal systems, which lead to different perspectives on the matter of charging interest and settlement by arbitration. The outcome of applying the NYC under these interpretations often has the opposite of its intended effect: the rejection of foreign arbitral awards. Due to such ambiguities, courts occasionally intervene in arbitration in all its stages. The interventions of national courts occur in three stages: enforcement of the arbitration agreement, enforcement of the contract under the applicable law to the agreement, and enforcement of the foreign arbitral award. The confusion between substantive and procedural laws also creates confusion with respect to public policy, non-arbitrability and enforceability. In addition, there may be a lack of clarity on the scope of arbitration with respect to the parties’ agreement, whether or not the parties have agreed to the interest rates and periods and whether or not they have agreed to the authority of the arbitrator. These issues affect the enforceability of an arbitration agreement, the law applicable to the disputed contract, the freedom of parties, the authority of the arbitrators and the enforceability of the awarded interest. The thesis studies how arbitral awards containing interest have been interpreted across the three aforementioned legal systems under the NYC 1958 in Saudi Arabia, Egypt, the UAE, England, France, and the US and the enforceability of such awards.
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Roost, Pauline. "Evaluation of the Dopaminergic System Using In Vivo PET Imaging and Post-Mortem Analyses in the Context of Mild Neurodegenerative and Neuroinflammatory PD Models." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS086.
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La pathologie cérébrale de la maladie de Parkinson (MP) est caractérisée par une perte neuronale progressive des neurones dopaminergiques de la substance noire pars compacta (SNc) et une accumulation d'α-synucléine agrégée. L’inflammation et la prédisposition génétique contribuent à la MP en tant que facteurs principaux de comorbidité. Dans cette thèse, j’ai étudié, in vivo et post mortem, les effets de trois facteurs sur le système dopaminergique: 1) l’agrégation d’α-synucléine, 2) la toxicité additionnelle des mutations LRRK2 et 3) une neuroinflammation modérée. Pour ce faire, l'imagerie par Tomographie par Emission de Positons (TEP) et des tests comportementaux ont été utilisés. J’ai utilisé les radiotraceurs [18F]LBT-999 et [18F]FMT pour mesurer respectivement les taux cérébraux du Transporteur de la dopamine (DAT) et de l’AADC, l’enzyme de synthèse de la dopamine. Pour évaluer l’inflammation j’ai utilisé le [18F]DPA714, un radiotraceur de référence pour la neuroinflammation radioligand du TSPO 18kDa,. Les résultats obtenus ont été validés par des techniques post mortem évaluant l'expression des gènes (qPCR) et des protéines (immunohistochimie). Les résultats de mes travaux montrent que la surexpression de l’α-synucleine humaine « sauvage » obtenue par transduction de la substance noire par des vecteurs viraux (AAV2/6-PGK-WT-α-synuclein) ne génère ni perte neuronale détectable dans la substance noire, ni déficits moteur, ni changements majeurs du système dopaminergique observé par imagerie TEP in vivo. D'autre part, utilisant cette même stratégie d’expression par vecteur viral (AAV2/6-PGK-A53T-α-synucléine), j'ai démontré une agrégation significative de l’α-synucléine mutée (A53T) dans la substance noire dès 8 semaines post-injection, celle-ci restant très faible dans le striatum. Les analyses quantitatives en microscopie montrent que la surexpression de l’α-synucléine induit une dégénérescence modérée mais significative des neurones dopaminergiques, s’aggravant au cour du temps. La perte des fibres dopaminergiques détectées par l’immunohistochimie de la Tyrosine Hydroxylase (TH) reste cependant très modérée dans le striatum. Les résultats obtenus par imagerie TEP montrent une réduction du DAT dans le striatum, au contraire de l’AADC dont les niveaux restent stables. Ainsi, les données in vivo combinées aux observations post-mortem suggèrent que l’imagerie TEP du DAT ne reflète pas seulement la perte neuronale induite par l’α-synucléine, mais aussi une dérégulation fonctionnelle de la synapse dopaminergique. Celle-ci pourrait permettre, via la baisse du transporteur, et en présence de niveau normaux de TH et AADC le maintien des concentrations synaptiques de dopamine dans le striatum. J’ai également montré que cette perte neuronale coïncidait avec une réponse inflammatoire initialement modérée, suivie d'une réponse microgliale plus prononcée. Enfin, dans le modèle viral de co-expression des vecteurs AAV2/6-PGK-A53T-α-synucléine et AAV2/6-PGK-G2019S-LRRK2, nous n’avons pas observé que la présence de LRRK2 mutée augmentait la toxicité de l’α-synucléine.Dans le modèle de neuroinflammation induite par l’injection de LPS, l’imagerie TEP et les analyses post-mortem montrent l’absence de perte des neurones dopaminergiques. Néanmoins, j'ai mis en évidence une corrélation inverse significative entre les marqueurs de sévérité de l'inflammation (l’imagerie TEP des TSPO, expression IBA1) et les marqueurs de production (TH) et de stockage (VMAT2) de la dopamine. Ces données renforcent l'hypothèse que la neuroinflammation altère la fonctionnalité du système dopaminergique, indépendamment de la perte neuronale dopaminergiqueThe cerebral pathology of Parkinson’s disease is characterized by a progressive loss of dopaminergic neurons of the substantia nigra, and an accumulation of α-synuclein aggregates. neuroinflammation and genetic predisposition contribute to PD as the main confounding factors. In this PhD thesis, I aimed to evaluate, in vivo and post-mortem, the effects of three factors on the dopaminergic system: 1) α-synuclein overexpression, 2) α-synuclein and LRRK2 co-expression, and 3) mild neuroinflammation, on the dopaminergic system and dopaminergic neuronal cell loss.To this end, positron emission tomography (PET) imaging and behavioural studies have been selected as the main in vivo tools. I have used [18F]LBT999 and [18F]FMT PET imaging to evaluate striatal levels of dopamine transporter (DAT) and the dopamine-synthesising AADC enzyme, respectively. To assess neuroinflammation, I have used [18F]DPA714 to evaluate 18kDa TSPO binding. The in vivo data were validated by post-mortem techniques evaluating the expression of genes (qPCR) and proteins (immunohistochemistry).The results of my work show that overexpression of human WT-α-synuclein in the substantia nigra through viral vectors (AAV2/6-PGK-WT-α-synuclein) does not generate detectable neuronal loss in the substantia nigra, nor does it generate in vivo motor deficits or changes in the dopaminergic system as seen by in vivo PET imaging. On the other hand, I have demonstrated here that overexpression of A53T-α-synuclein in the substantia nigra, using an AAV2/6-PGK-A53T-α-synuclein