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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Führt VIRTUAL-REALITY-Simulationstraining zur Stressreduktion bei angehenden interventionellen Kardiologen? : eine stratifiziert randomisierte Studie / Does training with virtual-reality-simulation reduce stress of interventional cardiologists?

Löbbert, Anne-Katrin January 2013 (has links) (PDF)
Die Simulationstechnologie in der Medizin hat in den letzten Jahren große Fortschritte gemacht. In der Zwischenzeit gibt es auch für Herzkatheteruntersuchungen und -interventionen „Virtual reality“ Simulatoren, die ein realistisches Training von Kathetereingriffen erlauben. Nicht geklärt ist bislang, ob Simulationstraining das Stressniveau des Untersuchers reduzieren kann. Im Rahmen dieser Studie wurde zur Beantwortung der genannten Fragestellung der Effekt von Virtual-Reality-Training auf das Stressniveau von Anfängern in der interventionellen Kardiologie untersucht. Hierzu wurde eine randomisiert-stratifizierte Studie bei 33 Anfängern in der interventionellen Kardiologie durchgeführt. Die Probanden wurden in eine Kontroll- und Simulationsgruppe aufgeteilt. Die Simulationsgruppe erhielt ein achtstündiges intensives Training an verschiedenen Simulatoren, während die Kontrollgruppe kein Simulationstraining, sondern lediglich eine theoretische Wissensvermittlung erhielt. Alle Teilnehmer mussten unter realitätsnahen Umständen im Herzkatheterlabor der Universitätsklinik Würzburg innerhalb von 30 Minuten eine PCI an einem pulsatilen Herzkreislaufmodell durchführen. Die Probanden dokumentierten vor und nach der Prä- und Postevaluation ihr aktuelles „Befinden“ anhand eines psychologi-schen Fragebogens PANAS. Ebenso wurden die Probanden hinsichtlich ihrer manuellen Fähigkeiten nach einem strukturierten Evaluationsbogen von einem interventionell tätigen Kardiologen bewertet Die Ergebnisse zeigten initial für die Parameter „aktiv, interessiert, freudig erregt, stark, angeregt, stolz, begeistert, wach, entschlossen und aufmerksam“ des Fragebogens PANAS keinen gruppenspezifischen Unterschied. Nach einem achtstündigen Simulationstraining gab die Simulationsgruppe eine signifikante Reduktion des Stressniveaus im Vergleich zur Kontrollgruppe an. Die aktuelle Studie zeigte, dass das Training an den Virtual Reality Simulatoren die herkömmliche Ausbildung in effektiver Weise ergänzen kann. Weitere Studien mit einer größeren und zugleich homogeneren Stichprobengröße sind nötig, um die genannten Hypothesen zu bestätigen. / In the following study the effect of virtual-reality-training has been analyzed in a randomised controlled trial at the university hospital of Würzburg. The study was performed using two simulation systems CATHI (Catheter Instruction System) and Immersion (CAE) in 33 participants, who have been beginners in interventional cardiology. 16 cardiologists were given 8 hours of intensive training at both simulation systems (=simulation-group). 17 participants represented the conventional education without receiving simulation-training (=control-group). All participants completed a pre- and post-evaluation with questionnaire PANAS (Positive and Negative Affect Schedule). In the beginning differences between the groups couldn´t be documented. After the virtual-reality-training the simulation group has shown a significantly positive affect (PA). The results prove that virtual-reality-simulation is a valuable tool to improve stress reduction in addition to the conventional education.
72

Implementing and studying the effects of a roll stability system in heavy vehicles using a moving simulator / Implementering samt undersökning av nyttoeffekter av ett rollstabiliseringssystem hos tunga fordon i en rörelsesimulator

Pettersson, Ulrika January 2010 (has links)
<p>This thesis presents the making and the implementation of a roll stability system for a simulator truck. The purpose of the system is to prevent rollover. The making of the system consists of three parts; calculating the roll angle, calculating a rollover index and constructing the control system. The roll angle was calculated using a one degree of freedom model of the truck with the measured lateral acceleration as input signal. Using the roll angle and the roll rate, a rollover index was calculated. The controller made the truck brake to avoid the impending rollover when the rollover index was at a critical point. The benefits of the system were measured by conducting a study in which test persons drove the simulator truck both with the stability system switched on and switched off. The scenario in the study was carefully constructed so that it would test the system thoroughly. The results were not unambiguous, in some situations the roll stability system prevented roll over, but in others it had the opposite effect.</p> / <p>I den här examensarbetesrapporten presenteras ett rollstabiliseringssystem för tunga fordon framtaget på VTIs (Statens väg- och transportforskningsinstitut) begäran. Systemet ska användas i VTIs simulator och det ska förhindra att fordonet välter. Utvecklingen av systemet kan delas in i tre större områden; beräkning av fordonets rollvinkel, framtagandet av ett rolloverindex samt skapandet av en regulator. Rollvinkeln är framtagen utifrån en lastbilsmodell med en frihestgrad, och skattades utifrån den mätta sidoaccelerationen. Rollhastigheten i sin tur skattades utifrån rollvinkeln. Ett rolloverindex som anger risken för vältning i varje ögonblick räknades fram med hjälp av rollvinkeln och rollhastigheten. Då indexet indikerar att vältning är nära aktiveras ett reglersystem. Detta system bromsar in lastbilen för att minska vältrisken. Examensarbetet avslutades med en studie utförd i simulatorn där försökspersoner körde både med och utan stabiliseringssytemet inkopplat. Scenariot i studien var speciellt utformat för att testa stabiliseringssystemet. Resultaten var inte entydiga, stabiliseringssystemet hjälpte i vissa situationer men i andra hade det motsatt effekt och fick lastbilen att välta snarare än att förhindra vältningen. Slutligen utvärderades nyttoeffekterna av det framtagna systemet.</p>
73

