Information transfer by vector spin chirality in finite magnetic chains

Vector spin chirality is one of the fundamental characteristics of complex magnets. For a one-dimensional spin-spiral state it can be interpreted as the handedness, or rotational sense of the spiral. Here, using spin-polarized scanning tunneling microscopy, we demonstrate the occurrence of an atomic-scale spin-spiral in finite individual bi-atomic Fe chains on the (5x1)-Ir(001) surface. We show that the broken inversion symmetry at the surface promotes one direction of the vector spin chirality, leading to a unique rotational sense of the spiral in all chains. Correspondingly, changes in the spin direction of one chain end can be probed tens of nanometers away, suggesting a new way of transmitting information about the state of magnetic objects on the nanoscale.Comment: accepted by Physical Review Letter

WEB SURVEY GAMIFICATION – INCREASING DATA QUALITY IN WEB SURVEYS BY USING GAME DESIGN ELEMENTS

Researchers and survey designers face the challenge of low data quality as web surveys are often not compelling. Thus, participants’ engagement declines while completing a survey resulting in participants tend to apply satisficing behavior (e.g., speeding, straight-lining) in order to complete the questionnaire or even break-off the completion of the questionnaire. Due to satisficing behavior, researchers are faced with the challenge of low data quality. Addressing this challenge, survey gamification promises to make web survey participation enjoyable, which might also engage participants to complete questionnaires by providing high-quality data. However, the research on the effects of gamifying web surveys (in particular on behavioral outcomes) is still inconclusive. Addressing this short-coming, we propose to examine the effects of two common game design elements – badges and a meaningful story – in an experimental study. Based on the theoretical background of gamification and the theory of cognitive absorption, we derive hypotheses and outline in detail our experimental design in this research-in-progress paper. Our proposed research study will contribute to research and practice by addressing an important challenge when conducting online surveys: the motivation to process surveys accurately

On a Fast Analytical Approximation of Natural Frequencies for Photovoltaic Modules

In this paper, an eigenvalue problem is considered, i.e., the free vibration of photovoltaic (PV) modules. This structure was selected for its peculiar layer contrast, which forms an anti-sandwich. The aim was to present an analytical procedure for obtaining the natural frequencies of the PV modules over a range of temperatures. To this end, the layered structure was homogenised into an equivalent single layer for which a closed-form solution is presented using the shear-rigid plate theory. Moreover, the finite element method was applied to simulate the behaviour of the discrete layers in terms of mesh sensitivity. By examining the findings and some benchmark values, it was found that the analytical procedure could provide a range for the results. More specifically, the Reuss-Voigt range covers the possible values for the natural frequencies in the examined temperature range. Moreover, the analytical method can predict the natural frequencies with a good accurracy in the temperature range of -40 to 15 C. In contrast, the computational analysis seemed to provide very good results in return for a modest computational effort. In conclusion, the provided analytical procedure could quickly determine the natural frequecies with a good accuracy in the mentioned range

Grounding the Simulation of Iconic Gestures in Gesture Typology

Bergmann K, Kopp S, Rieser H. Grounding the Simulation of Iconic Gestures in Gesture Typology. In: Efthimiou E, Kouroupetroglou G, eds. Proceedings of the 9th International Gesture Workshop: Gestures in Embodied Communication and Human-Computer Interaction. Berlin/Heidelberg, Germany: Springer; 2011: 33-36