In this thesis I inspect learning about adoption of technologies among cocoa farmers in Ghana, which are represented by non-labor inputs, particularly by fertilizer and hybrid seeds. Earlier research focused mainly on learning about returns associated with adoption of such innovative inputs. However, it is not clear whether the adopters learn about these returns or rather about what are the optimal amounts of these inputs. Therefore the focus of this thesis is to examine how do the farmers choose and learn about optimal amounts of inputs. Cocoa farming is very labor intensive, and thus this thesis concentrates on learning about both non-labor and labor inputs, which are closely connected. Similar research carried out in India suggests that heterogeneous returns among farmers might cause that the farmers rely rather on their own considerations than on observation of behavior of their village neighbors, i.e. social learning. The heterogeneous returns are also present among the Ghanaian cocoa farmers, which suggest that these farmers should similarly prefer individual learning over the social one. Using a model developed for estimation of the prevailing type of learning about the optimal amount of inputs, I show that the farmers do tend to prefer individual learning in case of the non-labor inputs but rather...

The two most common commercial copper baths are the acid sulfate copper bath and the alkaline cyanide copper bath. Alkaline copper baths are mostly used to coat parts with complex geometry and to avoid galvanic deposition when depositing a metal on a less noble substrate. Because of the toxicity of cyanide compounds, alternative baths have been developed using different complexing agents. The starting point of the present study is a cyanide-free strike bath developed for copper plating on Zamak substrates developed by the Institute for Technological Research of the State of São Paulo/ Brazil. The replacement of a raw material such as cyanide must be economically advantageous and technically feasible. Therefore, this study intended to propose an alternative to the treatment of liquid wastes from the mentioned bath, aiming at simultaneous water reclamation and chemicals recovery in a closed system. The electrodialysis membrane separation process was studied, using a laboratoryscale system operating with a synthetic solution simulating the rinsing waters from the HEDP-based bath. The feasibility of the technique was evaluated by analyzing operational parameters such as ion extraction, demineralization rate, concentration rate, current efficiency for each anionic specie and average energy consumption. Because HEDP is a chelating agent, the transport of Cu(II)-HEDP chelates through anion-exchange membranes was also evaluated by means of electrochemical methods. Chronopotentiometric and current-voltage curves were constructed for different model solutions containing the same compounds as the original bath. A relation between the presence of chelates in the solutions and the fixed ion exchange group could be established. Lastly, deposition tests were performed using electrolytes containing the recycled inputs and the characteristics of the coatings were analyzed. The results showed that an electrodialysis stack using strongly basic anion-exchange membranes was suitable to produce treated solutions and a concentrate containing the ions from the bath. The concentrate could be added to the copper bath to compensate eventual drag-out losses without affecting the quality of the coatings. Thus, the application of electrodialysis was shown to be a feasible alternative for recovering water and inputs from the evaluated solution, reducing the wastewater generation and saving natural resources. / Os dois banhos de cobre comerciais mais comuns são o banho ácido à base de sulfato e o banho alcalino à base de cianeto. Os banhos alcalinos são usados principalmente para recobrir peças com geometria complexa e para evitar a deposição por deslocamento galvânico quando se deposita um metal em um substrato menos nobre. Por causa da toxicidade dos compostos cianídricos, banhos alternativos vêm sendo desenvolvidos usando diferentes agentes complexantes. O ponto de partida do presente estudo é um banho toque isento de cianeto para deposição de cobre em substratos de Zamak, desenvolvido pelo Instituto de Pesquisas Tecnológicas / Brasil. A substituição de matérias-primas como o cianeto deve ser economicamente vantajosa e tecnicamente viável. Desta forma, este estudo pretendeu propor uma alternativa para o tratamento de resíduos líquidos do banho mencionado, visando à recuperação simultânea da água e das matérias-primas em um sistema fechado. Foi estudado o processo de separação por membranas de eletrodiálise, usando um sistema em escala laboratorial operando com uma solução sintética que simulava as águas de lavagem do banho à base de HEDP. A viabilidade da técnica foi avaliada por meio da análise de parâmetros operacionais, como a extração dos íons, a taxa de dessalinização, o percentual de concentração, a eficiência de corrente calculada para cada espécie iônica e o consumo médio de energia. Devido ao HEDP ser um agente quelante, o transporte de quelatos Cu(II)-HEDP através de membranas aniônicas foi avaliado por meio de métodos eletroquímicos. Curvas cronopotenciométricas e curvas corrente-potencial foram construídas para diferentes soluções sintéticas que continham os mesmos compostos que o banho original. A relação entre a presença de quelatos nas soluções e os grupos fixos de troca iônica pôde ser estabelecida. Por fim, testes de deposição foram realizados usando eletrólitos contendo os compostos reciclados e as características dos depósitos foram analisadas. Os resultados mostraram que o sistema de eletrodiálise usando membranas aniônicas contendo grupos de troca fortemente básicos pôde produzir soluções tratadas e um concentrado contendo os íons do banho. O concentrado pôde ser adicionado ao banho original para compensar eventuais perdas por arraste sem afetar a qualidade dos depósitos. Assim, a aplicação da eletrodiálise se mostrou uma alternativa viável para a recuperação de água e de insumos da solução avaliada, reduzindo a geração de efluentes e economizando recursos naturais.

