34 research outputs found
Quantifying cerebral asymmetries for language in dextrals and adextrals with random-effects meta analysis
Speech and language-related functions tend to depend on the left hemisphere more than the right in most right-handed (dextral) participants. This relationship is less clear in non-right handed (adextral) people, resulting in surprisingly polarized opinion on whether or not they are as lateralized as right handers. The present analysis investigates this issue by largely ignoring methodological differences between the different neuroscientific approaches to language lateralization, as well as discrepancies in how dextral and adextral participants were recruited or defined. Here we evaluate the tendency for dextrals to be more left hemisphere dominant than adextrals, using random effects meta analyses. In spite of several limitations, including sample size (in the adextrals in particular), missing details on proportions of groups who show directional effects in many experiments, and so on, the different paradigms all point to proportionally increased left hemispheric dominance in the dextrals. These results are analyzed in light of the theoretical importance of these subtle differences for understanding the cognitive neuroscience of language, as well as the unusual asymmetry in most adextrals
The Human Affectome
Over the last decades, the interdisciplinary field of the affective sciences has seen proliferation rather than integration of theoretical perspectives. This is due to differences in metaphysical and mechanistic assumptions about human affective phenomena (what they are and how they work) which, shaped by academic motivations and values, have determined the affective constructs and operationalizations. An assumption on the purpose of affective phenomena can be used as a teleological principle to guide the construction of a common set of metaphysical and mechanistic assumptionsâa framework for human affective research. In this capstone paper for the special issue âTowards an Integrated Understanding of the Human Affectomeâ, we gather the tiered purpose of human affective phenomena to synthesize assumptions that account for human affective phenomena collectively. This teleologically-grounded framework offers a principled agenda and launchpad for both organizing existing perspectives and generating new ones. Ultimately, we hope Human Affectome brings us a step closer to not only an integrated understanding of human affective phenomena, but an integrated field for affective research
Assessment of Multipath in Aeronautical Environments
In the last years the usage of Global Navigation Satellite Systems (GNSS) systems for aviation was a quickly growing field. In this context the problem of multipath reception becomes crucial as aviation demands high accuracy navigation based upon GNSS throughout all phases of flight and in particular with strong requirements for the approach and landing phase. To address this issue, simulations have been carried out on the basis of the satellite-to-aircraft navigation channel model developed by DLR in 2003, which was approved in February 2007 as major revision to recommendation ITU 682-1. A theoretical analysis based on the ground echo statistics is also performed, resulting in an approximation of the pseudo-range error distributions. This analysis gives an insight into the nature of the multipath threat of the aeronautical channel and confirms the observations made from the simulated error distributions. 1
Robustness vs. Accuracy: Multipath Effects on Land Mobile Satellite Navigation
Knowledge of performance for different signal options
in difficult environments is vital for improving mod-
ern satellite navigation systems. Currently, the ac-
curacy of the different transmission signals in real-
istic multipath environments is still not known in
current literature. In this study different classical
and advanced signals have been simulated using an
urban multipath channel model standardized by the
International Telecommunication Union (ITU). For
the given multipath channel, signal and receiver ef-
fects have been investigated.
The performance of GPS C/A and GALILEO open
service (OS) signals in this environment has been
compared. Additional simulation of wide band navi-
gation signals lead to the uncovering of an important
conflict between robustness and accuracy in terms of
signal bandwidth. This conflict is signal inherent and
not associated to a particular receiver. As a result of
this finding an improved satellite signal extension for
robust urban navigation has been proposed.
On the receiver side pure line-of-sight conditions
have been identified in which a novel particle filter
(PF) based receiver shows a comparable performance
as a classical delay locked loop (DLL). In a mixture
of line-of-sight and shadowing conditions the particle
receiver clearly outperformed the classical DLL. For
the classical DLL critical scenarios have been identi-
fied that are often causing a loss of lock (LOL)
Technical Note on the Implementation of the Land Mobile Satellite Channel Model - Software Usage
This document contains information related to the software implementation of the Land Mobile Satellite Channel Model (LMSCM). It gives a detailed overview of the model parameters that are accessible for the user of the LMSCM and describes their effects within the artificial LMSCM scenery. Furthermore the document covers handling of the software implementation and describes model input and output variables
Conversion reactions of solids: from a surprising three-step mechanism towards directed product formation
Directed conversion reactions from binary to multinary compounds are discovered from the reaction of Bi2S3 and Bi2Se3 with NiCl2 center dot 6H(2)O in polyol media under basic conditions. Control of the synthesis conditions allows the preparation of NiBiSe and superconducting Ni3Bi2S2 and Ni3Bi2Se2. The formation of Ni3Bi2S2 from Bi2S3 is found from an unexpected three-step reaction path with Bi and NiBi as intermediates. In the more complex Ni/Bi/Se system, the mechanism found can be used to selectively direct the reaction between the competing ternaries and to suppress sideproduct formation. Contrary to solid-state reactions (500-900 degrees C) control of product formation is reached at reaction temperatures and times between 166-300 degrees C and 0.5-10 h, respectively. The formation of different phases is discussed from results of DFT calculations
Signal simulations in urban environments
This publication explores the influence of a realistic
multipath channel model to satellite navigation applications in
urban environments.
In this context we have discovered that there is a tradeoff
between accuracy and robustness concerning the bandwidth.
While narrow band signals such as GPS C/A, BOC (1,1) proved
to be robust especially under shadowing situations the wideband
signals lost lock very likely in the shadowing situation while being
more accurate in LOS situations.
In severe multipath situations we have been able to prove the
performance of the particle filter receiver wich is clearly showing
a better performance than the conventional receivers and even
than a maximum likelihood estimation DLL.
Furthermore we have identified critical situations where
receivers tend to loose lock
GNSS Signal Simulations in Urban Environments
This publication explores the influence of a realistic
multipath channel model to satellite navigation applications in
urban environments.
In this context we have discovered that there is a tradeoff
between accuracy and robustness concerning the bandwidth.
While narrow band signals such as GPS C/A, BOC (1,1) proved
to be robust especially under shadowing situations the wideband
signals lost lock very likely in the shadowing situation while being
more accurate in LOS situations.
In severe multipath situations we have been able to prove the
performance of the particle filter receiver wich is clearly showing
a better performance than the conventional receivers and even
than a maximum likelihood estimation DLL.
Furthermore we have identified critical situations where
receivers tend to loose lock
Altered physiological, affective, and functional connectivity responses to acute stress in patients with alcohol use disorder
The present study examined physiological and affective responses to stress and functional connectivity in Alcohol Use Disorder