12,501 research outputs found
The image ray transform for structural feature detection
The use of analogies to physical phenomena is an exciting paradigm in computer vision that allows unorthodox approaches to feature extraction, creating new techniques with unique properties. A technique known as the "image ray transform" has been developed based upon an analogy to the propagation of light as rays. The transform analogises an image to a set of glass blocks with refractive index linked to pixel properties and then casts a large number of rays through the image. The course of these rays is accumulated into an output image. The technique can successfully extract tubular and circular features and we show successful circle detection, ear biometrics and retinal vessel extraction. The transform has also been extended through the use of multiple rays arranged as a beam to increase robustness to noise, and we show quantitative results for fully automatic ear recognition, achieving 95.2% rank one recognition across 63 subjects
The Accuracy of Perturbative Master Equations
We consider open quantum systems with dynamics described by master equations
that have perturbative expansions in the system-environment interaction. We
show that, contrary to intuition, full-time solutions of order-2n accuracy
require an order-(2n+2) master equation. We give two examples of such
inaccuracies in the solutions to an order-2n master equation: order-2n
inaccuracies in the steady state of the system and order-2n positivity
violations, and we show how these arise in a specific example for which exact
solutions are available. This result has a wide-ranging impact on the validity
of coupling (or friction) sensitive results derived from second-order
convolutionless, Nakajima-Zwanzig, Redfield, and Born-Markov master equations.Comment: 6 pages, 0 figures; v2 updated references; v3 updated references,
extension to full-time and nonlocal regime
An Investigation of the Relationship Between Formal Christian Education and the Religious Beliefs of Middle and High School Students Currently Attending a Christian School
Throughout the Common Era, large segments of mankind have used Biblical principles to guide their lives. In many instances, religion has served as the guiding force behind both positive and negative societal changes. So, it is not surprising that questions regarding the place of religion within the field of education have remained a source of controversy since the earliest days of the American republic. The purpose of this study was to a) examine the relationship between Christian education and the religious beliefs of middle school students currently attending a Christian school, b) to examine the relationship between Christian education and the religious beliefs of high school students currently attending a Christian school, and c) to examine the differences between the religious beliefs of middle and high school students currently attending a Christian school.
Two hundred twenty-one middle and high school students participated in this research study. The study participants responded to two questionnaires, a demographic questionnaire and a questionnaire designed to determine the level of religious beliefs. The demographic questionnaire collected information regarding the set of independent variables: grade level, gender, number of years of formal Christian education, and average number of hours spent per week participating in religious activities outside of school. The dependent variable, religious beliefs, was measured by the Religious Belief Questionnaire. To analyze the data collected, the following statistical procedures were utilized: frequency distributions, basic descriptive statistics, correlations, cross tabulations, regression analyses, Pearson product moment correlation coefficients and a t-test.
The data revealed that there were no statistically significant relationships between the religious beliefs of the middle and high school subjects attributable to the set of independent variables. When addressing the individual relationships of the independent variables, varied information was obtained.
The findings of this research study indicate various relationships between the dependent variable and each independent variable that should not be ignored. This research should prompt educational practitioners to no longer underestimate the importance of utilizing religious teachings in helping students develop to their fullest potential. The importance of this research challenges each of us to revisit our thoughts regarding the relationship between religion and education
The Intensities of Cosmic Ray H and He Nuclei at ~250 MeV/nuc Measured by Voyagers 1 and 2 - Using these Intensities to Determine the Solar Modulation Parameter in the Inner Heliosphere and the Heliosheath Over a 40 Year Time Period
We have determined the solar modulation potential, phi, vs. time that is
observed at Voyager 1 and 2 from measurements of the H and He nuclei
intensities at a common energy of 250 MeVnuc. The H nuclei have a rigidity 0.7
GV, the He nuclei 1.4 GV. These measurements cover a 40 year time period, which
includes almost 4 cycles of solar 11 year sunspot variations, throughout the
inner heliosphere out to the HTS at distances of 95 AU and 85 AU, respectively
at V1 and V2, and then beyond in the heliosheath. Inside the HTS the modulation
potential vs. time curves at V1 and V2 show a very similar temporal structure
to those observed at the Earth. During a later period of maximum solar
modulation from 2000.0 to 2005.0 when V1 and V2 are in the outer heliosphere
between 60-94 AU, the main temporal features of the modulation potential curves
at all 3 locations match up with appropriate time delays at V1 and V2 if it is
assumed that spatially coherent structures are moving outward past V1 and V2,
with outward speeds of up to 700 Kms negative 1. After 2004.0 V1 and V2 are at
latitudes of positive 35 and negative 30 respectively, placing lower limits on
the latitude extent of these structures. Beyond the HTS in the heliosheath the
modulation potential slowly decreases at both spacecraft with only a weak
evidence of the unusual modulation minimum observed at the Earth in 2009, for
example. A sudden decrease of the modulation potential 50 MV for both H and He
nuclei occurs at V1 just before the heliopause crossing at about 122 AU. This
decrease has not yet been observed at V2, which is now at 113 AU and still
observing a modulation potential 60 MV.Comment: 28 pages, 9 Figure
Evaporation from lakes
Evaporation can be determined by the aid of the first law of thermodynamics in such a way that wind velocity need not enter the calculation. Air temperature and humidity enter only as terms in a correction which can have a relatively small average value under typical conditions. The complete equation is E=(H-S-C)/L(1+R) where E is the evaporation, H the difference between the incoming and outgoing radiation, S the heat stored in a column of water having unit cross-section, C a correction for heat carried by flowing water and leakage of heat through the walls of the vessel, L the latent heat of water, and R is Bowen's ratio. A method of finding the difference between the incoming and outgoing radiation, by means of observations on a well insulated pan is described, and also a method of finding the ratio of sensible heat to latent heat transmitted through the air-water surface. Bowen's theoretical conclusions respecting this ratio were found to be consistent with observations.
