Aircraft control mechanisms, such as those that operate the flaps, ailerons, rudders, etc., are almost exclusively driven by hydraulic-based systems. Their popularity in flight control systems is not unfounded; hydraulic actuators are quite torque-dense and benefit from decades of development bringing operating performance to a high level. On the other hand the infrastructure to support this system increases weight, adds system development complexity, and reduces aircraft maintainability [Jensen et al, 2000]. Based on recent Electro-Mechanical Actuator (EMA) development and design efforts at the Robotics Research Group (RRG), a new opportunity exists to replace current hydraulic flight control systems with those powered by electricity through a national program [Tesar, 2005]. A literature review of the topic found a 30 year old effort by AiResearch to develop a similarly powered hingeline actuator with given traditional performance goals (torque capacity, redundancy, output speed, reliability). In this report,a thorough analysis is performed on each major component group to quantitatively evaluate this baseline device. Using component technologies developed at RRG, this report proposes a dual torque-summing electromechanical actuator, each with a star compound / hypocyclic combined gear train, designed to exceed the performance of the original (1976) AiResearch project. This preliminary design exercise includes a layout of the entire actuator along with an appropriate analysis of major components including bearings, gear train, motor, housing, and release mechanism. The performance of this gear train is critical to overall actuator success and fundamental analytics have already been developed in this area [Park and Tesar, 2005]. Finite Element Analysis on the gear train and housing provide early design feedback and verification of actuator performance characteristics. In particular, simulation results show the gear stiffness, load sharing, and torque capacities exceed analytical estimates. Finally, four different comparisons are presented that evaluate configuration variations of the two designs based on applicable performance criteria. Results show the RRG fault-tolerant actuator has a marked improvement over the baseline in average stiffness (14.2x), reflected inertia (3.2x) and nominal torque density (3.4x). The chapter next lists actuator test methods and aircraft qualification standards. Finally, a summary of future work is detailed in a ten step outline to bring this EMA technology to a level of early deployment in a large range of aircraft systems.

High speed trains are very popular in Europe. In Sweden there has been a long political debate about the necessity of them. In 2008 there was a strong political no to the idea. However after some years of debate the government decided to build a new high speed railway between Järna (south of Stockholm) and Linköping, called “Ostlänken”. This study is about the decision-making process of an investment of 35 billion SEK involving a new railway during 2017 up to 2028. This study includes interviews with prominent politicians from different parties. The first issue concerns what arguments were used to promote the new railway, and how the local and regional politicians work to agree on a common stand point. Special interest is focused on the Right party (Moderaterna), who lead the coalition that governed Sweden from 2006 to 2014. In sum, four main issues were in focus. One conclusion is that a lack of railway-capacity between Stockholm and Linköping is important for the decision. Another issue is that “arbetslinjen” played an important role. The political interest in investments in infrastructure has raised sharply which also is positive for “Ostlänken”. A fourth issue is that globalization requires better connections to big airports.

Målet med det här arbetet var att skapa en konceptuell designprototyp för en scenarioeditor åt en digital version av utbildningsverktyget Emergo Train System. Rapporten ämnar ta upp och presentera den arbetsprocess som lett fram till designprototypen och dess utvärdering. I rapporten tillkommer även en diskussion kring hur en scenarioeditor bör utformas för att stödja skapandet av ETS-scenarion samt hur ett flexibelt arbetssätt stöds i form av skapandet av scenariorepresentationer. Intervjuer genomfördes med instruktörer och systemansvarige för ETS, samt observationer av iordningställande av ett ETS-scenario. Datainsamlingen analyserades och resulterade i en kravspecifikation för den digitala scenarioeditorn. Den prototyp som utformades gjordes så i pappersformat och utvärderades tillsammans med personal från Katastrofmedicinskt centrum i Linköping.

In many studies efforts are made to decrease the energy consumption of trains by optimizing their drive style, e.g. accelerate and brake optimally and regenerate electricity when braking. In other studies the goal is to distribute the run time between stations in an optimal way to decrease the energy consumption, given a relatively simple drive style. In this report the goal is to combine these two energy saving methods to obtain as low energy consumption as possible. By coupling one software containing a drive style optimizer with another software which by different optimization methods calculates the optimal run time distribution on a given track this is accomplished. The study also contains a comparison between drive styles, with the goal to find a relatively simple but energy efficient drive style. Finally the dependence between run time distribution and energy consumption is further analysed. The results show that by redistributing the run times the energy consumption can be decreased compared to previously existing time tables. They also show that a relatively simple drive style gives comparable energy consumption compared to the one obtained using a drive style optimizer. Finally the results show that the dependence between run time and energy consumption can be approximated with a simple second order equation.

