Papers by ANDRE MEDEIROS SANTOS
IEEE Software, 2019
Feedback sessions are the moments when the management staff discusses positive features and oppor... more Feedback sessions are the moments when the management staff discusses positive features and opportunities for team members to improve their specific abilities. However, the traditional form of feedback, where sessions consist of evaluators and a single individual under evaluation, is not adequate given the teamwork nature of software development. This study presents a strategy to provide this feedback in a collaborative manner and the effects it has on team engagement, agreements, and potential evolution. The results show this strategy supports team members to reach agreements on their level of competences and actions that must be conducted to evolve or maintain such competences. Moreover, there is a better balance in the mutual perception of the member under evaluation, because such perception is a consolidation of different perspectives.

Brazilian Review of Finance, 2010
Robust optimization has been receiving increased attention in the recent few years due to the pos... more Robust optimization has been receiving increased attention in the recent few years due to the possibility of considering the problem of estimation error in the portfolio optimization problem. A question addressed so far by very few works is whether this approach is able to outperform traditional portfolio optimization techniques in terms of out-of-sample performance. Moreover, it is important to know whether this approach is able to deliver stable portfolio compositions over time, thus reducing management costs and facilitating practical implementation. We provide empirical evidence by assessing the out-of-sample performance and the stability of optimal portfolio compositions obtained with robust optimization and with traditional optimization techniques. The results indicated that, for simulated data, robust optimization performed better (both in terms of Sharpe ratios and portfolio turnover) than Markowitz's mean-variance portfolios and similarly to minimum-variance portfolios....

Ganhos De Eficiência e a Hipótese Do Caminho Aleatório Nos Mercados Futuro e De Ações Do Brasil Na Década De 90
Revista Alcance, Oct 28, 2009
Este artigo investiga a ocorrencia de ganhos de eficiencia nos mercados futuro e de acoes no Bras... more Este artigo investiga a ocorrencia de ganhos de eficiencia nos mercados futuro e de acoes no Brasil durante a decada de 90, mensurados por uma maior aproximacao das sucessivas variacoes dos precos ao comportamento random walk. Os principais conceitos da Hipotese dos Mercados Eficientes em sua forma fraca sao discutidos. Utilizando testes parametricos de autocorrelacao serial e testes naoparametricos de corrida de sinais em uma amostra de oito acoes e dois contratos futuros constatou-se a ocorrencia de elevados niveis de dependencia nas variacoes de preco com ate dois dias de defasagem. Os testes de corridas de sinais rejeitaram a hipotese de aleatoriedade nas variacoes de preco para o mercado de acoes, enquanto que para o mercado futuro constatou-se uma formacao de preco mais eficiente, ou seja, mais proxima ao modelo de caminho aleatorio.
De nuevo sobre el papel del juez en el proceso civil
Revista Ius Et Praxis, 2012

Usability requirements for mobile accessibility
Proceedings of the 14th International Conference on Mobile and Ubiquitous Multimedia, 2015
When multimedia applications intend to support accessibility, aspects of usability must be review... more When multimedia applications intend to support accessibility, aspects of usability must be reviewed to adapt or extend common functional requirements that are implemented to ensure an easy use of applications. Furthermore, these requirements must be identified and analyzed in a contextualized way, since different types of impairments require different types of requirements. This work analyzed 247 scientific and technological articles to identify requirements that are being considered to different types of impairments. The collected information was consolidated and classified according to groups of impairments. As result, this paper brings a checklist proposal focused on requirements for vision impaired users that should be considered by mobile multimedia applications to ensure accessibility with usability.