The above formula can be used in estimating evaporation from an actual lake whenever the requisite data can be obtained. Although from a physical standpoint the quantity of sensible heat passing through the air-water surface is not strictly negligible, nevertheless is most meteorological and engineering applications, the error caused by neglecting this quantity will be negligible in comparison with other errors that enter the main problem of which evaporation is a part
The Feeling of Color: A Haptic Feedback Device for the Visually Disabled
Tapson J, Gurari N, Diaz J, et al. The Feeling of Color: A Haptic Feedback Device for the Visually Disabled. Presented at the Biomedical Circuits and Systems Conference (BIOCAS), Baltimore, MD.We describe a sensory augmentation system designed to provide the visually disabled with a sense of color. Our system consists of a glove with short-range optical color sensors mounted on its fingertips, and a torso-worn belt on which tactors (haptic feedback actuators) are mounted. Each fingertip sensor detects the observed objectpsilas color. This information is encoded to the tactor through vibrations in respective locations and varying modulations. Early results suggest that detection of primary colors is possible with near 100% accuracy and moderate latency, with a minimum amount of training
What Skills Do Students Need? A Multi-Year Study of IT/IS Knowledge and Skills in Demand by Employers
In the fields of information technology and information systems, faculty must consistently adjust curriculum to meet the demands of the field. However, a challenge they often face is understanding what should be covered, especially given the limited number of courses most universities are able to offer. This research explores the knowledge and skills demanded in the field by surveying a variety of employers across various roles. The survey focused on IS/IT professionals with the inclusion of management who may oversee these professionals. Additionally, those involved in hiring IT/IS professionals were also surveyed to evaluate future hiring needs across various roles. A variety of technologies were examined, including databases, operating systems, networking technologies, and cloud platforms, to understand the technologies currently being utilized at organizations. Furthermore, specific skills (e.g., programming languages, general business, etc.) across a variety of roles were explored to understand what skills are currently sought by employers. The goal of this research is to understand the importance of various technologies and skills to better prepare students for the workforce. This is part of an ongoing study that has evaluated changes in the field over the past 15 years
Transient intensity changes of cosmic rays beyond the heliospheric termination shock as observed at Voyager 1
This paper continues our studies of temporal variations of cosmic rays beyond the heliospheric termination shock (HTS) using Voyager 1 (V1) data when V1 was beyond 94 AU. This new study utilizes cosmic ray protons and electrons of several energies. Notable transient decreases of 5–50% are observed in galactic cosmic ray nuclei and electrons at V1 shortly after similar decreases are observed at Voyager 2 (V2) still inside the HTS. These decreases at V1 appear to be related to the large solar events in September 2005 and December 2006 and the resulting outward moving interplanetary shock. These two large interplanetary shocks were the largest observed at V2 after V1 crossed the HTS at the end of 2004. They were observed at V2 just inside the HTS at 2006.16 and 2007.43 providing timing markers for V1. From the timing of the intensity decreases observed at V1 as the shocks first reach the HTS and then later reach V1 itself, we can estimate the shock speed beyond the HTS to be between 240 and 300 km s^(−1) in both cases. From the timing of the decreases observed when the shock first reaches the HTS and then several months later encounters the heliopause, we can estimate the heliosheath thickness to be 31 ± 4 and 37 ± 6 AU, respectively, for the two sequences of three decreases seen at V1. These values, along with the distances to the HTS that are determined, give distances from the Sun to the heliopause of 121 ± 4 and 124 ± 6 AU, respectively
The Field White Dwarf Mass Distribution
We revisit the properties and astrophysical implications of the field white
dwarf mass distribution in preparation of Gaia applications. Our study is based
on the two samples with the best established completeness and most precise
atmospheric parameters, the volume-complete survey within 20 pc and the Sloan
Digital Sky Survey (SDSS) magnitude-limited sample. We explore the modelling of
the observed mass distributions with Monte Carlo simulations, but find that it
is difficult to constrain independently the initial mass function (IMF), the
initial-to-final-mass relation (IFMR), the stellar formation history (SFH), the
variation of the Galactic disk vertical scale height as a function of stellar
age, and binary evolution. Each of these input ingredients has a moderate
effect on the predicted mass distributions, and we must also take into account
biases owing to unidentified faint objects (20 pc sample), as well as unknown
masses for magnetic white dwarfs and spectroscopic calibration issues (SDSS
sample). Nevertheless, we find that fixed standard assumptions for the above
parameters result in predicted mean masses that are in good qualitative
agreement with the observed values. It suggests that derived masses for both
studied samples are consistent with our current knowledge of stellar and
Galactic evolution. Our simulations overpredict by 40-50% the number of massive
white dwarfs (M > 0.75 Msun) for both surveys, although we can not exclude a
Salpeter IMF when we account for all biases. Furthermore, we find no evidence
of a population of double white dwarf mergers in the observed mass
distributions.Comment: 15 pages, 16 figures, accepted for publication in MNRA
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