Accuracy of a DTM derived from full-waveform laser scanning data under unstructured eucalypt forest: a case study

A Digital Terrain Model (DTM) is fundamental for extracting several forest canopy structure metrics from data acquired with small-footprint airborne laser scanning (ALS). This modern remote sensing technology is based on laser measurements from a laser system mounted on an aircraft and integrated with a geodetic GNSS receiver and an inertial measurement unit (IMU) or inertia navigation system (INS). In the context of a research project for deriving forest inventory parameters and fuel variables under eucalypt stands in Mediterranean climates, the vertical precision of the DTM obtained by automatic filtering of full-waveform ALS data had to be evaluated. The DTM accuracy estimation on a study area with peculiar characteristics, which are often avoided in related studies, will also allow verifying the performance of full- waveform ALS systems. The accuracy estimation is carried out in a novel way. By novel way, it is meant an exhaustive, well-planned collection of reliable control data in forest environment. The collection of the control data involves the production of DTM on 43 circular plots (radius = 11.28m) using total stations and geodetic GNSS receivers. These DTM, with a total of 3356 points, allowed one to evaluate consistently and reliably the vertical accuracy of the terrain surface produced with ALS under a eucalypt forest. This global accuracy, expressed by the Root Mean Square Error (RMSE) of the vertical differences between the field surveyed surface and the ALS derived DTM surface is 0.15m (mean=0.08m and std=0.09m). This impressive value indicates that, for an ALS point cloud density of 10pts/m2 and footprint of 20 cm, the methodology used to extract the DTM from full- waveform ALS data under an unstructured eucalypt forest is very accurate. In this article it is addressed both the strategy adopted to collect the control data and the quality assessment of the DTM produced by means of the ALS data

Effect of the Resolution and Accuracy of DTM produced with Aerial Photogrammetry and Terrestrial Laser Scanning on Slope- and Catchment-scale Erosion Assessment in a Recently Burnt Forest Area: a Case Study

Wildfires are a common phenomenon in Portugal, affecting on average 100.000 ha of rural areas per year and up to 400.000 ha in dramatic years like 2003 and 2005. Wildfires can strongly enhance the hydrological response and associated sediment losses in recently burnt forest catchments and, thereby, negatively affect land-use sustain- ability of the affected terrains as well as ecosystem functioning of downstream aquatic habitats. Therefore, the EROSFIRE-I and –II projects aim at developing a GIS-tool for predicting soil erosion hazard following wildfire and, ultimately, for assessing the implications of alternative post-fire land management practices. Assessment of runoff and soil erosion rates critically depends on accurate estimates of the corresponding runoff areas. In the case of catchments as well as unbounded erosion plots (arguably, the only practical solution for slope-scale measurements), delineation of runoff area requires a Digital Terrain Model (DTM) with an adequate resolution and accuracy. The DTM that was available for the Colmeal study area, localized in the mountain range of Lousã, in the central part of Portugal, of EROSFIRE-II project is that of the 1:25.000 topographic map produced by the Military Geographic Institute. Since the Colmeal area involves a rather small experimental catchment of roughly 10 ha and relatively short study slopes of less than 100 m long, two different data acquisition techniques were used to produce high-resolution and high-accuracy DTM. One of the data acquisition techniques is aerial photogrammetry whilst the other is terrestrial laser scanning. In order to produce a DTM by photogrammetric means, a dedicated digital aerial photography mission was carried out. The images have a pixel size of 10 cm. Manual measurements permitted to measure breaklines and were complemented by automatic measurements. In this way, a DTM in a TIN format was produced. This was further converted to grid format using the ArcGIS software system. Signalized control points allowed obtaining the DTM in the same global reference system as that employed for terrestrial laser scanning. The terrestrial laser scanning was done using a Riegl LMS Z360I, stationed in 8 points within the area to provide a complete coverage. The resulting dense cloud of points was filtered – by the company carrying out the scanning mission - to remove the non-terrain points (in particular vegetation). Several grids of different sizes were produced (0.10 x 0.10, 0.20 x 0.20, 0.50 x 0.50, 1 x 1 and 2 x 2 m2). This work will study the effect on runoff and erosion rates at the slope- and catchment-scale of DTM with differ- ent resolution, but produced with data collected with the same acquisition technique, and of DTM with the same resolution, but produced with data collected with the two different acquisition techniques. The study is being carried out in ArcGIS using DTM in a grid format. Preliminary results suggest that the conver- sion of TIN-to-grid in ArcGIS produces results that depend on the procedure being applied. Therefore, the different algorithms available at ArcGIS for TIN-to-grid conversion are currently being tested, using an artificially produced DTM. This testing includes various interpolation techniques for grid generation, and will be extended to different algorithms for computation of drainage flow direction

