A utilização de sistemas de controle para estabilidade de conjuntos de barras para pulverizadores agrícolas é uma tendência devida principalmente aos problemas ambientais e de custo. Neste trabalho, o comportamento dinâmico de um pulverizador de arrasto é analisado através de um modelo não linear, obtido através de técnicas de modelagem de sistemas multicorpos utilizando-se o programa ADAMS. Foram utilizadas duas estratégias de controle PID e \"fuzzy\" a partir de medidas obtidas com fusão de sensores. A estratégia de controle clássica PID foi desenvolvida e implementada no modelo não linear no ADAMS através de ferramentas internas existentes no programa. Já a estratégia \"fuzzy\" foi desenvolvida e implementada no modelo não linear no ADAMS através da técnica de co-simulação ADAMS/Matlab. O comportamento dos sistemas de controle foi investigado através de simulação computacional. Foram testados alguns tipos de entradas (entrada degrau, entrada harmônica, entrada randômica e entrada randômica com descontinuidades bruscas). Em todas as simulações os resultados obtidos com os sistemas de controles ativos mostraram melhor estabilidade do conjunto de barras. Entre as leis de controle implementadas (PID e \"fuzzy\") não houve grandes diferenças entre as oscilações da barra exceto na entrada do tipo randômica com descontinuidades bruscas. Neste caso a lei de controle \"fuzzy\" apresentou uma grande melhoria com boa atenuação das oscilações do conjunto de barras quando comparadas com a aplicação do sistema de controle PID. / The use of active control systems for stability of booms in agricultural sprayers trend is mainly due to the environmental and costs question. In this work, the dynamic behavior of a trailed sprayer is analyzed using a nonlinear model, obtained through techniques of modeling multibody systems using the ADAMS. It is used two active control strategies, PID classical control and fuzzy, with measured data from sensor fusion. The classical PID control strategy was developed and implemented in a nonlinear model on ADAMS software using existing tools built into the program. Fuzzy was another strategy developed and implemented in the nonlinear model on ADAMS software using a technique of co-simulation ADAMS/Matlab. The behavior of control systems was investigated through computer simulation. It was tested some types of inputs (step input, harmonic input, random input and random input with abrupt discontinuities). All simulations data obtained from the applications of active systems showed better stability for boom assembly. Among the implemented two active control laws (PID and \"fuzzy\") there were no significant differences between the oscillations attenuation of the boom, except with the random input with abrupt discontinuities. wherein this case the application of the active control \"fuzzy\" strategy developed better stability on boom than the application of PID control.

(in English) This thesis focuses on the theme of the destruction of a world in the Hispanic American literature. Its principal part is a detailed analysis of the novels The Villagers, written by the Ecuadorian author Jorge Icaza, and The Kingdom of this World, written by the Cuban novelist Alejo Carpentier. Additional parts of the thesis are a concise outline of significant literary works which include the theme of the destruction of a world and a brief corpus analysis. The analysis compares the frequency of the usage of several words which are connected with the theme in the Hispanic American and Spanish literature. The thesis aims to answer the following questions: Is the theme of the destruction of a world characteristic for the Hispanic American literature? In which forms does it occur? How is the theme demonstrated in the literary works, and what are its features? The thesis also examines the relation between the Hispanic American reality and the presence of the theme in the writings of the authors born in that part of the World. The relation between the analysed literary works and the historical background of the period in which it was written is important for the theses as well as selected facts of the life stories of the authors. To a certain extent, it determined their literary output.

Forests represent one of the biggest terrestrial ecosystems of Earth, that can produce important raw renewable materials such as wood with the help of sun, air and water. To efficiently extract these raw materials, the tree harvesting process is highly mechanized in developed countries, meaning that advanced forestry machines are continuously used to fell, to process and to transport the logs and biomass obtained from the forests. However, working with these machines is demanding both mentally and physically, which are known factors to negatively affect operator productivity. Mental fatigue is mostly due to the manual operation of the on-board knuckleboom crane, which requires advanced cognitive work with two joystick levers, while the most serious physical strains arise from cabin vibrations. These vibrations are generated from knuckleboom crane vibrations as a result of aggressive manual operation. To enhance operator workload, well-being, and to increase productivity of the logging process, semi-automation functions are suggested, which are supervised automatic executions of specific work elements. Some of the related issues are addressed in the current thesis. Therefore, the content is divided into: (1) the design and development of a semi-automation function focused only on the base joint actuator (slewing actuator) of a knuckleboom crane, and (2) active vibration damping solutions to treat crane structure vibrations induced by the main lift cylinder (inner boom actuator). The considered reference machine is a downsized knuckleboom crane of a forwarder machine, which is used to pick up log assortments from a harvesting site. The proposed semi-automation function presented in the first part could be beneficial for operators to use during log loading/unloading scenarios. It consists from a closed-loop position control architecture, to which smooth reference slewing trajectories are provided by a trajectory planner that is automated via operator commands. The used trajectory generation algorithms are taken from conventional robotics and adapted to semi-automation context with proposed modifications that can be customizable by operators. Further, the proposed active vibration damping solutions are aimed to reduce vibrations of the knuckleboom crane excited by the inner boom actuator due to aggressive manual commands. First, a popular input shaping control technique combined with a practical switching logic was investigated to deal with the excited payload oscillations. This technique proved to be useful with a fixed crane pose, however it did not provide much robustness in terms of different link configurations. To tackle this problem an H2-optimal controller is developed, which is active in the pressure feedback-loop and its solely purpose is to damp the same payload oscillations. During the design process, operator commands are treated and explained from input disturbance viewpoint. All of the hypothesis throughout this thesis were verified with extensive experimental studies using the reference machine.

