3,331 research outputs found
Jumble Java Byte Code to Measure the Effectiveness of Unit Tests
Jumble is a byte code level mutation testing tool for Java which inter-operates with JUnit. It has been designed to operate in an industrial setting with large projects. Heuristics have been included to speed the checking of mutations, for example, noting which test fails for each mutation and running this first in subsequent mutation checks. Significant effort has been put into ensuring that it can test code which uses custom class loading and reflection. This requires careful attention to class path handling and coexistence with foreign class-loaders. Jumble is currently used on a continuous basis within an agile programming environment with approximately 370,000 lines of Java code under source control. This checks out project code every fifteen minutes and runs an incremental set of unit tests and mutation tests for modified classes. Jumble is being made available as open source
First Season QUIET Observations: Measurements of Cosmic Microwave Background Polarization Power Spectra at 43 GHz in the Multipole Range 25 ā¤ ā ā¤ 475
The Q/U Imaging ExperimenT (QUIET) employs coherent receivers at 43 GHz and 94 GHz, operating on the Chajnantor plateau in the Atacama Desert in Chile, to measure the anisotropy in the polarization of the cosmic microwave background (CMB). QUIET primarily targets the B modes from primordial gravitational waves. The combination of these frequencies gives sensitivity to foreground contributions from diffuse Galactic synchrotron radiation. Between 2008 October and 2010 December, over 10,000 hr of data were collected, first with the 19 element 43 GHz array (3458 hr) and then with the 90 element 94 GHz array. Each array observes the same four fields, selected for low foregrounds, together covering ā1000 deg^2. This paper reports initial results from the 43 GHz receiver, which has an array sensitivity to CMB fluctuations of 69 Ī¼Kās. The data were extensively studied with a large suite of null tests before the power spectra, determined with two independent pipelines, were examined. Analysis choices, including data selection, were modified until the null tests passed. Cross-correlating maps with different telescope pointings is used to eliminate a bias. This paper reports the EE, BB, and EB power spectra in the multipole range ā = 25-475. With the exception of the lowest multipole bin for one of the fields, where a polarized foreground, consistent with Galactic synchrotron radiation, is detected with 3Ļ significance, the E-mode spectrum is consistent with the ĪCDM model, confirming the only previous detection of the first acoustic peak. The B-mode spectrum is consistent with zero, leading to a measurement of the tensor-to-scalar ratio of r = 0.35^(+1.06)_(ā0.87). The combination of a new time-stream "double-demodulation" technique, side-fed Dragonian optics, natural sky rotation, and frequent boresight rotation leads to the lowest level of systematic contamination in the B-mode power so far reported, below the level of r = 0.1
Physeal Growth Plate Fractures: Implications for the Pediatric Athlete
Pediatric musculoskeletal trauma accounts for most childhood injuries. The anatomy and physiology of the pediatric skeleton is unique as is its response to trauma. The pediatric skeleton has periods of rapid growth; therefore the effect of trauma to the musculoskeletal system may have significant long-term complications
Cryogenic microstripline-on-Kapton microwave interconnects
Simple broadband microwave interconnects are needed for increasing the size
of focal plane heterodyne radiometer arrays. We have measured loss and
cross-talk for arrays of microstrip transmission lines in flex circuit
technology at 297 and 77 K, finding good performance to at least 20 GHz. The
dielectric constant of Kapton substrates changes very little from 297 to 77 K,
and the electrical loss drops. The small cross-sectional area of metal in a
printed circuit structure yields overall thermal conductivities similar to
stainless steel coaxial cable. Operationally, the main performance tradeoffs
are between crosstalk and thermal conductivity. We tested a patterned ground
plane to reduce heat flux.Comment: 3 pages, 3 figures, submitted to The Review of Scientific Instrument
Pilot Implementation of a Heat Illness Prevention Program in the Southeastern US
Objective: To evaluate the ease of application of a heat illness prevention program (HIPP).
Design: A mixed-method research design was used: questionnaire and semi-structured interview.
Setting: Eleven South Florida high schools in August (mean ambient temperature=84.0Ā°F, mean relative humidity=69.5%) participated in the HIPP.
Participants: Certified Athletic Trainers (AT) (n=11; age=22.2+1.2yr; 63.6% female, 36.4% male; 63.6%) implemented the HIPP with their football athletes which included a pre-screening tool, the Heat Illness Index Score- Risk Assessment.
