363 research outputs found
Estimating posture-recognition performance in sensing garments using geometric wrinkle modeling
A fundamental challenge limiting information quality obtained from smart sensing garments is the influence of textile movement relative to limbs. We present and validate a comprehensive modeling and simulation framework to predict recognition performance in casual loose-fitting garments. A statistical posture and wrinkle-modeling approach is introduced to simulate sensor orientation errors pertained to local garment wrinkles. A metric was derived to assess fitting, the body-garment mobility. We validated our approach by analyzing simulations of shoulder and elbow rehabilitation postures with respect to experimental data using actual casual garments. Results confirmed congruent performance trends with estimation errors below 4% for all study participants. Our approach allows to estimate the impact of fitting before implementing a garment and performing evaluation studies with it. These simulations revealed critical design parameters for garment prototyping, related to performed body posture, utilized sensing modalities, and garment fitting. We concluded that our modeling approach can substantially expedite design and development of smart garments through early-stage performance analysis
Microcanonical Determination of the Interface Tension of Flat and Curved Interfaces from Monte Carlo Simulations
The investigation of phase coexistence in systems with multi-component order
parameters in finite systems is discussed, and as a generic example, Monte
Carlo simulations of the two-dimensional q-state Potts model (q=30) on LxL
square lattices (40<=L<=100) are presented. It is shown that the microcanonical
ensemble is well-suited both to find the precise location of the first order
phase transition and to obtain an accurate estimate for the interfacial free
energy between coexisting ordered and disordered phases. For this purpose, a
microcanonical version of the heatbath algorithm is implemented. The finite
size behaviour of the loop in the curve describing the inverse temperature
versus energy density is discussed, emphasizing that the extrema do not have
the meaning of van der Waals-like "spinodal points" separating metastable from
unstable states, but rather describe the onset of heterophase states:
droplet/bubble evaporation/condensation transitions. Thus all parts of these
loops, including the parts that correspond to a negative specific heat,
describe phase coexistence in full thermal equilibrium. However, the estimates
for the curvature-dependent interface tension of the droplets and bubbles
suffer from unexpected and unexplained large finite size effects which need
further study.Comment: submitted to special issue "Liquid Matter" of Journal of Physics C:
Condensed Matter on occasion of the 8th Liquid Matter Conference held Sept.
6-10, 2011 in Vienna, Austri
Finite strain Landau theory of high pressure phase transformations
The properties of materials near structural phase transitions are often
successfully described in the framework of Landau theory. While the focus is
usually on phase transitions, which are induced by temperature changes
approaching a critical temperature T-c, here we will discuss structural phase
transformations driven by high hydrostatic pressure, as they are of major
importance for understanding processes in the interior of the earth. Since at
very high pressures the deformations of a material are generally very large,
one needs to apply a fully nonlinear description taking physical as well as
geometrical nonlinearities (finite strains) into account. In particular it is
necessary to retune conventional Landau theory to describe such phase
transitions. In Troster et al (2002 Phys. Rev. Lett. 88 55503) we constructed a
Landau-type free energy based on an order parameter part, an order
parameter-(finite) strain coupling and a nonlinear elastic term. This model
provides an excellent and efficient framework for the systematic study of phase
transformations for a wide range of materials up to ultrahigh pressures
Influence of a loose-fitting sensing garment on posture recognition in rehabilitation
Several smart sensing garments have been proposed for postural and movement rehabilitation. Existing systems require a tight-fitting of the garment at body segments and precise sensor positioning. In this work, we analyzed errors of a loose-fitting sensing garment on the automatic recognition of 21 postures, relevant in shoulder and elbow-rehabilitation. The recognition performance of garment-attached acceleration sensors and additional skin-attached references was compared to discuss challenges in a garment-based classification of postures. The analysis was done with one fixed-size shirt worn by seven participants of varying body proportions. The classification accuracy using data from garment-integrated sensors was on average 13% lower compared to that of skin-attached reference sensors. This relation remained constant even after selecting an optimal input feature set. For garment-attached sensors, we observed that the loss in classification accuracy decreased, if the body dimension increased. Moreover, the alignment error of individual postures was analyzed, to identify movements and postures that are particularly affected by garment fitting aspects. Contrarily, we showed that 14 of the 21 rehabilitation-relevant postures result in a low sensor alignment error. We believe that these results indicate critical design aspects for the deployment of comfortable garments in movement rehabilitation and should be considered in garment and posture selection. © 2008 IEEE
Cosmic star formation history with tomographic CIB-galaxy cross-correlation
In this work, we probe the star formation history of the Universe using
tomographic cross-correlation between the cosmic infrared background (CIB) and
galaxy samples. The galaxy samples are from the Kilo-Degree Survey (KiDS),
while the CIB maps are made from \planck\, sky maps. We measure the
cross-correlation in harmonic space with a significance of 43. We model
the cross-correlation with a halo model, which links CIB anisotropies to star
formation rates (SFR) and galaxy abundance. We assume that SFR has a lognormal
dependence on halo mass, while galaxy abundance follows the halo occupation
distribution (HOD) model. The cross-correlations give a best-fit maximum star
formation efficiency of at a halo
mass . The derived
star formation rate density (SFRD) is well constrained up to . The
constraining power at high redshift is mainly limited by the KiDS survey depth.