Ten steps for writing a successful scientific article

O estudo apresenta dez passos para produzir artigo científico de sucesso

Long-term dependence in financial prices: evidence from the Belgian stock market returns

This article aims to contribute to the discussion of long-term dependence, focusing on the behavior of the main Belgian stock index. Non-parametric analyzes of the general characteristics of temporal frequency show that daily returns are non-ergodic and non-stationary. Therefore, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA), under the fractional Brownian motion approach, and we found slight evidence of long-term dependence. These results refute the random walk hypothesis with i.i.d. increments, which is the basis of the EMH in its weak form, and call into question some theoretical modeling of asset pricing. Other more localized complementary study, to identify the evolution of the degree of dependence over time windows, showed that the index has become less persistent from 2010. This may mean a maturing market by the extension of the effects of current financial crisis

Impacts of Basel III announcements on European bank business models

The Basel regulation put forth by the Basel Committee of Banking Supervision (BCBS) is an ambitious endeavor that aims at regulating the banking industry worldwide. The Basel III accord introduced in 2010 is the latest iteration of this effort. Implementation of Basel III is well underway today and programmed to take full effect in 2019. The criticism towards Basel III is mainly pointed towards the negative impact it could have on the economy and the profitability of banking institutions. In addition, the impacts on different banking business models could be heterogeneous, benefitting some models more than others. The main question this thesis tries to answer is if wealth effects on European exchange traded banks brought by Basel III will be negative and if different business models will be impacted differently. To answer this question a group of European banks were selected. Bank business models were assigned using the k-means clustering algorithm where banks are clustered into traditional vs. non-traditional categories depending on the asset and liability structure of the balance sheet. An event study is then conducted to measure the wealth effects caused by the introduction of Basel III on an aggregate level and by business model. The event studies are conducted on six key dates from press releases by the BCBS to better capture the full effects of Basel III. Lastly, a regression model is used to check whether there is any relationship between the abnormal returns on the pre-specified event dates and bank business models. This thesis finds that impacts on different event dates were not homogenous: some resulted in positive abnormal returns and some negative therefore it was not possible to conclude if the impact of Basel III was negative on European exchange traded banks. From the results, it was not possible to conclude if any business model is impacted more or less severely by Basel III. The results suggest that there are more dynamics at play that could influence the value of exchange traded European banks

Persistence characteristics in financial prices: evidence from the portuguese stock market returns

The objective of this article is to provide additional knowledge to the discussion of long-term memory, leaning over the behavior of the main Portuguese stock index. The first four moments are calculated using time windows of increasing size and sliding time windows of fixed size equal to 50 days and suggest that daily returns are non-ergodic and non-stationary. Seeming that the series is best described by a fractional Brownian motion approach, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA). The findings indicate evidence of long term memory in the form of persistence. This evidence of fractal structure suggests that the market is subject to greater predictability and contradicts the efficient market hypothesis in its weak form. This raises issues regarding theoretical modeling of asset pricing. In addition, we carried out a more localized (in time) study to identify the evolution of the degree of long-term dependency over time using windows 200-days and 400-days. The results show a switching feature in the index, from persistent to anti-persistent, quite evident from 2010

