1,226 research outputs found
Software for Optimizing Quality Assurance of Other Software
Software assurance is the planned and systematic set of activities that ensures that software processes and products conform to requirements, standards, and procedures. Examples of such activities are the following: code inspections, unit tests, design reviews, performance analyses, construction of traceability matrices, etc. In practice, software development projects have only limited resources (e.g., schedule, budget, and availability of personnel) to cover the entire development effort, of which assurance is but a part. Projects must therefore select judiciously from among the possible assurance activities. At its heart, this can be viewed as an optimization problem; namely, to determine the allocation of limited resources (time, money, and personnel) to minimize risk or, alternatively, to minimize the resources needed to reduce risk to an acceptable level. The end result of the work reported here is a means to optimize quality-assurance processes used in developing software
The Secret to Better AI and Better Software (Is Requirements Engineering)
Much has been written about the algorithmic role that AI plays for automation in SE. But what about the role of AI, augmented by human knowledge? Can we make a profound advance by combining human and artificial intelligence? Researchers in requirements engineering think so, arguing that requirement engineering is the secret weapon for better AI and better software
Holocene tephrostratigraphic framework and monsoon evolution of East Asia:Key tephra beds for synchronising palaeoclimate records
Do the nearby BHB stars belong to the Thick Disk or the Halo?
We study the Milky Way region Z<3.0 kpc, where the thick disk and inner halo
overlap, by using the kinematics of local blue horizontal branch (BHB) stars
(within 1 kpc) and new samples of BHB stars and A-type stars from the Century
Survey. We derive Galactic U,V,W velocities for these BHB and A-type star
samples using proper motions from the NOMAD catalog. The mean velocities and
the velocity dispersions of the BHB samples (Z<3 kpc) are characteristic of the
halo, while those of the Century Survey A-type stars are characteristic of the
thick disk. There is no evidence from our samples that the BHB stars rotate
with the thick disk in the region Z<3 kpc. Nearly a third of the nearby local
RR Lyrae stars have disk kinematics and are more metal-rich than [Fe/H]~-1.
Only a few percent of the Century Survey BHB stars have these properties. Only
one nearby BHB star (HD 130201) is likely to be such a disk star but selection
based on high proper motions will have tended to exclude such stars from the
local sample. The scale height derived from a sample of local RR Lyrae stars
agrees with that of the Century Survey BHB stars. The local samples of BHB
stars and metal-weak red giants are too incomplete for a similar comparison.Comment: 14 pages, accepted to A
Assembly, evolution and disruption of a magmatic plumbing system before and after a cataclysmic caldera-collapse eruption at Ischia volcano (Italy)
Cycling‐specific isometric resistance training improves peak power output in elite sprint cyclists
INTRODUCTION: This study aimed to assess the efficacy of a six-week cycling-specific, isometric resistance training programme on peak power output (PPO) in elite cyclists. METHODS: Twenty-four elite track sprint cyclists were allocated to EXP (n=13, PPO, 1537 ± 307 W) and CON (n=11, PPO, 1541 ± 389 W) groups. All participants completed a six-week training programme; training content was identical except participants in the EXP group replaced their usual compound lower body resistance training exercise with a cycling-specific, isometric resistance training stimulus. Cycling PPO, knee extensor and cycling-specific isometric strength, and measures of muscle architecture were assessed pre- and post-training. RESULTS: In EXP, absolute and relative PPO increased (46 ± 62 W and 0.8 ± 0.7 W⋅kg-1 , p < 0.05), and the change in relative PPO was different to CON (-0.1 ± 1.0 W⋅kg-1 , group × time interaction p = 0.02). The increase in PPO was concurrent with an increase in extrapolated maximal torque in EXP (7.1 ± 6.5 N⋅m, p = 0.007), but the effect was not different from the change in CON (2.4 ± 9.7 N⋅m, group × time p = 0.14). Cycling-specific isometric strength also increased more in EXP (group × time p = 0.002). There were no other between-group differences in response to training. CONCLUSION: A six-week novel, cycling-specific isometric resistance training period improved PPO in a group of elite sprint cyclists by 3-4%. These data support the use of a cycling-specific isometric resistance training stimulus in the preparation programmes of world-class cyclists
Employing a New BVIc Photometric Survey of IC 4665 to Investigate the Age of this Young Open Cluster
We present a new, BVIc photometric survey of the young open cluster IC4665,
which improves on previous studies of this young cluster by incorporating a
rigorous standardization procedure, thus providing high-fidelity colors and
magnitudes for cluster members. We use this new photometric dataset to
reevaluate the properties (age and distance) of IC4665. Namely, using a
statistical approach incorporating Tau^2 CMD modeling, we measure a
pre-main-sequence isochrone age and distance of 36+-9 Myr and 360+-12 pc, as
well as a upper-main-sequence turn-off age and distance of 42+-12 Myr and
357+-12 pc. These ages and distances are highly dependent on the isochrone
model and color used for the fitting procedure, with a possible range of ~10-20
Myr in age and ~20 pc in distance. This spread in calculated ages and distances
seen between colors and models is likely due to limitations in the individual
membership catalogs and/or systematic differences in the predicted stellar
parameters from the different sets of models. Interestingly, when we compare
the isochrone ages for IC4665 to the published lithium depletion boundary age,
28+-5 Myr, we observe that this cluster does not appear to follow the trend of
isochrone ages being 1.5 times smaller than lithium depletion boundary ages. In
addition, comparing the overall magnetic activity (X-ray and H-alpha emission)
in IC4665 with other well studied open clusters, we find the observed activity
distributions for this young cluster are best characterized by assuming an age
of 30-40 Myr, thus in agreement with our pre-main-sequence and turn-off
isochrone ages for IC4665. Overall, although some age discrepancies do exist,
particularly in the ages measured from pre-main-sequence isochrones, the range
of possible IC4665 ages derived from the various dating techniques employed
here is relatively small compared to that found for other well studied open
clusters.Comment: 17 pages, 13 figures, 6 tables; Accepted for publication in the
Astronomical Journa
Abnormal liver function tests as predictors of adverse maternal outcomes in women with preeclampsia.
