769 resultados para BITMAP INDEX
Resumo:
O estudo do comportamento de adoção de produtos e serviços baseados em tecnologia pelo consumidor tem representado um dos principais desafios para a área de marketing, pois, em meio à intensa proliferação destes produtos, diversos estudos apontam a crescente frustração do consumidor para interagir com a tecnologia. Tais evidências são especialmente importantes à medida que as crenças do consumidor estão positivamente relacionadas a sua aceitação ou resistência em adotar produtos e serviços tecnológicos. Nesse contexto, a prontidão para tecnologia emerge como constructo fundamental para o entendimento das atitudes do consumidor diante da tecnologia, e diz respeito à propensão dos indivíduos a adotar produtos e serviços tecnológicos a partir de condutores e inibidores mentais relacionados ao otimismo, inovatividade, desconforto e insegurança. A Technology Readiness Index (TRI) é o instrumento de medida desenvolvido por Parasuraman (2000) e Parasuraman & Colby (2001), para mensuração da prontidão para tecnologia dos consumidores. Este estudo teve como objetivo avaliar a aplicabilidade da TRI no contexto brasileiro, por meio da reaplicação do instrumento de medida a uma amostra de 731 consumidores, maiores de 18 (dezoito) anos, na cidade de Porto Alegre. Embora se tenha verificado uma estrutura subjacente à prontidão para tecnologia ligeiramente modificada, com 6 fatores, considera-se a TRI um instrumento válido para mensuração da prontidão para tecnologia dos consumidores. A qualidade da TRI foi comprovada através do exame da validade de conteúdo e de constructo. A validade de constructo foi verificada via avaliação da unidimensionalidade, confiabilidade, validade convergente e discriminante de cada dimensão da escala. Tal avaliação foi complementada com o exame da associação dos escores dos respondentes da TRI com as questões sobre posse e uso de produtos e serviços tecnológicos. Este estudo oferece algumas evidências sobre a capacidade da TRI de distinguir usuários de não usuários destes produtos e de predizer comportamentos de adoção.
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Looking closely at the PPP argument, it states that the currencies purchasing power should not change when comparing the same basket goods across countries, and these goods should all be tradable. Hence, if PPP is valid at all, it should be captured by the relative price indices that best Öts these two features. We ran a horse race among six di§erent price indices available from the IMF database to see which one would yield higher PPP evidence, and, therefore, better Öt the two features. We used RER proxies measured as the ratio of export unit values, wholesale prices, value added deáators, unit labor costs, normalized unit labor costs and consumer prices, for a sample of 16 industrial countries, with quarterly data from 1975 to 2002. PPP was tested using both the ADF and the DFGLS unit root test of the RER series. The RER measured as WPI ratios was the one for which PPP evidence was found for the larger number of countries: six out of sixteen when we use DF-GLS test with demeaned series. The worst measure of all was the RER based on the ratio of foreign CPIs and domestic WPI. No evidence of PPP at all was found for this measure.
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The increasing availability of social statistics in Latin America opens new possibilities in terms of accountability and incentive mechanisms for policy makers. This paper addresses these issues within the institutional context of the Brazilian educational system. We build a theoretical model based on the theory of incentives to analyze the role of the recently launched Basic Education Development Index (Ideb) in the provision of incentives at the sub-national level. The first result is to demonstrate that an education target system has the potential to improve the allocation of resources to education through conditional transfers to municipalities and schools. Second, we analyze the local government’s decision about how to allocate its education budget when seeking to accomplish the different objectives contemplated by the index, which involves the interaction between its two components, average proficiency and the passing rate. We discuss as well policy issues concerning the implementation of the synthetic education index in the light of this model arguing that there is room for improving the Ideb’s methodology itself. In addition, we analyze the desirable properties of an ideal education index and we argue in favor of an ex-post relative learning evaluation system for different municipalities (schools) based on the value added across different grades
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The objective of the paper is to build a Perceived Human Development Index (PHDI) framework by assembling the HDI components, namely indicators on income, health and education on their subjective version. We propose here to introduce a fourth dimension linked to perceptions on work conditions, given its role in the “happiness” literature and in social policy making. We study how perceptions on satisfaction about the individual’s satisfaction with income, education, work and health are related to their objective counterparts. We use a sample of LAC countries where we take advantage of a larger set of questions on the four groups of social variables mentioned included in the Gallup World Poll by the IADB. We emphasize the impacts of objective income and age on perceptions. Complementarily, in the appendix we use the full sample of 132 countries where a smaller set of variables can be included, which provides a greater degree of freedom to study the impact of objective HDI components observed at country level on the formation of individual’s perception on income, education, work, health and life satisfaction. These exercises provide useful insights about the workings of beneficiaries’ point of view to understand the transmission mechanism of key social policy ingredients into perceptions. In particular, the so-called PHDI may provide a complementary subjective reference to the HDI. We also study how one’s satisfaction with life is established, measuring the relative importance given to income vis-à-vis health and education. Estimating these “instantaneous happiness functions” will help to assess the relative weights attributed to income, health and education in the HDI, which is a benchmark in the multidimensional social indicators toolbox used in practice.