Memória de longo prazo nos retornos acionistas dos índices de referência da euronext, implicações para a hipótese de mercados eficientes e contributo fractal para aperfeiçoamento do capital asset pricing model

Não existe uma definição única de processo de memória de longo prazo. Esse processo é geralmente definido como uma série que possui um correlograma decaindo lentamente ou um espectro infinito de frequência zero. Também se refere que uma série com tal propriedade é caracterizada pela dependência a longo prazo e por não periódicos ciclos longos, ou que essa característica descreve a estrutura de correlação de uma série de longos desfasamentos ou que é convencionalmente expressa em termos do declínio da lei-potência da função auto-covariância. O interesse crescente da investigação internacional no aprofundamento do tema é justificado pela procura de um melhor entendimento da natureza dinâmica das séries temporais dos preços dos ativos financeiros. Em primeiro lugar, a falta de consistência entre os resultados reclama novos estudos e a utilização de várias metodologias complementares. Em segundo lugar, a confirmação de processos de memória longa tem implicações relevantes ao nível da (1) modelação teórica e econométrica (i.e., dos modelos martingale de preços e das regras técnicas de negociação), (2) dos testes estatísticos aos modelos de equilíbrio e avaliação, (3) das decisões ótimas de consumo / poupança e de portefólio e (4) da medição de eficiência e racionalidade. Em terceiro lugar, ainda permanecem questões científicas empíricas sobre a identificação do modelo geral teórico de mercado mais adequado para modelar a difusão das séries. Em quarto lugar, aos reguladores e gestores de risco importa saber se existem mercados persistentes e, por isso, ineficientes, que, portanto, possam produzir retornos anormais. O objetivo do trabalho de investigação da dissertação é duplo. Por um lado, pretende proporcionar conhecimento adicional para o debate da memória de longo prazo, debruçando-se sobre o comportamento das séries diárias de retornos dos principais índices acionistas da EURONEXT. Por outro lado, pretende contribuir para o aperfeiçoamento do capital asset pricing model CAPM, considerando uma medida de risco alternativa capaz de ultrapassar os constrangimentos da hipótese de mercado eficiente EMH na presença de séries financeiras com processos sem incrementos independentes e identicamente distribuídos (i.i.d.). O estudo empírico indica a possibilidade de utilização alternativa das obrigações do tesouro (OT’s) com maturidade de longo prazo no cálculo dos retornos do mercado, dado que o seu comportamento nos mercados de dívida soberana reflete a confiança dos investidores nas condições financeiras dos Estados e mede a forma como avaliam as respetiva economias com base no desempenho da generalidade dos seus ativos. Embora o modelo de difusão de preços definido pelo movimento Browniano geométrico gBm alegue proporcionar um bom ajustamento das séries temporais financeiras, os seus pressupostos de normalidade, estacionariedade e independência das inovações residuais são adulterados pelos dados empíricos analisados. Por isso, na procura de evidências sobre a propriedade de memória longa nos mercados recorre-se à rescaled-range analysis R/S e à detrended fluctuation analysis DFA, sob abordagem do movimento Browniano fracionário fBm, para estimar o expoente Hurst H em relação às séries de dados completas e para calcular o expoente Hurst “local” H t em janelas móveis. Complementarmente, são realizados testes estatísticos de hipóteses através do rescaled-range tests R/S , do modified rescaled-range test M - R/S e do fractional differencing test GPH. Em termos de uma conclusão única a partir de todos os métodos sobre a natureza da dependência para o mercado acionista em geral, os resultados empíricos são inconclusivos. Isso quer dizer que o grau de memória de longo prazo e, assim, qualquer classificação, depende de cada mercado particular. No entanto, os resultados gerais maioritariamente positivos suportam a presença de memória longa, sob a forma de persistência, nos retornos acionistas da Bélgica, Holanda e Portugal. Isto sugere que estes mercados estão mais sujeitos a maior previsibilidade (“efeito José”), mas também a tendências que podem ser inesperadamente interrompidas por descontinuidades (“efeito Noé”), e, por isso, tendem a ser mais arriscados para negociar. Apesar da evidência de dinâmica fractal ter suporte estatístico fraco, em sintonia com a maior parte dos estudos internacionais, refuta a hipótese de passeio aleatório com incrementos i.i.d., que é a base da EMH na sua forma fraca. Atendendo a isso, propõem-se contributos para aperfeiçoamento do CAPM, através da proposta de uma nova fractal capital market line FCML e de uma nova fractal security market line FSML. A nova proposta sugere que o elemento de risco (para o mercado e para um ativo) seja dado pelo expoente H de Hurst para desfasamentos de longo prazo dos retornos acionistas. O expoente H mede o grau de memória de longo prazo nos índices acionistas, quer quando as séries de retornos seguem um processo i.i.d. não correlacionado, descrito pelo gBm(em que H = 0,5 , confirmando- se a EMH e adequando-se o CAPM), quer quando seguem um processo com dependência estatística, descrito pelo fBm(em que H é diferente de 0,5, rejeitando-se a EMH e desadequando-se o CAPM). A vantagem da FCML e da FSML é que a medida de memória de longo prazo, definida por H, é