viral vector approach, resulted in significant α-synuclein aggregation in the substantia nigra as soon as 8wpi, but not in the striatum. Quantitative microscopic analyses show that A53T-α-synuclein aggregation induced a mild but progressive degeneration of dopaminergic neurons in the substantia nigra. The loss of dopaminergic fibres in the striatum as detected by immunohistochemistry of tyrosine hydroxylase (TH) remains, however, moderate. DAT-PET imaging, but not AADC-PET imaging, was able to measure the progressive neuronal loss. Taken together, our in vivo and post-mortem data suggest that DAT-PET does not only reflect neuronal loss induced by α-synuclein accumulation, but also functional compensation mechanisms of the dopaminergic synapse. A reduction in DAT levels, combined with normal TH and AADC levels, could normalise the synaptic dopamine concentrations in the striatum. In addition, this dopaminergic neuronal loss coincided with in initially moderate, followed by a more pronounced microglial response. Finally, in a viral vector model of co-overexpression of AAV2/6-PGK-A53T-α-synuclein and AAV2/6-PGK-G2019S-LRRK2, we did not observe added neurotoxicity of G2019S mutated LRRK2 to A53T-α-synuclein toxicity.In an acute neuroinflammatory model following LPS injection in the striatum, post-mortem analysis revealed the absence of dopaminergic neuronal loss in the substantia nigra and synaptic loss in the striatum. Nevertheless, I observed a significant inverse correlation between inflammation markers (TSPO-PET and IBA1 expression) and markers for dopamine production (TH) and storage (VMAT2). These data support the hypothesis that neuroinflammation may impair the functionality of the dopaminergic system, regardless of the presence dopaminergic neuron loss.In summary, my thesis results confirm the interest of PET in demonstrating functional damage in vivo, which cannot be demonstrated post-mortem in animal models of PD
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Jalboub, Mohamed K. "Investigation of the application of UPFC controllers for weak bus systems subjected to fault conditions. An investigation of the behaviour of a UPFC controller: the voltage stability and power transfer capability of the network and the effect of the position of unsymmetrical fault conditions." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5699.
Full textAbstract:
In order to identify the weakest bus in a power system so that the Unified Power Flow Controller could be connected, an investigation of static and dynamic voltage stability is presented. Two stability indices, static and dynamic, have been proposed in the thesis. Multi-Input Multi-Output (MIMO) analysis has been used for the dynamic stability analysis. Results based on the Western System Coordinate Council (WSCC) 3-machine, 9-bus test system and IEEE 14 bus Reliability Test System (RTS) shows that these indices detect with the degree of accuracy the weakest bus, the weakest line and the voltage stability margin in the test system before suffering from voltage collapse.
Recently, Flexible Alternating Current Transmission systems (FACTs) have become significant due to the need to strengthen existing power systems. The UPFC has been identified in literature as the most comprehensive and complex FACTs equipment that has emerged for the control and optimization of power flow in AC transmission systems. Significant research has been done on the UPFC. However, the extent of UPFC capability, connected to the weakest bus in maintaining the power flows under fault conditions, not only in the line where it is installed, but also in adjacent parallel lines, remains to be studied. In the literature, it has normally been assumed the UPFC is disconnected during a fault period. In this investigation it has been shown that fault conditions can affect the UPFC significantly, even if it occurred on far buses of the power system. This forms the main contribution presented in this thesis. The impact of UPFC in minimizing the disturbances in voltages, currents and power flows under fault conditions are investigated. The WSCC 3-machine, 9-bus test system is used to investigate the effect of an unsymmetrical fault type and position on the operation of UPFC controller in accordance to the G59 protection, stability and regulation. Results show that it is necessary to disconnect the UPFC controller from the power system during unsymmetrical fault conditions.Libyan Government
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Jalboub, Mohamed. "Investigation of the application of UPFC controllers for weak bus systems subjected to fault conditions : an investigation of the behaviour of a UPFC controller : the voltage stability and power transfer capability of the network and the effect of the position of unsymmetrical fault conditions." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5699.
Full textAbstract:
In order to identify the weakest bus in a power system so that the Unified Power Flow Controller could be connected, an investigation of static and dynamic voltage stability is presented. Two stability indices, static and dynamic, have been proposed in the thesis. Multi-Input Multi-Output (MIMO) analysis has been used for the dynamic stability analysis. Results based on the Western System Coordinate Council (WSCC) 3-machine, 9-bus test system and IEEE 14 bus Reliability Test System (RTS) shows that these indices detect with the degree of accuracy the weakest bus, the weakest line and the voltage stability margin in the test system before suffering from voltage collapse. Recently, Flexible Alternating Current Transmission systems (FACTs) have become significant due to the need to strengthen existing power systems. The UPFC has been identified in literature as the most comprehensive and complex FACTs equipment that has emerged for the control and optimization of power flow in AC transmission systems. Significant research has been done on the UPFC. However, the extent of UPFC capability, connected to the weakest bus in maintaining the power flows under fault conditions, not only in the line where it is installed, but also in adjacent parallel lines, remains to be studied. In the literature, it has normally been assumed the UPFC is disconnected during a fault period. In this investigation it has been shown that fault conditions can affect the UPFC significantly, even if it occurred on far buses of the power system. This forms the main contribution presented in this thesis. The impact of UPFC in minimizing the disturbances in voltages, currents and power flows under fault conditions are investigated. The WSCC 3-machine, 9-bus test system is used to investigate the effect of an unsymmetrical fault type and position on the operation of UPFC controller in accordance to the G59 protection, stability and regulation. Results show that it is necessary to disconnect the UPFC controller from the power system during unsymmetrical fault conditions.
