Nous nous intéressons à la mise en oeuvre effective d'applications temps réel dans une approche d'ordonnancementhors-ligne de systèmes de tâches périodiques. L'ordonnancement hors-ligne consiste à rechercher avantl'exécution de l'application une séquence pire cas, c'est-à-dire une suite de blocs indiquant une date de débutet de fin d'exécution d'une instance de tâche. Mettre en oeuvre une séquence suppose de spécifier ce qui doit sepasser quand les durées d'exécution réelles sont inférieures aux durées pire cas prévues par la séquence. Notrepremière contribution consiste en la proposition de deux politiques de mise en oeuvre : une politique inflexiblequi respecte strictement les dates de début des blocs ; et une politique flexible qui permet de les avancer. Nousprouvons que ces politiques préservent la validité des séquences. Nous proposons ensuite un modèle de coûtspour l'évaluation et la comparaison de techniques respectant les politiques proposées. La seconde contributionconcerne la proposition de techniques de mise en oeuvre. Dans un premier temps, nous proposons sept techniquesde mise en oeuvre dans un contexte de tâches indépendantes et séquences sans préemption. Nous étendonsensuite l'utilisation de ces techniques aux séquences avec préemption, et aux tâches partageant des ressourcescritiques ou soumises à des contraintes de précédence. La troisième contribution concerne la mise en oeuvresous Posix. Nous présentons des outils de génération de code issus de l'ingénierie dirigée par les modèles. Nousproposons également un outil d'observation de séquences effectives. Enfin, une étude de cas présente l'utilisationpratique de notre approche. / We address the implementation of periodic task sets for off-line scheduling. Off-line scheduling approach consistsin computing a worst-case schedule before runtime. Implementing a schedule requires to specify what must happenwhen the actual execution times of tasks are lower than the planned execution times. The first contributionconsist of the formalization of implementation policies. These policies consider the date by which a task maystart execution, which may or not occur before the planned start time. The inflexible policy does not allowa task to run before its planned start time, the flexible policy does. Since many implementations can complywith these two policies, we also propose a cost model which enables to perform some comparisons betweenthese implementations. The second contribution is the proposition and the presentation of a set of algorithmswhich implement the pre-computed schedules. We first deal with independent task sets in a non preemptivecontext. These algorithms are then adapted to be used in the context of preemptive scheduling, with sharedcritical ressources and precedence constraints. Using the model driven engeneering, we next provide a Posixcode generation tool. We also present a schedule observation tool. Finally, our work has been tested through apratical case study.