Simulators for formal languages, automata and theory of computation with focus on JFLAP

Fransson, Tobias January 2013 (has links)
This report discusses simulators in automata theory and which one should be best for use in laboratory assignments. Currently, the Formal Languages, Automata and Theory of Computation course (FABER) at Mälardalen University uses the JFLAP simulator for extra exercises. To see if any other simulators would be useful either along with JFLAP or standalone, tests were made with nine programs that are able to graphically simulate automata and formal languages. This thesis work started by making an overview of simulators currently available.After the reviews it has become clear to the author that JFLAP is the best choice for majority of cases. JFLAP is also the most popular simulator in automata theory courses worldwide.To support the use of JFLAP for the course a manual and course assignments are created to help the student to getting started with JFLAP. The assignments are expected to replace the current material in the FABER course and to help the uninitiated user to get more out of JFLAP.
74

Design and Development of a Dynamic Knee Injury Simulator

Cassidy, Karla January 2009 (has links)
The knee is one of the most complex joints in the body, relying entirely on ligaments and muscles for stabilization. With the rise in people participating in sports, including a significant increase in female athletes, the prevalence of anterior cruciate ligament (ACL) injuries is very evident. With recent research showing that ACL injuries lead to osteoarthritis 10-20 years after the injury, determining the cause of these injuries to be able to prevent them is crucial. To date, both in-vivo and in-vitro techniques have been used to analyze the influences of the ACL injury including neuromuscular, anatomical, and kinematic. In-vivo techniques used to investigate knee kinematics is limited by the inability to take real ACL strain measurements while in-vitro techniques used to investigate anatomical considerations is limited by the inability to apply true muscular and kinematic forces. The purpose of the present thesis is to show the design and validation of a dynamic knee injury simulator. The simulator puts a cadaver knee, original ligaments and patellar tendon still attached, through motions which put the ACL at a high-risk of injury with realistic influence of muscles. The muscular influences are applied with actuators pulling the same force pro les as natural muscles. To get realistic muscle pro files, Anybody Software is used. Anybody Software is a modeling software which puts a skeletal system through prescribed motions and using an optimization algorithm calculates the muscle force pro file. The motion of the knee in the sagittal plane is simulated with actuators. The simulator consists of four actuators which are used in force control mode to add the muscle influence to the knee. Another two belt actuators are used for the joint motions, one each for the hip and ankle. The hip will move along the resultant Z motion and the ankle will move along the resultant Y motion. Simple gait is used for initial validation, the actuators chosen have speed and force capabilities for high-risk motions. The gait was successfully simulated and muscle force versus time profi le tracked the input well. The regression coeffcient study shows very good comparison. The hamstring muscle group is the only one which does not show very good comparison however this is only due to the jumpy nature of the hamstring profi le. The ACL strain fell within a similar range to published gait ACL strain data. The validation was successful, and with greater available force and speeds in the actuators, showing the use of this simulator during high-risk motions is possible.
75

Design and Implementation of a User Friendly OpenModelica - Python interface

Ganeson, Anand January 2012 (has links)
How can Python users be empowered with the robust simulation, compilation and scripting abilities of a non-proprietary object-oriented, equation based modeling language such as Modelica? The immediate objective of this thesis work is to develop an application programming interface for the OpenModelica modeling and simulation environment that would bridge the gap between the two agile programming languages Python and Modelica. The Python interface to OpenModelica OMPython, is both a tool and a functional library that allows Python users to realize the full capabilities of Open- Modelica’s scripting and simulation environment requiring minimal setup actions. OMPython is designed to combine both simulation and model building. Thus domain experts (people writing the models) and computational engineers (people writing the solver code) can work on one unified tool that is industrially viable for optimization of Modelica models, while offering a flexible platform for algorithm development and research.
76

