Rice yield estimation based on weather conditions and on technological level of production systems in Brazil

The objective of this work was to evaluate an estimation system for rice yield in Brazil, based on simple agrometeorological models and on the technological level of production systems. This estimation system incorporates the conceptual basis proposed by Doorenbos & Kassam for potential and attainable yields with empirical adjusts for maximum yield and crop sensitivity to water deficit, considering five categories of rice yield. Rice yield was estimated from 2000/2001 to 2007/2008, and compared to IBGE yield data. Regression analyses between model estimates and data from IBGE surveys resulted in significant coefficients of determination, with less dispersion in the South than in the North and Northeast regions of the country. Index of model efficiency (E1') ranged from 0.01 in the lower yield classes to 0.45 in higher ones, and mean absolute error ranged from 58 to 250 kg ha‑1, respectively.

Technological level and epidemiological aspects of sheep husbandry in Minas Gerais, southeastern Brazil

Epidemiological and health aspects of sheep husbandry were assessed on 213 sheep flocks in 142 municipalities from the state of Minas Gerais, southeastern Brazil. An updated questionnaire was filled out for each flock, requesting data on the farm, the flock and the farmer by the veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária). Thirteen important variables were selected and scored to determine the technological level of the 117 farms; 0.9% of them was classified as high technological level, 45.3% as medium technological level and 53.0% as low technological level. Lamb production was the main objective of the farms and the main features were low-frequencies of individual identification of animals (16.9%), technical assistance (31.9%), use of quarantine for newly acquired animals (0.9%) the separation of animals by age group (3.7%) and requeste the sanitary certificate at purchasing of animals (11.7%). The main health problems reported were abortion (23.9%), keratoconjunctivitis (17.9%), contagious ecthyma (13.6%), pneumonia (10.3%), diarrhea (9.3%) and caseous lymphadenitis (6.1%). Information of the epidemiological situation and the mainly health measures used in the sheep farms are important to improve the productivity and quality of the lamb.

Energetic analysis of landrace varieties and hybrids of corn produced in different technological levels of management

The aim of this study was to analyze, under the energetic point of view, the cultivation of corn in three management systems (low, medium and high-tech), using two landrace varieties ('Argentino' and 'BR da Várzea'), a double hybrid cultivar (SHS 4080) and a simple hybrid (IAC 8333). Five performance indicators were used: energy efficiency, liquid cultural energy, cultural efficiency, energy balance and productive energy efficiency. From the perspective of family farming, it was verified the largest social importance of the systems under low and medium levels of technology, due to the increase employment capacity of rural labor. The liquid cultural energy and energy balance were more favorable for the system under high technological level, unlike cultural efficiency and productive energy efficiency, which were significantly higher for medium and low technological levels. The variety 'Argentino' showed lower productive energy efficiency. The variety 'BR da Várzea', on the other hand, presented the potential to generate energy as much as the hybrids. In general, the biggest sustainability in the corn crop was achieved when the management system under medium and lower levels of technology were used.

A Markovian model market-Akerlof`s lemons and the asymmetry of information

In this work we study an agent based model to investigate the role of asymmetric information degrees for market evolution. This model is quite simple and may be treated analytically since the consumers evaluate the quality of a certain good taking into account only the quality of the last good purchased plus her perceptive capacity beta. As a consequence, the system evolves according to a stationary Markov chain. The value of a good offered by the firms increases along with quality according to an exponent alpha, which is a measure of the technology. It incorporates all the technological capacity of the production systems such as education, scientific development and techniques that change the productivity rates. The technological level plays an important role to explain how the asymmetry of information may affect the market evolution in this model. We observe that, for high technological levels, the market can detect adverse selection. The model allows us to compute the maximum asymmetric information degree before the market collapses. Below this critical point the market evolves during a limited period of time and then dies out completely. When beta is closer to 1 (symmetric information), the market becomes more profitable for high quality goods, although high and low quality markets coexist. The maximum asymmetric information level is a consequence of an ergodicity breakdown in the process of quality evaluation. (C) 2011 Elsevier B.V. All rights reserved.

