Using association rule mining to enrich semantic concepts for video retrieval

In order to achieve true content-based information retrieval on video we should analyse and index video with high-level semantic concepts in addition to using user-generated tags and structured metadata like title, date, etc. However the range of such high-level semantic concepts, detected either manually or automatically, usually limited compared to the richness of information content in video and the potential vocabulary of available concepts for indexing. Even though there is work to improve the performance of individual concept classifiers, we should strive to make the best use of whatever partial sets of semantic concept occurrences are available to us. We describe in this paper our method for using association rule mining to automatically enrich the representation of video content through a set of semantic concepts based on concept co-occurrence patterns. We describe our experiments on the TRECVid 2005 video corpus annotated with the 449 concepts of the LSCOM ontology. The evaluation of our results shows the usefulness of our approach

Cold atom confinement in an all-optical dark ring trap

We demonstrate confinement of $^{85}$Rb atoms in a dark, toroidal optical trap. We use a spatial light modulator to convert a single blue-detuned Gaussian laser beam to a superposition of Laguerre-Gaussian modes that forms a ring-shaped intensity null bounded harmonically in all directions. We measure a 1/e spin-relaxation lifetime of ~1.5 seconds for a trap detuning of 4.0 nm. For smaller detunings, a time-dependent relaxation rate is observed. We use these relaxation rate measurements and imaging diagnostics to optimize trap alignment in a programmable manner with the modulator. The results are compared with numerical simulations.Comment: 5 pages, 4 figure

Analysis of Residue Probability Density Function and Comparator Offset Error in Pipelined ADCs

This paper presents a new approach to analyze the convergence of residue probability density function (pdf) in pipelined ADCs. Compared to the previous approaches, in the proposed approach, in addition to the analysis of residue pdfs for different input densities, the analysis of the sub-ADC comparator offsets impact on output pdf is possible. Using Fourier analysis, it will be shown that the residue density converges to uniformity. In the half-bit redundant structure, residue pdf concentrates in the center half of the stage full-scale range and 6 dB of extra resolution can be gained. Also, the share of each stage in this resolution improvement is investigated. Examining the sub-ADC threshold offsets impact on residue pdfs, it is observed that with respect to the impact on converter additional resolution, the final stages offset errors are more significant than the first stages offsets

Research notes: Glyceride structure variation in soybean varieties

The glyceride structure of an oil, i.e., the combinations of fatty acids that occur together in the triglycerides, may influence its stability to oxidation (Raghuveer and Hammond, 1967). Recently we examined the glyceride structure of about 20 varieties of soybean and related species by two techniques: stereospecific analysis and silver ion chromatography (Fatemi and Hammond, 1977a, 1977b) . Stereospecific analysis measures the proportion of each fatty acid on each of the three positions of glycerol

A low-loss photonic silica nanofiber for higher-order modes

Optical nanofibers confine light to subwavelength scales, and are of interest for the design, integration, and interconnection of nanophotonic devices. Here we demonstrate high transmission (> 97%) of the first family of excited modes through a 350 nm radius fiber, by appropriate choice of the fiber and precise control of the taper geometry. We can design the nanofibers so that these modes propagate with most of their energy outside the waist region. We also present an optical setup for selectively launching these modes with less than 1% fundamental mode contamination. Our experimental results are in good agreement with simulations of the propagation. Multimode optical nanofibers expand the photonic toolbox, and may aid in the realization of a fully integrated nanoscale device for communication science, laser science or other sensing applications.Comment: 12 pages, 5 figures, movies available onlin

Emergence of Bulk CsCl Structure in (CsCl)nCs+ Cluster Ions

The emergence of CsCl bulk structure in (CsCl)nCs+ cluster ions is investigated using a mixed quantum-mechanical/semiempirical theoretical approach. We find that rhombic dodecahedral fragments (with bulk CsCl symmetry) are more stable than rock-salt fragments after the completion of the fifth rhombic dodecahedral atomic shell. From this size (n=184) on, a new set of magic numbers should appear in the experimental mass spectra. We also propose another experimental test for this transition, which explicitely involves the electronic structure of the cluster. Finally, we perform more detailed calculations in the size range n=31--33, where recent experimental investigations have found indications of the presence of rhombic dodecahedral (CsCl)32Cs+ isomers in the cluster beams.Comment: LaTeX file. 6 pages and 4 pictures. Accepted for publication in Phys. Rev.

Clade identification of symbiotic zooxanthellae of dominant sclerectinian coral species of intertidal pools in Hengam Island

Zooxanthellae of reef-building corals are unicellular dinoflagellates of the Symbiodinium genus, which has an important role in bleaching phenomenon. Symbiodinium and their coral hosts are sensitive to environmental stresses that include salinity, high temperatures, low temperatures, extreme light levels and turbidity. Tidal pools have harsh conditions due to lack of nutrients, food and pronounced changes in physical conditions such as pH, salinity and temperature, hence the study of symbiotic zooxanthellae on coral reefs of tidal pool seems to be necessary. Samples of five coral species that include Siderastrea savignyana, Coscinaraea columna, Anomastrea irregulariis, Cyphastrea serailia, Psammocora superficialis were collected at intertidal pool of Hengam Island in the northern Persian Gulf. Partial 28S nuclear ribosomal (nr) DNA of Symbiodinium were amplified by polymerase chain reaction (PCR) and then PCR products were analyzed by the phylogenetic analyses of the LSU DNA sequences based on PAUP and Clustal X software. The results showed that there are at least two clades of Symbiodinium from Hengam Island. Clade D was detected from 3 of the coral species whileclade C was found in 2 species only. This study showed dominance of clade D at intertidal pool in Hengam Island and the dominace of clade D might be explained by the high environmental stresses for the Persian Gulf.Key words: Persian Gulf, clade D, tides, Symbiodinium and Hengam Island

Magnetically-controlled velocity selection in a cold atom sample using stimulated Raman transitions

We observe velocity-selective two-photon resonances in a cold atom cloud in the presence of a magnetic field. We use these resonances to demonstrate a simple magnetometer with sub-mG resolution. The technique is particularly useful for zeroing the magnetic field and does not require any additional laser frequencies than are already used for standard magneto-optical traps. We verify the effects using Faraday rotation spectroscopy.Comment: 5 pages, 6 figure