OBJECTIVES: To evaluate whether (1) the absolute magnitude of liver function test values, (2) the percentage change in liver function test values over time, or (3) the rate of change in liver function test values over time predicts adverse maternal outcomes in women with preeclampsia. METHODS: We used data from the PIERS (Pre-eclampsia Integrated Estimate of RiSk) study, a prospective multicentre cohort study assessing predictors of adverse maternal outcomes in women with preeclampsia. Women with at least one liver function test performed at the time of hospital admission were included. Liver functions were tested by serum concentrations of aspartate amino transferase (AST), alanine amino transferase (ALT), lactate dehydrogenase (LDH), albumin, total bilirubin, and the international normalized prothrombin time ratio. Parameters investigated were absolute levels, change within 48 hours of hospital admission, change from admission to delivery or outcome, and rate of change from admission to delivery or outcome of each liver function test. The ability of these parameters to predict adverse outcomes was assessed using logistic regression analyses and by calculating the receiver operating characteristic (ROC) area under the curve (AUC). RESULTS: Of the 2008 women, 1056 (53%) had at least one abnormal liver function test result. The odds of having an adverse maternal outcome were higher in women with any abnormal liver function test than in women with normal results. When test results were stratified into quartiles, women with results in the highest quartile (lowest quartile for albumin) were at higher risk of adverse outcomes than women in the lowest quartile for all parameters (highest for albumin). The absolute magnitude of AST, ALT, and LDH predicted adverse maternal outcomes (AST: ROC AUC 0.73 [95% CI 0.67 to 0.97]; ALT: ROC AUC 0.73 [95% CI 0.67 to 0.79]; LDH: ROC AUC 0.74 [95% CI 0.68 to 0.81]). Neither change of liver function test results, within 48 hours of admission or from admission to delivery or outcome, nor rate of change were predictive. CONCLUSION: We found abnormal liver function test results to be associated with an increased risk for adverse maternal outcomes. Levels of AST, ALT, and LDH were found to be modestly predictive of these outcomes
High level triggers for explosive mafic volcanism: Albano Maar, Italy
Colli Albani is a quiescent caldera complex located within the Roman Magmatic Province (RMP), Italy. The recent Via dei Laghi phreatomagmatic eruptions led to the formation of nested maars. Albano Maar is the largest and has erupted seven times between ca 69-33ka. The highly explosive nature of the Albano Maar eruptions is at odds with the predominant relatively mafic (SiO2=48-52wt.%) foiditic (K2O=9wt.%) composition of the magma. The deposits have been previously interpreted as phreatomagmatic, however they contain large amounts (up to 30%vol) of deep seated xenoliths, skarns and all pre-volcanic subsurface units. All of the xenoliths have been excavated from depths of up to 6km, rather than being limited to the depth at which magma and water interaction is likely to have occurred, suggesting an alternative trigger for eruption. High precision geochemical glass and mineral data of fresh juvenile (magmatic) clasts from the small volume explosive deposits indicate that the magmas have evolved along one of two evolutionary paths towards foidite or phonolite. The foiditic melts record ca. 50% mixing between the most primitive magma and Ca-rich melt, late stage prior to eruption. A major result of our study is finding that the generation of Ca-rich melts via assimilation of limestone, may provide storage for significant amounts of CO2 that can be released during a mixing event with silicate magma. Differences in melt evolution are inferred as having been controlled by variations in storage conditions: residence time and magma volume. © 2013
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