Implementation of proton therapy in the portuguese context of radiotherapy

Cancer is a national and international health care concern. It’s important to find strategies for early diagnosis as well as for the optimization of the various therapeutic options currently existing in Portugal. Cancer is the second leading cause of death in Portugal, the choice of this study, is due to the importance of radiotherapy approach in cancer treatment and because is the therapy used in 40% of oncology patients. Radiation therapy has evolve data technological level, that allows new treatment techniques that are more efficient and that also promotes greater professional satisfaction. The hadrons are charged particles, used in cancer therapy. These particles can bring a paradigm shift regarding the therapeutic approach in radiotherapy. The technique used is proton therapy, that reveal to be more accurate, efficacious and less toxic to surrounding tissue. Proton therapy may be a promising development in the field of oncology and how the treatment is given in radiotherapy. Although there is awareness of the benefits of proton therapy in oncology it’s also important to take in consideration the costs of these therapy, because they are considerably higher than conventional treatments of radiotherapy. Given the lack of a proton therapy service in Portugal, this study aims to be a documentary analysis of clinical records that will achieve the following objectives: to identify the number of cancer patients diagnosed in 2010 in Portugal and to calculate the estimated number of patients that could have been treated with proton therapy according to the Health Council of the Netherlands registration document.

Declarative approach to data extraction of web pages

Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfilment of the requirements for the degree of Master in Computer Science

Eficiência energética na iluminação pública

O presente trabalho aborda a temática da eficiência energética em sistemas de iluminação pública. A principal motivação prende-se com o peso significativo que a parcela energética destes sistemas ocupa na economia mundial. O uso eficiente de energia é uma crescente preocupação devido à diminuição de recursos, às consequências climáticas cada vez mais marcadas e ao elevado custo da energia, representando ainda um papel fundamental ao nível económico e de competitividade. A Iluminação Pública (IP) representa um peso importante nas despesas correntes dos municípios. É assim importante encontrar uma solução que permita manter níveis de segurança e conforto necessários às populações e que proporcione uma redução substancial do peso da IP nas despesas municipais. Neste sentido, este trabalho propõe-se estudar esta problemática, apresentando uma sistematização de soluções eficientes, quer a nível de lâmpadas e luminárias como também ao nível de tecnologias que auxiliem e complementem a eficiência de uma instalação de iluminação pública. A dissertação está dividida em duas partes. A primeira parte sistematiza os consumos verificados em Portugal, a vários níveis (consumo de energia elétrica, evolução do consumo energético de iluminação pública, etc.) abordando as políticas de eficiência energética, e são descritos alguns procedimentos que possibilitam a poupança energética na iluminação pública, aliada a instalações eficientes. A segunda parte da dissertação contempla o estudo de um caso prático cujo objetivo é propor soluções técnicas que permitam melhorar a eficiência energética na iluminação pública de Esposende, face à situação atual do concelho. Serão propostas várias soluções, tais como luminárias LED, balastros electrónicos reguláveis, lâmpadas de menor consumo e até mesmo o uso da telegestão.

Gestão de solventes nas atividades de revestimento e formulação de tintas

O presente trabalho teve como objetivo a realização de um plano de gestão de solventes e sua análise para propor melhorias no cumprimento dos valores legalmente impostos. Foram realizados dois planos distintos, um referente à indústria de revestimento e outro à indústria de formulação de tintas. As abordagens na realização e análise de resolução de problemas são distintas, uma vez que os limites legais são diferentes em ambos os casos. Os componentes que apresentam uma maior expressão face ao plano de gestão de solventes são os compostos orgânicos voláteis (COVs), e é a partir destes componentes que se efetuou toda a análise. Inicialmente foi necessário conhecer todo o funcionamento de cada empresa, os procedimentos adotados, a utilização dos produtos e as técnicas operacionais. Determinaram-se os pontos críticos na avaliação dos problemas que se verificaram nos planos de gestão de solventes e analisaram-se as possibilidades técnicas e tecnológicas passiveis de utilização para a resolução ou minimização desses problemas principalmente na empresa A que excede o limite legalmente imposto. As possibilidades centram-se a nível tecnológico de equipamentos e em produtos utilizados em ambos os casos.