Design and Development of a Dynamic Knee Injury Simulator

Cassidy, Karla January 2009 (has links)
The knee is one of the most complex joints in the body, relying entirely on ligaments and muscles for stabilization. With the rise in people participating in sports, including a significant increase in female athletes, the prevalence of anterior cruciate ligament (ACL) injuries is very evident. With recent research showing that ACL injuries lead to osteoarthritis 10-20 years after the injury, determining the cause of these injuries to be able to prevent them is crucial. To date, both in-vivo and in-vitro techniques have been used to analyze the influences of the ACL injury including neuromuscular, anatomical, and kinematic. In-vivo techniques used to investigate knee kinematics is limited by the inability to take real ACL strain measurements while in-vitro techniques used to investigate anatomical considerations is limited by the inability to apply true muscular and kinematic forces. The purpose of the present thesis is to show the design and validation of a dynamic knee injury simulator. The simulator puts a cadaver knee, original ligaments and patellar tendon still attached, through motions which put the ACL at a high-risk of injury with realistic influence of muscles. The muscular influences are applied with actuators pulling the same force pro les as natural muscles. To get realistic muscle pro files, Anybody Software is used. Anybody Software is a modeling software which puts a skeletal system through prescribed motions and using an optimization algorithm calculates the muscle force pro file. The motion of the knee in the sagittal plane is simulated with actuators. The simulator consists of four actuators which are used in force control mode to add the muscle influence to the knee. Another two belt actuators are used for the joint motions, one each for the hip and ankle. The hip will move along the resultant Z motion and the ankle will move along the resultant Y motion. Simple gait is used for initial validation, the actuators chosen have speed and force capabilities for high-risk motions. The gait was successfully simulated and muscle force versus time profi le tracked the input well. The regression coeffcient study shows very good comparison. The hamstring muscle group is the only one which does not show very good comparison however this is only due to the jumpy nature of the hamstring profi le. The ACL strain fell within a similar range to published gait ACL strain data. The validation was successful, and with greater available force and speeds in the actuators, showing the use of this simulator during high-risk motions is possible.
77

Software Design of an Architecture Description Language Simulator

Luo, Ming 21 February 2011 (has links)
In system-on-chips, system architecture designs greatly affect cost, performance, and power consumption of the systems. In system design time, we thus need to perform system architecture exploration. In order to effectively support architecture exploration, we improve de-efficiency of current architecture description languages and produce new ways of architecture description, including multiple architecture pattern descriptions and generalized coding description. Together with existing architecture description methods, we form a generalized architecture description language. In this thesis research, in order to support verification of designs in the generalized architecture description language, we designed its simulator software. The simulator should support the descriptions of the architecture description language, including structural description, behavioral description, coding description, multiple architecture pattern descriptions, and hardware data structures. We implemented the simulator software in several software modules, including simulator engine, parser design, interpreter design, generalized decoder design, multiple architecture pattern descriptions, and hardware data structures. We thus can effectively support the verification capability of the architecture description language.
78

An advanced fuel cell simulator

Acharya, Prabha Ramchandra 01 November 2005 (has links)
Fuel cell power generation systems provide a clean alternative to the conventional fossil fuel based systems. Fuel cell systems have a high e&#64259;ciency and use easily available hydrocarbons like methane. Moreover, since the by-product is water, they have a very low environmental impact. The fuel cell system consists of several subsystems requiring a lot of e&#64256;ort from engineers in diverse areas. Fuel cell simulators can provide a convenient and economic alternative for testing the electrical subsystems such as converters and inverters. This thesis proposes a low-cost and an easy-to-use fuel cell simulator using a programmable DC supply along with a control module written in LabVIEW. This simulator reproduces the electrical characteristics of a 5kW solid oxide fuel cell (SOFC) stack under various operating conditions. The experimental results indicate that the proposed simulator closely matches the voltage-current characteristic of the SOFC system under varying load conditions. E&#64256;ects of non-electrical parameters like hydrogen &#64258;ow rate are also modeled and these parameters are taken as dynamic inputs from the user. The simulator is customizable through a graphical user interface and allows the user to model other types of fuel cells with the respective voltage-current data. The simulator provides an inexpensive and accurate representation of a solid oxide fuel cell under steady state and transient conditions and can replace an actual fuel cell during testing of power conditioning equipment.
79

None

Hsiao, Wan-chi 16 July 2008 (has links)
The purpose of this research is through building a System Dynamics model to show hospital operating structure as a whole and to find out the interactions between variables. And through the Management Flight Simulator to simulate three policy¡X¡§retrenchment personnel policy¡¨, ¡§retrenchment personnel policy and ¡§raising salary¡¨, ¡§abundant personnel policy¡¨¡X to find out the best manage policy. The case in this research is a Regional Teaching Hospital in southern Taiwan. The model is built according to the information which got by many times interview. The model has four sub-systems; they are ¡§market sub-system¡¨, ¡§human resource sub-system¡¨, ¡§equipment sub-system¡¨ and ¡§finance sub-system¡¨. After the simulation and the evaluation, we find that ¡§abundant personnel policy¡¨ can save more cost than ¡§retrenchment personnel policy¡¨. That is because ¡§abundant personnel policy¡¨ not only can save the physical cost like recruiting cost and training cost, but also can save the invisible cost like the experience of employee can¡¦t be accumulated. Besides, raising salary although can slacken off the decreasing employee satisfaction due to the overloading, but it is cure the symptoms, not the disease. In long-term, it will lead to the increasing cost, decreasing the competitiveness.
80

Use of an independent visual background to alleviate simulator sickness in the virtual environments that employ wide-field displays /

Duh, Been-Lirn. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 95-104).

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