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Reversing Language Shift in Galicia : A Present-Day PerspectiveSkobel, Ekaterina January 2010 (has links)
The present thesis is about the current linguistic situation in the Spanish province of Galicia and about the prospects of the Galician language in modern times. The situation is analyzed through applying Joshua Fishman's model of reversing language shift (RLS).
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Path follower for reversing off-axle single-joint semitrailer trucksCerna Herrera, Fernando Javier January 2021 (has links)
Semitrailer trucks are widely used for transportation of goods in Sweden and around the world. Given their usefulness, and since they require specialized drivers, there is an increased need to automate the operation of these vehicles. In particular, reversing these vehicles is considered a challenging maneuver, mainly because of the jackknifing effect. To tackle this challenge, this thesis investigates path following for reversing single-joint semitrailer trucks, by comparing two path-following controllers, corresponding to a Linear Quadratic Regulator (LQR) and a Model Predictive Control (MPC), respectively. Both controllers receive kinematically feasible reference trajectories from a path planner (which is part of another thesis work), which makes it possible to avoid jackknifing as long as the reference joint angle between the trailer and the truck is closely followed. Moreover, they use a linearized and discretized 1-trailer kinematic model, defined in terms of the reference tracking errors for the truck as states. To evaluate the performance of the controllers, a Python simulation is implemented using the 1-trailer kinematic model. Using this simulation, the controllers are compared using metrics related to the reference tracking errors along the generated path and the controller execution time. The results show that the LQR and the MPC controllers perform similarly for most cases. Even though there are certain cases where the MPC outperforms the LQR, the execution time of the MPC is at least one order of magnitude slower, which makes the LQR an attractive solution for practical implementations, as long as certain assumptions (small initial deviations, reliable measurements) are ensured. As such, an LQR controller might be preferred by the industry because, while the performance from both controllers is similar, it can be considered a more efficient controller. / Lastbilar med olika släpvagnskombinationer används ofta för godstransporter i Sverige och runt om i världen. Med tanke på deras användbarhet och eftersom de kräver specialiserade förare finns det ett ökat behov av att automatisera driften av dessa fordon. I synnerhet anses backning av dessa fordon vara en utmanande manöver, främst på grund av jackknifseffekten. För att lösa detta problem undersöker denna rapport vägföljande för backande lastbilar med släp genom att jämföra två olika vägföljande styrenheter: Linear Quadtratic Regulator (LQR) och Model Predictive Control (MPC). Båda styrenheterna får kinematiskt genomförbara referensbanor från en vägplanerare (som är en del av en annan uppsats), vilket gör det möjligt att undvika jackknipning så länge referensvinkeln mellan släpet och lastbilen följs noggrant. Dessutom använder de en linjäriserad och diskretiserad kinematisk modell med en lastbil, definierad i termer av lastbilens referensspårningsfel som tillstånd. För att utvärdera kontrollernas prestanda implementeras en Python-simulering med den kinematisk modell med en lastbil. Med denna simulering jämförs de två styrenheterna med mått relaterade till referensspårningsfelen längs den generarade vägen och styrenheternas exekveringstid. Resultaten visar att LQR och MPCpresterar likadant i de flesta fallen. Även om det finns vissa fall där MPC överträffar LQR, är exekveringstiden för MPC åtminstone en storleksordning långsammare, vilket gör LQR till en attraktiv lösning för praktiska implementeringar, så länge som vissa antaganden (små initiala avvikelser, pålitliga mått) säkerställs. Som sådan kan en LQR-styrenhet föredras av industrin, för även om prestandan från båda styrenheterna är lika, kan den betraktas som en enklare styrenhet.