Made available in DSpace on 2016-04-26T20:23:38Z (GMT). No. of bitstreams: 1 Fernando Gomes Favacho.pdf: 1704449 bytes, checksum: 572c9097ef62025d6251eacefe267532 (MD5) Previous issue date: 2015-03-24 / The question studied in this work is the definition of inputs used on the non-cumulativity system in the Brazilian Social Securuty Contributions (named PIS/COFINS). We start this study using a method of defining objects by it's conceivable effects, namely the Peirce´s pragmaticism, wherein the construction of the concept evolves and is connected to its conceivable consequences. The work demonstrates the evolution of concepts through judicial decisions. The doctrine and previous administrative court trend decisions states that the "non-cumulative" PIS/COFINS, unlike the non-cumulative system of the Industrialized Products Tax (IPI), uses tax credits from inputs used not only directly in the product, with the physical wear, but also as other items used for the fulfillment of production. Through jurisprudential research, particularly in the courts aimed at stability trials, we have the content needed to create a prognosis to show us how to draw the formation of a habit when it comes to applying the concept of inputs at article 3, item II of the Brazilian Federal Law 10,627/2002 and 10,833/2003.The hypothesis created by abductive method, that is, through the repeated decisions, refutes the restrictive vision of the Federal Revenue of Brazil manifested on the Normative Instructions 247/2002 and 404/2004 and legal consultations answered by the Brazilian Federal Revenue Office in that coincides the inputs used by IPI. In a rare decision, the Administrative Board of Tax Appeals equates the concept to costs and expenses deductible for Corporate Income Tax, whereas in others - today majority position searches its own concept. In these, the idea of inputs is focused on the use of inputs for the production or service, which in our view is an application of the pragmatic maxim. The case brings us a prospect, a conjecture from the facts. The conclusion, therefore, is a prognosis. We will have here the possibility to see inputs as a general clause to be determined by the case. The conclusive prognosis makes the fact itself a part of the norm composed by the judge / A questão estudada neste trabalho é a definição de insumos na não cumulatividade da Contribuição ao PIS e da COFINS. Parte-se de um método que define o objeto por meio de consequências verificáveis, qual seja, o pragmaticismo, de Charles Sanders Peirce, em que a construção do conceito evolui e é ligada às suas consequências concebíveis. O estudo demonstra a evolução dos conceitos por meio de decisões judiciais. A tendência doutrinária e jurisprudencial administrativa afirma que a não cumulatividade do PIS/COFINS, diferentemente da não cumulatividade do IPI, usa créditos tributários oriundos de insumos utilizados não só diretamente no produto, com o desgaste físico, mas também como outros itens usados para o cumprimento da produção. Por meio de pesquisa jurisprudencial, em especial nos tribunais que visam à estabilidade dos julgamentos, temos o índice necessário para criar um prognóstico que nos mostre como se desenha a formação de um hábito, quando se trata de aplicar o conceito de insumo do art. 3º, II, das Leis 10.627/02 e 10.833/03. A hipótese criada pelo método abdutivo, ou seja, por meio de decisões reiteradas, afasta a visão restritiva da Receita Federal do Brasil manifestada nas Instruções Normativas 247/2002 e 404/2004 e em diversas soluções de consulta e de divergência em que se equipara aos insumos do IPI. Em rara decisão, o CARF equipara o conceito aos custos e despesas dedutíveis para fins de IRPJ, ao passo que em outras posição hoje majoritária busca um conceito próprio. Nessas, a ideia de insumos é focada na utilização dos insumos em relação à produção/prestação de serviço, o que a nosso ver é uma aplicação da máxima pragmática. A jurisprudência nos traz uma prospecção, uma conjectura a partir dos fatos. A conclusão, portanto, é um prognóstico. Teremos aqui a possibilidade de ver os insumos como cláusula geral a ser determinada pelo caso. O prognóstico conclusivo faz com que o fato participe da composição normativa por intermédio do julgador

