631 research outputs found
On the Frequency Dependency of Radio Channel's Delay Spread: Analyses and Findings From mmMAGIC Multi-frequency Channel Sounding
This paper analyzes the frequency dependency of the radio propagation
channel's root mean square (rms) delay spread (DS), based on the
multi-frequency measurement campaigns in the mmMAGIC project. The campaigns
cover indoor, outdoor, and outdoor-to-indoor (O2I) scenarios and a wide
frequency range from 2 to 86 GHz. Several requirements have been identified
that define the parameters which need to be aligned in order to make a
reasonable comparison among the different channel sounders employed for this
study. A new modelling approach enabling the evaluation of the statistical
significance of the model parameters from different measurements and the
establishment of a unified model is proposed. After careful analysis, the
conclusion is that any frequency trend of the DS is small considering its
confidence intervals. There is statistically significant difference from the
3GPP New Radio (NR) model TR 38.901, except for the O2I scenario.Comment: This paper has been accepted to the 2018 12th European Conference on
Antennas and Propagation (EuCAP), London, UK, April 201
Enhanced dielectrophoresis of nanocolloids by dimer formation
We investigate the dielectrophoretic motion of charge-neutral, polarizable
nanocolloids through molecular dynamics simulations. Comparison to analytical
results derived for continuum systems shows that the discrete charge
distributions on the nanocolloids have a significant impact on their coupling
to the external field. Aggregation of nanocolloids leads to enhanced
dielectrophoretic transport, provided that increase in the dipole moment upon
aggregation can overcome the related increase in friction. The dimer
orientation and the exact structure of the nanocolloid charge distribution are
shown to be important in the enhanced transport
Supplementary health insurance in Finland : Consumer preferences and behaviour.
This nationally representative questionnaire survey provides insight into the demographics, motivations and behaviour of consumers opting for supplementary health insurance (SHI), and the impact of SHI on consumer utilisation of healthcare services. The data was collected from a combination of online and paper-based surveys (N = 1,620, response rate 41%) in October 2013 – January 2014. The questionnaire covers both adult and children’s SHI. The data comprises information on respondents’ socio-economics, health insurance, motivations for purchasing (or not purchasing) SHI and utilisation of healthcare services. We analyse 1) the current utilisation of and trends in SHI, 2) the preferences and motivations of Finnish consumers in opting for SHI in relation to their background characteristics, and 3) the consequences of SHI on primary healthcare service utilisation. A total of 22.7% of Finnish adults and 52.0% of children had SHI. The reasons for purchasing SHI were faster access, wider choice, better quality and willingness to use private healthcare (PRH) services. For adults, labour market position, level of education, better health and household income were significantly associated with SHI. For children, the most important factor associated with purchasing insurance seems to be the educational level of the (responding) parent. There was a significant interdependence between parents' and children’s SHI. For adults, the insurance decreases the probability they will choose a public provider and increases the utilisation of private services. For children, the insurance increases the probability of choosing a private provider. The SHI decreases the utilisation of public services for adults and increases the utilisation of private services. For children, there seems to be no effect on the utilisation of public services, but a significant increase in the utilisation of private services. Also the mode of purchase, i.e. self-purchased or employer-purchased, seems to influence healthcare utilisation in the working population. Self-purchased SHI increases the utilisation of private services, but employer-purchased SHI has no impact on healthcare utilisation.
