2,511 research outputs found
Relation between stimulus range, direct laoudness estimation and averaged cortical V-potential
Twelve subjects estimated the loudness of stimuli, once in a short range (50, 60 and 68 dB). and once in a large range (20, 50, 60, 68 and 80 dB). Concurently, evoked cortical responses to SO and 68 dB were recorded. The range markedly influenced the loudness estimations but no significant range-effect was found in the peak-to-peak amplitude of the Nt - P2 waves
Assessing System of Systems Security Risk and Requirements with OASoSIS
When independent systems come together as a System of Systems (SoS) to achieve a new purpose, dealing with requirements conflicts across systems becomes a challenge. Moreover, assessing and modelling security risk for independent systems and the SoS as a whole is challenged by a gap in related research and approaches within the SoSs domain. In this paper, we present an approach for bridging SoS and Requirements Engineering by identifying aligning SoSs concepts to assess and model security risk and requirements. We introduce our OASoSIS approach modifying OCTAVE Allegro for SoSs using CAIRIS (Computer Aided Integration of Requirements and Information Security) with a medical evacuation (MEDEVAC) SoS exemplar for Security Requirements Engineering tool-support. Index Terms—System of Systems, Security, Risk, Human Factors, Requirements Engineering, CAIRIS
Determination of trace elements in the plants of Mt. Bozdag, Izmir, Turkey
The aim of this study was to determine the current level of atmospheric heavy metal content on the Bozdag Mountain of the Aegean Region, Turkey. Twenty nine different plants were selected to study their potential as biomonitors of trace elements such as Ni, Zn, Fe, Pb, Mn and Cd (μg g-1, dry weight). The samples were collected from two different altitudes of Mt. Bozdag. The concentrations of trace elements were determined by atomic absorption spectrometry. The mean concentrations determined at 1000 m altitude ranged from 0.025 to 1.609, 0.232 to 0.731, 0.578 to 5.983, 0.287 to 0.565 and 0.176 to 2.659 (μg g-1, dry weight), for Ni, Zn, Fe, Pb and Mn, respectively. At the altitude of 1600 m, the values ranged from 0.023 to 0.939, 0.258 to 1.254, 0.839 to 5.176, 0.301 to 1.341 and 0.405 to 3.351 (μg g-1, dry weight) for Ni, Zn, Fe, Pb and Mn, respectively. No Cd was detected at either altitude. Statistical significance was determined by the independent sample t-test and comparisons were made in order to determine if there were any differences between the averages of herbaceous and woody plants.
Intra-abdominal pressure values of emergency department intensive care unit patients and clinical outcomes
SPB stars in the open SMC cluster NGC 371
Pulsation in beta Cep and SPB stars are driven by the kappa mechanism which
depends critically on the metallicity. It has therefore been suggested that
beta Cep and SPB stars should be rare in the Magellanic Clouds which have lower
metallicities than the solar neighborhood. To test this prediction we have
observed the open SMC cluster NGC 371 for 12 nights in order to search for beta
Cep and SPB stars. Surprisingly, we find 29 short-period B-type variables in
the upper part of the main sequence, many of which are probably SPB stars. This
result indicates that pulsation is still driven by the kappa mechanism even in
low metallicity environments. All the identified variables have periods longer
than the fundamental radial period which means that they cannot be beta Cep
stars. Within an amplitude detection limit of 5 mmag no stars in the top of the
HR-diagram show variability with periods shorter than the fundamental radial
period. So if beta Cep stars are present in the cluster they oscillate with
amplitudes below 5 mmag, which is significantly lower than the mean amplitude
of beta Cep stars in the Galaxy. We see evidence that multimode pulsation is
more common in the upper part of the main sequence than in the lower. We have
also identified 5 eclipsing binaries and 3 periodic pulsating Be stars in the
cluster field.Comment: 8 pages, 11 figures. Accepted for publication in MNRA
Properties of 42 Solar-type Kepler Targets from the Asteroseismic Modeling Portal
Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved
into individual mode frequencies has increased dramatically. While only a few such data sets were available
for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds
of new targets. This rapid expansion in observational capacity has been accompanied by a shift in analysis
and modeling strategies to yield uniform sets of derived stellar properties more quickly and easily. We use
previously published asteroseismic and spectroscopic data sets to provide a uniform analysis of 42 solar-type
Kepler targets from the Asteroseismic Modeling Portal (AMP). We find that fitting the individual frequencies
typically doubles the precision of the asteroseismic radius, mass and age compared to grid-based modeling of
the global oscillation properties, and improves the precision of the radius and mass by about a factor of three
over empirical scaling relations. We demonstrate the utility of the derived properties with several applications
Discovery of Delta Scuti variables in eclipsing binary systems II.Southern TESS field search
The presence of pulsating stars in eclipsing binary systems (EBs) makes these
objects significant since they allow us to investigate the stellar interior
structure and evolution. Different types of pulsating stars could be found in
EBs such as Delta Scuti variables. Delta Scuti stars in EBs have been known for
decades and the increasing number of such systems is important for
understanding pulsational structure. Hence, in this study, a research was
carried out on the southern TESS field to discover new Delta Scuti stars in
EBs. We produced an algorithm to search for detached and semi-detached EBs
considering three steps; the orbital period (P)'s harmonics in the
Fourier spectrum, skewness of the light curves, and classification of
\textsc{UPSILON} program. If two of these steps classify a system as an EB, the
algorithm also identifies it as an EB. The TESS pixel files of targets were
also analyzed to see whether the fluxes are contaminated by other systems. No
contamination was found. We researched the existence of pulsation through EBs
with a visual inspection. To confirm Delta Scuti-type oscillations, the binary
variation was removed from the light curve, and residuals were analyzed.
Consequently, we identified 42 Delta Scuti candidates in EBs. The P,
, and M of systems were calculated. Their positions on the H-R diagram
and the known orbital-pulsation period relationship were analyzed. We also
examined our targets to find if any of them show frequency modulation with the
orbital period and discovered one candidate of tidally tilted pulsators.Comment: Published in MNRA
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