2 resultados para A-not-B error
em RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal
Resumo:
Teeth and astragali were used for a biometrical study concerning suids from V-a (upper Burdigalian) and V-b (Langhian) divisions from Lisbon's Miocene series. The Hyotherium (V-b) are identical to those from french localities, hence they all belong in the same species H. soemmeringi. Bunolistriodon populations from V-a and V-b are homogenous; no significant difference between them has been found, inspite of different geological age. Both may be ascribed to B. lockharti. No evolutive trend was detected. The presence of another form close to the north african B. massai could not be confirmed either. French localities' Bunolistriodon populations also seem homogenous and conspecific with those from Lisbon. Notwithstanding its essentially homogenous character, there can be distinguished two sets in both V-a and V-b populations according to M3 size; this remains to be explained, since the last molars are the most likely to show a broad range of variation and are not unequivocally related to sexual dimorphism. Classification of the rare Tayassuidae has been confirmed. All known taxa are shown (see tableau I).
Resumo:
This paper is mainly concerned with the tracking accuracy of Exchange Traded Funds (ETFs) listed on the London Stock Exchange (LSE) but also evaluates their performance and pricing efficiency. The findings show that ETFs offer virtually the same return but exhibit higher volatility than their benchmark. It seems that the pricing efficiency, which should come from the creation and redemption process, does not fully hold as equity ETFs show consistent price premiums. The tracking error of the funds is generally small and is decreasing over time. The risk of the ETF, daily price volatility and the total expense ratio explain a large part of the tracking error. Trading volume, fund size, bid-ask spread and average price premium or discount did not have an impact on the tracking error. Finally, it is concluded that market volatility and the tracking error are positively correlated.