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Hoarau, Gwenaël. "Étude de la limite de détection et des fausses alarmes émises par les moniteurs de mesure de la contamination radioactive atmosphérique dans les chantiers de démantèlement." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP055.
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Les moniteurs de mesure de la contamination radioactive atmosphérique sont utilisés dans les installations nucléaires afin d’assurer la radioprotection des travailleurs vis-à-vis de l’exposition aux aérosols radioactifs. Les performances de ces moniteurs sont évaluées dans des conditions normatives IEC, lesquelles couvrent une large gamme d’atmosphères de travail. Dans des situations typiques de celles mesurées en chantier de démantèlement nucléaire, lesquelles sont d’ailleurs hors cadre IEC, un comportement inattendu des moniteurs de mesure de la contamination radioactive atmosphérique est souvent observé. Celui-ci correspond à l’émission d’une alarme de type faux positif. L’objectif de ce travail de thèse est d’améliorer les connaissances sur le comportement des moniteurs de mesure de la contamination radioactive atmosphérique dans des situations hors conditions normative IEC. Pour ce faire, un dispositif expérimental spécifique a été conçu, à l’intérieur duquel la reproduction d’atmosphères typiques de celles mesurées en chantier de démantèlement est possible. Ainsi, ce dispositif a rendu possible l’étude en laboratoire du comportement d’un moniteur de mesure de la contamination radioactive atmosphérique de type ABPM203M. Cette étude expérimentale a permis d’une part, de mettre en avant les conditions qui conduisent à un comportement inattendu du moniteur et d’autre part, de démontrer les raisons pour lesquelles une alarme de type faux positif est souvent émise dans ces conditions hors IEC. A la synthèse des résultats de l’étude, un procédé nouveau de mesure a été proposé, lequel permet d’une part, de considérer à la fois les caractéristiques des aérosols non-radioactifs et celles des aérosols radioactifs et d’autre part, d’améliorer la mesure effectuée par le moniteur permettant de toujours assurer la radioprotection des travailleursThe Continuous Air monitors are used in the nuclear facilities for ensuring the radiation protection of workers who are likely to be confronted to radioactive aerosols. The CAM behavior are evaluated under IEC normative conditions. In atmospheric conditions as measured in decommissioning nuclear sites, outside of IEC, wrongs CAM behavior are observed. Which correspond to the false positives triggering. The aim of this thesis work is to enhance the knowledge about the CAM behavior when it is faced to outside IEC normative conditions. A specific experimental chamber has been designed, inside which the reproduction of the dismantling nuclear site atmosphere is achievable. Thus, this experimental chamber made it possible, in the laboratory, the study of the behavior of a CAM type ABPM203M. With the results we have, on the one hand, highlighted the conditions which lead to unexpected behavior of the CAM and, on the other hand, demonstrated the reasons why a false positive alarm is often emitted under these conditions, outside IEC. At the synthesis of the results of the study, a new measurement process was proposed, which makes it possible, on the one hand, to consider both the characteristics of non-radioactive aerosols and those of radioactive aerosols and on the other hand, to improve the measurement achieved out by the CAM to always ensure the radiation protection of workers
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Le, Bescond de Coatpont Mathieu. "La dépendance des distributeurs." Thesis, Lille 2, 2015. http://www.theses.fr/2015LIL20006.
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Les distributeurs sont des intermédiaires économiques car ils offrent sur le marché des produits ou services conçus, fabriqués ou exécutés par d’autres (les fournisseurs). Cette recherche démontre que le degré de protection accordé par le droit positif aux différents distributeurs n’est pas corrélé à leur degré de dépendance aux fournisseurs. Les qualifications de la dépendance sont multiples, incertaines, incohérentes et parfois artificiellement restrictives ou extensives, en droit du travail comme en droit économique. Des distributeurs connaissant un même degré de dépendance à leur fournisseur peuvent être traités de façon différente sans justification au regard des fondements des règles considérées. Il existe ainsi des inégalités de traitement. Il est donc proposé un nouveau droit de la dépendance des distributeurs, plus cohérent et égalitaire. Celui-ci se traduirait par un statut légal des distributeurs remplaçant les multiples statuts spéciaux existants, traçant une frontière plus nette avec le droit du travail et conciliant les intérêts des distributeurs avec la liberté des fournisseurs d’organiser la distribution de leurs produits et services. Dépassant la notion trop restrictive de contrat et les conflits de qualification, ce statut viserait la relation de distribution et prévoirait un régime appréhendant la complexité et l’évolutivité de la dépendance des distributeurs grâce à l’information, à une garantie de revenus et différentes indemnités de fin de relationDistributors are economic intermediaries because they offer on the market goods and services produced or served by others (the suppliers). This research demonstrates that the degree of protection offered by the Law to the various distributors isn’t correlated with their degree of dependence towards suppliers. The qualifications of dependence are numerous, incoherent and sometimes artificially restrictive or extensive, in labour law as in business law. Distributors experiencing a same degree of dependence towards their supplier can be treated differently without any justification regarding the grounds of the rules in question. Hence, appear inequalities towards the Law. Therefore, new legal rules are suggested. They would take the form of a statute ruling distributors and replacing the numerous statutes in force at the present time. It would draw a clearer line between labour law and business law and conciliate the distributors’ interests with the freedom of suppliers to organize the distribution of their goods and services. Going other the too restrictive notion of contact and the conflicts between qualifications, this statute would rule the relation of distribution and contain rules comprehending the complex and changing nature of dependence. It would ensure sufficient information of distributors and offer them an income guarantee and various compensations when the relation is terminated
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溫菘揮. "Position Error Compensation Study of the Open Loop Guideway System." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99751557509222382047.