Parmi les méthodes de diagnostic de défauts issue de l'automatique, la méthode des filtres résiduels permet de synthétiser des filtres générant des signaux (dits résidus) qui sont utilisés à des ns de détection de défauts. Dans notre approche, les filtres résiduels sont obtenus à partir d'observateurs réduits. L'objectif decette thèse est de synthétiser des observateurs et de mettre en évidence leur application à la détection de défauts pour les systèmes non linéaires. Ce mémoire est réparti en deux parties. Dans la première partie, deux contributions ont été présentées. La première concerne les observateurs à entrées inconnues pour les systèmes affines en l'état modulo une injection de sortie. L'approche proposée est une combinaison des techniques de découplage géométrique et des observateurs non linéaires. Des conditions suffisantes ont été données accompagnées d'un algorithme permettant de concevoir un observateur à entrées inconnues permettant d'estimer une partie de l'état indépendamment de la connaissance de certaines entrées. La deuxième contribution consiste à caractériser la classe des systèmes non linéaires qui se transforment en des systèmes en cascade pour lesquels un observateur peut être conçu. Tout d'abord, des conditions nécessaires et suffisantes théoriques ont été données, ensuite un algorithme permettant de calculer ces transformations (diéomorphismes) a été proposé. Enfin, l'ensemble de tous ces difféomorphismes a été caractérisé en montrant que ce dernier est une orbite d'une action d'un groupe particulier sur l'ensemble de tous les difféomorphismes. La deuxième partie de cette thèse concerne la synthèse d'un filtre polytopique Linéaires à Paramètres Variants (LPV) permettant de détecter, isoler et estimer de multiples défauts capteur. L'avantage de ce filtre est de générer deux types de résidus : l'un étant sensible aux défauts et l'autre insensible. Le résidu insensible est utilisé pour fournir une information qualitative supplémentaire de l'efficacité du filtre. La stabilité de ce dernier est analysée au moyen d'Inégalités Matricielles Linéaires (LMI) / Among the faults diagnosis methods, the method of residual filters allows to synthesize filters generating signals ( called residues) that are used for fault detection. In our approach, the residual filters are obtained from reduced observers. The objective of this thesis is to synthesize observers and highlight their application to fault detection for nonlinear systems. This thesis is divided into two parts. In the first part, two papers were presented. The rst one relates to the unknown input observers for state ane systems modulo an output injection. The proposed approach is a combination of geometric decoupling techniques and nonlinear observers. We have given sufficient conditions with an algorithm for designing an unknown input observer to estimate a part of the state without the knowledge of some inputs. The second contribution consists to characterize the class of nonlinear systems which can be transformed into cascade systems for which an observer can be designed. First, necessary and sufficient theoretical conditions were given, then an algorithm to compute these transformations (diffeomorphisms) was proposed. Finally, the set of all dieomorphisms was characterized by showing that it is an orbit of an action of a particular group on the set of all dieomorphisms. The second step of the thesis deals with the synthesis of a polytopic Linear Parameter-Varying (LPV) filter to detect, isolate and estimate multiple sensor faults. The advantage of this lter is to generate two types of residuals : one being sensitive to faults and the other is insensitive. The insensitive residual is used to generate an additional qualitative information of the filter efficiency. The stability of the latter has been performed using Linear Matrix Inequality (LMI)

Structural fire design represents one important aspect of the design of reinforced concrete buildings. The work presented in this thesis seeks to elucidate the structural behaviour of reinforced concrete slabs during exposure to heating from below, as would occur in the case of a building fire, with a particular focus on structural fire modelling using finite element analysis. The focus in on validating finite element models against experimental results and quantifying the sensitivity of model outputs to relevant thermal and mechanical input parameters. A primary goal of the work is to provide recommendations to structural fire engineering analysts and designers considering the performance-based design of reinforced concrete slabs for structural fire resistance using available finite element software. A critical review of the available knowledge of the structural fire response of reinforced concrete structures in