918 research outputs found
The dynamical balance, transport and circulation of the Antarctic Circumpolar Current
The physical ingredients of the ACC circulation are reviewed. A picture of thecirculation is sketched by means of recent observations of the WOCE decade. Wepresent and discuss the role of forcing functions (wind stress, surfacebuoyancy flux) in the balance of the (quasi)-zonal flow, the meridionalcirculation and their relation to the ACC transport. Emphasis will be on theinterrelation of the zonal momentum balance and the meridional circulation, theimportance of diapycnal mixing and eddy processes. Finally, new model conceptsare described: a model of the ACC transport dependence on wind stress andbuoyancy flux, based on linear wave theory; and a model of the meridionaloverturning of the Southern Ocean, based on zonally averaged dynamics with eddyparameterization
A large-scale evaluation framework for EEG deep learning architectures
EEG is the most common signal source for noninvasive BCI applications. For
such applications, the EEG signal needs to be decoded and translated into
appropriate actions. A recently emerging EEG decoding approach is deep learning
with Convolutional or Recurrent Neural Networks (CNNs, RNNs) with many
different architectures already published. Here we present a novel framework
for the large-scale evaluation of different deep-learning architectures on
different EEG datasets. This framework comprises (i) a collection of EEG
datasets currently including 100 examples (recording sessions) from six
different classification problems, (ii) a collection of different EEG decoding
algorithms, and (iii) a wrapper linking the decoders to the data as well as
handling structured documentation of all settings and (hyper-) parameters and
statistics, designed to ensure transparency and reproducibility. As an
applications example we used our framework by comparing three publicly
available CNN architectures: the Braindecode Deep4 ConvNet, Braindecode Shallow
ConvNet, and two versions of EEGNet. We also show how our framework can be used
to study similarities and differences in the performance of different decoding
methods across tasks. We argue that the deep learning EEG framework as
described here could help to tap the full potential of deep learning for BCI
applications.Comment: 7 pages, 3 figures, final version accepted for presentation at IEEE
SMC 2018 conferenc
TRUNK POSTURE AND STATICO-DYNAMICAL SPINE ANALYSISâ COMPARING ULTRASOUND BASED VS. OPTICALLY BASED MEASUREMENT SYSTEM
The purpose of this study was to compare two different methods measuring trunk posture and statico-dynamical spine analysis. 32 patients participated in this cross sectional study. Comparing measured values a wide congruence could be demonstrated with marginal underestimating in kyphosis and lordosis data for the ultrasound based system. The largest deviation could be shown for pelvic obliquity measured in mm. Trunk inclination, vertical deflection and pelvic obliquity measured in degree showed proper analogy for both measuring systems. Validity, reliability based on particular technical principles could be verified
Side-entrainment in a jet embedded in a sidewind
Numerical simulations of HH jets never show side-entrainment of environmental
material into the jet beam. This is because the bow shock associated with the
jet head pushes the surrounding environment into a dense shell, which is never
in direct contact with the sides of the jet beam. We present 3D simulations in
which a side-streaming motion (representing the motion of the outflow source
through the surrounding medium) pushes the post-bow shock shell into direct
contact with the jet beam. This is a possible mechanism for modelling well
collimated "molecular jets" as an atomic/ionic flow which entrains molecules
initially present only in the surrounding environment.Comment: 8 pages, 12 figures, 1 table, accepted for publication in Ap
SeawaterâDegradable PolymersâFighting the Marine Plastic Pollution
Polymers shape human life but they also have been identified as pollutants in the oceans due to their long lifetime and low degradability. Recently, various researchers have studied the impact of (micro)plastics on marine life, biodiversity, and potential toxicity. Even if the consequences are still heavily discussed, prevention of unnecessary waste is desired. Especially, newly designed polymers that degrade in seawater are discussed as potential alternatives to commodity polymers in certain applications. Biodegradable polymers that degrade in vivo (used for biomedical applications) or during composting often exhibit too slow degradation rates in seawater. To date, no comprehensive summary for the degradation performance of polymers in seawater has been reported, nor are the studies for seawater-degradation following uniform standards. This review summarizes concepts, mechanisms, and other factors affecting the degradation process in seawater of several biodegradable polymers or polymer blends. As most of such materials cannot degrade or degrade too slowly, strategies and innovative routes for the preparation of seawater-degradable polymers with rapid degradation in natural environments are reviewed. It is believed that this selection will help to further understand and drive the development of seawater-degradable polymers
PLANTAR PRESSURE MEASUREMENTS IN A SOCCER SHOE: CHARACTERIZATION OF SOCCER SPECIFIC MOVEMENTS AND EFFECTS AFTER SIX WEEKS OF AGING
The purposes of the study were (i) to characterize in-shoe pressure distribution (PD) measurements during soccer specific movements, (ii) to describe the changes on (PD) after six weeks of aging. 21 experienced male subjects participated in the study. Four different movements (run, cut, sprint and goal shot) were measured on a red cinder surface before and after six weeks of aging. Results showed specific loading characteristics for each movement: Compared to running, the medial part of the foot in cutting, the forefoot in sprinting and the lateral part in kicking were predominantly loaded. Peak pressures increased over 10% after six weeks of use in some high-load areas. Attention should be paid to sprinting and cutting with respect to overuse injuries. Sockliners should be exchanged on a regular basis to maintain a certain amount of cushioning
SPECIFIC TRAINING CAN IMPROVE SENSORIMOTOR CONTROL IN TYPE 2 DIABETIC PATIENTS
Diabetes mellitus often is associated with proprioceptive and sensory deficits as a result of distal diabetic polyneuropathy (DPN). The aim of this prospective controlled longitudinal trial was to evaluate a specific sport intervention program regarding sensorimotor capabilities in type 2 diabetic patients compared to healthy controls. A higher incidence of fall-related injuries is given in the literature (Allet et al.2008; Allet et al 2009)
Magnetic Soret effect: Application of the ferrofluid dynamics theory
The ferrofluid dynamics theory is applied to thermodiffusive problems in
magnetic fluids in the presence of magnetic fields. The analytical form for the
magnetic part of the chemical potential and the most general expression of the
mass flux are given. By employing these results to experiments, global Soret
coefficients in agreement with measurements are determined. Also an estimate
for a hitherto unknown transport coefficient is made.Comment: 7 pages, 2 figure
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