Journal of Economic Behavior & Organization, 2015
Individual investors often must reveal to others the outcome of their investments-e.g., a spouse ... more Individual investors often must reveal to others the outcome of their investments-e.g., a spouse who knows s/he will eventually have to communicate the performance of their stock portfolio to the significant other. Surprisingly, little is known about impact of public versus private outcomes on individual investors' decisions . In this paper, we systematically address this issue. Precisely, we investigate whether the expected disclosure (vs. secrecy) of investors' performance outcomes influences one of the most common and robust anomalies in behavioral finance, the so-called disposition effect (Dhar and Zhu 1996 The disposition effect refers to investors' tendency to sell the stocks that have increased in value relative to the purchase price and to hold the stocks that have decreased in value relative to the purchase price. In two experiments, participants make a series of investment decisions in a stock market simulation knowing that their final financial performance will either be made public or kept private. Independent of market trends or payoff structures, the results consistently show a significant increase in the disposition effect in the public condition--mainly due to a spike in the realization of paper gains. Participants' proneness to sell their gains in the public condition represents in part a strategic attempt to hedge against the embarrassment of ending the trading session at the bottom of the distribution.

Journal of Economic Behavior & Organization, 2015
Individual investors often must reveal to others the outcome of their investments-e.g., a spouse ... more Individual investors often must reveal to others the outcome of their investments-e.g., a spouse who knows s/he will eventually have to communicate the performance of their stock portfolio to the significant other. Surprisingly, little is known about impact of public versus private outcomes on individual investors' decisions . In this paper, we systematically address this issue. Precisely, we investigate whether the expected disclosure (vs. secrecy) of investors' performance outcomes influences one of the most common and robust anomalies in behavioral finance, the so-called disposition effect (Dhar and Zhu 1996 The disposition effect refers to investors' tendency to sell the stocks that have increased in value relative to the purchase price and to hold the stocks that have decreased in value relative to the purchase price. In two experiments, participants make a series of investment decisions in a stock market simulation knowing that their final financial performance will either be made public or kept private. Independent of market trends or payoff structures, the results consistently show a significant increase in the disposition effect in the public condition--mainly due to a spike in the realization of paper gains. Participants' proneness to sell their gains in the public condition represents in part a strategic attempt to hedge against the embarrassment of ending the trading session at the bottom of the distribution.
Paraconsistent and fuzzy logic applied to company profitability analysis
This study proposes an application of two models based on non-classical logic, the paraconsistent... more This study proposes an application of two models based on non-classical logic, the paraconsistent logic and the fuzzy logic, in company profitability analysis. We conduct interviews with market specialists in order to identify the main explanatory variables related to company profitability and apply the paraconsistent model in order to classify the data and to attribute a degree of favorable evidence and of contrary evidence to each profitability ratio. In the fuzzy model, the collected data is analyzed and classified using inference rules and membership functions, thus assigning a qualitative variable to each profitability index. The empirical implementation indicates that both models can be used as tools for assistance and validation of opinions of specialists in the analysis of a company's profitability.

The software perspective for energy-efficient mobile applications development
Proceedings of the 10th International Conference on Advances in Mobile Computing & Multimedia - MoMM '12, 2012
ABSTRACT Nowadays, there is a growing concern about the energy consumption of the ICT industry. T... more ABSTRACT Nowadays, there is a growing concern about the energy consumption of the ICT industry. This fact has given rise to a lot of energy saving research activities, which mainly focus on the hardware side of computational systems. However, it is tempting to suppose that only hardware dissipates power, not software. This paper discusses several software methods, which could be explored to develop energy-efficient mobile techniques. We argue that the development of applications that consider the energy saving, as one of their requirements, can result in a significant final energy saving because solutions will be part of the own software and they do not depend of external resources to obtain a lower consumption.
The growing processing capabilities of mobile devices coupled with portable and wearable sensors ... more The growing processing capabilities of mobile devices coupled with portable and wearable sensors have enabled the development of context-aware services tailored to the user environment and its daily activities. The problem of determining the user context at each particular point in time is one of the main challenges in this area. In this paper, we describe the approach pursued in the UPCASE project, which makes use of sensors available in the mobile device as well as sensors externally connected via Bluetooth. We describe the system architecture from raw data acquisition to feature extraction and context inference. As a proof of concept, the inference of contexts is based on a decision tree to learn and identify contexts automatically and dynamically at runtime. Preliminary results suggest that this is a promising approach for context inference in several application scenarios.
Physical Review E, 1998
The hydrodynamic equations for a gas of hard spheres with dissipative dynamics are derived from t... more The hydrodynamic equations for a gas of hard spheres with dissipative dynamics are derived from the Boltzmann equation. The heat and momentum fluxes are calculated to Navier-Stokes order and the transport coefficients are determined as explicit functions of the coefficient of restitution. The dispersion relations for the corresponding linearized equations are obtained and the stability of this linear description is discussed. This requires consideration of the linear Burnett contributions to the energy balance equation from the energy sink term. Finally, it is shown how these results can be imbedded in simpler kinetic model equations with the potential for analysis of more complex states. ͓S1063-651X͑98͒15709-4͔