general and concrete slabs in particular is presented, along with an awareness as to the importance of understanding structural response of concrete structures exposed to fires. Current techniques for structural fire design of concrete structures are reviewed, and shortcomings highlighted. Available experimental data are presented, and various finite element models of these slabs are developed and interrogated to identify important aspects for understanding, as well as for future improvement of similar studies (both experimental and numerical) with the intention of supporting future progress in structural fire engineering, in particular as regards performance based structural fire design of concrete slabs. A range of thermal and mechanical parameters that are potentially important and influential in the structural fire design of reinforced concrete slabs is then studied, including: fire scenario, thermal properties of materials (thermal conductivity and specific heat), heat transfer parameters (coefficient of convection and emissivity) and assumptions, restraint conditions at the supports, variations of span-to-depth ratio, reinforcement detailing, as well as plan aspect ratio are all investigated; their influence on the structural fire response of reinforced concrete slabs is studied and discussed. A key issue in validating finite element models against experimental results lies in defining the temperature inputs to the structural finite element models correctly. Variation of available thermal and mechanical input parameters, as recommended in Eurocodes, influences the predictive performance of thermal and structural finite element models, however these are not the main contributing factors in obtaining a credible prediction of response from the finite element models. The most challenging aspect in performing heat transfer analysis for fire furnace tested reinforced concrete slabs lies in defining the correct thermal boundary condition. For simply supported one-way spanning and two-way spanning slabs, increasing slab's thickness (lowering span-depth ratio) does not improve fire resistance rating for the slabs when both limiting deflection criteria and limiting tensile plastic strain are set as acceptance criteria. Two-way slabs with higher span-depth ratio have better fire resistance ratings, judging from the overall trends and magnitudes of mid-span deflections. The formation of plastic hinges is likely to occur for one-way spanning slabs modelled with finite rotational spring stiffness at supports, but not for two-way spanning slabs. A yield line mechanism in two-way slabs means that the behaviour is more complex as compared to the simple flexural mechanism for one-way slabs. In one-way slabs, plastic hinges potentially occur at the location where top reinforcement is curtailed, highlighting the importance of properly understanding the nuances in response of concrete slabs in fire. Investigation of the influence of aspect ratio in two-way spanning slabs confirms that slabs with lower aspect ratios have better structural fire resistance than slabs with higher aspect ratios when both limiting deflection criteria and limiting tensile strain in reinforcing steel were used as the performance indicators. A combination of both limiting mid-span deflection criteria as well as limiting tensile plastic strain is recommended for specifying acceptance criteria for both one-way and two-way slabs, since it gives more accurate and comprehensive assessment on the structural response of the slabs under exposure to severe heating from below.

In this paper we examine the stabilization of LTI discrete-time systems with control input constraints in the form of saturation nonlinearities. This kind of constraint is usually introduced to simulate the effect of actuator limitations. Since global controllability can not be assumed in the presence of constrained control, the controllable regions and their characterizations are analyzed first. We present an efficient algorithm for finding controllable regions in terms of their boundary hyperplanes (inequality constraints). A previously open question about the exact number of irredundant boundary hyperplanes is also resolved here. The main result of this research is a time-optimal nonlinear controller which stabilizes the system on its controllable region. We give analgorithm for on-line computation of control which is also implementable for high-order systems. Simulation results show superior response even in the presence of disturbances.

