1,242 research outputs found
A method for precise charge reconstruction with pixel detectors using binary hit information
A method is presented to precisely reconstruct charge spectra with pixel
detectors using binary hit information of individual pixels. The method is
independent of the charge information provided by the readout circuitry and has
a resolution mainly limited by the electronic noise. It relies on the ability
to change the detection threshold in small steps while counting hits from a
particle source. The errors are addressed and the performance of the method is
shown based on measurements with the ATLAS pixel chip FE-I4 bump bonded to a
230 {\mu}m 3D-silicon sensor. Charge spectra from radioactive sources and from
electron beams are presented serving as examples. It is demonstrated that a
charge resolution ({\sigma}<200 e) close to the electronic noise of the ATLAS
FE-I4 pixel chip can be achieved
Perceptual Differences for Modifications of the Elevation of Early Room Reflections
Acoustic room responses usually comprise components that propagate in non-horizontal directions. Oftentimes, audio capture and reproduction systems are not capable of maintaining such elevation information reliably hence it is important to understand their perceptual significance when auralizing rooms. This work investigates the ability of the human hearing system to distinguish between early reflections with different elevation angles by performing loudspeaker- and headphone-based listening experiments using manipulated spatial room impulse responses. The results show that changing the elevation of a strong early reflection can lead to clearly perceivable differences and factors that influence the detectability are identified. Projecting all elevated reflections of a spatial room impulse response with no very prominent ceiling reflection to the horizontal plane showed no perceivable differences
Perceptual Differences for Modifications of the Elevation of Early Room Reflections
Acoustic room responses usually comprise components that propagate in non-horizontal directions. Oftentimes, audio capture and reproduction systems are not capable of maintaining such elevation information reliably hence it is important to understand their perceptual significance when auralizing rooms. This work investigates the ability of the human hearing system to distinguish between early reflections with different elevation angles by performing loudspeaker- and headphone-based listening experiments using manipulated spatial room impulse responses. The results show that changing the elevation of a strong early reflection can lead to clearly perceivable differences and factors that influence the detectability are identified. Projecting all elevated reflections of a spatial room impulse response with no very prominent ceiling reflection to the horizontal plane showed no perceivable differences
Characterization and Verification Environment for the RD53A Pixel Readout Chip in 65 nm CMOS
The RD53 collaboration is currently designing a large scale prototype pixel
readout chip in 65 nm CMOS technology for the phase 2 upgrades at the HL-LHC.
The RD53A chip will be available by the end of the year 2017 and will be
extensively tested to confirm if the circuit and the architecture make a solid
foundation for the final pixel readout chips for the experiments at the HL-LHC.
A test and data acquisition system for the RD53A chip is currently under
development to perform single-chip and multi-chip module measurements. In
addition, the verification of the RD53A design is performed in a dedicated
simulation environment. The concept and the implementation of the test and data
acquisition system and the simulation environment, which are based on a modular
data acquisition and system testing framework, are presented in this work
Latent Dirichlet Allocation Uncovers Spectral Characteristics of Drought Stressed Plants
Understanding the adaptation process of plants to drought stress is essential
in improving management practices, breeding strategies as well as engineering
viable crops for a sustainable agriculture in the coming decades.
Hyper-spectral imaging provides a particularly promising approach to gain such
understanding since it allows to discover non-destructively spectral
characteristics of plants governed primarily by scattering and absorption
characteristics of the leaf internal structure and biochemical constituents.
Several drought stress indices have been derived using hyper-spectral imaging.
However, they are typically based on few hyper-spectral images only, rely on
interpretations of experts, and consider few wavelengths only. In this study,
we present the first data-driven approach to discovering spectral drought
stress indices, treating it as an unsupervised labeling problem at massive
scale. To make use of short range dependencies of spectral wavelengths, we
develop an online variational Bayes algorithm for latent Dirichlet allocation
with convolved Dirichlet regularizer. This approach scales to massive datasets
and, hence, provides a more objective complement to plant physiological
practices. The spectral topics found conform to plant physiological knowledge
and can be computed in a fraction of the time compared to existing LDA
approaches.Comment: Appears in Proceedings of the Twenty-Eighth Conference on Uncertainty
in Artificial Intelligence (UAI2012
Traffic Noise at Moderate Levels Affects Cognitive Performance: Do Distance-Induced Temporal Changes Matter?
Urbanization leads to an increased demand for urban housing, which can be met by building dwellings closer to streets. Regulations often limit equivalent sound pressure levels which do not account for changes in time structure that occur when decreasing the road distance. This study investigates the effect of such temporal changes on subjective workload and cognitive performance. A group of 42 participants performed a continuous performance test as well as a NASA-TLX workload test under three different sound conditions, i.e., close traffic, far traffic, both with the same equivalent sound pressure level of LAeq ≈ 40 dB, and silence. Additionally, participants answered a questionnaire regarding their preferred acoustic environment for concentrated working. Significant effects of the sound condition on the multivariate workload results as well as on the number of commission errors in the continuous performance test were found. Post hoc tests showed no significant differences between the two noise conditions, but there were significant differences between noise and silence. This indicates that moderate traffic noise levels can influence cognitive performance and perceived workload. If there is a difference in the human response to road traffic noise with constant LAeq but different time structures, the used methods are not suitable to detect them
Measurement, Simulation and Auralization of Indoor Road Traffic Noise
Building new houses in urban areas is often hindered by the presence of road traffic noise. Thereby, it is especially difficult to achieve sufficient fa\ue7ade sound insulation at low frequencies. Current regulations are mostly based on A-weighted levels and hence not only disregard low frequencies but also omit other factors that might influence the amount of disturbance such as time structure, traffic distance, proportion of heavy vehicles, driving speed and background noise. This motivates the need for experiments evaluating the human response to indoor traffic noise in a controlled virtual environment. Thereby, one challenge is to include the incidence angle dependent transfer paths through the fa\ue7ade in the auralization. The method presented in this paper utilises wave field synthesis in order to reproduce the sound field caused by moving sound sources on the outside of a window in a, specifically for this purpose designed, living room lab. In order to evaluate the auralization, a physical model of the source position dependent transfer path from a moving outdoor sound source through a window to an indoor receiver position was developed
NeuralLasso: Neural Networks Meet Lasso in Genomic Prediction
Prediction of complex traits based on genome-wide marker information is of central importance for both animal and plant breeding. Numerous models have been proposed for the prediction of complex traits and still considerable effort has been given to improve the prediction accuracy of these models, because various genetics factors like additive, dominance and epistasis effects can influence of the prediction accuracy of such models. Recently machine learning (ML) methods have been widely applied for prediction in both animal and plant breeding programs. In this study, we propose a new algorithm for genomic prediction which is based on neural networks, but incorporates classical elements of LASSO. Our new method is able to account for the local epistasis (higher order interaction between the neighboring markers) in the prediction. We compare the prediction accuracy of our new method with the most commonly used prediction methods, such as BayesA, BayesB, Bayesian Lasso (BL), genomic BLUP and Elastic Net (EN) using the heterogenous stock mouse and rice field data sets
- …