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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.
121

Compensação dos movimentos fisiológicos do coração em cirurgia robótica

Dill, Rafaela Brittes January 2013 (has links)
Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.
122

Compensação dos movimentos fisiológicos do coração em cirurgia robótica

Dill, Rafaela Brittes January 2013 (has links)
Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.
123

Compensação dos movimentos fisiológicos do coração em cirurgia robótica

Dill, Rafaela Brittes January 2013 (has links)
Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.
124

La position "méta" dans la schizophrénie en situation de groupe thérapeutique / The meta position in schizophrenia therapeutic group situation

Prévoteau, Chady 25 January 2016 (has links)
Dans cette recherche en psychologie clinique et en psychopathologie, nous interrogeons la nature et les caractéristiques de la position « méta ». Nous étudions plus spécifiquement le phénomène d’auto-observation qui constitue la position « méta », mais aussi les mécanismes psychiques qui sous-tendent ce fonctionnement : l’introjection du regard de l’autre, l’identification d’une part de soi à un autre, une dissociation fonctionnelle (ou une dissociation non-pathologique du Moi), l’auto-observation (où une part de soi observe une autre part de soi), la réflexivité, un dialogue interne. Nous nous intéressons également à l’évolution de la position « méta » au sein d’un dispositif de psychodrame psychanalytique de groupe composé de patients psychotiques, au regard des interactions avec les membres du groupe. / In this research in clinical psychology and psychopathology, we question the nature and characteristics of the « meta » position. We study more specifically the phenomenon of self-observation, which is the position « meta », but also the psychological mechanisms that underlie this operation : introjection the eyes of others the identification of a part of oneself to another, a functional separation (or non-pathological dissociation of the self) , self-observation (where self-hand observed another part of oneself) , reflexivity, an internal dialogue. We are also interested in the evolution of the position "meta" in a psychoanalytic psychodrama device group of psychotic pateints, in terms of interactions with group members.
125

Bibehållen position av endotrakealtub i munhålan : en kvantitativ deskriptiv tvärsnittsstudie / Maintaining the position of the endotracheal tube in the mouth : a quantitative descriptive cross-sectional study

Assadzadeh, Kamran January 2013 (has links)
Bakgrund: På intensivvårdsavdelningar finns olika rutiner kring huruvida endotrakealtubens position hos intuberade skall skiftas eller bibehållas i samma mungipa, då sidbyten kan leda till allvarliga komplikationer. Rutinen vid CIVA har varit att byta endotrakealtubens position på alla intuberade patienter en gång per dygn. Varken rutinen med skifte samt bibehållen position har utvärderats. Syftet med studien är att undersöka oralt intuberade patienters munhälsa vid bibehållen position av endotrakealtub under vårdtiden. Metod: Studien är en kvantitativ deskriptiv tvärsnittsstudie. Ett protokoll utformades för att undersöka hur stor andel av patienterna som får tryckskador i munnen med bibehållen tublägesposition. Resultat: Av totalt 85 oralt intuberade patienter utvecklade 10 rodnad och 7 sår medan 68 hade helt intakt slemhinna. Flest nyupptäckta sår uppkom efter 3-4 dagars intubering medan rodnader var jämnt fördelat. Slutsats: Endast ett fåtal patienter utvecklade tryckskador. Rutinen att bibehålla endotrakealtuben i samma position lämpar sig på patientkategorin på CIVA eftersom medelvårdtiden för intuberade är 3,2 dagar och flertalet extuberas under de 3 första dagarna. Klinisk betydelse: Studien ligger till grund för CIVA:s ändrade rutin att bibehålla endotrakealtubspositionen i samma mungipa och skulle på sikt kunna bidra till att minska samhällskostnaderna genom att reducera förekomsten av VAP och därmed patientvårdtiden / Background: Intensive care units have different routines whether the endotracheal tube position should be shifted or maintained in the same corner of the mouth. Repositioning of the tube can lead to serious complications. The routine at CIVA has been to change the endotracheal tube position in all intubated patients once per day. None of the routines have been evaluated. The objective of this study is to examine the oral health of intubated patients with maintained tube position. Method: The study is a quantitative descriptive cross-sectional study. A protocol was designed to examine the proportion of patients receiving pressure sores in the mouth. Results: Of a total of 85 orally intubated patients, 10 developed redness and 7 wounds while 68 had intact mucosa. The majority of the newly discovered sores occurred after 3-4 days of intubation. Conclusion: Only a few patients developed pressure sores. The routine to maintain the endotracheal tube in the same position is suitable for the patient category at CIVA since the average length of stay for intubated is 3.2 days and the majority were extubated during the first 3 days . Clinical significance: This study is the basis for CIVA's changed routine to maintain the endotracheal tube position in the same corner of the mouth and could eventually help to reduce the costs for society by reducing the incidence of VAP and thus patient care period.
126