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碩士國立彰化師範大學
機電工程學系
95
The purpose of this thesis is to improve the performance of a feed guideway control system under open loop structure. By using of the 「Visual C++」 software and the hardware components such as SYN-TEK M114G motion card and SANMOTION stepping driver and motor, the presented guideway feed system is integrated with a PC-based controller. In order to achieve the requirements of the guide way system position accuracy, the following items are discussed in this thesis: 1.Set up an axial guide way system. 2.Measurement the system errors and develop data base. 3.Repeat measurement and modify the data base. 4.Establish an open loop structure and reach the position accuracy in 2μm. 5.Develop a software system with data collect function as a data base of error compensation.
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朱子文. "Performance improvement on the position feedback electrohydraulic servovalve via digital compensation." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/57080269279227173965.
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Lin, Yi-sheng, and 林益生. "The position compensation of a 3-PRS error by optimization method." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/69891922972619140779.
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碩士國立中正大學
機械系
90
In compensation process, we will study three different cases by using the optimization methods. We assign the position error on the tool tip as the objective function and the maximum velocities and accelerations as constraints. In case one, the design variables are the accelerated time and decelerated time of the 2nd and 3rd ball screw. In case two, the maximum velocities of the 2nd and 3rd ball screw are also chosen as the design variables. In case three, an error was occurred on the tool tip, and the all the accelerated time and decelerated time of the three ball screws are now variables to overcome the error. The compensation is based on two optimization methods, which are the Gauss-Newton Method and the Sequential Quadratic Programming Method. The objective function is constructed from the summation of the position error on tool tip by using the Least Square Method. The constraints are the maximum velocity and acceleration of the ball screws, and the design variables are the accelerated and decelerated time of the ball screws without feed rate error. According to the numerical results, the moving paths of tool tip after compensation are improved with the modification of the accelerated and decelerated time of the ball screws by using the proposed optimization methods. The longer the decelerated time is, the better the result would be.
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Bao-Kim, Liu, and 劉寶磬. "The Research of Fuzzy Logic Applied on Antenna Axis-position Compensation." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/60709285607344546620.
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碩士中原大學
資訊工程學系
88
While the Antenna is tracking a moving target, it can only turn the detected angle passively by following the moving trace of that target. Which can not reduce the angle error between the target and Antenna. By researching and analysing the target’s past behavior the following moving trace can be predicted , and then guide the Antenna move to more accurate next position of target by applied the axis position compensation force. The compensation is adjusted by the fuzzy logic according to the moving distance and angle of target . So it can reduce the error and response quickly by computing compensation . The Fuzzy logic method used in this thesis is simulated by the Matlab and adjust the membership function by input a set of AZ and EL axis data , then compute the force of compensation which is decided from output of fuzzy fuzzy logic inference. The procedure of adjust the membership function continues until the error is unacceptable. Therefore the Antenna can predict the moving of target precisely.
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Johnson, Craig T. "Identification of friction and its compensation in precise, position controlled systems." 1992. http://catalog.hathitrust.org/api/volumes/oclc/32282553.html.
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Thesis (MS)--University of Wisconsin--Madison, 1992.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 139-141).
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Shiao, Chih-Mao, and 蕭志茂. "Study on High Position Accuracy of Magnetic Scale Signal Processing and Compensation." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45874297480177209539.
Full textAbstract:
碩士國立勤益科技大學
電子工程系
98
The research goal of this paper is to implement a high-precision magnetic scale measurement system. The magnetic scale measurement system is based on the feedback of signal to process signal and compensation. The system uses TI's TMS320F2801 DSP chip as the controller. The orthogonal sinusoidal signals are converted into digital signal output by using A / D converters of the DSP chip, in which the output signals are amplified through the amplifier due to the small SIN/COS amplitude of the magnetic field signal, about 50mV. The signal instability phenomenon, which is caused by the noise amplified at the same time, can reach to a stable state by adding filters to filter out noises and compensating the signal during the signal resolution. The stable signal is then processed by the fine segmentation to make the position feedback system meet the demand for high precision. In addition to having a high-precision position feedback, this system, which meets the industry demand, can not only replace the more expensive and environment -restricted optical measurement, but also will be beneficial and more widely accepted for industrial applications.
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Sung, Chrong-Yih, and 宋崇溢. "A Study of Piezoelectric Material of Aerostatic Bearing Via Position Motion Compensation." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/63377597622725666506.
Full textAbstract:
碩士國立彰化師範大學
工業教育學系
87
The piezoelectric material of aerostatic bearing via active positioning motion compensation is studied. Micro-positioning systems using piezoelectric actuators have a very wide range of applications including ultra-precision machine tools. The synergetic integration of mechanical engineering, electrical engineering and electronics in conjunction with high precision smart material and control technology is also examined . The externally presurized gas bearing was used in the fields of precision engineering, specially for the characteristics of high precision, low friction and high speed. The purpose of this study is to use the piezoelectric materials, which was able to have the fast response characteristics and fine positioning motion ability, which can be applied with the PCB drilling machine. The PCB table is actively compensated by the piezoelectric air bearing component in the future. In order to reach this purpose, a direct current Battery Charger Device is conductedfirst. Digital feature based power amplifier having a feedback control current compensation is achieved by the research development. An experimental study of active power compensation technique for high-precision positioning control involving the use of a Stacked type and multilayer type piezoelectric actuators are presented. In this thesis, one presents a novel implementation of applying a direct current battery charger device for the power consumption of developed piezoelectric actuator (PZT) utilized for precision motion control. Emphasis is placed here on controlling the PZT via the development of high-speed power amplifier by Battery Charger Device together with D/A interfacing and operational amplifier circuitry. The result shows that the power amplification has the stable ability of output constant linear voltage for driving the piezoelectric material under the condition of free load or load. The feedback current loop of the driver shows the abilities of ultra-precision and high-speed power supply. Characteristic micro-displacement of developed stacked type and multilayer piezoelectric actuators are experimentally tested. Keyward: Piezoelectric Actuator、Micrometer Displacement 、Precision Motion
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TAGHIZADEH, SASAN. "CONTROL OF A PNEUMATIC SYSTEM WITH ADAPTIVE NEURAL NETWORK COMPENSATION." Thesis, 2010. http://hdl.handle.net/1974/6125.