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Additive manufacturing : Optimization of process parameters for fused filament fabricationHayagrivan, Vishal January 2018 (has links)
An obstacle to the wide spread use of additive manufacturing (AM) is the difficulty in estimating the effects of process parameters on the mechanical properties of the manufactured part. The complex relationship between the geometry, parameters and mechanical properties makes it impractical to derive an analytical relationship and calls for the use of a numerical model. An approach to formulate a numerical model in developed in this thesis. The AM technique focused in this thesis is fused filament fabrication (FFF). A numerical model is developed by recreating FFF build process in a simulation environment. Machine instructions generated by a slicer to build a part is used to create a numerical model. The model acts as a basis to determine the effects of process parameters on the stiffness and the strength of a part. Determining the stiffness of the part is done by calculating the response of the model to a uniformly distributed load. The strength of the part depends on it's thermal history. The developed numerical model serves as a basis to implement models describing the relation between thermal history and strength. The developed model is suited to optimize FFF parameters as it encompass effects of all FFF parameters. A genetic algorithm is used to optimize the FFF parameters for minimum weight with a minimum stiffness constraint. / Ett hinder för att additiv tillverkning (AT), eller ”3D-printing”, ska få ett bredare genomslag är svårigheten att uppskatta effekterna av processparametrar på den tillverkade produktens mekaniska prestanda. Det komplexa förhållandet mellan geometri och processparametrar gör det opraktiskt och komplicerat att härleda analytiska uttryck för att förutsäga de mekaniska egenskaperna. Alternativet är att istället använda numeriska modeller. Huvudsyftet med denna avhandling har därför varit att utveckla en numerisk modell som kan användas för att förutsäga de mekaniska egenskaperna för detaljer tillverkade genom AT. AT-tekniken som avses är inriktad på Fused Filament Fabrication (FFF). En numerisk modell har utvecklats genom att återskapa FFF-byggprocessen i en simuleringsmiljö. Instruktioner (skriven i GCode) som används för att bygga en detalj genom FFF har här översatts till en numerisk FE-modell. Modellen används sen för att bestämma effekterna av processparametrar på styvheten och styrkan hos den tillverkade detaljen. I detta arbete har strukturstyvheten hos olika detaljer beräknats genom att utvärdera modellens svar för jämnt fördelade belastningsfall. Styrkan, vilket är starkt beroende på den tillverkade detaljens termiska historia, har inte utvärderats. Den utvecklade numeriska modellen kan dock fungera som underlag för implementering av modeller som beskriver relationen mellan termisk historia och styrka. Den utvecklade modellen är anpassad för optimering av FFF-parametrar då den omfattar effekterna av alla FFF-parametrar. En genetisk algoritm har använts i detta arbete för att optimera parametrarna med avseende på vikt för en given strukturstyvhet.
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The impact of family language policy (FLP) on the conservation of minority languages in ZimbabweMaseko, Busani 11 1900 (has links)
This study investigates the impact of Family Language Policy (FLP) on the conservation of minority languages in Zimbabwe. Family language policy is a newly emerging sub field of language planning and policy which focuses on the explicit and overt planning in relation to language use within the home among family members. The study is therefore predicated on the view that the conservation of any minority language largely depends on intergenerational transmission of the particular language. Intergenerational transmission is dependent in part, on the language practices in the home and therefore on family language policy. To understand the nature, practice and negotiation of family language policy in the context of minority language conservation, the study focuses on the perspectives of a sample of 34 L1 Kalanga parents and 28 L1 Tonga parents, who form the main target population. In this study, parents are considered to be the ‘authorities’ within the family, who have the capacity to articulate and influence language use and language practices. Also included in this study are the perspectives of language and culture associations representing minority languages regarding their role in the conservation of minority languages at the micro community level. Representatives of Kalanga Language and Cultural Development Association (KLCDA), Tonga Language and Culture Committee (TOLACCO) as well Zimbabwe Indigenous Languages Promotion Association (ZILPA) were targeted.
