Les avions légers sont conçus pour être utilisés dans les zones reculées d'un pays, où les infrastructures de transport sont inadéquates ou inexistantes. Ils peuvent atterrir sur différents types de piste (glace, gravier, sable, gros cailloux...). Le problème principal de ces avions est le défaut d’absorption d’énergie cinétique à l’atterrissage, bien qu'une partie des énergies de choc soit absorbée par les pneumatiques sous-gonflés. Des chocs et des rebonds peuvent se produire mettant en péril la sécurité de l’avion et des passagers. Le but de ce travail est de développer un outil numérique qui permet de modéliser les trains d'atterrissage, de prévoir leur réponse dynamique dans des conditions extrêmes, et de comparer leur capacité à dissiper l’énergie à la rencontre des obstacles. Étant donné son rôle primordial dans l'absorption des chocs, une étude expérimentale est dédiée à la caractérisation du pneumatique de brousse. Cette étude permet de construire un modèle éléments finis détaillé du pneumatique en prenant en compte la géométrie et la structure matérielle complexe. Une deuxième partie est consacrée à la modélisation numérique de quatre systèmes de trains d'atterrissage (existants ou proposés). De nombreuses simulations de roulement sont réalisées afin d'étudier, d'une part l'influence des conditions de roulement et l'influence de la taille et de la forme de l'obstacle d'autre part. L'analyse des amplitudes des efforts et des rebonds transmis à l'avion au cours du roulement permet d'évaluer les réponses dynamiques des différents trains et de comparer leur efficacité de dissipation / Light aircraft, such as bush planes, are designed for use in undeveloped areas of a country where transport infrastructure is inadequate or non-existent. They can land on different types of runways (ice, gravel, sand, big stones ...). The main problem with these aircraft is the lack of kinetic energy absorption at landing, although some of the shock energy is absorbed by the underinflated tires. Hard landing conditions such as shocks and rebounds may occur and endanger the safety of the aircraft and passengers. The aim of this work is to develop an efficient numerical tool for studying landing gear systems, predict their dynamic response in extreme conditions, and compare their energy dissipation. Given its primary role in shock absorption, an experimental study is dedicated to the characterization of the bush tire. Then, a detailed finite element model of the tire is developed, taking into account real geometry and material specificities. A second part is devoted to the numerical modeling of the different systems of landing gears (existing and proposed). Combined finite elements with structural elements are used. Thus, stress, deformation and energy within landing gears components could be obtained. Multiple dynamic rolling simulations are carried out in order to study, not only the influence of the rolling conditions (such as rolling velocity, tires inflation pressure, etc.), but also the influence of the size and the shape of obstacles. Systems' transient responses while rolling over ramp are evaluated, as well as the efforts and rebound displacements transmitted to the aircraft. A dissipation efficiency comparative study between the landing gears is conducted

The project simulates the passage of a moving train on the railway when it is passing a level crossing. The project uses hardware and software to simulate the signals that the relays, which are connected to the track, get when a train is passing the level crossing. This simulation is to evaluate a new level crossing system that is called Alex and will be used in Sweden in the future. One set of relays and two Alex systems will be installed at the Swedish school of transportation (Trafikverksskolan) in Ängelholm at a simulated level crossing for testing and training purposes. The project also evaluates the reactions of the relays of any level crossing without running any real train on them.

This study explores the concept of improved train infrastructure in Sweden and how it affects the attractiveness of cities. The research uses a difference-in-differences model to determine whether the construction of the Bothnia Line in northern Sweden has had an impact on real estate prices in the municipalities Nordmaling and Robertsfors between 2008-2016. By employing the hedonic price model, the study finds evidence that house-specific factors such total house size in square meters, location near water and size of backyard all play a role in determining the final purchase price of houses in the two municipalities. However, the findings of this study do not indicate that the launch or the subsequent investments on the Bothnia Line has had any measurable impact on the real estate prices in the region. This is in line with previous research on the project.

No description available.