The purpose of this case study was to examine the why the English language learners (ELLs) in the Beaufort County, South Carolina school system have been so successful. This school system has recently experienced a boom in its ESL student population, and this population has performed very well on standardized tests. This study used critical theory as its theoretical framework and examined why the students have been successful rather than marginalized in Beaufort County schools. This phenomenon was investigated using semi-structured interviews with the ESOL Coordinator for Beaufort County, 4 ESL-lead teachers, and 6 mainstream teachers. Data were collected using semi-structured interviews with Sarah Owen, the Beaufort County ESOL, Gifted and Talented, and World Languages coordinator. Based on the results of her interview, 4 themes emerged that were used for the semi-structured interviews with ESOL and mainstream teachers. The interviews centered on the themes of ESL policy, ESL leadership, and teacher training. The ESL and mainstream teacher interviews also revealed several subthemes that included teacher attitude, why Beaufort County has been successful with the ELLs, and the teachers’ recommendations for other schools systems trying to successfully accommodate a large ESL student population in mainstream classrooms. The findings from the teachers’ interviews revealed that additional training for the teachers without ESL experience helped them become comfortable instructing ELLs. This training should be conducted by the ESOL teachers for those without ESOL certification or endorsement. As the teachers had more training, they had better attitudes about teaching ESOL students in their classes. Finally, those who utilized the additional ESOL training and ESOL accommodations saw better student achievement in their classes. Based on the finding of this study, the researcher proposed a model for other school systems to follow in order to replicate the success of Beaufort County’s ELLs. The implications of this study focus on other schools systems and why ELLs are not obtaining the same level of success as those in Beaufort County’s schools. Finally, recommendations for further research are provided.

There is a lot of gravitational potential energy waste when hydraulic excavators work, which seriously affects the efficiency of the whole machine and produces a large amount of emissions. In order to reduce the energy consumption and emissions of large hydraulic excavators which the boom is driven by two hydraulic cylinders, an integrated drive and potential energy recuperation principle is proposed. In the implementation, the original two-chamber hydraulic cylinders are replaced by three-chamber hydraulic cylinders with energy storage chambers, and the energy storage chambers are directly connected with the hydraulic accumulator. The dead weight of the working device is balanced by the initial hydraulic pressure of the hydraulic accumulator, and the gravitational potential energy is directly recuperated. A digital prototype is established for the simulation work to verify the energy-saving effect. Then a test prototype is constructed according to the simulation work. The standard 90° loading duty cycle tests show that compared with the standard hydraulic excavators of the same type, in the case of meeting the same digging force, the working efficiency of the excavator increases by 20.7% and the fuel consumption decreases by 17.1%. In terms of 8 hours of work per day, a single excavator can save fuel up to 47 L per day and reduce carbon dioxide emissions by 123.6 kg.

