11 resultados para lower upper bound estimation
em University of Queensland eSpace - Australia
Resumo:
A scaling law is presented that provides a complete solution to the equations bounding the stability and rupture of thin films. The scaling law depends on the fundamental physicochemical properties of the film and interface to calculate bounds for the critical thickness and other key film thicknesses, the relevant waveforms associated with instability and rupture, and film lifetimes. Critical thicknesses calculated from the scaling law are shown to bound the values reported in the literature for numerous emulsion and foam films. The majority of critical thickness values are between 15 to 40% lower than the upper bound critical thickness provided by the scaling law.
Resumo:
For the Western-Pacific region spread-F has been found to occur with delays after geomagnetic activity (GA) ranging from 5 to 10 days as station groups are considered from low midlatitudes to equatorial regions. The statistical (superposed-epoch) analyses also indicate that at the equator the spread-F, and therefore associated medium-scale traveling ionospheric disturbances (MS-TIDs) occur with additional delays around 16, 22 and 28 days representing a 6-day modulation of the delay period. These results are compared with similar delays, including the modulation, for D-region enhanced hydroxyl emission (Shefov, 1969). It is proposed that this similarity may be explained by MS-TIDs influencing both the F and D regions as they travel. Long delays of over 20 days are also found near the equator for airglow-measured MS-TIDs (Sobral et al., 1997). These are recorded infrequently and have equatorward motions, while normally eastward motions are measured at the equator. Also in midlatitudes D-region absorption events have been shown (statistically) to have similar long delays after GA. It is suggested that atmospheric gravity waves and associated MS-TIDs may be generated by some of the precipitations responsible for the absorption. The recording of the delayed spread-F events depends on the GA being well below the average levels around sunset on the nights of recording. This implies that lower upper-atmosphere neutral particle densities are necessary.
Resumo:
We report the construction of the mouse full-length cDNA encyclopedia, the most extensive view of a complex transcriptome, on the basis of preparing and sequencing 246 libraries. Before cloning, cDNAs were enriched in full-length by Cap-Trapper, and in most cases, aggressively subtracted/normalized. We have produced 1,442,236 successful 3'-end sequences clustered into 171,144 groups, from which 60,770 clones were fully sequenced cDNAs annotated in the FANTOM-2 annotation. We have also produced 547,149 5' end reads, which clustered into 124,258 groups. Altogether, these cDNAs were further grouped in 70,000 transcriptional units (TU), which represent the best coverage of a transcriptome so far. By monitoring the extent of normalization/subtraction, we define the tentative equivalent coverage (TEC), which was estimated to be equivalent to >12,000,000 ESTs derived from standard libraries. High coverage explains discrepancies between the very large. numbers of clusters (and TUs) of this project, which also include non-protein-coding RNAs, and the lower gene number estimation of genome annotations. Altogether, S'-end clusters identify regions that are potential promoters for 8637 known genes and S'-end clusters suggest the presence of almost 63,000 transcriptional starting points. An estimate of the frequency of polyadenylation signals suggests that at least half of the singletons in the EST set represent real mRNAs. Clones accounting for about half of the predicted TUs await further sequencing. The continued high-discovery rate suggests that the task of transcriptome discovery is not yet complete.
Resumo:
A 4-cycle system of order n, denoted by 4CS(n), exists if and only if nequivalent to1 (mod 8). There are four configurations which can be formed by two 4-cycles in a 4CS(n). Formulas connecting the number of occurrences of each such configuration in a 4CS(n) are given. The number of occurrences of each configuration is determined completely by the number d of occurrences of the configuration D consisting of two 4-cycles sharing a common diagonal. It is shown that for every nequivalent to1 (mod 8) there exists a 4CS(n) which avoids the configuration D, i.e. for which d=0. The exact upper bound for d in a 4CS(n) is also determined.
Resumo:
We provide an easily computable formula for a bipartite mixed-state entanglement measure. Our formula can be applied to readily calculate the entanglement for any rank-2 mixed state of a bipartite system. We use this formula to provide a tight upper bound for the entanglement of formation for rank-2 states of a qubit and a qudit. We also outline situations where our formula could be applied to study the entanglement properties of complex quantum systems.
Resumo:
The maximum possible volume of a simple, non-Steiner (v, 3, 2) trade was determined for all v by Xhosrovshahi and Torabi (Ars Combinatoria 51 (1999), 211-223), except that in the-case v equivalent to 5 (mod 6), v >= 23, they were only able to provide an upper, bound on the volume. In this paper we construct trades with volume equal to that bound for all v equivalent to 5 (mod 6), thus completing the problem.