Full textAbstract:
Considerable research has been conducted on the control of pneumatic systems due to their potential as a low-cost, clean, high power-to-weight ratio actuators. However, nonlinearities such as those due to compressibility of air continue to limit their accuracy. Among the nonlinearities in a pneumatic system, friction can have a significant effect on tracking performance, especially in applications that use rodless cylinders which have higher Coulomb friction than rodded cylinders.
Compensation for nonlinearities in pneumatic systems has been a popular area of research in pneumatic system control. Most advanced nonlinear control strategies are based on a detailed mathematical model of the system. If a simplified mathematical model is used, then performance is sensitive to uncertainties and parameter variations in the robot. Although they show relatively good results, the requirement for model parameter identification has made these methods difficult to implement. This highlights the need for an adaptive controller that is not based on a mathematical model.
The objective of this thesis was to design and evaluate a position and velocity controller for application to a pneumatic gantry robot. An Adaptive Neural Network (ANN) structure was implemented as both a controller and as a compensator. The implemented ANN had online training as this was considered to be the algorithm that had the greatest potential to enhance the performance of the pneumatic system.
One axis of the robot was used to obtain results for the cases of velocity and position control. Seven different velocity controllers were tested and their performance compared. For position control, only two controllers were examined: conventional PID and PID with an ANN Compensator (ANNC). The position controllers were tuned for step changes in the setpoint. Their performance was evaluated as applied to sinusoid tracking.
It was shown that the addition of ANN as a compensator could improve the performance of both position and velocity control. For position control, the ANNC improved the tracking performance by over 20%. Although performance was better than with conventional PID control, it was concluded that the level of improvement with ANNC did not warrant the extra effort in tuning and implementation.Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-09-08 15:02:28.177
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Huang, Wen-Yi, and 黃文藝. "An Investigation of the Metal Deposition Process with the Compensation of Substrate Position Effect." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/96146966587384222058.
Full textAbstract:
碩士正修科技大學
機電工程研究所
97
As study on the density of metal film on substrate is considered in this investigation. There are material characteristic and reaction magnetic field issue during metal films deposition（Sputtering）, and there has stress issue after the metal film deposited upon the substrate surface, to reduce this stress issue can more effectively improve the deformation of substrate and density of metal film. This study is creating a metal film deposition system for substrate application with normal metal material. The sputtering source is 3 inch sputter gun where from Jun-San Tech Co. Ltd. in this system, and cylindrical chamber with CF series flange and expansibility design, thus there has extremely good sealing and repacking capability. To fit for high vacuum pressure and purity of Sputtering system, using Dry Screw Pump for Fore-line Pump to prevent oil vapor pollution, and build up a high vacuum environment by Turbo-molecular Pump. This thesis is studied to utilize the difference parameters in the substrate and target material（Target）. Numerical analysis indicating that the distance between the substrate and target materials may affect the density of metal film significantly.
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Wu, Jhen-yao, and 吳振耀. "Combined Image Analysis and Feedback Compensation Techniques to Position Control of a Ball-plate system." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/02522105143891013743.
Full textAbstract:
碩士國立雲林科技大學
電機工程系碩士班
94
Machine vision usually comes with image-aided servo control mechanism, which is widely used in the application of high-precision industrial measurement systems. With the aid of a high-speed digital camera, an instant image of a moving object can be captured and processed in real-time so that some important properties of moving object such as position, velocity and acceleration can be identified and transformed to actuating signals for drivers of some electromechanical servo systems. Specifically, for a two-dimensional ball and plate system, called HUNUSOFT Ball and Plate system in which a color ball is forced to move on a metal plate, is used as a test bed for the study of position servo control based-on image processing techniques. Two step motors used to drive the metal plate are located perpendicular to each other so that they can exert forces along the vertical and horizontal directions of the plate, respectively, to tilt the plate appropriately. The control object is to move the ball by tilting the plate to a desired position as quickly and accurately as possible. Because the system is too complicated to have a precise mathematical model describing the motion, we employ fuzzy control techniques to fulfill the design in this thesis. The compensation scheme consists of two feedback loops; the inner loop feedback angle control where ANALOG DEVICES ADXL204 is used as the angle sensor, and the outer loop feedback position control where Marlin F-033B high-speed camera is used as the position sensor. After extensive experiments, we have demonstrated that the position servo control scheme with the aid of the image processing techniques can effectively achieve the goal of moving the color ball to approach the arbitrarily assigned position on the plate in very short time. Nevertheless, the tracking precision seems not yet as good as expected and is needed to be further improved.
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Huang, Ding-Yang, and 黃碇洋. "The improvement and verification of position accuracy of the respiratory compensation system by the strain measurement." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/z3m3vx.
