Is it Worth Tracking Dollar/Real Implied Volatility?

In this paper we examine the relation between dollar-real exchange rate volatility implied in option prices and subsequent realized volatility, in the period of February 1999 to June 2000. Our results are in line with recent literature, suggesting that the implied volatility obtained from a simple option-pricing model, although an upward-biased estimator of future volatility does provide information about volatility over the remaining life of the option, which is not present in past returns. Results are robust to the choice of two alternative time series models to explore information embedded in returns, a fixed volatility and a GARCH (1,1) model, even allowing for in-sample forecasts by the GARCH (1,1) model. Results are also robust to the choice of measuring realized volatility in two alternative ways.

Testing the Expectations Hypothesis in the Brazilian Term Structure of Interest Rates

In this paper the Expectations Hypothesis (EH) is tested using cointegration techniques, for maturities ranging from 1-month to 12-months, for the Brazilian market. We found evidence suggesting that for the period 1995-2001, the cointegration implication generally seems to hold. We also found strong evidence supporting causality from short to long rates and also in the opposite direction. Empirical evidence supports the expectations theory of the term structure of interest rates. However, when using multivariate cointegration tests we reject the unbiasedness hypothesis implied in the pure EH.

Tracking Brazilian Exchange Rate Volatility

This paper examines the relation between dollar-real exchange rate volatility implied in option prices and subsequent realized volatility. It investigates whether implied volatilities contain information about volatility over the remaining life of the option which is not present in past returns. Using GMM estimation consistent with telescoping observations evidence suggests that implied volatilities give superior forecasts of realized volatility if compared to GARCH(p,q), and Moving Average predictors, and that econometric models forecasts do not provide significant incremental information to that contained in implied volatilities.implied volatility, telescoping observations, GMM

Is it worth tracking dollar/real implied volatility?

In this paper we examine the relation between dollar-real exchange rate volatility implied in option prices and subsequent realized volatility, in the period of February 1999 to February 2001. Our results are in line with recent literature, suggesting that the implied volatility obtained from a simple option pricing model, although an upward-biased estimator offuture volatility, does provide information about volatility over the remaining life ofthe option which is not present in past returns. Results are robust to the choice oftwo alternative time series models to explore information embedded in returns, a fixed volatility and a GARCH(1,1) model, even allowing for in-sample forecasts by the GARCH(1,1) model. Results are also robust to the choice ofmeasuring realized volatility in two alternative ways

FASHION AMARCORD: INTERVISTA A DUE GIOVANI DESIGNER

Due stilisti emergenti raccontano cosa significa per loro "usato" e il loro punto di vista sul fenomeno vintage

A extinção do contrato de compra e venda por inadimplemento do devedor : um paralelo entre a resolução do Código Civil brasileiro e a avoidance da convenção das nações unidas sobre contratos de venda internacional de mercadorias de 1980 (CISG)

O presente estudo objetiva analisar o término do contrato de compra e venda em razão do incumprimento de devedor em perspectiva comparada entre a Convenção das Nações Unidas sobre Venda Internacional de Mercadorias (CISG) e o Código Civil Brasileiro de 2002 (Código Civil Brasileiro). Para tanto, os institutos comparados são a avoidance, referida no Artigo 49 da CISG e a resolução, presente nos artigos 474, 475 e 480 do Código Civil Brasileiro. Na primeira parte, inicialmente, serão delineadas noções gerais de interpretação da CISG e medidas possíveis a serem adotadas pelo comprador em caso de inadimplemento. Em um segundo momento, tratar-se-á das causas da avoidance – a violação essencial do contrato e o inadimplemento da prestação no prazo adicional -, e de seus efeitos jurídicos – a liberação das partes, a indenização e a restituição das prestações. Na segunda parte, serão abordadas as causas da resolução contratual no direito brasileiro – o inadimplemento definitivo e a onerosidade excessiva -, e os efeitos jurídicos - a liberação das partes, a restituição e a indenização. Ao final, conclui-se que, embora a avoidance tenha sido recepcionada como resolução pelo sistema brasileiro, os institutos apresentam diferenças que devem ser levadas em consideração para correta aplicação pelo sistema brasileiro.This paper aims to analyzing the termination of the sales contract due to the breach of a contractual obligation by the seller with a comparative perspective between the Convention on Contracts for the International Sale of Goods of 1980 (CISG) and the Brazilian Civil Code. For such objective, the two legal institutions of comparison are the avoidance as referred by the Article 49 of CISG and the “resolução”, as referred by the Articles 474, 475 and 480 of the Brazilian Civil Code. The first part will briefly outline general principles of interpretation of the CISG and possible buyer’s remedies in case of breach by the seller. After it, it will expose the requirements of the avoidance - fundamental breach of contract and breach in the additional period -, and its juridical effects – release from obligation, restitution of the goods and damages. The second part will deal with the requirements of “resolução” in the Brazilian Civil Code – breach and the gross inequity -, and its juridical effects – release from obligation, restitution of the goods and damages. In conclusion, although the avoidance as proposed by the CISG was received as “resolução” by the Brazilian Law, they both present some differences that should be taken into account in order to certificate that the CISG will be correctly applied

Impactos do tipo de controle dos inversores da microgeração fotovoltaica na rede de distribuição

