864 resultados para Hierarchical sampling


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A tree-based dictionary learning model is developed for joint analysis of imagery and associated text. The dictionary learning may be applied directly to the imagery from patches, or to general feature vectors extracted from patches or superpixels (using any existing method for image feature extraction). Each image is associated with a path through the tree (from root to a leaf), and each of the multiple patches in a given image is associated with one node in that path. Nodes near the tree root are shared between multiple paths, representing image characteristics that are common among different types of images. Moving toward the leaves, nodes become specialized, representing details in image classes. If available, words (text) are also jointly modeled, with a path-dependent probability over words. The tree structure is inferred via a nested Dirichlet process, and a retrospective stick-breaking sampler is used to infer the tree depth and width.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pianists of the twenty-first century have a wealth of repertoire at their fingertips. They busily study music from the different periods -- Baroque, Classical, Romantic, and some of the twentieth century -- trying to understand the culture and performance practice of the time and the stylistic traits of each composer so they can communicate their music effectively. Unfortunately, this leaves little time to notice the composers who are writing music today. Whether this neglect proceeds from lack of time or lack of curiosity, I feel we should be connected to music that was written in our own lifetime, when we already understand the culture and have knowledge of the different styles that preceded us. Therefore, in an attempt to promote today’s composers, I have selected piano music written during my lifetime, to show that contemporary music is effective and worthwhile and deserves as much attention as the music that preceded it. This dissertation showcases piano music composed from 1978 to 2005. A point of departure in selecting the pieces for this recording project is to represent the major genres in the piano repertoire in order to show a variety of styles, moods, lengths, and difficulties. Therefore, from these recordings, there is enough variety to successfully program a complete contemporary recital from the selected works, and there is enough variety to meet the demands of pianists with different skill levels and recital programming needs. Since we live in an increasingly global society, music from all parts of the world is included to offer a fair representation of music being composed everywhere. Half of the music in this project comes from the United States. The other half comes from Australia, Japan, Russia, and Argentina. The composers represented in these recordings are: Lowell Liebermann, Richard Danielpour, Frederic Rzewski, Judith Lang Zaimont, Samuel Adler, Carl Vine, Nikolai Kapustin, Akira Miyoshi and Osvaldo Golijov. With the exception of one piano concerto, all the works are for solo piano. This recording project dissertation consists of two 60 minute CDs of selected repertoire, accompanied by a substantial document of in-depth program notes. The recordings are documented on compact discs that are housed within the University of Maryland Library System.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world's oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There is no abstract for this record.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The powerful general Pacala-Hassell host-parasitoid model for a patchy environment, which allows host density–dependent heterogeneity (HDD) to be distinguished from between-patch, host density–independent heterogeneity (HDI), is reformulated within the class of the generalized linear model (GLM) family. This improves accessibility through the provision of general software within well–known statistical systems, and allows a rich variety of models to be formulated. Covariates such as age class, host density and abiotic factors may be included easily. For the case where there is no HDI, the formulation is a simple GLM. When there is HDI in addition to HDD, the formulation is a hierarchical generalized linear model. Two forms of HDI model are considered, both with between-patch variability: one has binomial variation within patches and one has extra-binomial, overdispersed variation within patches. Examples are given demonstrating parameter estimation with standard errors, and hypothesis testing. For one example given, the extra-binomial component of the HDI heterogeneity in parasitism is itself shown to be strongly density dependent.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Continuous Plankton Recorder (CPR) samples from the English Channel and adjacent Celtic shelf, taken over the period 1958-1980, were analysed for sardine (Sardina pilchardus) eggs. Results showed the progression of sardine spawning along the English Channel from west to east from March to August and a return from east to west from September to November. This corresponds with the two seasonal peaks of sardine egg abundance in the western Channel: the main summer peak being in May/June, with a smaller autumn peak in October/November. Long-term changes in sardine egg abundance in CPR samples showed a decline in summer spawning from the late 1960s, but no clear trend in autumn-spawned egg abundance. Similar patterns were observed in the numbers of sardine eggs sampled by conventional plankton net tows at the time-series Station L5 off Plymouth. This supports the use of the longer time-series of sardine egg data at L5 as being representative of a wider area and emphasizes the importance in continuation of the L5 time-series.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the biological sciences, stereological techniques are frequently used to infer changes in structural parameters (volume fraction, for example) between samples from different populations or subject to differing treatment regimes. Non-homogeneity of these parameters is virtually guaranteed, both between experimental animals and within the organ under consideration. A two-stage strategy is then desirable, the first stage involving unbiased estimation of the required parameter, separately for each experimental unit, the latter being defined as a subset of the organ for which homogeneity can reasonably be assumed. In the second stage, these point estimates are used as data inputs to a hierarchical analysis of variance, to distinguish treatment effects from variability between animals, for example. Techniques are therefore required for unbiased estimation of parameters from potentially small numbers of sample profiles. This paper derives unbiased estimates of linear properties in one special case—the sampling of spherical particles by transmission microscopy, when the section thickness is not negligible and the resulting circular profiles are subject to lower truncation. The derivation uses the general integral equation formulation of Nicholson (1970); the resulting formulae are simplified, algebraically, and their efficient computation discussed. Bias arising from variability in slice thickness is shown to be negligible in typical cases. The strategy is illustrated for data examining the effects, on the secondary lysosomes in the digestive cells, of exposure of the common mussel to hydrocarbons. Prolonged exposure, at 30 μg 1−1 total oil-derived hydrocarbons, is seen to increase the average volume of a lysosome, and the volume fraction that lysosomes occupy, but to reduce their number.