Rapps Sistema de recomendação de apps de produtividade para Android

Nos últimos anos, a nossa sociedade sofreu alterações significativas ao nível tecnológico que têm vindo a modificar o quotidiano do cidadão e transportaram para a palma da mão um conjunto significativo de tarefas até há poucos anos impensáveis. Atualmente, torna-se possível realizar as mais simples tarefas como, a título de exemplo, efetuar um cálculo matemático, tirar fotografias ou registar numa agenda um compromisso, ou tarefas mais complexas, como por exemplo, escrever ou editar um documento, trabalhar numa folha de cálculo ou enviar um e-mail com um anexo, isto tudo com o recurso a um simples dispositivo móvel, conhecido como smartphone ou tablet. Apesar de existirem diversos tipos de apps que seriam um bom auxílio para o aumento da produtividade dos utilizadores de dispositivos móveis Android, nem todos têm conhecimento das mesmas, pelo que é importante que os utilizadores tenham conhecimentos das vantagens da utilização destes recursos e de tudo o que podem realizar com os seus dispositivos com o objetivo de aumentar a sua produtividade profissional ou pessoal. O presente estudo pretende contribuir para uma análise sobre a potencial utilização das novas tecnologias, mais propriamente estudando e recomendando apps de produtividade. Com este intuito foi criada uma app de recomendação de aplicações de produtividade com recurso a um método de sistemas de recomendação. São apresentados os resultados e as conclusões, com recurso a opiniões de potenciais utilizadores.

Deficit, human capital and economic growth dynamics

Long-run economic growth arouses a great interest since it can shed light on the income-path of an economy and try to explain the large differences in income we observe across countries and over time. The neoclassical model has been followed by several endogenous growth models which, contrarily to the former, seem to predict that economies with similar preferences and technological level, do not necessarily tend to converge to similar per capita income levels. This paper attempts to show a possible mechanismthrough which macroeconomic disequilibria and inefficiencies, represented by budget deficits, may hinder human capital accumulation and therefore economic growth. Using a mixed education system, deficit is characterized as a bug agent which may end up sharply reducing the resources devoted to education and training. The paper goes a step further from the literature on deficit by introducing a rich dynamic analysis of the effects of a deficit reduction on different economic aspects.Following a simple growth model and allowing for slight changes in the law of human capital accumulation, we reach a point where deficit might sharply reduce human capital accumulation. On the other hand, a deficit reduction carried on for a long time, taking that reduction as a more efficient management of the economy, may prove useful in inducing endogenous growth. Empirical evidence for a sample of countries seems to support the theoretical assumptions in the model: (1) evidence on an inverse relationship betweendeficit and human capital accumulation, (2) presence of a strongly negative associationbetween the quantity of deficit in the economy and the rate of growth. They may prove a certain role for budget deficit in economic growth

Deficit, human capital and economic growth dynamics

Long-run economic growth arouses a great interest since it can shed light on the income-path of an economy and try to explain the large differences in income we observe across countries and over time. The neoclassical model has been followed by several endogenous growth models which, contrarily to the former, seem to predict that economies with similar preferences and technological level, do not necessarily tend to converge to similar per capita income levels. This paper attempts to show a possible mechanismthrough which macroeconomic disequilibria and inefficiencies, represented by budget deficits, may hinder human capital accumulation and therefore economic growth. Using a mixed education system, deficit is characterized as a bug agent which may end up sharply reducing the resources devoted to education and training. The paper goes a step further from the literature on deficit by introducing a rich dynamic analysis of the effects of a deficit reduction on different economic aspects.Following a simple growth model and allowing for slight changes in the law of human capital accumulation, we reach a point where deficit might sharply reduce human capital accumulation. On the other hand, a deficit reduction carried on for a long time, taking that reduction as a more efficient management of the economy, may prove useful in inducing endogenous growth. Empirical evidence for a sample of countries seems to support the theoretical assumptions in the model: (1) evidence on an inverse relationship betweendeficit and human capital accumulation, (2) presence of a strongly negative associationbetween the quantity of deficit in the economy and the rate of growth. They may prove a certain role for budget deficit in economic growth

