1,803 research outputs found
Effects of angular shift transformations between movements and their visual feedback on coordination in unimanual circling
Tool actions are characterized by a transformation between movements and their resulting consequences in the environment. This transformation has to be taken into account when tool actions are planned and executed. We investigated how angular shift transformations between circling movements and their visual feedback affect the coordination of this feedback with visual events in the environment. We used a task that required participants to coordinate the visual feedback of a circular hand movement (presented on the right side of a screen) with a circling stimulus (presented on the left side of a screen). Four stimulus-visual feedback relations were instructed: same or different rotations of stimulus and visual feedback, either in same or different y-directions. Visual speed was varied in three levels (0.8, 1, and 1.2 Hz). The movement-visual feedback relation was manipulated using eight angular shifts: (-180, -135, -90, -45, 0, 45, 90, and 135°). Participants were not able to perform the different rotation/different y-direction pattern, but instead fell into the different rotation/same y-direction pattern. The different rotation/same y-direction pattern and the same rotation/same y-direction pattern were performed equally well, performance was worse in the same rotation/different y-direction pattern. Best performance was observed with angular shifts 0 and -45° and performance declined with larger angular shifts. Further, performance was better with negative angular shifts than with positive angular shifts. Participants did not fully take the angular shift transformation into account: when the angular shifts were negative the visual feedback was more in advance, and when angular shifts were positive the visual feedback was less in advance of the stimulus than in 0° angular shift. In conclusion, the presence and the magnitude of angular shift transformations affect performance. Internal models do not fully take the shift transformation into account
Composting of domestic refuse and sewage sludge. I. Evolution of temperature, pH, C/N ratio and cation-exchange capacity
Peer reviewe
ERP Effects Prior to Performance Errors in Musicians Indicate Fast Monitoring Processes
Background One central question in the context of motor control and action
monitoring is at what point in time errors can be detected. Previous
electrophysiological studies investigating this issue focused on brain
potentials elicited after erroneous responses, mainly in simple speeded
response tasks. In the present study, we investigated brain potentials before
the commission of errors in a natural and complex situation.
Methodology/Principal Findings Expert pianists bimanually played scales and
patterns while the electroencephalogram (EEG) was recorded. Event-related
potentials (ERPs) were computed for correct and incorrect performances.
Results revealed differences already 100 ms prior to the onset of a note
(i.e., prior to auditory feedback). We further observed that erroneous
keystrokes were delayed in time and pressed more slowly. Conclusions Our data
reveal neural mechanisms in musicians that are able to detect errors prior to
the execution of erroneous movements. The underlying mechanism probably relies
on predictive control processes that compare the predicted outcome of an
action with the action goal
Mental Accounting bei selbstständigen Steuerzahlern
Dieser Arbeit hatte zum Ziel das psychologische Konstrukt Mental Accounting bei steuerzahlenden Selbstständigen nachzuweisen und deren Einstellungen zum Steuerzahlen zu erheben, wobei der Fokus bei dieser Untersuchung auf der Einkommensteuer lag.
Dass Selbstständige ihre Steuern selbst deklarieren und diese auch eigenständig von ihren gesamten Einnahmen abliefern müssen, kann ein Verlustgefühl implizieren. Allerdings tritt dieser Verlust nur dann in Kraft, wenn das Bruttoeinkommen, angelehnt an die Prospect Theory von Kahneman und Tversky (1979), den Referenzpunkt darstellt, und die Steuerabgaben zu einem Verlust führen. Demzufolge kann durch eine Steuerhinterziehung dieser scheinbare Verlust ausgeglichen werden. Wenn jedoch die steuerlichen Einnahmen mental in ein separates Konto, im Sinne des Mental Accounting von Thaler (1990), gebucht werden, beschreibt der Referenzpunkt das Nettoeinkommen, und die Versuchung, Steuern zu hinterziehen, wird minimiert oder ist erst gar nicht gegeben. Folglich könnten Informationen über die Anwendung von Mental Accounting bei Selbstständigen einen wesentlichen Beitrag für das Steuerverhalten liefern.