Der weltweite Wasserkraftboom wird entweder mit seinen Vorteilen (Hochwasserschutz, Wirtschaftswachstum, erneuerbare Energieerzeugung) oder negativen Auswirkungen betrachtet (Zerstörung intakter Lebensräume, Verdrängung der Bevölkerung und Bedrohung von Existenzgrundlagen). Die vorliegende Arbeit versucht den Wasserkraftboom besser zu verstehen wie auch den Fakt, dass dieser bislang nicht zum Bau großer Wasserkraftwerke geführt hat. Eine Fallstudie wurde von Juli bis Oktober 2016 und Juli bis August 2017 in Bosnien und Herzegowina durchgeführt. Auch dort ist die Zahl der gebauten Wasserkraftprojekte im Vergleich zur Zahl der geplanten Projekte vernachlässigbar gering. Qualitative Forschungsmethoden wurden angewendet und drei wesentliche Schlussfolgerungen gezogen. Erstens (Kap. II) wird erläutert, warum der Boom in Bosnien und Herzegowina nicht in dem vorgesehenen Ausmaß stattfinden wird und inwieweit das Phänomen einer Übertragung auf globalen Maßstab standhält. Zweitens (Kap. III) wird deutlich, wie v.a. kleinere Wasserkraftprojekte von Akteuren zum persönlichen Vorteil genutzt werden. Korruption ist in diesem Sektor weit verbreitet und eng mit dem Diskurs über nachhaltige Entwicklung im Land verbunden. Die kleinen Wasserkraftprojekte schaffen einen sicheren Raum für korrupte Akteure. Schließlich (Kap. IV) wurde untersucht, wie die BewohnerInnen eines kleinen Dorfes in Bosnien und Herzegowina ihre Vorstellungen von Nachhaltigkeit rund um die Wasserkraft verändert haben. Dies taten sie in Übereinstimmung mit sich ändernden sozioökonomischen Bedingungen. Dieses Kapitel illustriert, wie die Flexibilität des Begriffs Nachhaltigkeit für marginalisierte lokale BewohnerInnen von Vorteil sein kann. Die vorliegende Dissertation zeigt, dass der Wasserkraftboom, obwohl bislang weitgehend nur "auf dem Papier" existent, dennoch bereits reale materielle Konsequenzen für nachhaltige Entwicklungsstrategien, Korruption und das lokale Leben mit sich bringt. / The global hydropower boom is a well-known phenomenon. It is either considered for its benefits to sustainable development or cautioned against its negative socio-environmental impacts. Yet the number of existing hydropower projects is not very high globally. This thesis thus aspires to develop a better understanding of the global hydropower boom and why this boom has not resulted in large-scale hydropower plant construction. The hydropower boom in Bosnia and Herzegovina was selected as the object of study. There, the number of constructed hydropower projects is negligible in comparison to the number of planned projects. Qualitative research methods were used to explore the case in depth. The data was collected between July and October, 2016 and between July and August, 2017. Three main conclusions were drawn from the fieldwork conducted. Chapter II shows and explains why the hydropower boom is unlikely to take place in Bosnia and Herzegovina to the extent foreseen. It also questions the phenomenon at a global scale. Chapter III shows how small-scale hydropower projects are used by various actors for personal benefit. Corruption is rife in the sector and closely connected to the sustainable development discourse in the country. A key finding here is that small-scale hydropower projects create a safe space for corrupt actors. Chapter IV explores how the inhabitants of a small village in Bosnia and Herzegovina changed their sustainability imaginaries around hydropower. They did this in accordance with changing socio-economic conditions. This chapter thus illustrates how the flexibility of the term sustainability can be beneficial to marginalised local inhabitants. In general, this thesis, therefore, contributes to the hydropower literature. It shows that the hydropower boom is largely ‘on-paper’ but with real material consequences for sustainable development strategies, corruption, and local lives.

The conduct of effective economic policy faces a multiplicity of macroeconomic challenges, which requires a wide scope of theoretical and empirical analyses. With a focus on the European Union, this doctoral dissertation consists of two parts which make empirical and methodological contributions to the literature on forecasting real economic activity and on the analysis of business cycles in a boom-bust framework in the light of the EMU enlargement. In the first part, we tackle the problem of publication lags and analyse the role of the information flow in computing short-term forecasts up to one quarter ahead for the euro area GDP and its main components. A huge dataset of monthly indicators is used to estimate simple bridge equations. The individual forecasts are then pooled, using different weighting schemes. To take into consideration the release calendar of each indicator, six forecasts are compiled successively during the quarter. We find that the sequencing of information determines the weight allocated to each block of indicators, especially when the first month of hard data becomes available. This conclusion extends the findings of the recent literature. Moreover, when combining forecasts, two weighting schemes are found to outperform the equal weighting scheme in almost all cases. In the second part, we focus on the potential accession of the new EU Member States in Central and Eastern Europe to the euro area. In contrast to the discussion of Optimum Currency Areas, we follow a non-standard approach for the discussion on abandonment of national currencies the boom-bust theory. We analyse whether evidence for boom-bust cycles is given and draw conclusions whether these countries should join the EMU in the near future. Using a broad range of data sets and empirical methods we document credit market imperfections, comprising asymmetric financing opportunities across sectors, excess foreign currency liabilities and contract enforceability problems both at macro and micro level. Furthermore, we depart from the standard analysis of comovements of business cycles among countries and rather consider long-run and short-run comovements across sectors. While the results differ across countries, we find evidence for credit market imperfections in Central and Eastern Europe and different sectoral reactions to shocks. This gives favour for the assessment of the potential euro accession using this supplementary, non-standard approach.

No description available.