On the industry experience premium and labor mobility

[cat] Hi ha evidència que l'experiència es remunera diferentment segons la indústria. Proposem un model teòric que explica aquestes diferències. Suposem que la mobilitat de treballadors aporta coneixement extern a l'empresa i això augmenta la seva productivitat. Els resultats mostren que l'experiència és millor remunerada en les indústries amb costos de mobilitat baixos, amb molt aprenentatge (learning-by-doing) i alt nivell tecnològic. A més, trobem una relació en forma de U entre la remuneració de l'experiència i el nivell d'absorció de coneixement extern, la substitutibilitat entre diferents tipus de treballadors i la varietat de coneixement dins la indústria. Els resultats són consistents amb l'evidència que les indústries intensives en I and D remuneren millor l'experiència.

Modelling diffusion of innovations in a social network

A simple model of diffusion of innovations in a social network with upgrading costs is introduced. Agents are characterized by a single real variable, their technological level. According to local information, agents decide whether to upgrade their level or not, balancing their possible benefit with the upgrading cost. A critical point where technological avalanches display a power-law behavior is also found. This critical point is characterized by a macroscopic observable that turns out to optimize technological growth in the stationary state. Analytical results supporting our findings are found for the globally coupled case.

Identity [R]Evolution: Multi-Disciplinary Perpectives

The identity [r]evolution is happening. Who are you, who am I in the information society? In recent years, the convergence of several factors - technological, political, economic - has accelerated a fundamental change in our networked world. On a technological level, information becomes easier to gather, to store, to exchange and to process. The belief that more information brings more security has been a strong political driver to promote information gathering since September 11. Profiling intends to transform information into knowledge in order to anticipate one's behaviour, or needs, or preferences. It can lead to categorizations according to some specific risk criteria, for example, or to direct and personalized marketing. As a consequence, new forms of identities appear. They are not necessarily related to our names anymore. They are based on information, on traces that we leave when we act or interact, when we go somewhere or just stay in one place, or even sometimes when we make a choice. They are related to the SIM cards of our mobile phones, to our credit card numbers, to the pseudonyms that we use on the Internet, to our email addresses, to the IP addresses of our computers, to our profiles... Like traditional identities, these new forms of identities can allow us to distinguish an individual within a group of people, or describe this person as belonging to a community or a category. How far have we moved through this process? The identity [r]evolution is already becoming part of our daily lives. People are eager to share information with their "friends" in social networks like Facebook, in chat rooms, or in Second Life. Customers take advantage of the numerous bonus cards that are made available. Video surveillance is becoming the rule. In several countries, traditional ID documents are being replaced by biometric passports with RFID technologies. This raises several privacy issues and might actually even result in changing the perception of the concept of privacy itself, in particular by the younger generation. In the information society, our (partial) identities become the illusory masks that we choose -or that we are assigned- to interplay and communicate with each other. Rights, obligations, responsibilities, even reputation are increasingly associated with these masks. On the one hand, these masks become the key to access restricted information and to use services. On the other hand, in case of a fraud or negative reputation, the owner of such a mask can be penalized: doors remain closed, access to services is denied. Hence the current preoccupying growth of impersonation, identity-theft and other identity-related crimes. Where is the path of the identity [r]evolution leading us? The booklet is giving a glance on possible scenarios in the field of identity.

On the industry experience premium and labor mobility

[cat] Hi ha evidència que l'experiència es remunera diferentment segons la indústria. Proposem un model teòric que explica aquestes diferències. Suposem que la mobilitat de treballadors aporta coneixement extern a l'empresa i això augmenta la seva productivitat. Els resultats mostren que l'experiència és millor remunerada en les indústries amb costos de mobilitat baixos, amb molt aprenentatge (learning-by-doing) i alt nivell tecnològic. A més, trobem una relació en forma de U entre la remuneració de l'experiència i el nivell d'absorció de coneixement extern, la substitutibilitat entre diferents tipus de treballadors i la varietat de coneixement dins la indústria. Els resultats són consistents amb l'evidència que les indústries intensives en I and D remuneren millor l'experiència.