Full textAbstract:
碩士國立臺北科技大學
製造科技研究所
100
This study drove the treatment couch for reverse motion, opposite from the direction of the targets, in order to offset organ displacement generated by respiratory motion. A strain gauge was used to replace a pressure transducer as a respiratory signal capture device to obtain abdomen respiratory signals. The simulated respiratory system (SRS) position error is approximately 0.45~1.42mm, while the respiratory compensating system (RCS) position error is approximately 0.48~1.42mm. Compare with the pressure transducer RCS, the position error can be improved by an amount of 67.7%. This study verified the effect of RCS in offsetting the target displacement by three methods. The first method was using the SRS to simulate organ displacements, human respiratory and being compensated by RCS. Then the target movement was analyzed by fluoroscopy images and the results suggested that compensated rate can be improved to 85.72%. The Second method was using LINAC to irradiate 300cGy dose on the EBT film. The results show that when the input respiratory signals of SRS are sine wave signals, the average dose in the target area and the 95% isodose area after compensation is improved by 1.4~24.4% and 15.3~76.9%, respectively. If human respiratory signals are input to the SRS, the average dose in the target area and the 95% isodose area after compensation is improved by 31.8~67.7% and 15.3~86.4%, respectively. Gamma passing rate after compensation can be improved to 100% only when the displacement of the respiratory motion is within 10~30mm. The third method was capturing patients’ respiratory signals, while using the fluoroscopy to observe their diaphragm and activating RCS to offset the displacements of targets. The experimental results suggested that, a displacement of 67.3~75.6% can be offset. The results proved that the proposed RCS can contribute the compensation of organ displacement caused by respiratory motion.
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Hsu, Ming-lin, and 許銘麟. "The Exploratory Study of the Recognition of Technology Managers in Using Equity Position as Compensation for Technology Transfer in Taiwan." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/81601620293617122069.
Full textAbstract:
碩士國立雲林科技大學
企業管理系碩士班
94
Exploiting academic achievements is one of the most important policies for economic development in most countries. One term used to describe the phenomenon of diffusing or spilling over those achievements from universities to industries is “university technology transfer.” In the past ten years, university technology transfer was changing rapidly. The most significant transformation maybe was the involvement of administration and the managerial perspective both by government and universities. Academic results are not belonged in public domain, and many compensation mechanisms were emerged out of to handle the transaction between universities and industries in the last decade. The most popular mechanism is licensing fee and running royalty. But this mechanism was challenged by consideration of financial reward and time-consumption negotiation in recent years. Equity position becomes another alternative to replace previous mechanism as a new aspiration of dealing technology transfer. In technology transfer of equity position, universities offer their technology, patent, know-how, and other valuable tangible/intangible property for licensee’s equity. The reason of adoption of taking equity is various, for example, licensee is cash-strived new enterprise therefore equity is the only thing they can offer, equity position may mitigate the potential for disputes and litigation both parties, it maybe provide more and faster financial reward than licensing, and it may signal to the outside world that the university is entrepreneurial. Though equity position is known widespread in some developed countries, it is novel for our country. Most technology transfer managers in our country knew this mechanism, but none of the case reported by National Science Console was equity position. According to behavior science, recognition is the prerequisite of actual behavior. The purpose of this study is an exploratory study to investigate the recognition of equity position as a compensation tool in lieu of licensing by university technology transfer managers. Prior related arts are rare in global publication and none of empirical/theoretical study domestically. By systematic constructing methodology, this study will interview all full-time technology managers in Taiwan, collecting their opinions and attitudes toward equity position as transaction tool, analyzing their consensus and dissenting view about this tool, and finalized by proposing some empirical propositions. The result： The factor which influence Taiwan technology manager in using equity position as Compensation for Technology Transfer：The policy of government or university、financial consideration(reward or risk)、the relationship with industry、TTO’s size and history (experience)、reduces the propensity for the university、the performance of TTO、hold something of technology value、accelerate social and economic benefit. The factor which influence Taiwan technology manager not using equity position as Compensation for Technology Transfer：Success of a start-ups is unpredictable、faculty entrepreneur lacks business skill、the performance of TTO.
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Qin, Jinna. "Commande hybride position/force robuste d'un robot manipulateur utilisé en usinageet/ou en soudage." Phd thesis, 2013. http://pastel.archives-ouvertes.fr/pastel-00940035.
Full textAbstract:
La problématique traitée dans cette thèse concerne la commande de robots manipulateurs industriels légèrement flexibles utilisés pour la robotisation de procédés d'usinage et de soudage FSW. Le premier objectif est la modélisation des robots et des procédés. Les modèles développés concernant la cinématique et la dynamique de robots 6 axes à architecture série et à flexibilité localisées aux articulations. Les paramètres du modèle dynamique et les raideurs sont identifiés avec la méthode à erreur de sortie qui donne une bonne précision d'estimation. La norme relative du résidu du modèle après identification est de 3,2%. Le deuxième objectif est l'amélioration des performances de la robotisation des procédés. Un simulateur a été développé qui intègre le modèle dynamique du robot flexible, les modèles de procédés et le modèle du contrôleur de robot y compris les lois de commande en temps réel des axes et le générateur de trajectoires. Un observateur non-linéaire à grands gains est proposé pour estimer l'état complet du robot flexible ainsi que les efforts d'interaction. Ensuite, un compensateur basé sur l'observateur est proposé pour corriger les erreurs de positionnement en temps réel. La validation expérimentale sur un robot industriel Kuka, montre une très bonne estimation de l'état complet par l'observateur. Un soudage FSW précis grâce à la compensation en temps réel de la flexibilité du manipulateur a pu être effectué avec succès.
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FRÖSTLOVÁ, Daniela. "Pohybová náročnost vybraných pracovních profesí, sestavení vhodného kompenzačního programu pro profese se sedavým typem zaměstnání." Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-263255.
Full textAbstract:
The main theme of my work is finding the locomotive load in selected professions and build a compensation program for professionals with a sedentary job. When selecting this topic for me was the decisive topicality of the selected topic, I see especially in the ever-growing problems with musculoskeletal system of persons employed in sedentary occupations, which are one of the consequences of their employment. The first theoretical part of the thesis includes a detailed analysis of the issues examined based on theories that describe the anatomy and physiology of the musculoskeletal system. I characterize also the sedentary lifestyle and sedentary employment in general and describe workplace ergonomics professionals selected for the needs of my thesis. In theory there need explaining motion compensation modes based on medical aspects of the workforce in selected professions sedentary jobs. The practical part of the thesis was to determine the quantitative research on a sample of probands peace musculoskeletal load in connection with the exercise of their profession. Results of the research were my starting point to build a compensation programs that would positively affect the quality of life of current probands. To meet the targets I have been primarily assisting methods of quantitative research using questionnaires. The reason for choosing this method is smooth and straightforward data collection enabling the rapid analysis and processing. The research group of people that was chosen includes professions that are characterized by their sedentary job: professional driver, an office worker and painter Christmas decorations. I observed the objectivity of the research questions musculoskeletal load in selected professions, I firmly establish the criteria on the basis of purposive sampling was assembled group of three professionals with a sedentary job. During the research, I pay attention to individual cases, carried out their detailed descriptions and subsequently proposed compensatory exercises by the parties for some time applied. After this time was collected by new data and a qualitative comparison with the data starting. I am convinced that the results of my research work can help all persons working in occupations with a sedentary job, provided the inclusion of adequate compensatory exercises in his career, but also leisure life.
