18,589 research outputs found
Motives for investment in human capital of children: evidence from Indonesian Family Life Survey Data
Two alternative models of parental investments in children's human capital are considered and tested empirically using the Indonesian Family Life Survey (IFLS). The pure loan model and the reciprocity with two-sided altruism model yield different predictions about the effect of children's education level and number of children on intergenerational transfers. Using these predictions, a specification test is carried out to differentiate these two models with the data. The evidence favors the second model of reciprocity with two-sided altruism.Human capital, pure loan, altruism, Indonesian Family Life Survey Data
Strength and flexibility properties of advanced ceramic fabrics
The mechanical properties of four advanced ceramic fabrics are measured at a temperature range of 23 C to 1200 C. The fabrics evaluated are silica, high-and low-boria content aluminoborosilicate, and silicon carbide. Properties studied include fabric break strengths from room temperature to 1200 C, and bending durability after temperature conditioning at 1200 C and 1400 C. The interaction of the fabric and ceramic insulation is also studied for shrinkage, appearance, bend resistance, and fabric-to-insulation bonding. Based on these tests, the low-boria content aluminoborosilicate fabric retains more strength and fabric durability than the other fabrics studied at high temperature
Wearable Sensor Data Based Human Activity Recognition using Machine Learning: A new approach
Recent years have witnessed the rapid development of human activity
recognition (HAR) based on wearable sensor data. One can find many practical
applications in this area, especially in the field of health care. Many machine
learning algorithms such as Decision Trees, Support Vector Machine, Naive
Bayes, K-Nearest Neighbor, and Multilayer Perceptron are successfully used in
HAR. Although these methods are fast and easy for implementation, they still
have some limitations due to poor performance in a number of situations. In
this paper, we propose a novel method based on the ensemble learning to boost
the performance of these machine learning methods for HAR
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Early Recognition of Burn- and Trauma-Related Acute Kidney Injury: A Pilot Comparison of Machine Learning Techniques.
Severely burned and non-burned trauma patients are at risk for acute kidney injury (AKI). The study objective was to assess the theoretical performance of artificial intelligence (AI)/machine learning (ML) algorithms to augment AKI recognition using the novel biomarker, neutrophil gelatinase associated lipocalin (NGAL), combined with contemporary biomarkers such as N-terminal pro B-type natriuretic peptide (NT-proBNP), urine output (UOP), and plasma creatinine. Machine learning approaches including logistic regression (LR), k-nearest neighbor (k-NN), support vector machine (SVM), random forest (RF), and deep neural networks (DNN) were used in this study. The AI/ML algorithm helped predict AKI 61.8 (32.5) hours faster than the Kidney Disease and Improving Global Disease Outcomes (KDIGO) criteria for burn and non-burned trauma patients. NGAL was analytically superior to traditional AKI biomarkers such as creatinine and UOP. With ML, the AKI predictive capability of NGAL was further enhanced when combined with NT-proBNP or creatinine. The use of AI/ML could be employed with NGAL to accelerate detection of AKI in at-risk burn and non-burned trauma patients
Fractional Chern Insulators from the nth Root of Bandstructure
We provide a parton construction of wavefunctions and effective field
theories for fractional Chern insulators. We also analyze a strong coupling
expansion in lattice gauge theory that enables us to reliably map the parton
gauge theory onto the microsopic Hamiltonian. We show that this strong coupling
expansion is useful because of a special hierarchy of energy scales in
fractional quantum Hall physics. Our procedure is illustrated using the
Hofstadter model and then applied to bosons at 1/2 filling and fermions at 1/3
filling in a checkerboard lattice model recently studied numerically. Because
our construction provides a more or less unique mapping from microscopic model
to effective parton description, we obtain wavefunctions in the same phase as
the observed fractional Chern insulators without tuning any continuous
parameters.Comment: 9+3 pages, 6 figures; v2: added refs, amplified discussion of
deconfinement, improved discussion of translation invarianc
Euclidean-signature Supergravities, Dualities and Instantons
We study the Euclidean-signature supergravities that arise by compactifying
D=11 supergravity or type IIB supergravity on a torus that includes the time
direction. We show that the usual T-duality relation between type IIA and type
IIB supergravities compactified on a spatial circle no longer holds if the
reduction is performed on the time direction. Thus there are two inequivalent
Euclidean-signature nine-dimensional maximal supergravities. They become
equivalent upon further spatial compactification to D=8. We also show that
duality symmetries of Euclidean-signature supergravities allow the harmonic
functions of any single-charge or multi-charge instanton to be rescaled and
shifted by constant factors. Combined with the usual diagonal dimensional
reduction and oxidation procedures, this allows us to use the duality
symmetries to map any single-charge or multi-charge p-brane soliton, or any
intersection, into its near-horizon regime. Similar transformations can also be
made on non-extremal p-branes. We also study the structures of duality
multiplets of instanton and (D-3)-brane solutions.Comment: Latex, 50 pages, typos corrected and references adde
A molecular perspective on the limits of life: Enzymes under pressure
From a purely operational standpoint, the existence of microbes that can grow
under extreme conditions, or "extremophiles", leads to the question of how the
molecules making up these microbes can maintain both their structure and
function. While microbes that live under extremes of temperature have been
heavily studied, those that live under extremes of pressure have been
neglected, in part due to the difficulty of collecting samples and performing
experiments under the ambient conditions of the microbe. However, thermodynamic
arguments imply that the effects of pressure might lead to different organismal
solutions than from the effects of temperature. Observationally, some of these
solutions might be in the condensed matter properties of the intracellular
milieu in addition to genetic modifications of the macromolecules or repair
mechanisms for the macromolecules. Here, the effects of pressure on enzymes,
which are proteins essential for the growth and reproduction of an organism,
and some adaptations against these effects are reviewed and amplified by the
results from molecular dynamics simulations. The aim is to provide biological
background for soft matter studies of these systems under pressure.Comment: 16 pages, 8 figure
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