REAd. Revista Eletrônica de Administração (Porto Alegre), 2012
Este estudo identificou as correlações entre as estratégias de remuneração e a tipologia de cultu... more Este estudo identificou as correlações entre as estratégias de remuneração e a tipologia de cultura organizacional proposta por Handy (2003) baseada nas dimensões do grau de formalização e centralização que identifica a cultura: Zeus (poder), Apolo (papéis), Atena (tarefa), e Dionísio (pessoa). A pesquisa foi aplicada a gestores de remuneração de 76 empresas associadas ao Grupo de Permuta de Informações Salariais (Grupisa), e os questionários com um construto composto por doze componentes da remuneração organizacional foram analisados utilizando Correlação de Pearson e Regressão Múltipla. Concluímos que as variáveis de remuneração se correlacionam de forma diferente com cada um dos tipos de cultura: (i) organizações "Zeus" devem enfatizar os fatores comportamentais em todas as esferas do sistema de remuneração; (ii) para as organizações "Apolo" a ênfase deve ser aplicada nas oportunidades de crescimento e desenvolvimento, (iii) nas organizações "Atena" ...

Chemistry, an Asian journal, Jan 14, 2015
We have investigated the photophysical and photochemical features of a luminescent heteroleptic R... more We have investigated the photophysical and photochemical features of a luminescent heteroleptic Ru(II) -polypyridyl probe and of its corresponding Ru(II) -Cu(II) dinuclear complex formed upon the analyte binding through extensive density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The molecular probe contains the tailored imidazo[4,5-f]-1,10-phenanthroline (IIP) ligand for simultaneously binding the Ru(II) core and the target metal ion in aqueous solution. We have rationalized the static photoluminescence quenching observed upon the Cu(II) coordination, on the grounds of distinct excited state deactivation mechanisms which are absent in the free Ru(II) complex probe. Additionally, the emission quenching found upon increasing the solution pH has also been investigated. When coordinated IIP deprotonates, the nature of the lowest excited state of its complex changes from (3) MLCT to (3) LLCT/(3) IL. The strong base-induced emission quenching can be understood ...

IMF Working Papers, 2006
This Working Paper should not be reported as representing the views of the IMF. The views express... more This Working Paper should not be reported as representing the views of the IMF. The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. Currency mismatches in corporate balance sheets have been singled out as an important factor underlying the severity of recent financial crises. We propose several structural models for measuring default risk for firms with currency mismatches in their asset/liability structure. The proposed models can be adapted to different exchange rate regimes, are analytically tractable, and can be estimated using available equity price and balance sheet data. The paper provides a detailed explanation on how to calibrate the models and discusses two applications to financial surveillance: the measurement of systematic risk in the corporate sector and the estimation of prudential leverage ratios consistent with regulatory capital ratios in the banking sector.

SSRN Electronic Journal, 2009
This Working Paper should not be reported as representing the views of the IMF. The views express... more This Working Paper should not be reported as representing the views of the IMF. The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. As is well known, most models of credit risk have failed to measure the credit risks in the context of the global financial crisis. In this context, financial industry representatives, regulators and academics worldwide have given new impetus to efforts to improve credit risk modeling for countries, corporations, financial institutions, and financial instruments. The paper summarizes some of the recent advances in this regard. It considers modifications of structural models, including of the classical Merton model, and efforts to reconcile the structural and the reduced-form models. It also discusses the reassessment of the default correlations using copulas, the pricing of credit index options, and the determination of the prices of distressed debt and estimation of recovery values.