Tällä väestöä edustavaan otokseen perustuvalla tutkimuksella selvitetään vakuutusten hankkimisen sosio-demografiaa, kansalaisten motivaatioita, käyttäytymistä ja vakuutusten vaikutusta terveyspalvelusten käyttöön. Aineisto on koottu yhdistetyllä verkko- ja paperilomakekyselyllä (N = 1 620, vastausprosentti oli 41 %) lokakuun 2013 ja tammikuun 2014 välisenä aikana. Tutkimus kattaa sekä aikuisten että heidän lastensa terveyteen liittyvät vakuutukset. Aineisto sisältää tietoja vastaajien sosio-ekonomisesta asemasta, terveysvakuutuksista, vakuutuksen valinnan (tai valitsematta jättämisen) motiiveista, vakuutuksen käytöstä ja vaikutuksesta terveyspalvelujen käyttöön. Selvitämme tässä tutkimuksessa; 1) terveysvakuutusten määrää ja niiden käytön trendejä, 2) kansalaisten preferenssejä ja motiiveja vakuutusten hankinnassa ja 3) vakuutusten seurauksia terveyspalvelujen käytössä. Suomalaisista aikuisista 22,7 %:lla ja lapsiperheistä 52,0 %:lla on yksityinen terveysvakuutus. Syyt vakuutuksen hankintaan ovat nopea hoitoon pääsy, laajempi palveluvalikoima ja koettu yksityisten palvelujen parempi laatu. Aikuisten vakuutuksen valintaa selittävät työmarkkina-asema, koulutustaso ja kotitalouden tulot. Aikuisilla vakuutuksen omaajilla on parempi terveydentila kuin ilman vakuutusta olevilla. Aikuisten ja lasten vakuutukset keskittyvät samoihin kotitalouksiin. Lasten vakuutusten valintaa selittää ensisijaisesti vanhemman koulutus. Aikuisten ja lasten vakuuttamista selittävät täten hieman erilaiset seikat. Vakuutus selittää terveyspalvelujen tuottajan valintaa ja palvelujen käytettyä määrää. Vakuutus näyttää johtavan yksityisten palvelujen käyttöön ja lisääntyneeseen palvelukäyttöön erityisesti lapsilla. Aikuisilla vakuutus vähentää julkisen ja lisää yksityisen palveluntuottajan valinnan todennäköisyyttä. Lapsilla taas vakuutus lisää yksityisen tuottajan valinnan todennäköisyyttä. Vakuutus vähentää aikuisilla julkisten ja lisää yksityisen palvelujen käytettyä määrää. Lapsilla julkisten palvelujen käyttö ei vähene, mutta yksityisten palvelujen käyttö lisääntyy. Myös vakuutuksen hankinnan tavalla on yhteys palvelujen käyttöön. Työssäkäyvien aikuisten itse hankkima vakuutus tuottaa lisäyksen yksityisten palvelujen käytetyssä määrässä, mutta työnantajan hankkima vakuutus ei ole yhteydessä julkisten, yksityisten tai työterveyshuollon palvelujen käytettyyn määrään
Collapses and explosions in self-gravitating systems
Collapse and reverse to collapse explosion transition in self-gravitating
systems are studied by molecular dynamics simulations. A microcanonical
ensemble of point particles confined to a spherical box is considered; the
particles interact via an attractive soft Coulomb potential. It is observed
that the collapse in the particle system indeed takes place when the energy of
the uniform state is put near or below the metastability-instability threshold
(collapse energy), predicted by the mean-field theory. Similarly, the explosion
in the particle system occurs when the energy of the core-halo state is
increased above the explosion energy, where according to the mean field
predictions the core-halo state becomes unstable. For a system consisting of
125 -- 500 particles, the collapse takes about single particle crossing
times to complete, while a typical explosion is by an order of magnitude
faster. A finite lifetime of metastable states is observed. It is also found
that the mean-field description of the uniform and the core-halo states is
exact within the statistical uncertainty of the molecular dynamics data.Comment: 9 pages, 14 figure
FOXP3(+) T cells are present in kidney biopsy samples in children with tubulointerstitial nephritis and uveitis syndrome
Tubulointerstitial nephritis (TIN) is an inflammatory disease of unknown pathogenesis. To evaluate a possible role of regulatory T cells (Tregs) in the pathophysiology of TIN with (TINU) and without uveitis, we investigated the presence and quantity of FOXP3(+) T regulatory lymphocytes in diagnostic kidney biopsies from pediatric patients. A total of 33 patients (14 TIN and 19 TINU) were enrolled. The quantity of CD4(+), FOXP3(+) and double-positive T cells in formalin-fixed kidney biopsies was determined using double label immunohistochemistry with anti-human CD4 and FOXP3 antibodies. FOXP3 staining was successful in all 33 patients. In patients with chronic uveitis, the density of FOXP3(+) cells was significantly lower (p = 0.046) than in TIN patients without uveitis or with uveitis lasting <3 months. CD4(+) staining was successful in 23 patients. The density of all lymphocytes (CD4(+), CD4(+)FOXP3(+) and FOXP3(+) cells) was significantly lower (p = 0.023) in patients with chronic uveitis than in other patients. FOXP3(+) T cells are present in kidney biopsy samples from TIN and TINU patients. In patients with chronic uveitis, the density of FOXP3(+) T cells is significantly lower than in other patients, suggesting a different pathomechanism for these clinical conditions.Peer reviewe
Dielectrophoresis of charged colloidal suspensions
We present a theoretical study of dielectrophoretic (DEP) crossover spectrum
of two polarizable particles under the action of a nonuniform AC electric
field. For two approaching particles, the mutual polarization interaction
yields a change in their respective dipole moments, and hence, in the DEP
crossover spectrum. The induced polarization effects are captured by the
multiple image method. Using spectral representation theory, an analytic
expression for the DEP force is derived. We find that the mutual polarization
effects can change the crossover frequency at which the DEP force changes sign.