Denna förstudie behandlar robotisering av en process som monterar två stiftade tåtar i en plastkontakt, detta bildar ett kablage. Idag monteras tåten till plastkontakten manuellt. Förstudien undersökte om robotisering är tekniskt möjlig och ekonomiskt försvarbar. Robotiseringen sker genom att en robot fattar tag i en stiftad tåt i stiftmaskinen med ett gripdon, sedan förs den stiftade tåten in i en plastkontakt med hjälp av roboten. Stiftmaskinen är en Schleuniger 67 cc. Simuleringar av två koncept genomfördes med en mock-up av maskinen och ligger som underlag för de uppskattade cykeltiderna för den robotiserade processen. Två laborationer genomfördes för att undersöka svårigheterna vid robotiseringen av processen och om det är tekniskt möjligt. Första laborationen bestod av att utforma ett gripdon som kunde hantera produkterna utan att skada dem. Andra laborationen gav underlag för ett uppskattat kvalitetsbyte för processen.  Första laborationen bestod av hur det konstruerade gripdonet skulle kunde fatta tag i den stiftade tåten utan att skada tåten eller ändra dess position eller orientering. Genomförandet av laborationen var i enlighet med ``try and fail`` metoden. Laborationen gav riktlinjer avseende på konstruktionen av gripdonet och vilket arbetstryck som är lämpligt för operationen. För högt arbetstryck resulterade i att gripdonet skadade tåten, för lågt arbetstryck resulterade i att friktionskraften mellan tåten och gripdonet blev för låg för att stiftet skulle föras in i kontakten. Andra laborationen bestod av att utröna ett approximativt värde av den robotiserade processens kvalitetsutbyte. I denna laboration utfördes 65 stycken försök till att bilda ett kablage med roboten och antalet godkända noterades. Resultatet från laborationen med de berörda produkterna som används idag vid montering av ett kablage gav kvalitetsutbytet 51%. Företaget som skall eventuellt investera har krav på att kvalitetsutbytet är 95% för att robotisering av processen skall genomföras. En omfattande analys av resultatet från denna laboration ger indikationer på att kravet kan uppnås med vidare produktutveckling av berörda produkter och gripdon.   En ekonomisk analys i form av en pay-off kalkyl ligger som underlag för att bedöma om robotiseringen är ekonomiskt försvarbar, och gav ett approximativt värde för hur mycket förädling av produkten som den robotiserade processen skall ta över från den manuella monteringen. Den förädling som görs av den robotiserade processen kallas i denna förstudie för automatiseringsgrad. Analys av pay-off kalkylen, produkterna samt resultat från laborationerna, anser författaren att robotisering av processen är teknisk möjligt och ekonomiskt försvarbart med de approximativa värdena för automatiseringsgrad på 22 % av den manuella monteringen och med 95% kvalitetsutbyte. / This pilot study investigated the robotization of a process that connects two pined conductors to a plastic contact and thereby forming a cabling. The pilot study examined if the process is technically possible and economically feasible to robotize. Today the pined conductors are attached to the cabling manually. Introduction of robotization is done so that a robot seizes one pined conductor at a time in the pin machine (Schleuniger 67) with a gripper and inserts same into the plastic contact. To determine if the process is technical possible to robotize two experiments were conducted with a gripper that was designed for this purpose. The purpose of the first was to investigate how the gripper could engage the pined conductor without damaging same or change its position or orientation. The experiment was carried out as a “try and fail” type. The experiment resulted in guidelines regarding the design of the gripper and which working pressure was recommendable for the process. A too high pressure could damage the pined conductor and a too low would cause the friction force between the conductor and the gripper to be too low to insert the pined conductor into the plastic contact. The goal of second experiment was to find an approximate value for the quality yield of the process (that is the number of approved cablings in %). In this experiment 65 attempts to form a cabling was performed and the number of approved cablings was checked and documented. The result from the experiment – using the present conductors and plastic components – was a quality approval rate of 51%. The company requires that the quality yield is higher than 95% in order to robotize the process. A thorough analysis of the result of the experiment and discussion with company representatives indicates that the required quality yield can be reached with some further development of the involved components and the gripper making the designs more “automation friendly”. A financial analysis was made using a pay-back calculation in order to determine when and if robotization is financially justified and resulted in an approximate value regarding how much of the value –added in the operation that is to be automated. This value-added that will be performed by the robot is defined as the degree of automation. The conclusion is that robotization (automation) is technically feasible with a degree of automation of 22% and a quality yield of 95%. This is based upon: the pay-back analysis, the present design of the used components and the result from the experiments.

High speed cornering of an off-road vehicle poses considerable challenges to the development of an autonomous vehicle due to the non-linear dynamics of the tyre road interface as well as those of the vehicle as a whole during high lateral accelerations. Most driver models are developed for low speed applications using linear control methods under the assumption of linear vehicle dy- namics. The dynamics of a vehicle however become highly non-linear as the lateral acceleration increases, thus rendering these linear models unusable during high speed manoeuvres. In this study, two robust driver models for use in an autonomous vehicle capable of path following at both low and high speeds are presented. Both models make use of the relationship between the yaw acceleration and steering rate to control the yaw angle of the vehicle. The first driver model is derived from the simulation of a full non-linear vehicle model in ADAMS. The Magic Tyre Formula is used to model the relationship between the vehicle's yaw acceleration and steer rate as a function of vehicle speed. The second driver model is a mathematical model which incorporates a form of sliding control. The model includes the lateral tyre dynamics as modelled by the Pacejka '89 tyre model. Both driver models are coupled with a gain scheduling proportional derivative controller to reduce the cross-track error. The two driver models were implemented on a Land Rover Defender and experimentally validated by performing a double lane change manoeuvre at speeds up to 80km/h. The vehicle remained stable even though the lateral accelerations experienced were 80% of the vehicle limits. The result is a robust controller capable of path following at various speeds and at high lateral accelerations. Copyright / Dissertation (MEng)--University of Pretoria, 2011. / Mechanical and Aeronautical Engineering / Unrestricted

