Symptoms after surgery and anaesthesia influence the patient´s ability to resume daily activities. If postoperative symptoms are controlled rehabilitation may be accelerated. The aims of this dissertation were to identify disturbing symptoms reported by patients after gynaecological surgery, to investigate what effect prohylactic treatment with antiemetics has on these symptoms and whether or not sensory simulation of the P6-acupressure has an effect on postoperative nausea and vomiting (PONV) and motion sickness. Methods: Total 1138 women participated in three clinical trials (Studies I, II, III) and one experimental study (Study IV). A questionnaire investigating postoperative symptoms was constructed and validated. The questionnaire was used in a prospective, consecutive, doubleblind, randomised, multicentre, and controlled study to identify incidence, and intensity of postoperative symptoms and the effect of common antiemetics (droperidol and granisetron) (Study III). The patients were followed for 24 h. In two studies (I, II) P6-acupressure was compared (prospective, double-blind, ransomised, controlled) with placebo acupressure and a reference group where the effect on PONV was followed over 24 h. The effect of P6-acupressure and placebo acupressure on motion sickness induced by a nauseogenic motion challenge was studied (Study III). Results: A high incidence and severity of postoperative symptoms were found after gynaecological surgery in a group with a high risk (>30%) for PONV. Sixty-four per cent (107/165) of the patients experienced disturbing symptoms after surgery and 46 % (76/165) scored their symptoms as moderate to very severe. Fourty-eight per cent (79/165) had two or more symptoms. A higher incidence of symptoms were reported in the groups with prophylactic treatment, granisetron 74% (123/165) and droperidol 80% (133/165) compared to the control group 41% (69/165) (P <0.05). The relative risk reduction for PONV with granisetron or droperidol prophylaxis is 27% respective 22%. The relative risk increase for headache is 63% after granisetron, and 44% for difficulty with accommodation after droperidol. Less PONV was seen after P6-acupressure, 33% (44/135) compared to reference group 46% (63/136) (p = 0.019), number needed to treat (NNT) was 7 [95% confidence interval (CI) 4- 6]. When comparing laparoscopic and vaginal surgery (subgroup analysis) the main effect was in the vaginal group (day-case surgery), 36% (27/75) in the reference group to 27% (23/86) in the placebo group and to 20% (17/84) in the P6-acupressure group, (P = 0.017), NNT for the vaginal group was 6 [95% CI 3-18]. P6-acupressure increased time to nausea after a laboratory motion challenge and reduced the total number of symptoms reported (p <0.009). Conclusions: There is no clinical efficacy in the form of reduced postoperative symptoms after prophylactic antiemetics (droperidol and granisetron) in females with a high risk (>30%) for PONV undergoing gynaecological surgery. P6-acupressure reduces the incidence of PONV after gynaecological surgery in females with a high (>30%) risk for PONV. The effect seems to be most prominent after vaginal surgery. P6-acupressure increased tolerance to experimental nausogenic stimuli and reduced the total number of symptoms reported in females with a history of motion sickness. / On the day of the public defence the status of article IV was: Submitted.

Dans ce travail nous nous intéressons aux comportement de vagues soumises à l’action d’une pression atmosphérique non constante, un fond mobile et la force de Coriolis. Une première partie est dédiée à l’étude de la résonance de Proudman. Nous proposons une approche mathématique rigoureuse pour étudier ce phénomène. Nous commençons par démontrer un résultat d’existence locale dans un cadre irrotationnel sur les équations des vagues (appelées aussi formulation de Zakharov/Craig-Sulem). Puis, nous justifions différents modèles asymptotiques pour généraliser cette résonance dans diverses situations physiques. Nous proposons en particulier une étude détaillée dans des eaux profondes dans un régime linéaire. Nous étudions aussi la propagation de vagues dans des eaux profondes dans un régime faiblement non-linéaire grâce aux équations de Saut-Xu et nous proposons un schéma numérique pour résoudre ces équations. Dans une deuxième partie, nous étudions l’effet de la force de Coriolis sur les vagues. Nous démontrons un résultat d’existence locale sur les équations Castro-Lannes, équations qui généralisent la formulation de Zakharov/Craig-Sulem dans un cadre rotationnel. Nous justifions ensuite différents modèles asymptotiques dans des eaux peu profondes en présence de la force de Coriolis. En particulier, nous proposons une généralisation des équations de Boussinesq (modèle asymptotique dans un régime faiblement linéaire) lorsque la force de Coriolis n’est pas négligeable. Ces équations nous permettent ensuite de justifier mathématiquement les ondes de Poincaré puis l’équation d’Ostrovsky qui généralise l’équation de Korteweg-De-Vries en présence de la force de Coriolis. / In this work, we are interested in the evolution of water waves under the influence of a non constant atmospheric pressure, a moving bottom and a Coriolis forcing. In a first part, we study the Proudman resonance. We propose a mathematical approach to understand this phenomenon. First, we prove a local wellposedness result in a irrotational framework on the water waves equations (also called the Zakharov/Craig-Sulem formulation). Then, we fully justify different asymptotic models. In particular, we carefully study the Proudman resonance in deep water in the linear regime. Finally, we study the propagation of water waves in a weakly nonlinear regime thanks to the Saut-Xu equations and we propose a numerical scheme in order to solve these equations. In a second part, we study the influence of a Coriolis forcing on water waves. We prove a local wellposedness result on the Castro-Lannes equations, which generalize the Zakharov/Craig-Sulem formulation in the rotational framework. Then, we fully justify different asymptotic models when we take into account a Coriolis forcing. In particular, we generalize the Boussinesq equations (asymptotic model in a weakly nonlinear regime) in this setting. Thanks to these equations, we justify the Poincaré waves and then the Ostrovsky equation, which generalize the Korteweg-De- Vries equation when a Coriolis forcing is taking into account.