In this paper we examine the stabilization of LTI discrete-time systems with control input constraints in the form of saturation nonlinearities. This kind of constraint is usually introduced to simulate the effect of actuator limitations. Since global controllability can not be assumed in the presence of constrained control, the controllable regions and their characterizations are analyzed first. We present an efficient algorithm for finding controllable regions in terms of their boundary hyperplanes (inequality constraints). A previously open question about the exact number of irredundant boundary hyperplanes is also resolved here. The main result of this research is a time-optimal nonlinear controller which stabilizes the system on its controllable region. We give analgorithm for on-line computation of control which is also implementable for high-order systems. Simulation results show superior response even in the presence of disturbances.

The reversible logic has the promising applications in emerging computing paradigm such as quantum computing, quantum dot cellular automata, optical computing, etc. In reversible logic gates there is a unique one-to-one mapping between the inputs and outputs. To generate an useful gate function the reversible gates require some constant ancillary inputs called ancilla inputs. Also to maintain the reversibility of the circuits some additional unused outputs are required that are referred as the garbage outputs. The number of ancilla inputs, number of garbage outputs and quantum cost plays an important role in the evaluation of reversible circuits. Thus minimizing these parameters are important for designing an efficient reversible circuit. Barrel shifter is an integral component of many computing systems due to its useful property that it can shift and rotate multiple bits in a single cycle. The main contribution of this thesis is a set of design methodologies for the reversible realization of reversible barrel shifters where the designs are based on the Fredkin gate and the Feynman gate. The Fredkin gate can implement the 2:1 MUX with minimum quantum cost, minimum number of ancilla inputs and minimum number of garbage outputs and the Feynman gate can be used so as to avoid the fanout, as fanout is not allowed in reversible logic. The design methodologies considered in this work targets 1.) Reversible logical right- shifter, 2.) Reversible universal right shifter that supports logical right shift, arithmetic right shift and the right rotate, 3.) Reversible bidirectional logical shifter, 4.) Reversible bidirectional arithmetic and logical shifter, 5) Reversible universal bidirectional shifter that supports bidirectional logical and arithmetic shift and rotate operations. The proposed design methodologies are evaluated in terms of the number of the garbage outputs, the number of ancilla inputs and the quantum cost. The detailed architecture and the design of a (8,3) reversible logical right-shifter and the (8,3) reversible universal right shifter are presented for illustration of the proposed methodologies.

Uppsatsens syfte är att undersöka hur Sveriges utrikeshandel har påverkat arbetskraftenssammansättning. Det är viktigt att utreda då den internationella handeln ständigt ökar. Enligthandelsteori leder utrikeshandel till att produktion av varor och tjänster specialiseras efter dekomparativa fördelar som förekommer. I Sveriges fall innebär det specialisering motkapitalintensiv produktion vilket bör leda till en ökad efterfråga på högskoleutbildadarbetskraft.Syftet besvaras med hjälp av en ekonometrisk studie där data från svensk tillverkningsindustriför åren 1995 – 2005 struktureras som paneldata. Andelen importerade insatsvaror användssom proxyvariabel för utrikeshandelns påverkan. Arbetskraftens sammansättning definierassom fördelningen mellan individer med och utan högskoleutbildning.Uppsatsens resultat är att utrikeshandel kan ha påverkat arbetskraftens sammansättning itillverkningsindustrin då efterfrågan på högskoleutbildad arbetskraft har ökat under studeradtidsperiod. Kapitalintensiva näringsgrenar påverkas i lägre grad jämfört medarbetskraftsintensiva näringsgrenar av en förändring i andelen importerade insatsvaror. / The purpose of this study is to analyse how Sweden’s foreign trade has affected thecomposition of the country’s workforce. International trade is growing constantly; thereforethere is a need to understand the importance and consequences of this. According to tradetheory, international trade will lead to specialisation of the production of goods and servicestowards areas where comparative advantages are prominent. In Sweden’s case, this meansspecialisation in capital-intensive production, which should increase the demand for skilledlabour.An econometric study of the Swedish manufacturing industry for the years 1995 – 2005 is thebasis for the study. Data is structured as panel data where the share of imported inputs is usedas a proxy for the impact of foreign trade on the composition of the workforce. Thecomposition consists of skilled and non-skilled labour.Results of this study demonstrate that foreign trade has affected the composition of theworkforce in the manufacturing industry, as the demand for skilled labour has increasedduring the time period.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.