Positionsbestämning av en roterande axel i en vinkelgivare / Position determination of a rotating axis in an angle sensor

Frough, Bahman Jahan January 2017 (has links)
This thesis includes a study of a touch-free sensor systems and different principles for measuring a magnetic field. An in-depth study was conducted to describe two important principles in these contexts, i.e. Magnetoresistance principle and the Hall Effect principle. A market evaluation of different sensor chips developed on these principles was conducted. Furthermore, the study should be linked to existing principles to determine the position of a rotating axis. Function tests show that the performance requirement for each component was met. The results based on verification tests show that it is important to have a better mechanical connection between drive and device. Temperature tests show that the system meets the project specification at room temperature, but large angular deviations occur in temperature change, especially when driving with short steps. This thesis can be continued by reprogramming the source code and developing new software that can control more parameters and make it more accurate at positioning. Another recommendation would be to investigate and compare other sensor chips because there are several sensors that can apply to the system. Further improvements can be made by performing more tests on the system. / Examensarbetet innefattar en studie om beröringsfritt givarsystem och olika principer för att mäta ett magnetfält. En fördjupad litteraturstudie utfördes för att förklara två viktiga principer i dessa sammanhang d.v.s. magnetoresistiva principen och hallgivarprincipen. En marknadsutvärdering av olika sensor-chip som utvecklats enligt dessa principer genomfördes. Vidare ska studien kopplas till kända principer för att bestämma positionen för en roterande axel. Funktionstester visar att prestandakravet för varje komponent uppfylldes. Resultaten baserade på verifieringstester visar att det är viktigt att ha en bättre mekanisk koppling mellan drivdon och enhet. Temperaturtester visar att systemet uppfyller projektets kravspecifikation vid rumstemperaturen men det uppkommer stora vinkelavvikelser vid temperaturförändring framför allt vid körning med korta steg. Detta arbete kan fortsättas genom omprogrammering av källkoden och utveckling av ny programvara som kan styra fler parametrar och göra det mer exakt vid positionsbestämning. En annan rekommendation skulle vara att undersöka och jämföra andra sensorchip eftersom det finns flera sensorer som kan tillämpa i systemet. Ytterligare förbättringar kan göras genom att utföra fler tester på systemet.
127

Theory and performance of an X-band radio frequency phase-differencing position tracking system

Dutton, Kevin E. January 2003 (has links)
No description available.
128

Characterizing and Improving the Non-Collaborative and Collaborative Localization Problems