This research takes on a qualitative approach. Methodologically, the study deployed the interview as the main data collection tool. Semi structured interviews were conducted with L1 Kalanga and L1 Tonga parents while unstructured interviews were conducted with the representatives of language and culture associations. This study deploys the language management theory and the reversing language shift theory as the analytical lenses that enable the study to understand the mechanics of family language policy and their impact on intergenerational transmission of minority languages in Zimbabwe. Language management theory allows for the extendibility of the tenets of language policy into the family domain and specifically affords the study to explore the dialectics of parental language ideologies and family language practices in the context of minority language conservation in Zimbabwe. The reversing language shift theory also emphasises the importance of the home domain in facilitating intergenerational transmission of minority languages.
Findings of the study demonstrate that family language policy is an important aspect in intergenerational transmission of minority languages, itself a nuanced and muddled process. The research demonstrates that there is a correlation between parental language ideologies and parental disposition to articulate and persue a particular kind of family language policy. In particular, the study identified a pro-minority home language and pro- bilingual family language policies as the major parental language ideologies driving family language policies. However, the research reveals that parental language ideologies and parental explicitly articulated family language polices alone do not guarantee intergenerational transmission of minority languages, although they are very pertinent. This, as the study argues, is because family language policy is not immune to external language practices such as the school language policy or the wider language policy at the macro state level. Despite parents being the main articulators of family language policy, the study found out that in some instances, parental ideologies do not usually coincide with children’s practices. The mismatch between parental preferences and their children’s language practices at home are a reproduction, in the home, of extra familial language practices. This impacts family language practices by informing the child resistant agency to parental family language policy, leading to a renegotiation of family language policy. The research also demonstrates that parents, especially those with high impact beliefs are disposed to take active steps, or to employ language management strategies to realise their desired language practices in the home. The study demonstrates that these parental strategies may succeed in part, particularly when complemented by an enabling sociolinguistic environment beyond the home. The articulation of a pro-Tonga only family language policy was reproduced in the children’s language practices, while the preference for a pro- bilingual family language policy by the majority L1 Kalanga parents was snubbed for a predominantly Ndebele-only practice by their children. In most cases, the research found out that language use in formal domains impacted on the success of FLP. Tonga is widely taught in Schools within Binga districts while Kalanga is not as widespread in Bulilima and Mangwe schools. Ndebele is the most widespread language in Bulilima and Mangwe schools. As such; children of L1 Kalanga parents tend to evaluate Kalanga negatively while having positive associations with Ndebele. All these language practices are deemed to impact on family language policy and therefore on intergenerational transmission of minority languages in Zimbabwe. The desire by parents for the upward mobility of children results in them capitulating to the wider socio political reality and therefore to the demands of their children in terms of language use in the home.
The study therefore concludes that family language policy is an important frontier in the fight against language shift and language endangerment, given the importance of the home in intergenerational transmission of minority languages. The study therefore implores future research to focus on this very important but largely unresearched sub field of language policy. The study observes that most researches have focused on the activities of larger state institutions and organisations and how they impact on minority language conservation, to the detriment of the uncontestable fact that the survival of any language depends on the active use of the language by the speakers. The research also recommends that future practice of language policy should not attempt to promote minority languages by discouraging the use of other majority languages, but rather, speakers should embrace bilingualism as a benefit and a resource and not as a liability. The interaction between the top down state language policy and the bottom up micro family language policy should be acknowledged and exploited, in such a way that the two can be deployed as complementary approaches in minority language conservation. / Linguistics and Modern Languages / D. Litt. et Phil. (Languages, Linguistics and Literature)
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Prozessübergreifende Berechnung der Temperatur und des Gefüges im Laufe des reversierenden Warmwalzens am Beispiel der Magnesiumlegierung AZ31Nam, Alexander 07 January 2020 (has links)
In der vorliegenden Arbeit wird ein prozessübergreifendes Simulationsmodell für die Temperatur- und Gefügeentwicklung im Band und Coil beim reversierenden Warmwalzen entwickelt. In der Software werden die erstmals aufgestellten Modelle der Bandab- und aufwicklung implementiert. Die Temperatur- und Gefügeveränderungen im gewalzten Warmband werden lokal und prozessübergreifend betrachtet. Die für das gesamte Modell notwendigen Koeffizienten zur Beschreibung der Wärmeübertragung wurden mittels der inversen Methode bestimmt. Die Bestimmung der radialen Wärmeübertragung im Coil erfolgte mit Hilfe von Laboruntersuchungen in Abhängigkeit von der Temperatur, der Banddicke und des radialen Druckes. Die Validierung des Modells für die Temperatur- und Gefügeentwicklung erfolgte am Beispiel des reversierenden Warmwalzens der Magnesiumlegierung AZ31. Zu diesem Zweck wurden Versuche zu Temperaturmessungen in den einzelnen Phasen der Prozesskette durchgeführt. Die Ermittlung der Einflüsse der Umformbedingungen auf die Temperatur- und Gefügeentwicklung während des reversierenden Warmbandwalzens erfolgte abschließend mit Hilfe des entwickelten Modells. Die Ergebnisse zeigen auf, wie sich die Walzbedingungen auf die Entwicklung der Temperatur und des Gefüges auswirken.