a referência adequada para traduzir o risco em modelos que possam ser aplicados a séries de dados que sigam processos i.i.d. e processos com dependência não linear. Então, estas formulações contemplam a EMH como um caso particular possível.There is not a single definition for long term process memory. That process is normally defined as a series which has a correlogram decaying slowly or an infinite spectrum of zero frequency. It is also referred that a series having such property is characterized by the long term dependence and not by periodical long cycles, or that such characteristic describes the correlation structure of a series of long lags or it is conventionally expressed in terms of the power-law decay of the autocovariance function. The growing interest of international research towards a deepening study of such domain is justified by the search for a better understanding of the dynamic nature of time series of financial assets prices. First of all the lack of consistency between results claims new studies and surveys, as well as using different complementary methodology. Secondly, the confirmation of long term memory processes has got relevant implications at the level of (1) theoretical and econometric modeling (i.e. of martingale models of asset prices and technical trading rules), (2) of statistic testing to pricing models, (3) of optimum consumption / savings decisions and of portfolios and (4) of measuring efficiency and rationality. Thirdly, there still remain empirical scientific questions about the identification of the most suitable general theoretical paradigm to model the series’ diffusion. Fourthly, to regulators and risk capital managers it is important to know if there are persistent markets and so, inefficient, which can therefore produce abnormal returns. The working purpose of this research dissertation is double. In the one side, it aims to provide additional knowledge for discussion of long term memory, devoting a daily behavior of returns series of EURONEXT main stock indexes. On the other side, it aims to provide for the improvement of capital asset pricing model CAPM, considering an alternative risk measure capable of overcoming the constraints of the efficient market hypothesis EMH in the presence of financial series with not independent and identically distributed (i.i.d.) processes. The empirical study indicates the possibility of alternative use of Government Bonds with long term maturities in calculation of market returns, since their behavior in the sovereign debt markets reflects the investors’ trust in the financial conditions of the states and measures the way how investors evaluate the respective economies based on the performance of generality of their assets. Although the price diffusion model defined by the geometric Brownian motion gBm claims to provide a good adjustment of financial time series, its assumptions of normality, stationarity and independence of residual innovations are adulterated by the empirical data analyzed. Thus, in the search for evidence about long term memory in the markets, the dissertation resorts to rescaled-range analysis R/S and detrended fluctuation analysis DFA, on the approach of fractional Brownian motion fBm, to estimate the Hurst exponent H in relation to the complete data series and to calculate the “local” Hurst exponent H t in moving time windows. In addition, hypothesis statistical tests are implemented through rescaled-range tests R/S, modified rescaled-range test M - R/S and of fractional differencing test GPH. In terms of a unique conclusion from the overall methods on the nature of dependence to the stock market In general, the empiric results are inconclusive. That means the long term memory degree and so any classification, depends on each particular market. Notwithstanding, the majority of positive general results support the presence of long run memory, under the persistence form, stock returns in Belgium, Netherlands and Portugal. That suggests that those markets are more subject to a greater predictability (“Joseph effect”), but also to tendencies that can be unexpectedly interrupted by discontinuity (“Noah effect”), and, for that reason, tend to be riskier to trading. Despite the evidence of the fractal dynamics having a weak support, in harmony with most of the international studies, it refutes the hypothesis of random walk with i.d.d. increments, which is the basis of the EMH in its weak form. Having that in mind, contributions for CAPM improvement are suggested, through the proposal of a new fractal capital market line FCML and a new fractal security market line FSML. The new proposal proposes that the element of risk (for market and for an asset) will be provided by the Hurst exponent H for long term lags of stock returns. The H exponent measures the long term memory degree in stock indexes, whether when the returns series follows a non-correlate i.d.d. process, described by gBm(in which H = 0,5, being confirmed the EMH and being appropriate the CAPM), or when follows a process with statistical dependence, described by fBm(in which H is different than 0,5, rejecting the EMH and misadjusting the CAPM). The advantage of FCML and FSML is that the long term memory measure, defined by H, is the adequate reference to express the risk in models that might be applied to data series that follow i.d.d. processes and processes with nonlinear dependence. So, these formulations contemplate the EMH as a possible particular case