SSRN Electronic Journal, 2010
This Working Paper should not be reported as representing the views of the IMF. The views express... more This Working Paper should not be reported as representing the views of the IMF. The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. This paper introduces the Asset and Liability Management (ALM) compound option model. The model builds on the observation that the public sector net worth in a multi-period setting corresponds to the value of an option on an option on total government assets. Hence, the ALM compound option model is better suited for analyzing and evaluating the risk profile of public debt than existing one-period models, and is especially useful for analyzing the soundness of exit strategies from the large fiscal expansions undertaken by G-20 countries in the wake of the recent financial crisis. As an illustration, the model is used to analyze the risk profile and sustainability of Australia's public debt under different policies.

Psicologia: Reflexão e Crítica, 2009
Resumo A pesquisa comparou os índices de estresse em 60 pacientes internados para a realização da... more Resumo A pesquisa comparou os índices de estresse em 60 pacientes internados para a realização da cirurgia de colecistectomia, sendo 30 do Sistema Único de Saúde (SUS) e 30 de convênios. Utilizou-se o Inventário de Sintomas de Stress para Adultos de Lipp e dois questionários: um sociodemográfico e outro sobre variáveis clínicas relativas à cirurgia. Os resultados mostraram que mais pacientes do grupo SUS tiveram estresse (93,3%) em relação ao grupo dos conveniados (33,3%; p<0,05). Como variáveis que apresentaram diferença estatística em relação ao estresse, encontrou-se que: o sexo feminino, não ter realizado a consulta pré-anestésica e possuir escolaridade em nível fundamental foram fatores que estiveram relacionados ao estresse na amostra total (p<0,05), destacando-se que todos estes tiveram maior freqüência no grupo SUS (p<0,05). Palavras-chave: Estresse; cirurgia; Sistema Único de Saúde (SUS); acompanhamento dos cuidados de saúde.
PLoS ONE, 2013
We assess the psychophysiological characteristics underlying the disposition effect and find that... more We assess the psychophysiological characteristics underlying the disposition effect and find that subjects showing greater disposition effect are those who sweat more and present lower body temperature and heart rate.
Photochemical & Photobiological Sciences, 2009
The photochromic diarylethene derivative 1,2-bis(5-(4-ethynylphenyl)-2-methylthiophen-3-yl)perflu... more The photochromic diarylethene derivative 1,2-bis(5-(4-ethynylphenyl)-2-methylthiophen-3-yl)perfluorocyclopentene (1) was submitted to photochemical, thermal stability and fatigue resistance studies in acetonitrile, also to evaluate its possible application as a new actinometer. This photochromic system covers a wide spectral absorption range, with intense bands in the UV and visible regions for the open-ring and closed-ring isomers, respectively. Very high ring-closure quantum yield values were obtained, in contrast with the low ring-opening quantum yields, which are nevertheless high enough to exploit 1 as an actinometer. The procedure required to determine the photon flux of an irradiation source with this fatigue resistant compound is indeed very simple.

Mobile Networks and Applications, 2010
Embedded systems are considered one of the areas with more potential for future innovations. Two ... more Embedded systems are considered one of the areas with more potential for future innovations. Two embedded fields that will most certainly take a primary role in future innovations are mobile robotics and mobile computing. Mobile robots and smartphones are growing in number and functionalities, becoming a presence in our daily life. In this paper, we study the current feasibility of a smartphone to execute navigation algorithms and provide autonomous control, e.g., for a mobile robot. We tested four navigation problems: Mapping, Localization, Simultaneous Localization and Mapping, and Path Planning. We selected representative algorithms for the navigation problems, developed them in J2ME, and performed tests on the field. Results show the current mobile Java capacity for executing computationally demanding algorithms and reveal the real possibility of using smartphones for autonomous navigation.
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Papers by ANDRE MEDEIROS SANTOS