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Разработка новых конструкций реверсивных шестеренных насосов для систем смазки возвратно-вращательных механизмов экскаваторов : магистерская диссертация / Development of new designs of reversible gear pumps for lubrication systems of return-rotational mechanisms of excavatorsЧибиров, А. Б., Chibirov, A. B. January 2019 (has links)
Диссертация на тему «Разработка новых конструкций реверсивных шестеренных насосов для систем смазки возвратно-вращательных механизмов экскаваторов» содержит 95 страниц текста, рисунков – 49, формул – 22, использованных источников – 18, иллюстрационный альбом, включающий 15 листов формата А1 графической части. Ключевые слова: системы смазки, реверсивные механизмы, реверсивный насос, шестеренный насос, консистентная смазка, циркуляционная смазка, карьерные экскаваторы, привод поворота, привод подъемной лебедки. Предмет исследования: проблемы систем смазки современных карьерных экскаваторов. Цель работы: разработка схемы и конструкции насоса, обеспечивающего бесперебойную подачу смазывающего вещества при постоянном реверсировании его ведущего вала. Итогом работы является разработка двух концептуальных вариантов шестеренного реверсивного насоса для узлов, совершающих возвратно-вращательные движений. Насосы могут работать от основного привода, без использования дополнительного двигателя. Так же в работе представлен пример использования данных насосов в узлах карьерного экскаватора ЭКГ-20, таких как редуктор подъемной лебедки и редуктор привода поворота с расчетом параметров насоса для последнего. В процессе работы над диссертацией была оформлена заявка на патент на полезную модель «Реверсивный шестеренный насос». Заявка зарегистрирована в Роспатенте с приоритетом от 23.04.2019. Регистрационный номер заявки 2019112339. / The dissertation on the theme "Development of new designs of reversible gear pumps for lubrication systems of return-rotational mechanisms of excavators" contains 95 pages of text, figures – 49, formulas – 22, used sources – 18, an illustrative album, including 15 sheets of A1 format of the graphic part. Key words: lubrication system, reversing mechanisms, a reversible pump, gear pump, grease lubrication, circulating lubrication, mining shovels, swing drive, the drive of the lifting winch. Subject of research: problems of lubrication systems of modern mining excavators. The purpose of the work: development of the scheme and design of the pump, ensuring uninterrupted supply of lubricant with constant reversal of its drive shaft. The result of the work is the development of two conceptual variants of the gear reversible pump for units performing reciprocating movements. Pumps can operate from the main drive, without the use of an additional engine. Also the paper presents an example of the use of these pumps at the nodes of a mining shovel EKG-20, such as reducer lift winch, and the gear drive rotation calculation of pump parameters for the latter. In the process of working on the thesis was issued a patent application for a utility model "Reversible gear pump". Application to patent with priority of 23.04.2019. Registration number of the application 2019112339. The practical usefulness of the work lies in the fact that this pump is ready for use in many areas of engineering, as shown by the example of mining equipment.
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