Several boom segments form the crane boom. These segments are often truss structures formed out of circular hollow sections, which are welded together forming the truss joints. A adequate modelling of these truss joints is very important for operational strength and life. Due to the large boom sizes, efficient models are used in the finite element method, generally built of beam elements. These models have problems capturing the proper bending moments working in the truss joints. This is caused by a insufficient portrayal of the joint stiffness. In the literature several modelling techniques with beam elements are proposed, which capture the joint stiffness better. These different modelling methods are implemented in a parametric boom section and compared with a shell element FE model. From this comparison the most appropriate modelling method is selected, which improve the portrayal of internal loads and nominal stresses. With these improved nominal stress values, it is investigated to implement a different fatigue assessment. The structural stress can be calculated from the nominal stress in combination with stress concentration factor (SCF) equations. To implement the structural stress method as fatigue assessment, several modelling and extrapolation methods have been compared. Which lead to a method for evaluating the structural stress in a efficient matter. This method is compared with existing SCF K truss joint equations, from which a new set of SCF equations is derived. These equations are constructed from a larger dataset, hold a wider validity range and fit better with the FE models. When applying these SCF equations with the improved beam modelling method in a boom section, the structural stress is not adequately captured. This is caused by unsymmetrical stressed braces in the K truss joints. Both the modelling methods and SCF equations account for uniformly stressed braces forming the truss joints. More research needs to be conducted to this uneven behaviour. If the structural stress method needs to be implemented with efficient FE models, submodels out of shell elements combined with beam elements are recommended. For fatigue evaluation with the nominal stress method, beam models which account for the local joint flexibility give sufficient realistic results. / Flera kranarmsegment bildar kranarmen. Dessa segment är ofta fackverk utformade av cirkulära ihåliga profiler, som är sammansvetsade och bildar fackverkslederna. En ordentlig modellering av dessa fackförband är mycket viktig för dess driftsstyrka och livslängd. På grund av storleken används finita elementmetoden, vanligtvis uppbyggt av balkelement. Dessa modeller har problem med att beräkna de korrekta böjmomenten som uppstår i fackverkslederna. Detta orsakas av en otillräcklig beskrivning av ledstyvheten. I litteraturen föreslås flera modelleringstekniker med balkelement som tar hänsyn till ledens styvhet bättre. Dessa olika modelleringsmetoder implementeras i en parametrisk kranarmsektion och jämförs med en FE-modell med skalelement. Med denna jämförelse väljs den mest lämpliga modelleringsmetoden, vilket bör förbättra skildringen av interna belastningar och nominella spänningar. Med dessa förbättrade nominella spänningsvärden, undersöks det att genomföra en annan utmattningsbedömning. Den strukturella spänningen kan beräknas utifrån den nominella spänningen i kombination med spänningskoncentrationsfaktor- (SCF) ekvationerna. För att implementera strukturella spänningsmetoden som utmattningsbedömning, har flera modellerings- och extrapoleringsmetoder jämförts. Detta leder till en metod för att utvärdera den strukturella spänningen effektivt. Denna metod jämförs med befintliga SCF-ekvationer, från vilka en ny uppsättning SCF-ekvationer härleds. Dessa ekvationer är konstruerade från en större datauppsättning, har ett bredare giltighetsområde och passar bättre med FE-modellerna. När man applicerar dessa SCF-ekvationer med den förbättrade balkmodelleringsmetoden i en kranarmsektion, uppsamlas strukturella spänningar inte tillräckligt, detta orsakas av ojämna spänningar i diagonalelementen i fackverkslederna. Både modelleringsmetoderna och SCF-ekvationerna tar hänsyn till jämnt spända diagonalelement som uppstår i fackverkslederna. Mer forskning bör göras över detta ojämna beteende. Om den strukturella spänningsmetoden måste implementeras med effektiva FE-modeller, rekommenderas undermodeller av skalelement kombinerade med balkelement. För utmattningsutvärdering med den nominella spänningsmetoden, ger balkmodeller som tar hänsyn till den lokala ledflexibiliteten tillräckligt realistiska resultat.

OF THE THESIS: The novel Captain Pantoja and the Special Service introduces the second period of Mario Vargas Llosa's literary production, which is caracterized by the simplification of the narration and the discovery of humour. The thesis focuses on the formal and thematic analysis of the novel with the objective to prove that despite the novel is in general humorous and parodic, there could be found some constant topics, known to the readers from Llosa's previous novels, which he had always treated very critically, and he also did so in this erotic and humorous work. Therefore, apart from the analysis of humour the thesis also examines the critical approach to the social problems present in the novel. The analysis also shows that the narration is slightly simplified in comparison to the author's formers works, but it still perfectly demonstrates the unconventional narrative techniques, which Vargas Llosa has used since the 1960's, since the period of the new hispano-american novel. KEY WORDS: Mario Vargas Llosa, Captain Pantoja and the Special Service, The Time of the Hero, The Green House, Latin American boom, Hispano-American new novel, total novel, experimental narrative techniques, types of humour and irony, humorous prose, parody, erotic novel, libertine prose, rainforest, criticism of the...