Bisherige empirische Studien beschränkten sich auf den englischsprachigen Raum und bezogen sich ausschließlich auf die Umsatzsteuer. In der hier vorliegenden Studie wird zum ersten Mal versucht durch qualitative Interviews die wissenschaftliche Lücke über den Berufstypus der Selbstständigen im Rahmen des Mental Accountings zu füllen. Das Augenmerk liegt dabei in erster Linie auf den Nachweis einer mentalen Buchführung (Mental Accounting) und in zweiter Linie auf der Eruierung der Einstellung zum Steuerzahlen. Der Fokus konzentriert sich im Vergleich zu bisherigen Untersuchungen auf die Einkommensteuer.
Mittels qualitativer Methodik wurden 30 Selbstständige interviewt, wobei die Berufssparten der Immobilienmakler und Grafiker zwei Schwerpunkte darstellten. Die Befragung beinhaltete neben dem Interview, welches mittels eines Interviewleitfadens durchgeführt wurde, auch einen Fragebogen, der einige Items der Motivational Postures beinhaltete. Während der Fragebogen statistischen ausgewertet wurde, kamen bei den Interviews, nach der Transkription, die qualitative Inhaltsanalyse nach Mayring (2008) zum Einsatz.
Die Ergebnisse zeigen, dass das psychologische Konstrukt Mental Accounting bei Selbstständigen angewendet werden kann, um – im Sinne der kognitiven Psychologie – die Gedankengänge selbstständiger Steuerzahler besser zu verstehen. In Bezug zu der Einstellung zum Steuerzahlen konnten keine Unterschiede zwischen jenen, die die Einkommensteuer mental in einem separaten Konto führten (Segregierer), und jenen, die dies nicht taten (Integrierer), festgestellt werden. Die Untersuchungsergebnisse der Arbeit geben Anlass zu weiteren Folgestudien, in denen das Steuerverhalten der Selbstständigen sowie deren Einstellungen zum Thema Steuern genauer untersucht und die Auswirkungen genau analysiert werden sollten. Lassen sich die vorliegenden Ergebnisse in nachfolgenden Studien replizieren, so könnte dies für die Praxis verschiedene Konsequenzen bedeuten. Zum Beispiel könnte versucht werden, durch gezieltes Marketing des Finanzministeriums oder in Vorbereitungskursen für angehende Selbstständige, die mentale Buchhaltung der Steuerzahler positiv zu beeinflussen
Action-sentence compatibility: the role of action effects and timing
Research on embodied approaches to language comprehension suggests that we understand linguistic descriptions of actions by mentally simulating these actions. Evidence is provided by the action-sentence compatibility effect (ACE) which shows that sensibility judgments for sentences are faster when the direction of the described action matches the response direction. In two experiments, we investigated whether the ACE relies on actions or on intended action effects. Participants gave sensibility judgments of auditorily presented sentences by producing an action effect on a screen at a location near the body or far from the body. These action effects were achieved by pressing a response button that was located in either the same spatial direction as the action effect, or in the opposite direction. We used a go/no-go task in which the direction of the to-be-produced action effect was either cued at the onset of each sentence (Experiment 1) or at different points in time before and after sentence onset (Experiment 2). Overall, results showed a relationship between the direction of the described action and the direction of the action effect. Furthermore, Experiment 2 indicated that depending on the timing between cue presentation and sentence onset, participants responded either faster when the direction of the described action matched the direction of the action effect (positive ACE), or slower (negative ACE). These results provide evidence that the comprehension of action sentences involves the activation of representations of action effects. Concurrently activated representations in sentence comprehension and action planning can lead to both priming and interference, which is discussed in the context of the theory of event coding
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Process-based modelling of the impacts of land use change on the water balance in the Cerrado biome (Rio das Mortes, Brazil)
Since the 1980s, the state of Mato Grosso, Brazil, exhibits high rates of Cerrado conversion in favour of soybean expansion and cattle ranching. This conversion process becomes obvious in the upper Rio das Mortes macro-catchment. The objective of this study was to assess the influence of future land use changes on the discharge dynamics of the Rio das Mortes River. A single catchment approach was applied with the physically-based water balance simulation model WaSiM 8.5.0 (Schulla and jaSper 2007) to simulate land use scenarios. In Scenario 1, only small pasture sites (< 1 km²) were converted into the respective land use type surrounding them (i.e. cropland or Cerrado vegetation), whereas in Scenario 2 all pasture sites were converted into cropland and all Cerrado patches were then transformed into pastures. The WaSiM model was calibrated and validated based on discharge data measured at two gauging stations, achieving Nash-Sutcliffe coeffcients of 0.81 calibration) and 0.68 (validation). Main problems in