Bostadsbristen är ett ständigt faktum i Sverige idag och i takt med att boendepriserna ökar så ökar också intresset för att bygga sin egen bostad. Arkitektfirman Tengbom i Karlstad har startat upp ett projekt, Portable Empowerment, som bygger på visionen om att skapa en portabel bostad som ska kunna fungera som en lösning när ett plötsligt behov av bostäder uppstår. För att bostäderna ska kunna flyttas runt krävs det att lösningar för energi- och avloppssystem finns integrerade i bostaden och ska kunna flyttas med för att göra bostaden portabel. För att detta ska vara möjligt krävs det avlopps- och energisystem som är off grid. Off grid betyder att systemet inte är kopplat till kommunalt avlopp eller elnät. Det finns sedan länge sätt att lösa både avlopp och energiförsörjning off grid och några exempel där det tillämpas är husvagnen och den klassiska sommarstugan, men de är allt som oftast inte anpassade för bruk året runt. Målet med denna studie är att identifiera samt värdera avlopps- och energisystem som kan tillgodose behoven i en liten bostad som brukas året runt av två personer. Bostaden har sin utgångspunkt i de ritningar som tagits fram av Tengbom för deras projekt Portable Empowerment. För att identifiera system som kan tillgodose behoven i bostaden har modeller byggts upp och simuleringar skett där system lämpade för off grid inkluderats. Lösningarna har sedan jämförts med varandra med hjälp av värderingsmatriser där portabilitet, kostnad, miljö och användarvänlighet för varje system värderats. Resultatet av studien visar att det finns flera system för både energi och avlopp som kan tillgodose behoven i bostaden året om. Flera av systemen uppfyller kraven för en portabel bostad och det är med andra ord möjligt att uppfylla Tengboms vision om ett fullständigt portabelt boende. Jämfört med en ”vanlig” bostad som är ansluten till vatten- och elnät är dock off grid-lösningarna betydligt mer tidskrävande. Genom att installera ett eget system med lösningar för enbart den egna bostaden tar brukaren också på sig det fulla ansvaret, något som kan tänkas vara en belastning för vissa brukare och en frihet för andra. Ur ekonomisk synpunkt visar studien att på energisidan är det svårt att hitta ett off grid-system som är billigare än on grid-systemet där en luftvärmepump installerats. Däremot är anslutningen till ett kommunalt avlopp betydligt dyrare, mellan 100 000-150 000 kronor mer, än att anlägga till exempel en egen infiltrationsanläggning i anslutning till den egna bostaden. För att utveckla denna studie bör möjligheten att bygga off grid-byar undersökas. Genom att bygga upp ett samhälle om ett stort bostadsbehov skulle uppstå kan energi- och avloppsanläggningar delas. Anläggningarna har större kapacitet och genom att dela på dessa kan både ansvar och kostnad minskas.

The Thesis is conducted based on analysis of a business shared service centre, all factors to consider before the establishment, its scope, model, and the most important is to see advantages as well as to realize the shortcomings of this kind of business model. The country which is analyzed is the Czech Republic; more particular is the city of Prague; and the company is SAP Business Service Centre of Europe (BSCE). In this Thesis, first of all, the PEST (Political, Economic, Social and Technology) environmental analysis has been conducted. The work continues with the SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis of the company SAP AG, from which, we can see that opening a SAP BSCE is a part of SAP strategy which supposes to benefit the company. In order to establish the BSCE, the SAP management board has to consider the factors such as Organization, People, Processes and IT Infrastructure. After analyzing approximately 20 cities in Europe, SAP has chosen Prague as the best mix of quality and costs factors. SAP BSCE covers the functions of Human Resource and Finance and Administration, which provide services to internal and external customers of many countries in Europe, Middle East, and Africa. SAP BSCE has brought back many advantages such as cost-savings, high quality service, business availability and flexibility, and business transparency and legal compliance. On the other hand, there are still many short-comings, such as the high turn-over rate of staff, difficulties in harmonization and standardization of processes and IT infrastructure, and how to prove the quality of service. Despite these challenges, SAP BSCE has put efforts into trying to overcome these problems. At the end of the Thesis, as per analysis of SAP financial results of business activities during the crisis, it is proven the setting up a shared service centre was a good decision of SAP and it paid off with the contribution to help SAP overcome the impacts of crisis.