The research presented in this thesis is aimed at developing a limit state design methodology for railway track for recommendation to Standards Australia's next revision of the 'Permanent way materials: prestressed concrete sleepers' code (AS1085.14, 2003). There is widespread suspicion that the railway track, particularly concrete sleepers, have untapped reserves of strength that has potential engineering and economic advantages for track owners. Through quantifying the effects of train speed, wheel impact loadings and distribution of vehicle loads, track engineers would be able to design railway track more accurately and hence uncover the reserves of strengths in railway track. To achieve this improvement a comprehensive set of wheel/rail impact measurements has been collected over a one year period to establish a distribution of track loadings. The wheel/rail impact data collected showed a logarithmically linear distribution which shows that impact forces are randomly occurring events. The linearity of the data also allows for wheel/rail impact forces to be forecasted allowing for a more rational risk based design of the railway track. To help with an investigation of the influence of changes to train operation on the wheel/rail impact force distributions, development of a new dynamic track computer model capable of simulating the complex interaction between the train and track was completed within this research. The model known as DTRACK (Dynamic analysis of rail TRACK) was benchmarked against other dynamic models and field data to validate its outputs. The field measurements and DTRACK simulations became the basis for development of a limit state design methodology for railway track (risk based approach) for railway track in place of an allowable limit state (compliance based) approach. This new approach will allow track owners to assess the track capacity based on more realistic loads and is expected to allow an increase in the capacity of existing track infrastructure which will allow railways to be more commercially competitive and viable.

Thesis (M.A.)--Bowling Green State University, 2005. / Document formatted into pages; contains [vii], 105 p. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin, Madison, 1921.

In this thesis we describe how to estimate the distance spanned in the pants graph by a train track splitting sequence on a surface, up to multiplicative and additive constants. If some moderate assumptions on a splitting sequence are satisfied, each vertex set of a train track in it will represent a vertex of a graph which is naturally quasi-isometric to the pants graph; moreover the splitting sequence gives an edge-path in this graph so, more precisely, our distance estimate holds between the extreme points of this path. The present distance estimate is inspired by a result of Masur, Mosher and Schleimer for distances in the marking graph. However, we can apply their line of proof only after some manipulation of the splitting sequence: a rearrangement, changing the order the elementary moves are performed in, so that the ones producing Dehn twists are brought together; and then an untwisting, which suppresses the majority of these latter moves to give a new sequence, which does not end with the same track as before, but does not include any portion that is almost stationary in the pants graph. The required distance is then, up to constants, the number of splits occurring in the untwisted sequence. A consequence of our main theorem together with a result of Brock is that, given a pseudo-Anosov self-diffeomorphism ψ of a surface S, the maximal splitting sequence introduced by Agol gives us an estimate for the hyperbolic volume of the mapping torus built from S and ψ. There are also some interesting consequences for the hyperbolic volume of a solid torus minus a closed braid, via a machinery employed by Dynnikov and Wiest.

