65 resultados para Series
Resumo:
The tree index structure is a traditional method for searching similar data in large datasets. It is based on the presupposition that most sub-trees are pruned in the searching process. As a result, the number of page accesses is reduced. However, time-series datasets generally have a very high dimensionality. Because of the so-called dimensionality curse, the pruning effectiveness is reduced in high dimensionality. Consequently, the tree index structure is not a suitable method for time-series datasets. In this paper, we propose a two-phase (filtering and refinement) method for searching time-series datasets. In the filtering step, a quantizing time-series is used to construct a compact file which is scanned for filtering out irrelevant. A small set of candidates is translated to the second step for refinement. In this step, we introduce an effective index compression method named grid-based datawise dimensionality reduction (DRR) which attempts to preserve the characteristics of the time-series. An experimental comparison with existing techniques demonstrates the utility of our approach.
Resumo:
Competitive interactions between Galaxias maculatus, native to southeastern Australia, and Gambusia holbrooki, an exotic pest, were examined in relation to two types of artificial cover and a food source. Experiments were performed in an 800 l tank using photographic techniques. The relative distance of G. maculatus from cover or food source before and after the introduction of G. holbrooki were compared. Also, the proportions of the species were altered to examine the effects of unequal numbers on dominance behaviour. It was found that G. holbrooki was unable to out compete G. maculatus for either cover or food. The distance of G. maculatus from a food source was seen to increase following the introduction of G. holbrooki, when they outnumbered G. maculatus by 3 to 1. Although the distance from the food of G.maculatus increased following the introduction of G. holbrooki, in all cases the mean distance of G.␣maculatus from cover or food was less than that of G. holbrooki. Significant intra-species competition appeared to occur between G. maculatus and it may be that this competition had a greater effect than the competitive pressure G. holbrooki was able to place on the natives. This study revealed that the exotic pest species, G. holbrooki, could not out compete a small native Australian fish species.
Resumo:
Purpose. NaCl has proven to be an effective bitterness inhibitor, but the reason remains unclear. The purpose of this study was to examine the influence of a variety of cations and anions on the bitterness of selected oral pharmaceuticals and bitter taste stimuli: pseudoephedrine, ranitidine, acetaminophen, quinine, and urea.
Method. Human psychophysical taste evaluation using a whole mouth exposure procedure was used.
Results. The cations (all associated with the acetate anion) inhibited bitterness when mixed with pharmaceutical solutions to varying degrees. The sodium cation significantly (P < 0.003) inhibited bitterness of the pharmaceuticals more than the other cations. The anions (all associated with the sodium cation) also inhibited bitterness to varying degrees. With the exception of salicylate, the glutamate and adenosine monophosphate anions significantly (P < 0.001) inhibited bitterness of the pharmaceuticals more than the other anions. Also, there were several specific inhibitory interactions between ammonium, sodium and salicylate and certain pharmaceuticals.
Conclusions. We conclude that sodium was the most successful cation and glutamate and AMP were the most successful anions at inhibiting bitterness. Structure forming and breaking properties of ions, as predicted by the Hofmeister series, and other physical-chemical ion properties failed to significantly predict bitterness inhibition.
Resumo:
Carnegie and Edwards (2001) suggest that the formation of an organisational body is just one of the 'signals of movement' within the dynamic process of professionalisation of an occupation and they list the sponsoring of professorial posts and research activities at universities as further examples. While the literature on this process in Australia does refer to the sponsorship of chairs of accounting (Carnegie & Williams, 2001), little has been written identifying the range of other areas of sponsorship by the organised accounting bodies. This paper presents details of the first fifty years presentations of the Annual Accounting Research Lectures held at The University of Melbourne, Australia. They have been presented continuously since 1940, when they were inaugurated with sponsorship from the Commonwealth Institute of Accountants. The paper presents the first complete listing of details relating to the presenter (including name, gender, residency and occupational area), title of the paper, date of presentation (where known) and details of publication (where appropriate). The initial and subsequent motivation for the presentation of the series and the influence of the lectures in promoting research and fostering relations between the professional bodies and the university, during a period of great significance in the development of accounting education and the professionalisation of accounting in Australia, is also discussed.
Resumo:
This paper describes fourteen brachiopod species in eleven genera from the Late Permian Wuchiapingian Coal Series (Lungtan Formation) of South China. Of these, the shell bed fauna from the basal Lungtan Formation is interpreted to represent the onset of the recovery of shelly faunas in the aftermath of the Guadalupian/Lopingian (G/L) mass extinction in South China. The post-extinction brachiopod faunas in the Wuchiapingian are characterized by the presence of numerous Lazarus taxa, survivors, and newly originating taxa. These elements capable of adapting their life habits were relatively more resistant to the G/L crisis. The post-extinction faunas, including survivors and the elements originating in the recovery period, have no life habit preference, but they were all adapted to a variety of newly vacated niches in the Late Permian oceans. Two new species, Meekella beipeiensis and Niutoushania chongqingensis, are described, and two Chinese genera, Niutoushania and Chengxianoproductus, are emended based on re-examination of the type specimens and new topotype materials from the Lungtan Formation.
Resumo:
This paper investigates the high-earning children's series, A Series of Unfortunate Events, in relation to the skills young people require to survive and thrive in what Ulrich Beck calls risk society. Children's textual culture has been traditionally informed by assumptions about childhood happiness and the need to reassure young readers that the world is safe. The genre is consequently vexed by adult anxiety about children's exposure to certain kinds of knowledge. This paper discusses the implications of the representation of adversity in the Lemony Snicket series via its subversions of the conventions of children's fiction and metafictional strategies. Its central claim is that the self-consciousness or self-reflexivity of A Series of Unfortunate Events} models one of the forms of reflexivity children need to be resilient in the face of adversity and to empower them to undertake the biographical project risk society requires of them.
Resumo:
Labour productivity plays a significant role in economic growth, labour demand and employment situation of a particular economy. In this light, the presence of a structural break in productivity, and its unit root property, has important consequences for the overall economy and in major sectors such as manufacturing. In this article, using some recently developed unit root tests, we examine: (i) the null hypothesis of a unit root in the log-level of labour productivity for 38 manufacturing subdivisions against the alternative of trend stationarity over a three-decade period; and (ii) the presence of a structural break in the series, and whether the break has had a permanent or a transitory effect on manufacturing labour productivity. Our main finding is that shocks to labour productivity have had a transitory effect, implying that policies are likely to have only short-term effects.
Resumo:
We examine the unit root properties of 16 Australian macroeconomic time series using monthly data spanning the period 1960–2004. In addition to the standard Augmented Dickey Fuller (ADF) test, we implement one- and two-break endogenous structural break ADF-type unit root tests as well as one- and two-break Lagrange multiplier (LM) unit root tests. While the ADF test provides relatively little evidence against the unit root null hypothesis, once we allow for structural breaks we are able to reject the unit root null for just under half of the variables at the 10% level or better.