Know2Look: Commonsense Knowledge for Visual Search

With the rise in popularity of social media, images accompanied by contextual text form a huge section of the web. However, search and retrieval of documents are still largely dependent on solely textual cues. Although visual cues have started to gain focus, the imperfection in object/scene detection do not lead to significantly improved results. We hypothesize that the use of background commonsense knowledge on query terms can significantly aid in retrieval of documents with associated images. To this end we deploy three different modalities - text, visual cues, and commonsense knowledge pertaining to the query - as a recipe for efficient search and retrieval

An Imaging Polarimeter(IMPOL) for multi-wavelength observations

Taking advantage of the advances in array detector technology, an imaging polarimeter (IMPOL) has been constructed for measuring linear polarization in the wavelength band from 400-800 nm. It makes use of a Wollaston prism as the analyser to measure simultaneously the two orthogonal polarization components that define a Stoke's parameter. An achromatic half-wave plate is used to rotate the plane of polarization with respect to the axis of the analyser so that the second Stoke's parameter also can be determined. With a field of view correponding to about 30x30 sq. mm for a 1.2 m, f/13 telescope, a sensitive, liquid-nitrogen cooled CCD camera as the detector and a built-in acquisition and guidance unit, the instrument can be used for studying stellar fields or extended objects with an angular resolution close to 2 arcsec. The instrumental polarization is less than 0.05% and the accuracies of measurement are primarily limited by photon noise for typical observations.Comment: 10 pages including 5 embedded figures; submitted to Astronomy and Astrophysics Supplement Series; available on request to A. N. Ramaprakash ([email protected] or [email protected]); quote report n

Studying the Imaging Characteristics of Ultra Violet Imaging Telescope (UVIT) through Numerical Simulations

Ultra-Violet Imaging Telescope (UVIT) is one of the five payloads aboard the Indian Space Research Organization (ISRO)'s ASTROSAT space mission. The science objectives of UVIT are broad, extending from individual hot stars, star-forming regions to active galactic nuclei. Imaging performance of UVIT would depend on several factors in addition to the optics, e.g. resolution of the detectors, Satellite Drift and Jitter, image frame acquisition rate, sky background, source intensity etc. The use of intensified CMOS-imager based photon counting detectors in UVIT put their own complexity over reconstruction of the images. All these factors could lead to several systematic effects in the reconstructed images. A study has been done through numerical simulations with artificial point sources and archival image of a galaxy from GALEX data archive, to explore the effects of all the above mentioned parameters on the reconstructed images. In particular the issues of angular resolution, photometric accuracy and photometric-nonlinearity associated with the intensified CMOS-imager based photon counting detectors have been investigated. The photon events in image frames are detected by three different centroid algorithms with some energy thresholds. Our results show that in presence of bright sources, reconstructed images from UVIT would suffer from photometric distortion in a complex way and the presence of overlapping photon events could lead to complex patterns near the bright sources. Further the angular resolution, photometric accuracy and distortion would depend on the values of various thresholds chosen to detect photon events.Comment: Submitted to PASP, 16 Pages, 9 figure

Geomagnetic Activity and Solar M-regions for the Current Epoch of the Sunspot Minimum

The analysis of geomagnetic activity has been made for the period 1950-54 and four sequences of annual variations have been detected. It has been shown that the most predominant effect of M-regions is observable only on particular dates separated at an interval of 27 days. In the last section the possibility of the association of M-regions with various solar features has been discussed and it is found that they can be identified with unipolar magnetic regions which may also be the seat of low coronal line intensities

New opportunities for Indian space astronomy

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Adsorption efficiency of carbon prepared from agricultural waste materials in removing basic dye from aqueous solution

Management of solid waste is the burgeoning issue of the current times. Agriculture waste is rich in org. material like cellulose, lignin etc. and can be of great use if utilized as right resource at right time and right place. In the current study agriculture waste material has been used for adsorption of color from waste water. Sugarcane bagasse and paddy straw have been recycled to activated carbon and have been utilized and compared as the adsorbent for the removal of basic dye from aq. soln. A basic dye, methylene blue has been used as the adsorbate. Two different mineral acids have been used for activation of raw material and it was obsd. that both H3PO4 and HNO3 were good activating agent but impregnation efficiency was in following order H3PO4 > HNO3. Adsorption expts. were conducted by varying several parameters namely pH, adsorbent dose, initial concn. of dye and contact time. It was obsd. that color was effectively removed at all selected pH and the increase in activated carbon dose showed an increase in its adsorption efficiency. The percentage of color removal decreased with an increase in the initial dye concn. More than 90 % adsorption efficiency of dye from soln. contg. 10 mg​/L of dye was attained with an adsorbent dosage of 0.1 g after 45 min of contact time at all pH. Results obtained indicate that agriculture waste material could be employed as a low cost alternative to com. activated carbon in wastewater treatment for dye removal and can thus be a good example of wealth from waste

Adsorption efficiency of carbon from treated sugarcane bagasse in removing chromium (VI) from aqueous solutions by optimization of adsorption parameters

Adsorption is one of the effective techniques for removal of chromium (VI) from wastewater. In the present study, efforts have been made to develop adsorption technology for removing Chromium (Cr) VI from aqueous solutions by using sugarcane bagasse a waste which is left after taking out the juice. Activated carbon was prepared from waste sugarcane bagasse by chemical activation with orthophosphoric acid and burning for 3 hrs. Batch adsorption studies carried out showed that the adsorbent prepared from sugarcane bagasse has a significantcapacity in removing Cr (VI) from aqueous solutions. Optimization of certain adsorption process factors i.e. pH, agitation time; adsorbent dose and adsorbate concentration were also made

A Model for the Lubrication Mechanism in Knee Joint Replacement

Analytical studies are presented for the understanding of the lubrication mechanism occuring in knee joint replacement under restricted motion. The idealised model has been shown to produce results consistent with those in normal situations. Effects of increase in viscoelastic parameter of the lubricant are similar to those of increase in the concentration of hyaluronic acid molecules in synovial fluid. Slip velocity occuring at the poroelastic boundary helps in normal functioning of the joints