Aim The aim of this study was to establish a method to create a difference between groups in muscle glycogen content as well as to investigate the effect of training in low muscle glycogen state on metabolic and physiological parameters. Method During two trials, a subject group of ten highly trained male road or mountain bike cyclists ((mean±SD) age, hight, body weight, VO2max, and VO2max·kg-1 was 28±5 years, 74.7±6.3 kg, 183±6 cm, 4876±332 mL min-1, 64.4±2.8 mL·kg-1 min-1), performed a glycogen depletion exercise followed by a night’s rest and a second exercise session. In the study, which was a crossover design, the subjects were randomly chosen to perform the first trial on a carbohydrate rich diet or a diet with no of carbohydrates. All the testing was performed on a Monark 839E ergometer bike and muscle biopsy sampling was collected before depletion exercise, before the exercise the following day and three hours post exercise. Plasma FFA and glucose was analyzed from venous blood collected at rest. Results Muscle glycogen pre depletion exercise was 623±180 and 645±133 mmol·kg dw-1 glycosyl units for non-CHO and CHO trials respectively. The depletion exercise followed by 13 hours of rest resulted in a significant decrease in muscle glycogen in the non-CHO (p<0.0001), and CHO trials (p<0.01) to 166±71 and 478±111 mmol·kg dw-1 respectively. In the non-CHO trial net glycogen depletion correlated positively with pre depletion glycogen storage.  After the completion of exercise 2 and the following three hour rest period, glycogen content in non-CHO and CHO-trial was 130±52 and477±97 mmol·kg dw-1, respectively. In low glycogen state, the non-CHO trial resulted in an increase in FFA measured in blood plasma at rest and in an increase in Borg rating of perceived exertion (RPE) as well as a reduction in blood glucose during exercise.  Conclusion The protocol used in the present study was successful in creating a difference in muscle glycogen storage and training in low glycogen state was associated with an increase of several physiological parameters indicating a possible impairment of endurance exercise performance. / Syfte Syftet med denna studie var att skapa en metod för att åstadkomma skillnader i muskelglykogen samt observera den akuta effekten av träning med låga muskelglykogennivåer på metabola och fysiologiska parametrar. Metod Vid två tillfällen fick tio vältränade mountainbike- eller landsvägscyklister ((medel±SD) ålder, längd, kroppsvikt, VO2max och VO2max·kg-1 var 28±5 years, 74,7±6,3 kg, 183±6 cm, 4876±332 mL min-1, 64,4±2,8 mL·kg min-1) genomföra ett träningspass i syfte att tömma muskelglykogendepåerna följt av en natts vila och sedan ett andra träningspass. Studien följde ett randomiserat crossover-upplägg och det ena försökstillfället genomfördes med en diet hög på kolhydrater och det andra tillfället med en diet utan kolhydrater (CHO). All testning genomfördes på en Monark 839E ergometer och muskelbiopsier togs före tömningspass, efter en natts vila före det andra träningspasset och tre timmar efter det andra träningspasset. Venösa blodprov togs i vila före biopsitagning för analys av plasma FFA och glukos. Resultat Koncentrationen av muskelglykogen före tömningspasset var 623±180 and 645±133 mmol·kg dw-1 vid försök utan respektive med CHO. Tömningspasset och 13  timmars vila resulterade i en signifikant minskning av muskelglykogen vid försök utan CHO (p<0.0001), och med CHO (p<0.01) till 166±71 och 478±111 mmol·kg dw-1. Nettominskningen av muskelglykogen vid tömningspasset utan CHO korrelerade positivt med glykogenkoncentration före tömning Efter genomförande av det andra träningspasset och tre timmars efterföljande vila var muskelglykogenmängden vid försöken utan CHO och med CHO 130±52 och477±97 mmol·kg dw-1. Vid träning med lågt muskelglykogen fanns det en kraftig ökning av fria fettsyror i blod vid vila och under arbete noterades en ökning skattning av Borg subjektivt skattad ansträngning (RPE) samt en sänkning av blodglukos. Slutsats Protokollet som användes i denna studie skapade framgångsrikt en minskning av muskelglykogen och träning med låga glykogennivåer kunde sammankopplas med flera fysiologiska parametrar som indikerar en möjlig sänkning av prestationsförmåga under uthållighetsarbete.

In this study a closed-loop cruise controller to minimise the running costs of the heavy-haul train is proposed. The running costs of a heavy-haul train are dependent on its travelling time, maintenance costs and energy consumption during the trip. The Coallink train with the new train technologies, Distributed Power (DP) traction and Electronically Controlled Pneumatic (ECP) brake system, is the centre of the study. A literature study on existing train control, both passenger and heavy-haul trains, is carried out to build up a knowledge base. Many different techniques for train handling were observed, their features in relation to heavy-haul ECP trains are discussed. From these backgrounds, a comprehensive longitudinal train model is proposed and successfully validated with real-life data from Spoornet. In the model, both static and dynamic in-train forces are studied, as well as energy consumption. This is possible by modelling each locomotive and wagon as an individual unit. The equations of motion for the train with coupled units and additional non-linearities, such as traction power limits, are considered. An open-loop controller for maintaining equilibrium velocity is designed. During transient velocity changes, a transient controller for calculating the required additional acceleration and deceleration is designed and validated. Because locomotive traction settings are only available in discrete notches, quantisation conversion from force into notches results in input chattering. In addition, during brake to traction transitions, the locomotives receive a sudden traction demand which results in spikes in in-train forces. To avoid these problems, input filtering is performed for these inputs. Closed-loop controllers based on LQR method, optimised for in-train forces, energy consumption and velocity regulation respectively, are designed and compared. To overcome the communication constraints, a fencing concept is introduced whereby the controller is reconfigured adaptively to the current track topology. Different train configurations in terms of availability of additional control channels for both traction and braking are compared, as well as their effects on dynamic and static in-train force. These configurations are unified, distributed and individual traction and brake controls. The results from these different configurations are compared to recorded train data and given in this study. From the results, it is found that the closed-loop controller optimised for in-train force is able to provide the best overall improvement out of the three controllers. / Dissertation (MEng)--University of Pretoria, 2007. / Electrical, Electronic and Computer Engineering / Unrestricted