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This paper performs a thorough statistical examination of the time-series properties of the daily market volatility index (VIX) from the Chicago Board Options Exchange (CBOE). The motivation lies not only on the widespread consensus that the VIX is a barometer of the overall market sentiment as to what concerns investors' risk appetite, but also on the fact that there are many trading strategies that rely on the VIX index for hedging and speculative purposes. Preliminary analysis suggests that the VIX index displays long-range dependence. This is well in line with the strong empirical evidence in the literature supporting long memory in both options-implied and realized variances. We thus resort to both parametric and semiparametric heterogeneous autoregressive (HAR) processes for modeling and forecasting purposes. Our main ndings are as follows. First, we con rm the evidence in the literature that there is a negative relationship between the VIX index and the S&P 500 index return as well as a positive contemporaneous link with the volume of the S&P 500 index. Second, the term spread has a slightly negative long-run impact in the VIX index, when possible multicollinearity and endogeneity are controlled for. Finally, we cannot reject the linearity of the above relationships, neither in sample nor out of sample. As for the latter, we actually show that it is pretty hard to beat the pure HAR process because of the very persistent nature of the VIX index.
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This paper examines the price impact of trading due to expected changes in the FTSE 100 index composition. We focus on the latter index because it employs publicly-known objective criteria to determine membership and hence it provides a natural context to investigate anticipatory trading e ects. We propose a panel-regression event study that backs out these anticipatory e ects by looking at the price impact of the ex-ante proba-bility of changing index membership status. Our ndings reveal that anticipative trading explains about 40% and 23% of the cumulative abnormal returns of additions and deletions, respectively. We con rm these in-sample results out of sample by tracking the performance of a trading strategy that relies on the addition/deletion probability estimates. The perfor-mance is indeed very promising in that it entails an average daily excess return of 11 basis points over the FTSE 100 index.
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A new form of composition of the indicators employed to generate the United Nations Human Development Index (HDI) is presented here. This form of composition is based on the assumption that random errors affect the measurement of each indicator. This assumption allows for replacing the vector of evaluations according to each indicator by vectors of probabilities of being the best or the worst according to such attribute. The probabilistic composition of such probabilities of preference according to each indicator into probabilities of being the best or the worst according to all of them generates indices that may unveil, on one hand, performances to be followed and, on the other hand, extreme conditions that an additive composition would hide. Differences between the results of application of the diverse forms of composition are examined in the case of the HDI and in the case of the districts version of the HDI employed to compare Brazilian municipalities. It is verified that the smallest correlation between the education.
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In the past decade, indicators have been created to assess the sustainability performance of companies listed in stock exchange markets. Academics and practitioners expect companies to benefit from being listed in such indexes, but evidence of value creation is still scarce. Since virtually all studies about the Corporate Sustainability Index (ISE) of the S~ ao Paulo Stock Exchange (Brazil) e the object of the present study e focused on the value of shares, we initially looked for answers in the finance theory. We collected secondary data about the financial and economic performance of companies forming the ISE's ‘theoretical portfolio’, as these kinds of indexes are also known. In a second stage, we sought additional motivations for companies to make efforts to be listed in the index. We collected additional data and interviewed representatives of key companies listed in the ISE, as well as industry leaders who chose not to participate in the selection process. The results support the main propositions of the institutional theory, as well as the ‘pays to be green’ literature e that the intangible value created by voluntary environmental initiatives, such as access to knowledge, new capabilities and reputational gain, better explain the efforts companies make to be listed in the ISE index
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The aim of this work was to develop a quality index method (QIM) scheme for whole ice-boxed refrigerated blackspot seabream and to perform shelf-life evaluations, using sensory analysis, GR Torrymeter measurements and bacterial counts of specific spoilage organisms (SSO) during chilled storage. A QIM scheme based on a total of 30 demerit points was developed. Sensory, physical and microbiological data were integrated and used to determine the rejection point. Results indicated that the shelf-life of blackspot seabream is around 12-13 days. (C) 2011 Elsevier Ltd. All rights reserved.