Data Collection and Analysis: Participants completed a 17-item questionnaire, 4 of which provided space for open-ended responses. Additionally, semi-structured interviews were voice recorded, and separately transcribed.
Results: Three participants (27.7%) were unable to implement the HIPP with any of their athletes. Of the 7 participants (63.6%) who implemented the HIPP to greater than 50% of their athletes, a majority reported that the HIPP was difficult (54.5%) or exceedingly difficult (18.2%) to implement. Lack of appropriate instrumentation (81.8%, n=9/11), lack of coaching staff/administrative support (54.5%, n=6/11), insufficient support staff (54.5%, n=6/11), too many athletes (45.5%, n=5/11), and financial restrictions (36.4%, n=4/11) deterred complete implementation of the HIPP.
Conclusions: Because AT in the high school setting often lack the resources, time, and coachesā support to identify risk factors, predisposing athletes to exertional heat Illnesses (EHI) researchers should develop and validate a suitable screening tool. Further, ATs charged with the health care of high school athletes should seek out prevention programs and screening tools to identify high-risk athletes and monitor athletes throughout exercise in extreme environments
Core Stability and Athletic Performance in Male and Female Lacrosse Players
International Journal of Exercise Science 12(4): 1138-1148, 2019. This study determined the relationship of core stability with power production, agility, and dynamic stability of collegiate lacrosse players and whether core stability is more evident in these performance variables in either males or females. Twenty male and female collegiate lacrosse players (20.3 Ā± 1.0 years, 173.2 Ā± 11.8 cm, 72.6 Ā± 13.0 kg) performed the pro-agility shuttle, the countermovement jump (CMJ), the Star Excursion Balance Test (SEBT), and prone, right lateral, and left lateral planks on two sessions- familiarization and testing. Independent T-tests were used to compare sexes. SPSS 24.0 was used; significance was accepted at p\u3c 0.05. Pearson correlations were used to compare the relationship of core stability to the performance variables in participants. There was a significant relationship found between the prone plank and pro-agility shuttle in all participants (r = -0.50). No significant relationships were found between core stability and performance variables. A significant difference was found in the pro-agility shuttle (p= 0.001) and the CMJ (p= 0.001) but not in core stability or dynamic stability. Agility, power production, and dynamic stability were not related to core stability in neither male or female lacrosse players. There were no significant differences in core stability and dynamic stability between males and females. A significant difference was found in dynamic stability in the SEBT right leg and left leg composite scores between sexes. From these results, it is suggested that core stability may not directly influence the performance variables in collegiate male and female lacrosse players
The Q/U Imaging Experiment: Polarization Measurements of Radio Sources at 43 and 95 GHz
We present polarization measurements of extragalactic radio sources observed during the cosmic microwave background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine sources selected at 20 GHz from the public, >40 mJy catalog of the Australia Telescope (AT20G) survey. There are ~480 such sources within QUIET's four low-foreground survey patches, including the nearby radio galaxies Centaurus A and Pictor A. The median error on our polarized flux density measurements is 30ā40 mJy per Stokes parameter. At signal-to-noise ratio > 3 significance, we detect linear polarization for seven sources in Q-band and six in W-band; only 1.3 Ā± 1.1 detections per frequency band are expected by chance. For sources without a detection of polarized emission, we find that half of the sources have polarization amplitudes below 90 mJy (Q-band) and 106 mJy (W-band), at 95% confidence. Finally, we compare our polarization measurements to intensity and polarization measurements of the same sources from the literature. For the four sources with WMAP and Planck intensity measurements >1 Jy, the polarization fractions are above 1% in both QUIET bands. At high significance, we compute polarization fractions as much as 10%ā20% for some sources, but the effects of source variability may cut that level in half for contemporaneous comparisons. Our results indicate that simple modelsāones that scale a fixed polarization fraction with frequencyāare inadequate to model the behavior of these sources and their contributions to polarization maps
Scattering of Phonons by a Vortex in a Superfluid
Recent work gives a transverse force on an isolated moving vortex which is
independent of the normal fluid velocity, but it is widely believed that the
asymmetry of phonon scattering by a vortex leads to a transverse force
dependent on the relative motion of the normal component and the vortex. We
show that a widely accepted derivation of the transverse force is in error, and
that a careful evaluation leads to a much smaller transverse force. We argue
that a different approach is needed to get the correct expression.
\pacs{67.40.Vs,67.57.Fg,47.37.+q,47.32.Cc}Comment: 4 page
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