1,745 research outputs found
Mixture regression for observational data, with application to functional regression models
In a regression analysis, suppose we suspect that there are several
heterogeneous groups in the population that a sample represents. Mixture
regression models have been applied to address such problems. By modeling the
conditional distribution of the response given the covariate as a mixture, the
sample can be clustered into groups and the individual regression models for
the groups can be estimated simultaneously. This approach treats the covariate
as deterministic so that the covariate carries no information as to which group
the subject is likely to belong to. Although this assumption may be reasonable
in experiments where the covariate is completely determined by the
experimenter, in observational data the covariate may behave differently across
the groups. Thus the model should also incorporate the heterogeneity of the
covariate, which allows us to estimate the membership of the subject from the
covariate.
In this paper, we consider a mixture regression model where the joint
distribution of the response and the covariate is modeled as a mixture. Given a
new observation of the covariate, this approach allows us to compute the
posterior probabilities that the subject belongs to each group. Using these
posterior probabilities, the prediction of the response can adaptively use the
covariate. We introduce an inference procedure for this approach and show its
properties concerning estimation and prediction. The model is explored for the
functional covariate as well as the multivariate covariate. We present a
real-data example where our approach outperforms the traditional approach,
using the well-analyzed Berkeley growth study data
A macroscopic scale model of bacterial flagellar bundling
Escherichia coli and other bacteria use rotating helical filaments to swim.
Each cell typically has about four filaments, which bundle or disperse
depending on the sense of motor rotation. To study the bundling process, we
built a macroscopic scale model consisting of stepper-motor-driven polymer
helices in a tank filled with a high-viscosity silicone oil. The Reynolds
number, the ratio of viscous to elastic stresses, and the helix geometry of our
experimental model approximately match the corresponding quantities of the full
scale E. coli cells. We analyze digital video images of the rotating helices to
show that the initial rate of bundling is proportional to the motor frequency
and is independent of the characteristic relaxation time of the filament. We
also determine which combinations of helix handedness and sense of motor
rotation lead to bundling.Comment: 6 pages, 4 figures (3 in color). A supporting movie is published at
the PNAS websit
A Study to Optimize Heterogeneous Resources for Open IoT
Recently, IoT technologies have been progressed, and many sensors and
actuators are connected to networks. Previously, IoT services were developed by
vertical integration style. But now Open IoT concept has attracted attentions
which achieves various IoT services by integrating horizontal separated devices
and services. For Open IoT era, we have proposed the Tacit Computing technology
to discover the devices with necessary data for users on demand and use them
dynamically. We also implemented elemental technologies of Tacit Computing. In
this paper, we propose three layers optimizations to reduce operation cost and
improve performance of Tacit computing service, in order to make as a
continuous service of discovered devices by Tacit Computing. In optimization
process, appropriate function allocation or offloading specific functions are
calculated on device, network and cloud layer before full-scale operation.Comment: 3 pages, 1 figure, 2017 Fifth International Symposium on Computing
and Networking (CANDAR2017), Nov. 201
Price and Wage Setting in Japan: An Empirical Investigation
This paper empirically analyzes whether a hypothesis from Aukrust (1977) applies to two phenomena in Japan: wage spillover between internationally competitive industries (exposed sectors) and domestically protected industries (sheltered sectors), and wage- and price- setting in those industries. We find that Aukrust's assumptions hold in the case of Japan, as all three of the cointegrating relations assumed by the Aukrust model are confirmed to exist. We also find the causal relations in Japan are more complex than the relations assumed by Aukrust.
50 mm diameter Sn-doped (001) beta-Ga2O3 crystal growth using the vertical Bridgeman technique in ambient air
Available online 3 July 202050 mm-diameter Sn-doped beta-Ga2O3 crystals with growth orientation perpendicular to (001) plane were grown with the newly-developed resistance heating vertical Bridgeman furnace using platinum-rhodium alloy crucibles in ambient air. Weak low angle grain boundaries and several small grains were detected on the both-side mirror polished 50 mm-diameter (001) wafer, using high resolution refraction x-ray topography. However, no imperfections were observed over the whole wafer area when using crossed polarizer analysis. Measured values of both the full width at half maximum and the dislocation densities were widely distributed in the wafer, ranging from 10 to 50 arcsec and 100 to 2000/cm(2) respectively with no distinctive correlations among them. The Sndoped crystals with concentrations ranging from 5 x 10(17) to 5 x 10(18) atom/cm(3) could be grown by Sn-doping in a range from 0.05 to 0.1 mol%, and (001) oriented, 50 mm-diameter n-type oxide semiconductor wafers with a carrier density of 3.6 x 10(18)/cm(3), a mobility of 60 cm(2)/Vsec and a resistivity of 0.03 Omega.cm, were obtained from a 0.1 mol% Sn-doped crystal.ArticleJOURNAL OF CRYSTAL GROWTH.546:125778(2020)journal articl
Immunocytochemical analysis of p63 and 34βE12 in fine needle aspiration cytology specimens for breast lesions: a potentially useful discriminatory marker between intraductal papilloma and ductal carcinoma in situ
学位記番号:保博甲第87
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