Search results for " Feedback"
showing 10 items of 291 documents
On the Effects of Relative Performance Feedback in a Risk Elicitation Task: Evidence From a Lab Experiment
2018
This paper experimentally investigates the influence of different non-payoff-relevant feedback regimes on motivation, competitiveness and risk-taking behaviors in a risk elicitation task. We explore four feedback regimes: private feedback, full ranking feedback, top-5 ranking feedback, and non-ranking feedback based on the median performance of peers. We found that providing relative performance feedback increases risk-taking behavior, especially when using a top-5 ranking. Feedback regimes that provide a user with rank-based feedback have adverse effects on the users' attitudes as they increase competitiveness while failing to increase intrinsic motivation and performance motivation. In co…
The variation of acetylcholine release from myenteric neurones with stimulation frequency and train length. Role of presynaptic muscarine receptors.
1983
1. The effects of scopolamine on the release of 3H-acetylcholine (ACh) from the guinea-pig myenteric plexus were studied at different stimulation frequencies (0.03–10 Hz) and train lengths (1–180 pulses). Release of 3H-ACh was measured in the absence of cholinesterase inhibitors as the outflow of tritium from myenteric plexus-longitudinal muscle preparations preloaded with 3H-choline. 2. In control experiments the volley output of 3H-ACh declined with increasing train length and increasing stimulation frequency. Stimulation by one pulse produced the highest volley output. 3. Scopolamine facilitated the evoked output of 3H-ACh via blockade of presynaptic muscarine receptors. A significant in…
Influence of light polarization on the dynamics of optically pumped lasers.
1990
The dynamic behavior of a coherently pumped ring laser with a homogeneously broadened four-level medium is analyzed theoretically, considering linearly polarized pump and generated laser beams. The laser is shown to be much more stable when these polarizations are parallel than when they are orthogonal. In the latter case the instability pump threshold can be as low as four times the first laser threshold, and the laser dynamics shows Lorenz-type features.
Comprehensive Theoretical and Experimental Study of Short- and Long-Term Stability in a Passively Mode-Locked Solitonic Fiber Laser
2015
We demonstrate the short- and long-term stable operation of an all-polarization-maintained Fabry–Perot cavity passively mode-locked fiber laser. The laser operates in an all-anomalous-dispersion solitonic regime. Laser stability is studied by a variety of measurements, which confirm the high stability of the laser in the temporal and spectral–both optical and electrical-domains. Pulse durations of 540 fs, period-relative time jitters of $\sim$ 0.015‰, and long-term uninterrumped operation with 0.4% variation (standard deviation) in the average output power are obtained. The highly stable operation of the laser oscillator was maintained after amplifying the laser output with a conventional E…
Threshold of a Symmetrically Pumped Distributed Feedback Fiber Laser With a Variable Phase Shift
2008
In this paper, we study, both theoretically and experimentally, the threshold characteristics of a distributed feedback fiber laser that depend on the value of a phase shift introduced into the fiber Bragg grating structure. We show that as the phase shift possesses a noticeable birefringence, the laser oscillates at any phase shift value. We also reveal that the laser threshold is different for the cavity eigen polarizations and depends on the phase shift value. We derive a simple analytical formula to calculate the laser threshold in the case of pi phase shift; this formula can be utilized to estimate a minimal threshold value for the laser with certain active fiber and Bragg grating para…
Transverse effects in ring fiber laser multimode instabilities
2000
We study the influence of the transverse structure of pump and lasing fields and of the width of the doped region on the conditions for the appearance of the multimode instability in an ${\mathrm{Er}}^{3+}$-doped ring fiber laser. We show that the instability can be inhibited while maintaining a large output power when the radius of the doped region is a fraction of the core radius.
Short-wavelength soft-x-ray laser pumped in double-pulse single-beam non-normal incidence
2010
We demonstrated a $7.36$ nm Ni-like samarium soft-x-ray laser, pumped by $36$ J of a neodymium:glass chirped-pulse amplification laser. Double-pulse single-beam non-normal-incidence pumping was applied for efficient soft-x-ray laser generation. In this case, the applied technique included a single-optic focusing geometry for large beam diameters, a single-pass grating compressor, traveling-wave tuning capability, and an optimized high-energy laser double pulse. This scheme has the potential for even shorter-wavelength soft-x-ray laser pumping.
Integrated InGaAlAs/InP laser-modulator using an identical multiple quantum well active layer
2005
We present experimental results on 40 Gb/s large-signal modulation performance of 1.31 μm monolithic integrated laser-modulator in the InGaAlAs/InP material system, exploiting the gain and absorption properties of an identical multiple quantum well (MQW) active layer. In continuous wave operation, at 15◦ C, the devices achieved threshold currents < 28 mA, fiber coupled optical power levels up to +0.4 dBm. The measured small signal modulation bandwidth was about 32 GHz. An air-cavity based Fabry-Perot interferometer has been realized to characterize the spectral chirp of the integrated structures in the time domain up to 40 Gb/s.
Collimation of Target Induced Halo Following MAGIX at MESA
2019
The Mainz Energy-recovering Superconducting Accelerator (MESA) will be an electron accelerator allowing operation in energy-recovery linac (ERL) mode. It provides the opportunity to operate scattering experiments at energies of ~100 MeV with thin gas-targets. The MESA Internal Gas Target Experiment (MAGIX) aims to operate windowless jet targets and different gases up to Xenon to search for possible dark photon interactions, to precisely measure the magnetic proton radius and astrophysical S-factors. Investigations on the impact of the target on beam dynamics and beam losses are required for machine safety and to examine limits to ERL operation. The goal of this work is to understand target …
A wearable multimodal interface for exploring urban points of interest
2015
Locating points of interest (POIs) in cities is typically facilitated by visual aids such as paper maps, brochures, and mobile applications. However, these techniques require visual attention, which ideally should be on the surroundings. Non-visual techniques for navigating towards specific POIs typically lack support for free exploration of the city or more detailed guidance. To overcome these issues, we propose a multimodal, wearable system for alerting the user of nearby recommended POIs. The system, built around a tactile glove, provides audio-tactile cues when a new POI is in the vicinity, and more detailed information and guidance if the user expresses interest in this POI. We evaluat…