A combination with external SFRD measurements from previous studies gives
. This tightens
the SFRD constraint up to , yielding a peak SFRD of
at
, corresponding to a lookback time of
Gyr. Both constraints are consistent, and the derived
SFRD agrees with previous studies and simulations. Additionally, we estimate
the galaxy bias of KiDS galaxies from the constrained HOD parameters and
yield an increasing bias from at to
at . Finally, we provide a forecast for future
galaxy surveys and conclude that, due to their considerable depth, future
surveys will yield a much tighter constraint on the evolution of the SFRD.Comment: 22 pages, 14 figures, 3 tables, the abstract is abridge
KiDS-1000: cosmic shear with enhanced redshift calibration
We present a cosmic shear analysis with an improved redshift calibration for
the fourth data release of the Kilo-Degree Survey (KiDS-1000) using
self-organising maps (SOMs). Compared to the previous analysis of the KiDS-1000
data, we expand the redshift calibration sample to more than twice its size,
now consisting of data of 17 spectroscopic redshift campaigns, and
significantly extending the fraction of KiDS galaxies we are able to calibrate
with our SOM redshift methodology. We then enhance the calibration sample with
precision photometric redshifts from COSMOS2015 and the Physics of the
Accelerated Universe Survey (PAUS), allowing us to fill gaps in the
spectroscopic coverage of the KiDS data. Finally we perform a Complete
Orthogonal Sets of E/B-Integrals (COSEBIs) cosmic shear analysis of the newly
calibrated KiDS sample. We find , which is in
good agreement with previous KiDS studies and increases the tension with
measurements of the cosmic microwave background to 3.4{\sigma}. We repeat the
redshift calibration with different subsets of the full calibration sample and
obtain, in all cases, agreement within at most 0.5{\sigma} in compared to
our fiducial analysis. Including additional photometric redshifts allows us to
calibrate an additional 6 % of the source galaxy sample. Even though further
systematic testing with simulated data is necessary to quantify the impact of
redshift outliers, precision photometric redshifts can be beneficial at high
redshifts and to mitigate selection effects commonly found in spectroscopically
selected calibration samples.Comment: 18 pages, 15 figures, 6 table
Probing hot gas around luminous red galaxies through the Sunyaev-Zel'dovich effect
We construct the mean thermal Sunyaev-Zel'dovich (tSZ) Comptonization y profile around Luminous Red Galaxies (LRGs) in the redshift range 0.16 < z < 0.47 from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) using the Planck y map. The mean central tSZ signal for the full sample is y ~ 1.8 * 10^(-7) and we detect tSZ emission out to ~30 arcmin, which is well beyond the 10 arcmin angular resolution of the y map and well beyond the virial radii of the LRGs. We compare the measured profile with predictions from the cosmo-OWLS suite of cosmological hydrodynamical simulations. This comparison agrees well for models that include feedback from active galactic nuclei (AGN), but not with hydrodynamic models without this energetic feedback mechanism. This suggests that an additional heating mechanism is required over SNe feedback and star formation to explain the y data profile. We also compare our results with predictions based on the halo model with a universal pressure profile (UPP) giving the y signal. The predicted profile is consistent with the data, but only if we account for the clustering of haloes via a two-halo term and if halo masses are estimated using the mean stellar-to-halo mass (SHM) relation of Coupon et al. (2015) or Wang et al.(2016) estimated from gravitational lensing measurements. We also discuss the importance of scatter in the SHM relation on the model predictions
Molecular systematics of Campylobacter isolated from the human clinical environment.