Thompson, Benton K. 21 September 2011 (has links)
This thesis focuses on the least-squares formulation of the non-collaborative and collabo- rative position location problems. For the non-collaborative problem, characterization encompassing the number of minima and the causes thereof is provided. Based on these efforts, we propose an improvement to the existing modified parallel projection method (MPPM), the reflected parallel projection method (RPPM). We show that the global minimum to the non-collaborative objective function can nearly always be found using the non-optimal reflected parallel projection method (RPPM). For the collaborative position location problem, we provide a characterization that shows a heavy tail of root-mean-square (RMS) error due to a small percentage of simulated node/anchor layouts when solved by the iterative parallel projection method (IPPM). We provide an identification technique that successfully identifies most layouts that show large RMS error followed by a proposed solution to improve the accuracy in those problematic layouts. Finally, we report the findings of a measurement campaign that validates our Gaussian model for line-of-sight (LOS) noise and shows that, for these particular measurements, non-line-of-sight (NLOS) noise is difficult to accurately model and can be very large. This research was supported by a Bradley Fellowship from Virginia Tech's Bradley Department of Electrical and Computer Engineering, made possible by an endowment from the Harry Lynde Bradley Foundation. / Master of Science
129

Smart Environment Based On Real-Time Human Position Tracking For Remote Presence And Collaboration

Bharambe, Sachin Vasant 19 July 2017 (has links)
Real-time, virtual and mixed reality systems have diverse uses for real-world data visualization, representation, and remote collaboration in distant learning settings, especially in universities. Design of such systems involves challenges in mapping the real world data and physical world structure accurately to digital form of physical space, also called as virtual models. Researchers have created similar systems using multiple cameras, stereo cameras, accelerometers, and motion detectors. This report presents a platform to detect and track real-time locations of people present in buildings and map their location information into virtual models as avatars using omni-directional cameras installed in the physical space. These models were created as part of the Mirror Worlds project. The project infrastructure is funded by National Science Foundation. This infrastructure enables users to connect virtual and physical aspects of the environment through a coordinate-based data networking system to enable interaction with the rest of the system including environment objects and other users. This is an interdisciplinary project where students from various departments have worked on the development of virtual model of the Moss Art Center and Torgersen Hall in Unity / X3D. Some students from the Department of Computer Science have developed a coordinate-based data networking system. The prototype of a detection and tracking algorithm to extract the location information was developed using background subtraction in MATLAB. The proposed approach was developed using the combination of background subtraction and neural networks along with heuristics based on spatial information about the physical space. The system was scaled to work across multiple buildings, extract the location information of people present in the physical space, and map location information into shared virtual space as an avatar. The concept of remote presence was extended to create a collaborative object manipulation application using Leap Motion controller. Effects of fidelity were evaluated to perform the collaborative object manipulation task in shared virtual space based on user study conducted for this application. Since no annotated people video dataset is publicly available with overhead view from omni-directional cameras, three videos were annotated manually to test the performance of the approach. The current approach almost works at near real-time rates. All three video sequences were evaluated to compute frame based detection accuracy. Precision and recall obtained for the first video sequence of people detection is 93.85% and 95.06% respectively. / Master of Science
130

Optimum positioning for anteroposterior pelvis radiography: A literature review

Alzyoud, K., Hogg, P., Snaith, Beverly, Flintham, K., England, A. 15 May 2018 (has links)
Yes / Pelvic radiography is used for the identification of hip joint changes, including pathologies such as osteoarthritis. Several studies have recommended that the position for this radiological procedure should be standing, not supine, to reflect the functional appearances of the hip joint. The aim of this review was to evaluate pelvis radiography positioning with respect to the image appearances and information provided for clinical decision-making. Aside from this, potential recommendations to the radiographic technique for an erect pelvis projection will be considered. Method: A literature search was performed using databases/ systems (ScienceDirect, Web of Science, PubMed, and MEDLINE). Only articles written in English were included. Results: Twenty-five articles were identified. Findings from the review describe the effect of repositioning from supine to erect on a series of specific hip measurements. These include pelvic tilt, joint space width, and the acetabular component. Conclusion: Evidence within the literature illustrates that in several studies, there were differences when repositioning from supine to standing for a number of pelvic metrics. Standing positioning is promoted by some authors since this may facilitate the early diagnosis of hip joint pathology and assist in the planning of surgical interventions. Literature is very limited on how to optimally perform erect pelvis radiography, and this should be an area for future research.

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