Cette thèse concerne l'étude et la réduction de la consommation de puissance durant le test par scan des circuits digitaux. Afin de détecter les défauts de délai de transition, les deux principales structures sont utilisés dans la pratique: Launch-Off-Shift (LOS) et launch-Off-Capture (LOC). L'ensemble des travaux réalises montre que le test LOS est plus efficace que le test LOC en terme de couverture de fautes de transition et la longueur de test. Toutefois, le test LOS nécessite une puissance plus élevée lors du launch-to-capture (LTC) du cycle, notamment en terme de consommation de puissance de pic. Ainsi, nous proposons une nouvelle approche de génération de vecteurs de test LOS basée sur la consommation. La technique proposée est capable de réduire et d'évaluer la puissance de pic de test se rapprochant le plus possible de la puissance fonctionnelle. Les avantages qui en résultent permettent de résoudre le problème lié à la perte de rendement et de s'abstenir du test se produisant lorsque la puissance de test est trop faible par rapport à la puissance fonctionnelle. / This thesis relates to study and reduction of power consumption during at-speed scan delay testing for digital circuits. To detect transition delay faults, two main testing schemes are used in practice: Launch-Off-Shift (LOS) and Launch-Off-Capture (LOC). In this work, we prove that LOS testing is more efficient than LOC testing in terms of transition fault coverage (TFC) and test length. However, LOS presents higher power during the launch-to-capture (LTC) cycle, especially in terms of peak power. For this purpose, we propose a novel power-aware test pattern generation technique for LOS testing. The proposed approach is able to reduce and map the test peak power as close as possible to the functional power. The important feature of this framework is that, in additional to solving the yield loss problem, it also avoids test escape that may occur when test power is too much reduced compared to functional power.

This thesis examines the classic ride comfort vs. handling compromise when designing a vehicle suspension system. A controllable suspension system, that can, through the use of suitable control algorithms, eliminate this compromise, is proposed and implemented. It is a well known fact that if a vehicle suspension system is designed for best ride comfort, then handling performance will suffer and vice versa. This is especially true for the class of vehicle that need to perform well both on- and off-road such as Sports Utility Vehicles (SUV’s) and wheeled military vehicles. These vehicles form the focus of this investigation. The ride comfort and handling of a Land Rover Defender 110 Sports Utility Vehicle is investigated using mathematical modelling and field tests. The full vehicle, non-linear mathematical model, built in MSC ADAMS software, is verified against test data, with favourable correlation between modelled and measured results. The model is subsequently modified to incorporate hydropneumatic springs and used to obtain optimised spring and damper characteristics for ride comfort and handling respectively. Ride comfort is optimised by minimising vertical acceleration when driving in a straight line over a rough, off-road terrain profile. Handling is optimised by minimising the body roll angle through a double lane change manoeuvre. It is found that these optimised results are at opposite corners of the design space, i.e. ride comfort requires a soft suspension while handling requires a stiff suspension. It is shown that the ride comfort vs. handling compromise can only be eliminated by having an active suspension system, or a controllable suspension system that can switch between a soft and a stiff spring, as well as low and high damping. This switching must occur rapidly and automatically without driver intervention. A prototype 4 State Semi-active Suspension System (4S4) is designed, manufactured, tested and modelled mathematically. This system enables switching between low and high damping, as well as between soft and stiff springs in less than 100 milliseconds. A control strategy to switch the suspension system between the “ride” mode and the “handling” mode is proposed, implemented on a test vehicle and evaluated during vehicle tests over various on- and off-road terrains and for various handling manoeuvres. The control strategy is found to be simple and cost effective to implement and works extremely well. Improvements of the order of 50% can be achieved for both ride comfort and handling. AFRIKAANS : In hierdie proefskrif word die klassieke kompromie wat getref moet word tussen ritgemak en hantering, tydens die ontwerp van ‘n voertuig suspensiestelsel ondersoek. ‘n Beheerbare suspensiestelsel, wat die kompromie kan elimineer deur gebruik te maak van toepaslike beheeralgoritmes, word voorgestel en geïmplementeer. Dit is ‘n bekende feit dat, wanneer die karakteristieke van ‘n voertuigsuspensiestelsel ontwerp word vir die beste moontlike ritgemak, die hantering nie na wense is nie, en ook omgekeerd. Dit is veral waar vir ‘n spesifieke kategorie van voertuie, soos veldvoertuie en militêre wielvoertuie, wat oor goeie ritgemak en hantering, beide op paaie en in die veld, moet beskik. Die fokus van die huidige studie val op hierdie kategorie voertuie. Die ritgemak en hantering van ‘n Land Rover Defender 110 veldvoertuig is ondersoek deur gebruik te maak van wiskundige modellering en veldtoetse. Die volvoertuig, nielineêre wiskundige model, soos ontwikkel met behulp van MSC ADAMS sagteware, is geverifieer teen eksperimentele data en goeie korrelasie is verkry. Die model is verander ten einde ‘n hidropneumatiese veer-en-demperstelsel te inkorporeer en verder gebruik om optimale veer- en demperkarakteristieke vir onderskeidelik ritgemak en hantering te verkry. Ritgemak is geoptimeer deur in ‘n reguit lyn oor ‘n rowwe veldterreinprofiel te ry, terwyl hantering geoptimeer is deur ‘n dubbelbaanveranderingsmaneuver uit te voer. Die resultaat is dat die geoptimeerde karakteristieke op die twee uiterstes van die ontwerpsgebied lê. Beste ritgemak benodig ‘n sagte suspensie terwyl beste hantering ‘n harde suspensie benodig. Daar word aangedui dat die ritgemak vs. hantering kompromie slegs elimineer kan word deur gebruik van ‘n aktiewe suspensiestelsel, of ‘n beheerbare suspensiestelsel wat kan skakel tussen ‘n sagte en stywe veer, asook hoë en lae demping. Dié oorskakeling moet vinnig en outomaties geskied sonder enige ingryping van die voertuigbestuurder. ‘n Prototipe 4 Stadium Semi-aktiewe Suspensie Stelsel (4S4) is ontwerp, vervaardig,getoets en wiskundig gemodelleer. Die stelsel skakel tussen hoë en lae demping, asook tussen ‘n stywe en sagte veer binne 100 millisekondes. ‘n Beheerstrategie wat die suspensiestelsel skakel tussen die “ritgemak” en “hantering” modes is voorgestel, op ‘n toetsvoertuig geïmplementeer en evalueer tydens voertuigtoetse oor verskeie pad- en veldry toestande, asook tydens omrol- en hanteringstoetse. Die beheerstrategie is koste-effektief en maklik om te implementeer en werk besonder goed. Verbeterings in die orde van 50% kan behaal word vir beide ritgemak en hantering. / Thesis (PhD (Mechanical Engineering))--University of Pretoria, 2011. / Mechanical and Aeronautical Engineering / unrestricted