modelling arise because of scarce spatial distributed data on subsurface parameter and vegetation parameter (Cerrado biome). Therefore, the use of the numerical groundwater model and manifold calibration runs were essential in this modelling approach to allow the simulation of the high levels of baseflow during the dry season and the transition from the dry to the wet season. The immediate rise of the baseflow in response to the increasing precipitation at beginning of the rainy season is a result of high soil hydraulic conductivity and groundwater recharge. These soil characteristics apparently persist on newly-created pasture and cropland sites, which still exhibit high ksat values after deforestation. Simulated evapotranspiration is comparable to literature values (Eddy flux measurements, MODIS-EVI calculation) and recently done paired micro-catchment studies in this catchment. The scenario analysis indicates that there are only small differences in runoff
volume, which is directly related to the precipitation changes. In the scenario 2, groundwater recharge and base flow increase, whereas surface runoff does not. Therefore, the ongoing land use intensification with pasture conversion to cropland, remaining high infiltration and slight increase of evapotranspiration may not change runoff volume and discharge characteristics
Highly Localized RBF Lagrange Functions for Finite Difference Methods on Spheres
The aim of this paper is to show how rapidly decaying RBF Lagrange functions
on the spheres can be used to create effective, stable finite difference
methods based on radial basis functions (RBF-FD). For certain classes of PDEs
this approach leads to precise convergence estimates for stencils which grow
moderately with increasing discretization fineness
Blood Product Supply on Germany: The Impact of Apheresis and Pooled Platelet Concentrates
Background: In Germany, about 60% of all produced platelet concentrates (PCs) are apheresis PCs (APCs). Ongoing discussions on APC reimbursement and costs might lead to a potential shift in pooled PC (PPC)/APC production. Objective of this analysis was to build a comprehensive model from the societal perspective to evaluate consequences associated with shifts in platelet supply and demand. Methods: Literature search, desktop researches on platelet supply and demand. Model calculations, time horizon one year: model input from the Paul Ehrlich -Institute, data 2013. Base case: 19.2% of annual whole blood donations (WBDs) were used for production of 38.5% PPCs, decay of 46,218 PCs (8.0%). Scenarios calculated: variation in PPC proportion of 10-100%. Results: Base case: during PPC production 41,957-83,913 red blood cell concentrates (RBCCs) are estimated to be lost, which corresponds to 1-2% of annual RBCCs in Germany. Scenarios were calculated for a production of 60-100% PPCs: loss is estimated to be 1.5-5.0% of annual RBCCs (65,430-218,099), decay 54,189-69,022 PCs (9.4-12.0%). Conclusion: Production of different blood components is interlinked and sensitive to unidimensional decisions. Increasing PPC proportion has negative impact on the RBCC production and on the antigen-matched APC donor pool. Completion of the model calculations to predict the optimal PPC/APC proportion would require evidence on the number of refractory patients, donor pool sizes, and incidences of diseases requiring platelet transfusions. (C) 2016 S. Karger GmbH, Freibur
One rate does not fit all: An empirical analysis of electricity tariffs for residential microgrids
Increasingly, residential customers are deploying PV units to lower electricity bills and contribute to a more sustainable use of resources. This selective decentralization of power generation, however, creates significant challenges, because current transmission and distribution grids were designed for centralized power generation and unidirectional flows. Restructuring residential neighborhoods as residential microgrids might solve these problems to an extent, but energy retailers and system operators have yet to identify ways of fitting residential microgrids into the energy value chain. One promising way of doing so is the tailoring of residential microgrid tariffs, as this encourages grid-stabilizing behavior and fairly re-distributes the associated costs. We thus identify a set of twelve tariff candidates and estimate their probable effects on energy bills as well as load and generation profiles. Specifically, we model 100 residential microgrids and simulate how these microgrids might respond to each of the twelve tariffs. Our analyses reveal three important insights. Number one: volumetric tariffs would not only inflate electricity bills but also encourage sharp load and generation peaks, while failing to reliably allocate system costs. Number two: under tariffs with capacity charges, time-varying rates would have little impact on both electricity bills and load and generation peaks. Number three: tariffs that bill system and energy retailer costs via capacity and customer charges respectively would lower electricity bills, foster peak shaving, and facilitate stable cost allocation
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