Currently, the vast major of utility distribution companies around the globe require frequency inverters connected to the power grid to operate with unit power factor. However, due to the increase in presence of distributed generation (DG), it’s been discussed the role of DGs in the daily operation of the grid, using different types of control of the frequency inverters. Based on these new assignments to this equipment, this work has as subject the evaluation of the impacts of different types of control of microgeneration photovoltaic frequency inverters on distribution power networks, by monitoring certain performance indices, such as voltage levels, transformers loading and active power losses. Four types of control are considered, all analyzed at different levels of photovoltaic penetration. The software SIMULIGHT is used to perform the static and dynamic studies using the modified IEEE 34 bus feeder, by applying typical load and photovoltaic curves whereas clear sky.Atualmente, a maioria das distribuidoras de energia pelo mundo permitem que os inversores de frequência conectados à rede trabalhem com fator de potência unitário. Entretanto, com o aumento da presença de geração distribuída (GD), deu-se início a discussões sobre o papel desta na operação do sistema, a partir de diferentes tipos de controle nos inversores de frequência. Com base nestas novas atribuições ao equipamento, este trabalho tem como objetivo a avaliação do impacto em redes de distribuição dos controles dos inversores fotovoltaicos, através do monitoramento de certos índices de desempenho, como níveis de tensão, carregamento de transformadores e perdas ativas. São considerados quatro tipos de controle, analisados em diferentes níveis de penetração. O software SIMULIGHT é empregado para realização dos estudos estáticos e dinâmicos no sistema IEEE 34 barras modificado, em que são consideradas curvas típicas de demanda e geração fotovoltaica a céu aberto

Value of speckle-tracking echocardiography changes in monitoring myocardial dysfunction during treatment of sepsis: potential prognostic implications

Speckle-tracking echocardiography (STE) has been increasingly used for detection of sepsis-related myocardial dysfunction. However, the impact of strain changes during sepsis treatment has not been defined. This study assessed STE at admission and during the treatment of patients with sepsis to evaluate its changes as a potential factor for predicting in-hospital outcome. This study included 26 patients with sepsis who underwent STE echocardiography on day 1 and 7 during treatment. Myocardial deformation of both ventricles was assessed using global longitudinal strain. The endpoint was in-hospital mortality. The mean age was 51.4±18.3 years, and 54% were female. The average SOFA score at T0 was 8.6±3.8 points and at day 7 was 4.9±4.7 points. The left ventricular (LV) ejection fraction at baseline was 65.6±9.1%, without changes in echocardiographic parameters during treatment. LV and RV longitudinal strain increased significantly in the patients who survived (− 18.8±3.6 at D1 vs − 20.8±2.5 at D7; p=0.003; and −21.3±4.9 at D1 vs − 24.3±5.8 at D7; p=0.035, respectively), whereas strain values remained unchanged in those who died. After adjustment for the SOFA score, RV longitudinal strain at admission was associated with in-hospital mortality [adjusted odds ratio (OR) 0.760; 95% confidence interval (CI) 0.591–0.977; p −0.033]. STE improved significantly after the first week of treatment in patients with sepsis who survived compared with those patients who died during hospitalization. RV strain at admission predicted in-hospital mortality. An improvement in STE during sepsis treatment appears to be a useful tool for predicting in-hospital outcome

EFFECT OF WORKING RANGE ON PRODUCTIVITY AND COSTS OF HARVESTING MACHINES IN A EUCALYPTUS STAND

Wood harvesting should be planned to reduce environmental impacts by minimizing machine traffic, increase productivity and reduce costs. In this context, the aim of this study was evaluate the effect of working range on operational performance of a harvester and forwarder in a Eucalyptus saligna stand under a clear cutting regime. The study was carried out in Paraná State, Brazil, in a cut‐to‐length system in cutting and wood extraction operations in two working ranges: T1 - width of 12 m with a cut of four planting lines; and T2 - width of 18 m with a cut of six planting lines. A time and motion study was performed to determine work cycle times, productivity, production costs, and machine traffic, with working ranges compared by the t-test (α = 0.05) for independent samples. The results showed that the wood processing and loading elements consumed the longest operating cycle time in cutting and wood extraction. The harvester machine presented higher productivity (61.05 m³ PMH0-1) in the T1 working range, while the forwarder was superior (48.32 m³ PMH0-1) in the T2 working range. Regarding the wood harvesting system, it was observed that the T2 working range enabled a reduction of 1% in production costs, which is important when considering the large scale production of the company, while there was a 33.4% reduction in traffic. Therefore, an increase in machines’ working range can provide operational and environmental benefits to wood harvesting operations in forest plantations.Wood harvesting should be planned to reduce environmental impacts by minimizing machine traffic, increase productivity and reduce costs. In this context, the aim of this study was evaluate the effect of working range on operational performance of a harvester and forwarder in a Eucalyptus saligna stand under a clear cutting regime. The study was carried out in Paraná State, Brazil, in a cut‐to‐length system in cutting and wood extraction operations in two working ranges: T1 - width of 12 m with a cut of four planting lines; and T2 - width of 18 m with a cut of six planting lines. A time and motion study was performed to determine work cycle times, productivity, production costs, and machine traffic, with working ranges compared by the t-test (α = 0.05) for independent samples. The results showed that the wood processing and loading elements consumed the longest operating cycle time in cutting and wood extraction. The harvester machine presented higher productivity (61.05 m³ PMH0-1) in the T1 working range, while the forwarder was superior (48.32 m³ PMH0-1) in the T2 working range. Regarding the wood harvesting system, it was observed that the T2 working range enabled a reduction of 1% in production costs, which is important when considering the large scale production of the company, while there was a 33.4% reduction in traffic. Therefore, an increase in machines’ working range can provide operational and environmental benefits to wood harvesting operations in forest plantations