12,102 research outputs found
Statistical mechanics of a Feshbach coupled Bose-Fermi gas in an optical lattice
We consider an atomic Fermi gas confined in a uniform optical lattice
potential, where the atoms can pair into molecules via a magnetic field
controlled narrow Feshbach resonance. The phase diagram of the resulting
atom-molecule mixture in chemical and thermal equilibrium is determined
numerically in the absence of interactions under the constraint of particle
conservation. In the limiting cases of vanishing or large lattice depth we
derive simple analytical results for important thermodynamic quantities. One
such quantity is the dissociation energy, defined as the detuning of the
molecular energy spectrum with respect to the atomic one for which half of the
atoms have been converted into dimers. Importantly we find that the
dissociation energy has a non-monotonic dependence on lattice depth.Comment: 9 pages, 5 figure
Tracking 3-D body motion for docking and robot control
An advanced method of tracking three-dimensional motion of bodies has been developed. This system has the potential to dynamically characterize machine and other structural motion, even in the presence of structural flexibility, thus facilitating closed loop structural motion control. The system's operation is based on the concept that the intersection of three planes defines a point. Three rotating planes of laser light, fixed and moving photovoltaic diode targets, and a pipe-lined architecture of analog and digital electronics are used to locate multiple targets whose number is only limited by available computer memory. Data collection rates are a function of the laser scan rotation speed and are currently selectable up to 480 Hz. The tested performance on a preliminary prototype designed for 0.1 in accuracy (for tracking human motion) at a 480 Hz data rate includes a worst case resolution of 0.8 mm (0.03 inches), a repeatability of plus or minus 0.635 mm (plus or minus 0.025 inches), and an absolute accuracy of plus or minus 2.0 mm (plus or minus 0.08 inches) within an eight cubic meter volume with all results applicable at the 95 percent level of confidence along each coordinate region. The full six degrees of freedom of a body can be computed by attaching three or more target detectors to the body of interest
Deep transfer learning for improving single-EEG arousal detection
Datasets in sleep science present challenges for machine learning algorithms
due to differences in recording setups across clinics. We investigate two deep
transfer learning strategies for overcoming the channel mismatch problem for
cases where two datasets do not contain exactly the same setup leading to
degraded performance in single-EEG models. Specifically, we train a baseline
model on multivariate polysomnography data and subsequently replace the first
two layers to prepare the architecture for single-channel
electroencephalography data. Using a fine-tuning strategy, our model yields
similar performance to the baseline model (F1=0.682 and F1=0.694,
respectively), and was significantly better than a comparable single-channel
model. Our results are promising for researchers working with small databases
who wish to use deep learning models pre-trained on larger databases.Comment: Accepted for presentation at EMBC202
Analysis of change in discrete variables
Versucht wird, eine Annäherung an die Analyse der Veränderung von diskreten Variablen zu leisten. Als methodisches Modell wird die Marcov-Kette benutzt, die einen brauchbaren Rahmen für die Analyse abgibt und in Zusammenhang mit ereignisgeschichtlichen Daten die Veränderungsraten bestimmbar macht. Kritik an der Brauchbarkeit der Marcov-Kette wird vom Autor zurückgewiesen. Er zeigt, daß dieses Modell auch den ad hoc statistischen Techniken Überlegen ist, weil diese ereignisgeschichtliche Daten von Veränderung nicht adäquat in die Bestimmung von historischen Veränderungen einbeziehen. Und gerade ereignisgeschichtliche Daten erlauben die direkte Analyse von Veränderungen, und deshalb ist hier ein entsprechendes methodisches Modell notwendig. (BG
Early intensive behavioral intervention for autism: Is it actually more intensive than a typical child\u27s day?
Autism Spectrum Disorder (ASD) is a pervasive developmental disorder characterized by deficits in social interaction, communication, and excessive ritualistic and repetitive behavior. Numerous treatments for autism devised over the last half-century have proven ineffective, or have never been scientifically evaluated. Despite the state of the research, the most demonstrably effective treatment, Early Intensive Behavioral Intervention (EIBI), has been a target of much criticism, including accusations of being too intense. A large number of learning trials in relatively short periods of time supposedly induce children to have disordered stress responses. To explore the intensity of EIBI, behavior samples from children engaging in EIBI and typical children engaging in everyday activities were gathered and coded for rates of behavior. Operational definitions of what constituted a single behavioral interaction were developed, and those samples were used to calculate behavior rates. The results suggest that the rate of behavior exhibited by typical children exceeds the rate of behaviors in early intensive behavioral therapy, by a factor of two to three. Simply put, EIBI is generally not nearly as behaviorally intense as are ordinary child activities, and thus this dimension of EIBI is unlikely to be a precipitant for disordered stress responses
Group Psychotherapy: A Review of Literature
Group psychotherapy has been described as uniquely American. It is indeed a consequence of the pragmatism of American psychiatry, which appeared willing to explore any new and possibly helpful technique
Different quantization mechanisms in single-electron pumps driven by surface acoustic waves
We have studied the acoustoelectric current in single-electron pumps driven
by surface acoustic waves. We have found that in certain parameter ranges two
different sets of quantized steps dominate the acoustoelectric current versus
gate-voltage characteristics. In some cases, both types of quantized steps
appear simultaneously though at different current values, as if they were
superposed on each other. This could indicate two independent quantization
mechanisms for the acoustoelectric current.Comment: 6 pages, 3 figure
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