2,173 research outputs found
Making Sense of Long-Term Physical Activity Tracker Data: The challenge of Incompleteness
Millions of people have already collected weeks, months and even years of data about their own health and physical activity levels. The potential is enormous for use in personal applications as well as for public health analysis of large populations at low cost. However, the reality is many people fail to wear their tracker and record data all day every day especially over the long-term. The resulting incompleteness in data poses an important challenge for interpreting long-term tracker data, in terms of both making sense of it and in dealing with the uncertainty of inferences based on it. Surprisingly, there has been little work into defining the problem, its extent and how it should be measured and addressed. This thesis tackles this key challenge and we demonstrate the need for a term to describe and quantify this challenge. We introduce the term, adherence, which quantifies the completeness in such data. We also offer interface designs that accounted for adherence to support self-monitoring and reflection. Bringing these together, we provide broader definitions and guidelines for incorporating adherence when making sense of long-term physical activity tracker data, both in personal applications and in public health research results. This thesis is based on three studies. First is a semester-long study of tracker use by 237 University students. Second is a study of 21 existing long-term physical activity trackers and provided the first richly qualitative exploration of physical activity and adherence of such users. It also evaluated the iStuckWithIt, a long-term physical activity data user interface, and reported on insights gained within and as aided by a tutorial and reflection scaffolding. In the final study, we drew on 12 diverse datasets, for 753 users, with over 77,000 days with data and 73,000 days missing to explore the impact of different definitions of adherence and methods for dealing with its implications
Anisotropic flow in Cu+Au collisions at GeV
The anisotropic flow of charged hadrons in asymmetric Cu+Au collisions at the
Relativistic Heavy Ion Collider is studied in a multi-phase transport model.
Compared with previous results for symmetric Au+Au collisions, charged hadrons
produced around midrapidity in asymmetric collisions are found to have a
stronger directed flow and their elliptic flow is also more
sensitive to the parton scattering cross section. While higher-order flows
and are small at all rapidities, both and in
these collisions are appreciable and show an asymmetry in forward and backward
rapidities.Comment: 7 pages, 7 figures, Title changed, revised version to appear in PR
and production in relativistic heavy ion collisions in a dynamical quark coalescence model
Based on the phase-space information obtained from a multi-phase transport
model within the string melting scenario for strange and antistrange quarks, we
study the yields and transverse momentum spectra of mesons and () baryons as well as their anisotropic flows
in Au+Au collisions at RHIC using a dynamical quark coalescence model that
includes the effect due to quark phase-space distributions inside hadrons. With
current quark masses and fixing the and radii from fitting
measured yields, we first study the ratio of the yield of baryons to
that of mesons as well as their elliptic and fourth-order flows as
functions of their transverse momentum. How the elliptic and fourth-order flows
of mesons and baryons are related to those of strange and
antistrange quarks is then examined. The dependence of above results on
and radii as well as on the strange quark mass is also studied.Comment: 15 pages, 18 figures, Title changed, revised version to appear in PR
Penerapan Transfer Pricing Dalam Penilaian Kinerja Suatu Pusat Pertanggungjawaban Sebagai Alat Untuk Memotivasi Manajer Divisi Guna Mencapai Keselarasan Tujuan Pada PT. ABC Di Situbondo
Di pasar internasional, Indonesia dengan komoditas udang yang mempunyai nilai jual yang relatif tinggi dibandingkan dengan komoditas perikanan lainnya, menghadapi persaingan ketat dengan negara yang menghasilkan komoditas sejenis seperti Thailand, RRC, Philipina dan Vietnam. Prospek udang tropis Indonesia sebagai tulang punggung ekspor nasional di sektor perikanan tetap menjanjikan, paling tidak dari segi peningkatan volume ekspor yang hampir mencapai 17% per tahun dan dari segi geografinya pun, Indonesia memiliki potensi yang besar untuk meningkatkan produksi udang karena Indonesia sebagai negara kepulauan memiliki garis pantai yang panjang, ditunjang oleh potensi sumber daya perairan dan tekno1ogi hasil penelitian cukup tersedia serta sampai saat ini jumlah areal pertambakan masih sekitar 28% yang sudah digunakan dari jumlah areal yang potensial ..
Contributions of hyperon-hyperon scattering to subthreshold cascade production in heavy ion collisions
Using a gauged flavor SU(3)-invariant hadronic Lagrangian, we calculate the
cross sections for the strangeness-exchange reactions YY to N\Xi (Y=\Lambda,
\Sigma) in the Born approximation. These cross sections are then used in the
Relativistic Vlasov-Uehling-Uhlenbeck (RVUU) transport model to study \Xi
production in Ar+KCl collisions at incident energy of 1.76A GeV and impact
parameter b=3.5 fm. We find that including the contributions of hyperon-hyperon
scattering channels strongly enhances the yield of \Xi, leading to the
abundance ratio \Xi^{-}/(\Lambda+\Sigma^{0})=3.38E-3, which is essentially
consistent with the recently measured value of by the HADES collaboration at GSI.Comment: 8 pages, 5 figure
Transition density and pressure in hot neutron stars
Using the momentum-dependent MDI effective interaction for nucleons, we have
studied the transition density and pressure at the boundary between the inner
crust and liquid core of hot neutron stars. We find that their values are
larger in neutrino-trapped neutron stars than in neutrino-free neutron stars.
Furthermore, both are found to decrease with increasing temperature of a
neutron star as well as increasing slope parameter of the nuclear symmetry
energy, except that the transition pressure in neutrino-trapped neutron stars
for the case of small symmetry energy slope parameter first increases and then
decreases with increasing temperature. We have also studied the effect of the
nuclear symmetry energy on the critical temperature above which the inner crust
in a hot neutron star disappears and found that with increasing value of the
symmetry energy slope parameter, the critical temperature decreases slightly in
neutrino-trapped neutron stars but first decreases and then increases in
neutrino-free neutron stars.Comment: 7 pages, 6 figures, version to appear in Phys. Rev.
Probing QCD critical fluctuations from light nuclei production in relativistic heavy-ion collisions
Based on the coalescence model for light nuclei production, we show that the
yield ratio of
, d, and H in heavy-ion collisions is sensitive to the neutron relative
density fluctuation
at kinetic freeze-out. From recent experimental data in central Pb+Pb
collisions at ~GeV, ~GeV, ~GeV, ~GeV and
~GeV measured by the NA49 Collaboration at the CERN Super Proton
Synchrotron (SPS), we find a possible non-monotonic behavior of as a
function of the collision energy with a peak at ~GeV,
indicating that the density fluctuations become the largest in collisions at
this energy. With the known chemical freeze-out conditions determined from the
statistical model fit to experimental data, we obtain a chemical freeze-out
temperature of MeV and baryon chemical potential of MeV
at this collision energy, which are close to the critical endpoint in the QCD
phase diagram predicted by various theoretical studies. Our results thus
suggest the potential usefulness of the yield ratio of light nuclei in
relativistic heavy-ion collisions as a direct probe of the large density
fluctuations associated with the QCD critical phenomena.Comment: 6 pages, 1 figure, 2 tables. Correlations between neutron and proton
density fluctuations considered and presentation improved. Accepted version
to appear in PL
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