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Qiao, Feng. "Approaches for respiratory motion compensation in positron emission tomography imaging." Thesis, 2008. http://hdl.handle.net/1911/22237.
Full textAbstract:
Respiratory patient motion often causes image blur and inaccurate quantitation results in positron emission tomography (PET) imaging. Traditional gated acquisition approach corrects motion artifacts by generating a snapshot sequence. Each snapshot, however, is of poor image quality due to insufficient photon counts. This dissertation addresses the problem of how to correct motion artifacts without sacrificing image quality or extending scan duration. To this end, a motion-incorporated model of the PET imaging system has been developed which enables utilization of data acquired during the entire scanning period in an image reconstruction process, thereby improving photon statistics while eliminating motion artifacts. Three related approaches within this framework are presented. In the first approach, motion information is first derived from a corresponding four-dimensional computed tomography image sequence, and then incorporated into the PET system model to get a motion-free image. The second approach develops a region of interest extension to the motion-incorporated system model to improve efficiency and accuracy of motion estimation. Finally, the motion-incorporated system model is integrated with an anatomy based image reconstruction algorithm, thereby enabling utilization of mismatched anatomical information during the image reconstruction process to improve image quality and quantitation performance.
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Chien, Chien-Chou, and 簡建州. "Recurrent Neural Network Compensating Model Predictive Control for PMSM Position Control." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/qzr9zv.
Full textAbstract:
碩士國立中央大學
電機工程學系
106
The purpose of this research is to drive Permanent Magnet Synchronous Motor(PMSM) position control system by Model Predictive Control (MPC) and Recurrent Neural Network (RNN) as an uncertainty observer base on Digital Signal Processing (DSP). Base on traditional Field Oriented Control(FOC) structure and then design model predictive controller to replace PI controller apply to PMSM position control system . But model predictive control in PMSM position control system should know parameters of PMSM.So actually it is difficult to design an efficiency model predictive controller in real system. This dissertation uses recurrent neural network to derive adaptive laws to estimate parameter uncertainties of PMSM and compensate MPC to eliminate the errors that caused by parameter uncertainties. Fially, the proposed PMSM position control system is implemented in a 32-bits floating-point DSP, TMS320F28335.And compare the experimental results with before and after compensation of recurrent neural network.
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Yang, Chih-Chieh, and 楊智傑. "Dynamic Position Tracking Compensator Design for Stepper Motor Drive by FPGA." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/zpx3s9.
Full textAbstract:
碩士國立勤益科技大學
電機工程系
106
Programmable Logic Controller (PLC) is one of the line interpreting and execution controller. The performance of a PLC-based system is limited by the amount of line commands and the processing times of the CPU embedded. The cycle time of scanning all the command lines once is an important index to evaluate the performance of PLC. A short cycle time means the possibility to increase the system performance by more acts in the system, it also shows that a more powerful system is. In the research, owing to the time limitation of PLC about the cycle time to complete the scan from the beginning to the end of the program, such that the position control by a general PLC is fail to efficiently reach to the desired performance about the positioning precision. Thus, we used the Field Programmable Gate Array (FPGA) to cooperate with the PLC to complete the compensation about the positioning. The position control is handled by the FPGA-based compensator which accepts the position error from the position sensor and analog to digital converter (ADC), and outputs the pulse commands processed by digital difference analyzer (DDA) to move the stepper motor to conserve the position error in the pre-defined range. Through the experimental results, the positioning precisions can be improved than those only controlled by PLCs.
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Rahmim, Arman. "Statistical list-mode image reconstruction and motion compensation techniques in high-resolution positron emission tomography (PET)." Thesis, 2005. http://hdl.handle.net/2429/17062.
Full textAbstract:
The work presented here is devoted to the proposal and investigation of
3D image reconstruction algorithms suitable for high resolution positron
emission tomography (PET). In particular, we have studied imaging techniques
applicable to the high resolution research tomograph (HRRT): a 3Donly
state-of-the-art dedicated brain tomograph. The HRRT poses a number
of unique challenges, most significant of which include presence of gaps
in-between the detector heads, as well as the very large number of lines-ofresponse
(LORs) which it is able to measure (~4.5x10⁹), exceeding most
modern PET scanners by 2-3 orders of magnitude.
To address the existing issues, we have developed and implemented statistical
list-mode image reconstruction as a powerful technique applicable to the
high resolution data obtained by the HRRT. We have furthermore verified
applicability of this technique to dynamic (4D) PET imaging, thus qualifying
the technique as viable and accurate for the research intended to be
performed on the scanner. We have paid particular attention to the study
of convergent algorithms; i.e. iterative algorithms which (with further iterations)
consistently improve such figures of merit as resolution and contrast,
relevant to research and clinical tasks.
With the spatial resolution in modern high resolution tomographs (including
the HRRT) reaching the 2-3mm FWHM range, small patient movements
during PET imaging can become a significant source of resolution
degradation. We have thus devoted a portion of this dissertation to the proposal
of new, accurate and practical motion-compensation techniques, and
studied them on the HRRT. We have theoretically proposed and experimentally
validated the benefits of modeling the motion into the reconstruction
task, thus signaling the way beyond the existing purely event-driven motioncompensation
techniques.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Langner, Jens [Verfasser]. "Event-driven motion compensation in positron emission tomography: development of a clinically applicable method / submitted by Jens Langner." 2008. http://d-nb.info/1007525657/34.