Background: The rate of overweight and obesity among adolescents aged 12-19 years has quadrupled since 1980. Reducing obesity is a key public health priority, as obesity is associated with individual and population-level health and economic consequences. Afterschool-based obesity prevention programs that aim to develop nutrition and culinary self-efficacy have shown promise. However, the level of aptitude among program instructors is directly correlated with student success, suggesting the importance of effective train-the-trainer (TTT) mechanisms for implementing and scaling up these strategies. Pink and Dude Chefs (PDC) is an afterschool nutrition education and culinary skills program for middle-school adolescents aged between 11-14 years. The PDC online TTT platform trains lay instructors on program content and preparation, lesson delivery, and classroom and kitchen safety. Trained instructors deliver PDC lessons on topics ranging from macronutrients and USDA MyPlate to knife skills and food preparation. The literature on online TTT models and instructor impact on student outcomes is limited and the PDC online training mechanism has not been evaluated. The current project sought to address these critical gaps with the aim of creating the most effective intervention model. Methods: This project was implemented in Santa Maria, Guadalupe, and New Cuyama, California from Fall 2015 to Spring 2016. Eleven instructors and 68 middle school students participated and comprehensive surveys were used to evaluate instructor and student outcomes. Results: Instructors’ performance on all three domains (food and kitchen safety, program knowledge, and overall knowledge) increased following training (45%, 63%, and 53%, respectively), all p≤0.01. Students outcomes (food and kitchen safety, nutrition knowledge, and overall knowledge) also improved following participation (14%, 33%, and 23%, respectively), all p≤0.001. Impact analyses revealed that students with instructors who scored high in overall knowledge performed better than students with low-scoring instructors (p=0.01). Conclusion: If obesity prevention programs that incorporate online TTT mechanisms, such as PDC, continue to show promising outcomes for both instructors and adolescents, larger scale efforts may contribute to decreasing the public health and economic burdens associated with obesity.

The purpose of this thesis is to evaluate a new paediatric trauma victim bank for the simulation tool Emergo Train System® (ETS). The area of child trauma care is rather small and there is limited knowledge about potential emergency events. The emergency care for children should not be considering the same as for adults. Relevant personnel should, therefore, be to able train and prepare for potential crisis. Hence, a suitable victim bank within ETS exercises is needed. In order to develop a suitable victim bank, this thesis have tested and evaluated a new paediatric trauma victim bank. The test was conducted through an ETS exercise with a subsequent evaluation questionnaire. With the help of the exercise the paediatric victim bank was evaluated. The result of exercise was compiled through mean and standard deviation of the questions within the questionnaire and potential correlation between the questions. The result showed that the participants thought that knowledge and information they gained during the exercise would help them in further real-life situations and that the victim trauma bank were relevant for training paediatric trauma care personnel. The results also showed further recommendations that could improve the validation process of ETS exercises.

Med 6000 resenärer per dag är spånga en av Sveriges större stationer. Stationen genomgick sin senaste ombyggnad 2004 där endast halva stationen byggdes om. Resultatet blev att stationen idag består av två delar från två olika årtionden. Detta har medfört problem i såväl stationens arkitektoniska utformning som i dess planlösning i kombination med resenärers rörelsemönster. Den befintliga planlösningen orsakar köbildningar samt trängsel vid rusningstrafik i flera delar av stationen. Det är placeringen av trapporna som orsakar trängsel och försvårar orienteringen i byggnaden. I projektet utfördes en undersökning som visade att de största problemen uppstår vid rusningstrafik 06:00-08:00 för avresande till Stockholms centralstation och 16:00-18:00 för ankommande från Stockholm centralstation. Utefter detta blev syftet till projektet att skapa en planlösning som bidrog med bättre komfort för ankommande och avresande. Stationen skulle dessutom utformas så att den blev mer välkomnande för besökande och förbipasserande. Arbetet grundar sig på att besvara frågeställningen: Går det att utföra en ombyggnad som eliminerar de mest framstående problemområdena? Den största begränsningen i detta projekt var perrongens förutbestämda bredd. Arbetet är även avgränsat till den arkitektoniska aspekten av ombyggnaden. Utefter detta byggdes målet att, genom undersökningar av Spånga station, skapa en planlösning som bidrar till bättre funktion än idag. Dessutom skulle den utvändiga utformningen ge en estetiskt sammanhållen byggnad. För detta projekt användes AutoCAD för skissprocessen och Revit Architecture 2015 för att färdigställa förslagshandlingarna. Resultatet blev en byggnad med stora glaspartier som möjliggör ett bra dagsljusinsläpp samt en större planlösning med två utbyggnader i form av vänthallar. I den nya planlösningen kunde nästan alla problemområden elimineras. Då perrongens bredd visade sig vara en större avgränsning är trott behövdes en del behandlingar av problemområden uteslutas. De nya utbyggnaderna har lett till att stationen har fått en mera enhetlig utformning då trappuppgången intill kopplats till den befintliga byggnaden. Nu har stationen också fått en mer helhetsbild då de stora glaspartierna vandrar kring byggnaden och binder ihop alla delar. Det stora glaspartiet bidrar också till mer öppenhet mot resenärer och förbipasserande. / With an entirety of 6000 travelers per day Spånga station is one the most frequented stations. The commuter station underwent its latest reconstruction 2004 where only half the station was rebuilt. The adjustments made where not thorough, subsequently dividing the station into two parts from different time periods. This has caused problems with the station floor plans and architectural design. The current floor plans encourage queues and congestion at rush hour in several parts of the station. The cause for this is the placement of the stairs since their location results in the orientation of the building. The project conducted a study which revealed that the main problems arise during rush hour, which is 06: 00-08: 00 for departures to Stockholm Central Station and 16:00-18:00 for arrivals from Stockholm Central Station. The purpose of the project was to create floor plans that provided a more flexible flow pattern for all passengers. The stations exterior design would be formed more welcoming for the travelers. The project is based on answering the question: Is it possible to perform a reconstruction that eliminates the most prominent problems? The station would also be designed so that it became more welcoming to visitors and passersby. The main limitations of this project were the platform predetermined width. The work was also limited to the architectural restrictions of the reconstruction. The aim is to contribute floor plans that provide better arrangements by studies made during the project. Furthermore, the exterior design is meant provide an aesthetically cohesive building. AutoCAD was used to obtain primary drawings and Revit Architecture 2015 to finalize the draft documents. The station's exterior shape is linked together with a glass section that delivers more sunlight into the station. The station has been expanded with two larger waiting rooms providing a more spacious feeling. Draft documents show that the new floorplan has eliminated practically all the problem areas. All the faults with the station could not be abolished for various reasons but mainly due to the restrictions placed by the platforms size. The concept drawings for the new station show that there is a more distinct connection through the stations exterior. The glass section extends around the entire building which creates a link to the remaining parts of the station whilst providing an agreeable view for by-passers and travelers

