1,341 research outputs found

    Expanding the Family of Grassmannian Kernels: An Embedding Perspective

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    Modeling videos and image-sets as linear subspaces has proven beneficial for many visual recognition tasks. However, it also incurs challenges arising from the fact that linear subspaces do not obey Euclidean geometry, but lie on a special type of Riemannian manifolds known as Grassmannian. To leverage the techniques developed for Euclidean spaces (e.g, support vector machines) with subspaces, several recent studies have proposed to embed the Grassmannian into a Hilbert space by making use of a positive definite kernel. Unfortunately, only two Grassmannian kernels are known, none of which -as we will show- is universal, which limits their ability to approximate a target function arbitrarily well. Here, we introduce several positive definite Grassmannian kernels, including universal ones, and demonstrate their superiority over previously-known kernels in various tasks, such as classification, clustering, sparse coding and hashing

    The Evolution of the Global Star Formation History as Measured from the Hubble Deep Field

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    The Hubble Deep Field (HDF) is the deepest set of multicolor optical photometric observations ever undertaken, and offers a valuable data set with which to study galaxy evolution. Combining the optical WFPC2 data with ground-based near-infrared photometry, we derive photometrically estimated redshifts for HDF galaxies with J<23.5. We demonstrate that incorporating the near-infrared data reduces the uncertainty in the estimated redshifts by approximately 40% and is required to remove systematic uncertainties within the redshift range 1<z<2. Utilizing these photometric redshifts, we determine the evolution of the comoving ultraviolet (2800 A) luminosity density (presumed to be proportional to the global star formation rate) from a redshift of z=0.5 to z=2. We find that the global star formation rate increases rapidly with redshift, rising by a factor of 12 from a redshift of zero to a peak at z~1.5. For redshifts beyond 1.5, it decreases monotonically. Our measures of the star formation rate are consistent with those found by Lilly et al. (1996) from the CFRS at z 2, and bridge the redshift gap between those two samples. The overall star formation or metal enrichment rate history is consistent with the predictions of Pei and Fall (1995) based on the evolving HI content of Lyman-alpha QSO absorption line systems.Comment: Latex format, 10 pages, 3 postscript figures. Accepted for publication in Ap J Letter

    RECOGNITION OF BUS PATH AND FUEL ECHELON OBSERVE SYSTEM USING IOT TECHNOLOGY

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    The demand for effective public delivery frame such as buses is genuinely swiftly stronger due to the boosting in populace; the guests must recognize the precise shipping possibility from that bus to the sure terminal and after that bear in mind their enjoy of their domestic. Fuel surveillance has virtually been clearly the primary issue that a whole lot of bus carriers making plans to remedy. This newspaper hooked up a bus tracking and also checking the fuel as well as velocity device to offer a middle for the manipulate criteria by means of the supervisor. The encouraged body according to ARM 7, GSM/GPS and also chart suit ASP.MVC which give the actuated shipping possibility aside from graphically offering the bus area on Google chart. The fashion additionally makes it feasible for the owner from the buses to look at the bus instantly for the reason that the unit supervisor may want to conveniently maintain statistics supply relevant records from buses as well as its very own electricity box at any second from the answer

    Deliberate Apprenticeship in the Pediatric Emergency Department Improves Experience for Third-year Students

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    INTRODUCTION: The Pediatric Emergency Department (PED) provides medical students with learning in a high-volume, fast-paced environment; characteristics that can be stressful for new students. Shadowing can improve transitioning, yet this alone does not facilitate students’ development of independent medical care competencies. This study evaluates if third-year medical students’ deliberate apprenticeship with senior residents increases students’ comfort and patient exposure in the PED. METHODS: This study took place over the 2011-2012 academic year, and study participants were all third-year medical students during their pediatric clerkship rotation. This was a prospective educational intervention assigning students to randomized control blocks of deliberate apprenticeship (DA) intervention or control. DA students were paired with a senior resident who oriented and worked with the student, while control students were unpaired. All students completed a 20-question structured survey at shift end, which included questions about their perception of the learning environment, comfort with, and number of patient care responsibilities performed. We used independent Mann-Whitney and t-tests to compare experiences between the groups. Statistical significance was defined as p<0.05. We used the constant comparative method to qualitatively analyze students’ comments. RESULTS: Response rate was 85% (145/169). Students also rated on 5-point Likert-scale their level of comfort with defined aspects of working in the PED. DA students (n=76) were significantly more comfortable obtaining histories (4.2 versus 3.8) and formulating differential diagnoses (3.9 versus 3.4). DA students also performed more physical exams (2.9 versus 2.4). We categorized themes from the qualitative analysis of the students’ comments about their PED experience. The titles for these themes are as follows: PED provides a good learning experience; uncertainty about the medical student’s role in the PED; third-year medical students compete with other learners for teaching attention; opportunities provided to medical students for inclusion in patient care; personal knowledge deficits limit the ability to participate in the PED; PED pace affects learning opportunities. CONCLUSION: DA constitutes a feasible approach to the clinical learning environment that increases students’ patient care experiences and may ease transitioning for undergraduate medical students to new clinical environments