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Objective To establish the correlation between the bispectral index (BIS) and different rates of infusion of propofol in dogs.Study design Prospective experimental trial.Animals Eight adult dogs weighing 6-20 kg.Methods Eight animals underwent three treatments at intervals of 20 days. Propofol was used for induction of anesthesia (10 mg kg(-1) IV), followed by a continuous rate infusion (CRI) at 0.2 mg kg(-1) minute(-1) (P2), 0.4 mg kg(-1) minute(-1) (P4) or 0.8 mg kg(-1) minute(-1) (P8) for 55 minutes. The BIS values were measured at 10, 20, 30, 40, and 50 minutes (T10, T20, T30, T40, and T50, respectively) after the CRI of propofol was started. Numeric data were submitted to analysis of variance followed by Tukey test (p < 0.05).Results The BIS differed significantly among groups at T40, when P8 was lower than P2 and P4. At T50, P8 was lower than P2. The electromyographic activity (EMG) in P2 and P4 was higher than P8 at T40 and T50.Conclusion An increase in propofol infusion rates decreases the BIS values and EMG.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Patógenos em sementes de milho (Zea mays) causam sérios problemas, como a perda de sua capacidade germinativa. O objetivo do trabalho foi determinar qual o melhor tempo para infecção das sementes de milho com Fusarium graminearum, para posterior avaliação dos danos causados pelo fungo na germinação e vigor das mesmas. As sementes foram colocadas sobre meio de BDA contendo o patógeno e incubadas por 4, 8, 16 e 32 h. Após os respectivos períodos de incubação, estas foram submetidas ao teste de sanidade (papel de filtro), com duas variações, sem e com assepsia superficial, usando hipoclorito de sódio a 1% de cloro ativo, por 3 min. Determinado o melhor tempo para infecção, outras sementes foram infetadas com o patógeno, para realização dos testes de germinação e vigor (envelhecimento acelerado e teste de frio) com uma mistura de sementes sadias (colocadas sobre o meio BDA) e sementes inoculadas, resultando em 0, 20, 40, 60, 80 e 100% de sementes infetadas com o fungo em estudo. Os resultados obtidos mostraram que o período de incubação de 32 h foi suficiente para se obter sementes infetadas. Com relação à germinação, não houve diferenças significativas entre os diferentes níveis de infecção, provavelmente devido ao alto vigor das sementes de milho testadas. Quanto aos testes de vigor, os níveis de infecção diferiram significativamente da testemunha, apesar de não terem diferido entre si.
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Parent, L. E., Natale, W. and Ziadi, N. 2009. Compositional nutrient diagnosis of corn using the Mahalanobis distance as nutrient imbalance index. Can. J. Soil Sci. 89: 383-390. Compositional nutrient diagnosis (CND) provides a plant nutrient imbalance index (CND - r(2)) with assumed chi(2) distribution. The Mahalanobis distance D(2), which detects outliers in compositional data sets, also has a chi(2) distribution. The objective of this paper was to compare D(2) and CND - r(2) nutrient imbalance indexes in corn (Zea mays L.). We measured grain yield as well as N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn concentrations in the ear leaf at silk stage for 210 calibration sites in the St. Lawrence Lowlands [2300-2700 corn thermal units (CTU)] as well as 30 phosphorus (2300-2700 CTU; 10 sites) and 10 nitrogen (1900-2100 CTU; one site) replicated fertilizer treatments for validation. We derived CND norms as mean, standard deviation, and the inverse covariance matrix of centred log ratios (clr) for high yielding specimens (>= 9.0 Mg grain ha(-1) at 150 g H(2)O kg(-1) moisture content) in the 2300-2700 CTU zone. Using chi(2) = 17 (P < 0.05) with nine degrees of freedom (i.e., nine nutrients) as a rejection criterion for outliers and a yield threshold of 8.6 Mg ha(-1) after Cate-Nelson partitioning between low- and high-yielders in the P validation data set, D(2) misclassified two specimens compared with nine for CND -r(2). The D(2) classification was not significantly different from a chi(2) classification (P > 0.05), but the CND - r(2) classification differed significantly from chi(2) or D(2) (P < 0.001). A threshold value for nutrient imbalance could thus be derived probabilistically for conducting D(2) diagnosis, while the CND - r(2) nutrient imbalance threshold must be calibrated using fertilizer trials. In the proposed CND - D(2) procedure, D(2) is first computed to classify the specimen as possible outlier. Thereafter, nutrient indices are ranked in their order of limitation. The D(2) norms appeared less effective in the 1900-2100 CTU zone.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)