The purpose of the project is to investigate the difference in performance between ballasted and ballastless railway bridges dedicated to high speed trains by taking into account both static and dynamic requirements. The main questions are: a) whether choosing a ballastless bridge results in a more slender section due to the lower self-weight b) if the design of bridges for high speed trains is governed by the static or by the dynamic requirements. The method followed was to first make a complete static design of a ballasted and a ballastless bridge, and then subject them to a 2D dynamic analyses in order to see if the cross section dimensions must be changed. Some of the bridges required a more thorough dynamic analyses, and for these, a 3D model was developed. The analysed bridge is a simply supported beam with a T section carrying one track. Some variations were also considered, namely a simply supported bridge with a double T section carrying two tracks, as well as a single track bridge in two spans. It was found that all of the analysed bridges are somewhat more slender for the ballastless alternative, and require a 10 -30% less reinforcement. Simply supported bridges carrying one track are governed by the dynamic requirements; the bridges in two spans are for shorter spans governed by the statics and for longer spans by the dynamics. Bridges in double T fulfilled all the requirements according to the 2D analyses, but were found to be greatly affected by the 3 dimensional effects and failed to satisfy the criteria when these were taken into account. Finally, the optimal design according to these analyses is a ballastless bridge in a simple T section. If the bridge constructed should carry two tracks, then it should be constructed as two T beams that are not connected to one another in order to avoid the unfavourable 3D effects.

The main control task in many speed-controlled drives is to eliminate or reduce the load speed error caused by the load torque disturbance and reduce oscillations as quickly as possible. This thesis addresses different aspects of identification and control of such resonant elastic systems. In most industrial applications it is not practical to measure the load speed. Instead, we advocate model based control design that optimizes load speed while using motor speed as the feedback signal. For this to be possible one needs a mechanical model of the system and we suggest finding the mechanical parameters by estimation from experimental data. Hence a method has been developed which finds the mechanical parameters, including backlash, through a series of three dedicated experiments. At first this procedure is developed for the situation of one manipulated input, the motor torque, and one measured output, the motor speed. For drive systems with a very large motor in comparison to the load, it becomes very difficult to estimate all mechanical parameters from motor speed measurements only. An alternative estimation method has been developed for this purpose, using an additional sensor for the shaft torque. One more rather specific control problem is treated in the thesis, namely for drive systems with tandem coupled motors, where control structures have been developed with and without an extra sensor for shaft torque. / QC 20101221

Since the population growth of Stockholm Region is rapid, leading to larger demand on Public Transport and especially metro, four Municipalities of the Region have agreed on the expansion of the metro network. Blue metro line will be extended to Nacka and Hagsatra in the south and Barkarby in the north of the Swedish capital. The new railway line connections have been already planned, while the operation of the expanded line is analyzed in the current thesis. Taking the expected increase of passenger volumes and the operation of the current Blue line into account and following the safety restrictions, two alternative regular timetables of the expanded Blue line, limited to the morning rush service on a working weekday, have been constructed. The operation at stations of low expected passenger volume on the train is evaluated concerning the satisfaction of the operator. The rst alternative metro operation with trac every 4 minutes during the rush hour is concluded to be less ecient than the second alternative with 5 minutes headway, as 21 % larger amount of rolling stock is needed and more seats are not occupied. Finally, in order to achieve higher operational eciency at the low-demanded stations, a third Blue line operation, that is based on the second alternative and it includes short services, operating on a part of the line and not on the full-length of it, has been proposed. Although the number of trains needed for the morning peak hour operation remains constant between the second and third alternative operations, the proportion of empty seats at the analyzed stations is expected to be lower during the last alternative operation, resulting in a metro line scheduling that satises the operator most.