The results are found to be in agreement with recent experimental observation
and as they go beyond the standard theory, they help to clarify the important
question of the underlying polarization mechanisms
Electrokinetic behavior of two touching inhomogeneous biological cells and colloidal particles: Effects of multipolar interactions
We present a theory to investigate electro-kinetic behavior, namely,
electrorotation and dielectrophoresis under alternating current (AC) applied
fields for a pair of touching inhomogeneous colloidal particles and biological
cells. These inhomogeneous particles are treated as graded ones with physically
motivated model dielectric and conductivity profiles. The mutual polarization
interaction between the particles yields a change in their respective dipole
moments, and hence in the AC electrokinetic spectra. The multipolar
interactions between polarized particles are accurately captured by the
multiple images method. In the point-dipole limit, our theory reproduces the
known results. We find that the multipolar interactions as well as the spatial
fluctuations inside the particles can affect the AC electrokinetic spectra
significantly.Comment: Revised version with minor changes: References added and discussion
extende
Dynamics of driven interfaces near isotropic percolation transition
We consider the dynamics and kinetic roughening of interfaces embedded in
uniformly random media near percolation treshold. In particular, we study
simple discrete ``forest fire'' lattice models through Monte Carlo simulations
in two and three spatial dimensions. An interface generated in the models is
found to display complex behavior. Away from the percolation transition, the
interface is self-affine with asymptotic dynamics consistent with the
Kardar-Parisi-Zhang universality class. However, in the vicinity of the
percolation transition, there is a different behavior at earlier times. By
scaling arguments we show that the global scaling exponents associated with the
kinetic roughening of the interface can be obtained from the properties of the
underlying percolation cluster. Our numerical results are in good agreement
with theory. However, we demonstrate that at the depinning transition, the
interface as defined in the models is no longer self-affine. Finally, we
compare these results to those obtained from a more realistic
reaction-diffusion model of slow combustion.Comment: 7 pages, 9 figures, to appear in Phys. Rev. E (1998
HFST—Framework for Compiling and Applying Morphologies
HFST–Helsinki Finite-State Technology ( hfst.sf.net ) is a framework for compiling and applying linguistic descriptions with finite-state methods. HFST currently connects some of the most important finite-state tools for creating morphologies and spellers into one open-source platform and supports extending and improving the descriptions with weights to accommodate the modeling of statistical information. HFST offers a path from language descriptions to efficient language applications in key environments and operating systems. HFST also provides an opportunity to exchange transducers between different software providers in order to get the best out of each finite-state library.Peer reviewe
Defects, order, and hysteresis in driven charge-density waves
We model driven two-dimensional charge-density waves in random media via a
modified Swift-Hohenberg equation, which includes both amplitude and phase
fluctuations of the condensate. As the driving force is increased, we find that
the defect density first increases and then decreases. Furthermore, we find
switching phenomena, due to the formation of channels of dislocations. These
results are in qualitative accord with recent dynamical x-ray scattering
experiments by Ringlandet al. and transport experiments by Lemay et al.Comment: Accepted to Phys. Rev. Lett. Click here for
"http://www-theory.mpip-mainz.mpg.de/~karttune/CDW/", movies of driven CDW
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