Motivação ao Ensino/Aprendizagem da Língua Inglesa no ensino médio

Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Arte, Cultura e História da Universidade Federal da Integração Latino-americana - UNILA, como requisito parcial para obtenção do título de Especialista em Línguas Adicionais. Orientador: Prof. Dr. Rinaldo Vitor CostaNesta pesquisa é analisado o ensino da língua inglesa como uma forma de aceder à informação, contribuindo para incrementar o nível de conhecimento. O mundo contemporâneo se encontra em movimento, estamos na era da tecnologia, tudo se encontra em transição. A aprendizagem da língua inglesa (LI) é de suma importância já que esta gera oportunidades a nível geral, compreendendo que a LI está arraigada na história, já seja pela industrialização, globalização ou outros fatores. Os professores podem fazer uso dessa informação gerando uma consciência crítica, criando ferramentas fundamentadas em fatos reais para os alunos se motivarem aprender a LI. Esta pesquisa pretende mostrar como por médio da motivação os alunos das escolas podem se incentivar em aprender a LI, entender que a linguagem vai além da linguística, que está faz parte de um universo social e cultural. Dessa forma se incentivaria aos alunos a conhecer essa realidade atual, através da língua estrangeira (LE), especificamente a LI. É grande a falta de interesse dos jovens à aprendizagem da língua inglesa, diante dessas situações, a proposta metodológica neste trabalho é uma análise qualitativa por meio da pesquisa bibliográfica e o analises dos discursos que circulam em blog. Mostra-se a importância de gerar motivação também nos professores durante o processo de ensino/aprendizagem aos estudantes do ensino médio, e que assim tenham a visão das oportunidades que serão disponibilizadas com o aprendizado do inglês. A finalidade desta pesquisa é mostrar que se pode incentivar/motivar por médios de ferramentas atuais, principalmente da internet, e dos discursos ou da linguagem social que se utiliza atualmente nos blogs, ou em outras redes de informação, de forma que isto se aplique com ênfase ao ensino no Projeto Político Pedagógico das escolas (PPP)This research aims to analyze the teaching of the English language as a way to access information, contributes to increase the level of knowledge and also with opportunities in the labor market. One of the purposes of this work is to show the need and importance of learning a foreign language such as English, especially at the public schools, since generating English language teaching would bring new experiences, whether in the workplace, as the most basic situations manage to communicate, in addition to being able to have a job in English-speaking countries. This research will help the reader to have a better vision about the foreign language (LE), specifically in the case of the English language to encourage the application of the teaching in the PPP - Political-Pedagogical Project of the schools. The purpose of this work is to generate this motivation in teachers to motivate the students of high school, so that they learn English in a simple way, getting the vision of the opportunities that will be available with the learning of English in the different areas of lifeEn esta investigación es analizada la enseñanza de la lengua inglesa como una forma de acceder a la información, contribuyendo para incrementar el nivel de conocimiento. El mundo contemporáneo se encuentra en movimiento, estamos en la era de la tecnología, todo se encuentra en transición. El aprendizaje de la lengua inglesa (LI), es de suma importancia ya que esta genera oportunidades a nivel general, comprendiendo que esta se encuentra arraigada en la historia, ya sea por la industrialización, globalización, u otros factores. Los profesores pueden hacer uso de esa información generando una conciencia crítica, creando herramientas fundamentales en hechos reales para los alumnos ser motivados a aprender la LI. Esta investigación pretende mostrar como por medio de la motivación los alumnos de las escuelas pueden ser incentivados a aprender la LI, entender que el lenguaje va más allá de la lingüística, que este hace parte de un universo social y cultural. De esa forma se incentivaría a los alumnos a conocer esa realidad actual a través de la lengua extranjera (LE). Específicamente la LI. Es grande la falta de interés del os jóvenes el aprendizaje de la LI, ante estas situaciones, la propuesta metodológica en este trabajo es un análisis cualitativo por medio de la revisión bibliográfica y análisis de discursos que circulan en blogs. Se muestra la importancia de generar motivación también en los profesores durante el proceso de enseñanza /aprendizaje a los estudiantes de bachillerato, y que así tengan la visión de las oportunidades que estarán disponibles con el aprendizaje del inglés. La finalidad de esta investigación es mostrar que se puede incentivar /motivar por medio de herramientas actuales, principalmente el internet, y de los discursos o del lenguaje social que es utilizado en blogs, o en otras redes de información, de forma que esto se aplique con énfasis a la enseñanza en el Proyecto Político Pedagógico de las escuelas (PPP