archives@tulane.edu / 1 / Caitlin Rose Bumby

abstract: The rationale of this thesis is to provide a thorough understanding of spalling for semiconductor materials and develop a low temperature spalling technology that reduces the surface roughness of the spalled wafers for Photovoltaics applications. / Dissertation/Thesis / Doctoral Dissertation Materials Science and Engineering 2020

Since the failure of the Scan Line Corrector (SLC) instrument on Landsat 7, observable gaps occur in the acquired Landsat 7 imagery, impacting the spatial continuity of observed imagery. Due to the highly geometric and radiometric accuracy provided by Landsat 7, a number of approaches have been proposed to fill the gaps. However, all proposed approaches have evident constraints for universal application. The main issues in gap-filling are an inability to describe the continuity features such as meandering streams or roads, or maintaining the shape of small objects when filling gaps in heterogeneous areas. The aim of the study is to validate the feasibility of using the Direct Sampling multiple-point geostatistical method, which has been shown to reconstruct complicated geological structures satisfactorily, to fill Landsat 7 gaps. The Direct Sampling method uses a conditional stochastic resampling of known locations within a target image to fill gaps and can generate multiple reconstructions for one simulation case. The Direct Sampling method was examined across a range of land cover types including deserts, sparse rural areas, dense farmlands, urban areas, braided rivers and coastal areas to demonstrate its capacity to recover gaps accurately for various land cover types. The prediction accuracy of the Direct Sampling method was also compared with other gap-filling approaches, which have been previously demonstrated to offer satisfactory results, under both homogeneous area and heterogeneous area situations. Studies have shown that the Direct Sampling method provides sufficiently accurate prediction results for a variety of land cover types from homogeneous areas to heterogeneous land cover types. Likewise, it exhibits superior performances when used to fill gaps in heterogeneous land cover types without input image or with an input image that is temporally far from the target image in comparison with other gap-filling approaches.