Campylobacter jejuni is the major cause of campylobacteriosis in humans. This thesis recorded the distribution of C. jejuni and C. coli isolates in a hospital environment during 1997/98. 105 clinical isolates of Campylobacter were examined using flaA and gmhA PCR-RFLP analysis. Isolates were collected from 84 patients who presented at Christchurch Public Hospital or from the South Canterbury region. Males accounted for 63.1 % of the sample. The largest number of cases was reported in the age group 20-29 years. flaA specific primers were applied to all samples with 83.8 % generating a 1.7 kb amplicon. RFLP analysis using DdeI provided 17 different flaA profiles, with flaA 6 being the most common type identified in this study. 82.9 % of the sample generated a distinguishable profile. This technique provided a D value of 92 % (D = Simpson's index of diversity). gmhA primers were also applied to this sample, with 71.4 % generating either a 900 bp, 1.6 kb or multiple band profile. 62.9 % of the sample provided a distinguishable RFLP profile. gmhA 1 was the most commonly observed profile. This technique provided a D value of 74 %. When combining these two genetic markers, discrimination was increased. 59 % (n=62) of the isolates had provided both flaA and gmhA profiles. These isolates were distributed into 22 different classifications. MLEE analysis was applied to the largest flaA group in an attempt to further assess relationships. This analysis allowed flaA 6 to be subdivided into a further five groups, therefore increasing strain discrimination. PCR-RFLP procedures were highly reproducible, robust, discriminative and rapid to perform. However 17.1 % and 37.1 % were untypeable by flaA and gmhA respectively. 20 environmental (sheep) isolates from Massey University were also examined using flaA and gmhA PCR-RFLP analysis. Four flaA types and two gmhA types were observed amongst these isolates. The flaA and gmhA types had been previously observed in the clinical isolates, therefore suggesting that no strain was specific to a particular environment. However not all isolates were typeable with these two methods
Criteria for the diagnosis of corticobasal degeneration
Current criteria for the clinical diagnosis of pathologically confirmed corticobasal degeneration (CBD) no longer reflect the expanding understanding of this disease and its clinicopathologic correlations. An international consortium of behavioral neurology, neuropsychology, and movement disorders specialists developed new criteria based on consensus and a systematic literature review. Clinical diagnoses (early or late) were identified for 267 nonoverlapping pathologically confirmed CBD cases from published reports and brain banks. Combined with consensus, 4 CBD phenotypes emerged: corticobasal syndrome (CBS), frontal behavioral-spatial syndrome (FBS), nonfluent/agrammatic variant of primary progressive aphasia (naPPA), and progressive supranuclear palsy syndrome (PSPS). Clinical features of CBD cases were extracted from descriptions of 209 brain bank and published patients, providing a comprehensive description of CBD and correcting common misconceptions. Clinical CBD phenotypes and features were combined to create 2 sets of criteria: more specific clinical research criteria for probable CBD and broader criteria for possible CBD that are more inclusive but have a higher chance to detect other tau-based pathologies. Probable CBD criteria require insidious onset and gradual progression for at least 1 year, age at onset ≥50 years, no similar family history or known tau mutations, and a clinical phenotype of probable CBS or either FBS or naPPA with at least 1 CBS feature. The possible CBD category uses similar criteria but has no restrictions on age or family history, allows tau mutations, permits less rigorous phenotype fulfillment, and includes a PSPS phenotype. Future validation and refinement of the proposed criteria are needed
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