Resumo:
This second and concluding part of a comprehensive palynological study of the Lower to Middle Ordovician succession of the central-northeastern Canning Basin completes the systematic documentation of the palynomorphs, i.e., chitinozoans, and formulates a palynostratigraphic zonation scheme embracing all three constituent formations of this investigation, viz., the Willara, Goldwyer, and Nita formations. A total of 21 species of chitinozoans (five genera), detailed systematically herein, are identified. Although chitinozoan recovery per sample proved variable, the following species occur fairly persistently in the productive samples: Belonechitina micracantha, Conochitina subcylindrica, C. poumoti, C. langei, Calpichitina windjana, and Rhabdochitina magna. Five, stratigraphically successive acritarch/prasinophyte assemblage zones, ranging in age from early Arenig through late Llanvirn, are proposed as follows (ascending order): Athabascaella rossii Assemblage Zone (corresponding to the lower Willara Formation; and dated as early-mid Arenig); Comasphaeridium setaricum Assemblage Zone (upper Willara and lowermost Goldwyer; late Arenig-earliest Llanvirn); Sacculidium aduncum Assemblage Zone (lower Goldwyer; early Llanvirn); Aremorica-nium solaris Assemblage Zone (middle and lower upper Goldwyer; mid Llanvirn); and Dactylofusa striatogranulata Assemblage Zone (upper Goldwyer and lower Nita; late Llanvirn). Four chitinozoan assemblage zones, stratigraphically coinciding (within the limits of sampling) with the acritarch/prasinophyte zones, comprise (in ascending order): Lagenochitina combazi Assemblage Zone (equivalent to the A. rossii and L. heterorhabda Assemblage Zones); Conochitina langei Assemblage Zone; Conocbitina subcylindrica Assemblage Zone; and Belonecbitina micracantha Assemblage Zone. Chronostratigraphic assignments are based principally on associated conodont and graptolite faunas. Whereas the acritarch/prasinophyte zones bear scant similarities to those established globally elsewhere, the chitinozoan zones show significant affiliations with those known from Laurentia.
Resumo:
This paper describes investigations into an optimal transmission scheme for a multiple input multiple output (MIMO) system operating in a Rician fading environment. The considerations are reduced to determining a covariance matrix of transmitted signals which maximizes the MIMO capacity under the condition that the receiver has perfect knowledge of the channel while the transmitter has the information about selected statistical quantities which are measured at the receiver. An optimal covariance matrix, which requires information of the Rice factor and the signal to noise ratio, is determined. The transmission scheme relying on the choice of the proposed covariance matrix outperforms the other transmission schemes which were reported earlier in the literature. The proposed scheme realizes an upper bound limit for the MIMO capacity under arbitrary Rician fading conditions. ©2005 IEEE
Resumo:
Four new species of dinoflagellate cysts are described from Callovian to lower Oxfordian (Jurassic) sediments of the Timor Sea, northwestern Australia. These comprise Evansia? lacryma, Egmontodinium elongatum, Leptodinium? ancoralium, and Nannoceratopsis reticulata. They are rare to common constituents of the Rigaudella aemula dinoflagellate cyst Interval Zone, and may prove useful for regional biostratigraphic correlation. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
Fine-scale spatial genetic structure (SGS) in natural tree populations is largely a result of restricted pollen and seed dispersal. Understanding the link between limitations to dispersal in gene vectors and SGS is of key interest to biologists and the availability of highly variable molecular markers has facilitated fine-scale analysis of populations. However, estimation of SGS may depend strongly on the type of genetic marker and sampling strategy (of both loci and individuals). To explore sampling limits, we created a model population with simulated distributions of dominant and codominant alleles, resulting from natural regeneration with restricted gene flow. SGS estimates from subsamples (simulating collection and analysis with amplified fragment length polymorphism (AFLP) and microsatellite markers) were correlated with the 'real' estimate (from the full model population). For both marker types, sampling ranges were evident, with lower limits below which estimation was poorly correlated and upper limits above which sampling became inefficient. Lower limits (correlation of 0.9) were 100 individuals, 10 loci for microsatellites and 150 individuals, 100 loci for AFLPs. Upper limits were 200 individuals, five loci for microsatellites and 200 individuals, 100 loci for AFLPs. The limits indicated by simulation were compared with data sets from real species. Instances where sampling effort had been either insufficient or inefficient were identified. The model results should form practical boundaries for studies aiming to detect SGS. However, greater sample sizes will be required in cases where SGS is weaker than for our simulated population, for example, in species with effective pollen/seed dispersal mechanisms.