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Lin, Tzu-Da, and 林孜達. "The Impact of Service Type with Compensation Type to Customers’ Satisfaction, Positive WOM and Repurchase Intention." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99928185579868266727.
Full textAbstract:
碩士東吳大學
企業管理學系
95
Service failure often happens in the service industry, so the effective service recovery is important for the service provider. It can help the service provider to improve customers’ satisfaction, repurchase intention and positive world-of-mouth. In the past litature, justice theory is often discussed in the area of service recovery. However, how to match different service types and different compensation types is an important question which can increase customers’ satisfaction. This study used the “Benefit Congruency Framework” developed by Chandon, Wansink, and Laurent (2000) as a framework to explore the relationship between between service types（utilitarian service vs. hedonic service）and compensation type（utilitarian compensation vs. hedonic compensation）, and find out the influence to customers’ satisfaction, repurchase intention and positive WOM. This study used the experiment design to test the hypotheses. In the study 1, students served as the sample pool（145 valid datas） for this investigation. A 2 (service type: utilitarian service-bank vs. hedonic service-KTV) × 2 (compensation type: utilitarian compensation-coupon vs. hedonic compensation-KTV’s free singing ticket) between-subjects design was used in the study 1. In the study 2, on-the-job people served as the sample pool（136 valid datas）. A 2 (service type: utilitarian service-business hotel vs. hedonic service-resort hotel) × 2 (compensation type: utilitarian compensation-coupon vs. hedonic compensation-theme park’s ticket) between-subjects design was used in the study 2. The result of this study shows that it is more effective to increase customers’ satisfaction, repurchase intention and positive WOM under the service recovery’s benefit congruency principle which implies that the service provider gives the utilitarian compensation in the utilitarian service and gives the hedonic compensation in the hedonic service. This empirical finding contributes to a new framework of service recovery which is beyond the justice theory in the academics, and an effective way to decide a service recovery strategy for different kinds of service providers who are in the environment that service industry become more and more important.
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LIU, ERH-CHEN, and 劉二榛. "Empirical Analysis on the Positive Correlation of Non-financial Information (Corporate Governance, Employee Compensation) and Enterprise Value." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/84233188241709262630.
Full textAbstract:
碩士國立中正大學
會計資訊與法律數位學習碩士在職專班
104
Abstract Previous studies evaluated the relevant enterprises, mostly limited to the scope of accounting information and the value of the stake is difficult to escape the stereotype of the financial statements information about the application, the lack of ability to explain the excess of surplus and non-financial information. In this study, through a combination of accounting information and to measure the operating performance of the market, the company's financial statements can not be covered by the control variables into the enterprise evaluation model to explore the company's ownership structure and corporate governance and compensation of employees and other factors at stake and Corporate Value sex. Equity evaluation model Ohlson (1995) proposed by the theory builds on the concepts of the remaining net profit, has implied cost of capital to meet the business requirements of investors, and this corporate governance system to ensure that the concept of equitable remuneration consistent fund providers, its focus on long-term enterprise value creation hypothesis seems the ultimate goal of corporate governance coincide. Therefore, this study adopted Ohlson (1995) equity evaluation model for 2007-2013 listed companies in Taiwan and OTC companies for the study, investigate and Enterprise Value message connotation stake of corporate governance and employee reward characteristics passed through binding financial and non-financial information in order to effectively explain the equity value of the business. First, this paper Directorate scale structure, the ratio of directors and supervisors, board size and ratio of three inside directors, whether and operating performance are relevant? Secondly, to explore the outside (independent) directors and management performance among the correlation? Further analysis organization legal, dual nature, the Board shares earnings stability and significant deviation from the standard of four poor;? then after operating performance as instrumental variable, once again analyze how corporate governance variables on the enterprise value of explanatory power Secondly, the Board of Directors and two dual nature significant level variables and how? and external (independent) directors and the board of directors of the enterprise value of the correlation? Employee compensation in the year 2008, China is not recognized as costs, earnings serious distortion, to solve the long-standing dispute, and with the international accounting standards convergence reasons, our country since January 1, 2008 implementation of Financial Accounting Standards No. 39 Communique " share based payment accounting treatment guidelines, "the communique since the implementation of the company's employees placement policies have a considerable impact. So investigate reward employees of the enterprise value of the correlation? Key words: evaluation, corporate governance, and the remaining net profit, Ohlson equity evaluation model, the dual nature
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Chiu, I.-hsin, and 邱逸欣. "Asymmetric sensitivity of CEO cash compensation to positive and negative stock returns-the moderate effect of Board Effectiveness." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/06514817309441562931.
Full textAbstract:
碩士國立成功大學
會計學系碩博士班
96
This paper examines the asymmetric sensitivity of CEO cash compensation to positive and negative stock returns. Moreover, this study also examine whether board effectiveness affects the aforementioned asymmetric sensitivity. In theory, efficient cash compensation contracts should be conservative, in the sense that cash compensation should be more sensitive to unrealized losses than to unrealized gains. Since returns include both unrealized gains and unrealized losses, we expect cash compensation to be less sensitive to stock returns when returns contain unrealized gains (good news) than when returns contain unrealized losses (bad news). Moreover, CEO cash compensation is expected to be more efficient when the board is more effective. That is, the sensitivity of CEO cash compensation to positive (negative) stock return will decrease (increase) when the board is more effective. Using data from ExecuComp from 2000 to 2005, I find that cash compensation is roughly triple as sensitive to negative stock returns as to positive stock returns, suggesting that cash compensation reacts asymmetrically to positive and negative stock returns. The evidence also indicates that the sensitivity of cash compensation to negative stock returns is larger for high effective board. However, I find no evidence that the sensitivity of cash compensation to positive stock returns is different between high effective and low effective boards.