Inflation Targeting in Brazil: a Keynesian Approach

O Regime de Meta de Inflação se Tornou Dominante na Formulação de Políticas dos Bancos Centrais nos Últimos 15 Anos. a Teoria Subjacente, Particularmente a Regra de Taylor, Pode ser Vista como uma Competente Generalização Desse Comportamento. de um Ponto de Vista Keynesiano, Ele Será Aceitável se Encararmos a Taxa de Juros de Equilíbrio como Apenas uma Convenção Variável e se a Combinarmos ou com uma Taxa de Câmbio ou com uma Meta de Emprego. no Caso do Brasil, Porém, Além Dessa Ressalva Teórica e da Condição do Duplo Mandato, o Regime de Metas de Inflação Enfrenta um Problema de Incoerência. esta é uma Política que se Destinava a ser Utilizada na Administração da Política Monetária, não na Mudança do Regime de Política Monetária . a Política de Metas de Inflação foi Introduzida no Brasil em 1999 como um Substituto para a Âncora Cambial, que Havia Sido Usada Desastrosamente entre 1995 e 1998. Durante Muitos Anos, o País Havia Enfrentado uma Armadilha de Alta Taxa de Juros / Taxa de Câmbio Valorizada E, Portanto, Precisava Mudar seu Regime de Política Monetária Antes de Eventualmente Adotar o Regime de Meta de Inflação. Essa Mudança, que Começou com a Flutuação de Janeiro de 1999, Deveria ter Sido Completada com Reformas Específicas (Fim da Indexação dos Serviços Públicos e dos Próprios Juros Básicos). no Entanto, em Lugar de Desenvolver uma Estratégia para Reduzir a Taxa de Juros, o Governo Continuou a Definir a Inflação como o Principal Problema a ser Enfrentado e Adotou uma Política Formal de Metas de Inflação. a Conseqüência é que Desde 1999 Essa Política se Tornou o Obstáculo que a Economia Brasileira Enfrenta para Escapar da Armadilha da Taxa de Juros