    The Near-Infrared Number Counts and Luminosity Functions of Local Galaxies

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    This study presents a wide-field near-infrared (K-band) survey in two fields; SA 68 and Lynx 2. The survey covers an area of 0.6 deg.2^2, complete to K=16.5. A total of 867 galaxies are detected in this survey of which 175 have available redshifts. The near-infrared number counts to K=16.5 mag. are estimated from the complete photometric survey and are found to be in close agreement with other available studies. The sample is corrected for incompleteness in redshift space, using selection function in the form of a Fermi-Dirac distribution. This is then used to estimate the local near-infrared luminosity function of galaxies. A Schechter fit to the infrared data gives: MK=25.1±0.3^\ast_K = -25.1 \pm 0.3, α=1.3±0.2\alpha = -1.3\pm 0.2 and ϕ=(1.5±0.5)×103\phi^\ast =(1.5\pm 0.5)\times 10^{-3} Mpc3^{-3} (for H0=50_0=50 Km/sec/Mpc and q0=0.5_0=0.5). When reduced to α=1\alpha=-1, this agrees with other available estimates of the local IRLF. We find a steeper slope for the faint-end of the infrared luminosity function when compared to previous studies. This is interpreted as due to the presence of a population of faint but evolved (metal rich) galaxies in the local Universe. However, it is not from the same population as the faint blue galaxies found in the optical surveys. The characteristic magnitude (MKM^\ast_K) of the local IRLF indicates that the bright red galaxies (MK27M_K\sim -27 mag.) have a space density of 5×105\le 5\times 10^{-5} Mpc3^{-3} and hence, are not likely to be local objects.Comment: 24 pages, 8 figures, AASTEX 4.0, published in ApJ 492, 45

    TRENDS IN THE DIAGNOSIS OF HUMAN IMMUNODEFICIENCY VIRUS

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    Ever since the first HIV case reported, there is a dramatic increase in the prevalence of HIV infection which urged the need for an effective diagnostic method.  There are several improvements in diagnostic methods employing various technologies to screen for HIV infection using enzyme immunoassays and rapid diagnostic tests which simultaneously detect antigen and antibody with significantly reduced window period.  Further, western blot or immunofluorescence methods are used to confirm the results. Nucleic acid amplification tests, though sensitive, are expensive and hence not employed for screening but instead used to monitor the antiretroviral drug response. In spite of appreciable advancements in the sensitivity and specificity of the detection techniques, the algorithms are still the method of choice for ensuring the accuracy of test results

    Decay of Samarium-153

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    Radiations emitted in the decay of Samarium-153 have been studied in the Siegbahn-Slatis beta-ray spectrometer. Using the internal conversion electron spectrum and the photo-electron spectrum with tin as radiator, the internal conversion coefficient αk has been determined for 102 Kev. and 70 Kev.gamma-rays. The relative intensities of the three beta-ray branches have been determined. A weak gamma-ray of energy 83 Kev. has been found and can be interpreted as a transition to the ground state from the first rotational level in Europium-153. The multipole order and character of the 102 Kev. transition is discussed

    Characterizations of the diurnal shapes of OI 630.0 nm dayglow intensity variations: inferences

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    International audienceMeasurements of OI 630.0 nm thermospheric dayglow emission by means of the Dayglow Photometer (DGP) at Mt. Abu (24.6° N, 73.7° E, dip lat 19.09° N), a station under the crest of Equatorial Ionization Anomaly (EIA), reveal day-to-day changes in the shapes of the diurnal profiles of dayglow intensity variations. These shapes have been characterized using the magnetometer data from equatorial and low-latitude stations. Substantial changes have been noticed in the shapes of the dayglow intensity variations between 10:00?15:00 IST (Indian Standard Time) during the days when normal and counter electrojet events are present over the equator. It is found that the width (the time span corresponding to 0.8 times the maximum dayglow intensity) of the diurnal profile has a linear relationship with the integrated electrojet strength. Occasional deviation from this linear relationship is attributed to the presence of substantial mean meridional wind
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