The aim of this thesis has been to provide the reader with an intuitive insight into the mechanisms of the Coriolis effect. Apart from thoroughly describing the phenomenon, the essay attempts to eliminate as many myths prevailing around the Coriolis effect as possible. To get there, only a few mathematical derivations and calculations have been presented – the focus has been on a pure conceptual level. Furthermore, delusive textbook explanations have been examined and discussed in case studies. In the conclusion, the goal is reached by summarising the sought intuitive description of the Coriolis effect into one single sentence.

No description available.

ABSTRACT IMPLEMENTATION OF NORTHFINDING TECHNIQUES Oguz, Pinar MS, Department of Electrical and Electronics Engineering Supervisor: Assoc. Prof. Dr. T.Engin Tuncer June 2006, 131 pages The fundamental problem of navigation is to find the initial north angle of the body with respect to the reference frame. Determination of the north angle of the body frame is required in spacecraft, aircraft, sea-craft, land-craft and missile control and guidance. This thesis discusses implementation and comparison of four northfinding techniques. These are GPS (Global Positioning System) based with integer search, GPS based with Kalman filter, accelerometer based and IMU (Inertial Measurement Unit) based techniques. The north angle is determined by the processing of difference measurements of the GPS carrier phase between two antennas at GPS based northfinding techniques. Carrier phase ambiguity resolution is the main problem in GPS based techniques. Since, GPS receiver measures only the fractional part of the carrier phase. Therefore, integer part remains unknown. Two distinct ideas are applied to solve carrier phase ambiguities in two techniques. One of them is integer search on single phase difference. Suitable integer sets are checked on the cost function which is constructed from the single phase difference between two antennas. The other technique uses integer estimator and attitude estimator with Kalman filter rely on double difference phase measurements which are obtained from carrier phase differences of two antennas and two satellites at one instant. To test the GPS based techniques, a realistic GPS emulator is implemented. GPS emulator provides typical GPS raw navigation data including satellite positions, pseudoranges and carrier phases. Accelerometer based northfinding technique is composed of a vertically placed linear accelerometer on a rotating platform. The north angle is found by Coriolis acceleration due to Earth and platform rotation. Implementation problems of this technique in practice are discussed. IMU based northfinding technique has inertial sensor components such as gyroscopes and accelerometers to sense the Earth rotation rate and gravitational force respectively. The north angle is found by the processing of these inertial sensors output. Real set-up is established to test the IMU based technique.

Detta projekt syftar till att undersöka om det går att kurskorrigera en av Weda AB:s poolrengöringsrobotar med hjälp av ett MEMS-gyroskop. Den valda rengöringsroboten styrs idag av en PLC, och konceptet är att komplettera styrenheten med ett MEMS gyroskop som kan detektera kursavvikelser. Undersökandet av möjligheterna för implementeringen börjar med att samla information om MEMS gyroskopens funktion och i vilka tekniker de används idag. Vidare utförs beräkningar mot Wedas definition av rak kurs, det resulterade i för höga krav på känsligheten i gyroskopet. Trots det otillfredsställande resultatet beslutar Weda att projektet ska fortsätta undersöka gyroskopets möjligheter. En marknadsundersöknings med 9 tillverkningsföretag genomförs i syfte att se vad marknaden erbjuder för MEMS gyroskop idag. Sedan konsulteras distribueringsföretaget Avnet som bidrar med sina kunskaper, erfarenheter och rekommendationer för konceptet. Ett av de framstående gyroskopen i undersökningen användes för att genomföra två tester. Syftet av dem var att simulera olika situationer som rengöringsroboten kan utsättas för. Resultatet visar att repetitionsnoggrannheten är god men att gyroskopet inte är tillförlitligt i låga hastigheter, vilket är en dålig egenskap för rengöringsroboten W2000 som körs med en hastighet 0,2 m/s. Testresultatet diskuterades med Bosch och dem tror att gyroskopets automatiska kalibrering är orsaken till att det inte ger tillförlitliga mätdata vid låga hastigheter. / During this project the possibilities to monitor and adjust the direction of a pool cleaning robot with a MEMS gyroscope are evaluated. The robot chosen for the evaluation is manufactured by Weda AB. The concept is to add a MEMS gyroscope to the robot, which will give the control unit (PLC) feedback regarding the direction of the robot. The evaluation includes general information about MEMS gyroscopes, where they are used, common built in errors etc. To be able to select a suitable MEMS gyroscope the needed sensitivity is calculated. The needed sensitivity is based on requirements from Weda AB. The evaluation also includes a market survey which shows that the needed sensitivity cannot be fulfilled by products available on the market. The market survey is based on nine manufacturing companies and a recommendation from a distribution company called Avnet. One of the prominent MEMS gyroscopes was used to carry out two tests. The tests were designed to mimic motions of the pool cleaning robot. The test result shows that the gyroscope has good repetition accuracy, but it is not trustworthy when the rotation speed is low. The test result was discussed with the manufacturer and they think that the non positive result is caused by the automatic calibration.