Optimal dynamic control of predator–prey models

Central European Journal of Operations Research - This paper combines work to use a decision support tool for sustainable economic development, while acknowledging interdependent dynamics of...     

Aluminum-enhanced sharpening of silicon nanocones

Here we report on the fabrication of high-density aligned Si nanotip arrays by chemical vapor deposition followed by dry oxidation and an etching treatment. The dry oxidation investigations indicated that Al-catalyst particles located at the tip of Si nanocones enhance their sharpening. This oxidation behavior is quite different from that of Au-catalyzed Si nanowires and is more favorable to form very sharp Si nanotips. Field emission from an individual Si nanotip showed good field-emission characteristic with a high emission current density of 1×10⁴ A/cm² because of its sharp tip geography, suggesting their potential application for field emitters. Our work provides an effective approach to fabricate high-density Si nanotip arrays, which overcomes some problems in the conventional fabrication approaches, such as high cost, poor controllability, and complicated process.     

Educational effects in an experiment with the management game SINTO-Market

This paper examines how the educational background influences the performance of managers’ strategies. The research is based on data collected by an experiment with the management game SINTO-Market. This management game puts the players in a competitive situation in the branded food product sector, within which the subjects take over the role of the managers who have to find out the most successful strategy. From experimental research with this management game we will draw some interesting conclusions about human behavior in complex economic decision-making situations. To investigate educational effects the management game SINTO-Market was performed with students of different educational levels 17 times. The results show some significant differences between graduates and undergraduates.     

Heuristic modeling of expectation formation in a complex experimental information environment

Academic subjects made judgmental forecasts of a graphically presented time series in a laboratory experiment. Besides the past realizations of the time series itself, the only available information for the forecasting task was provided by leading series, i.e. indicators with a constant lead period of one. The number and the quality of the leading series were varied systematically between seven versions of the experiment resulting in different levels of information complexity. We present a heuristic that explains the subjects’ average forecasting behavior better than the rational expectations hypothesis in all versions of the experiment. Furthermore, we find that the forecasting accuracy of the subjects increases with the number of reliable indicators but their efficiency declines with increasing complexity.     

Correcting lateral photon scattering in an InSb infrared detector

Both luminescence and lock‐in thermography imaging, which are also evaluated quantitatively, are valuable methods for characterizing solar cells. For luminescence imaging of silicon solar cells it was recently discovered that photon scattering in the detector of the used camera leads to a certain amount of blurring, which may be corrected by image deconvolution for enabling a correct quantitative image interpretation. In this work the same effect is investigated for an infrared camera employing a cooled InSb‐based quantum detector. It is found that also here the photon scattering effect exists, though its influence is weaker than for luminescence imaging.     

The role of stacking faults for the formation of shunts during potential‐induced degradation of crystalline Si solar cells

Mono‐ and multicrystalline solar cells have been stressed by potential‐induced degradation (PID). Cell pieces with PID‐shunts are imaged by SEM using the EBIC technique in plan view as well as after FIB cross‐section preparation. A linear shaped signature is found in plan‐view EBIC images at every potential‐induced shunt position on both mono‐ and multicrystalline solar cells. Cross‐sectional SEM and TEM images reveal stacking faults in a {111} plane. Combined TEM/EDX measurements show that the stacking faults are strongly decorated with sodium. Thus, the electric conductivity of stacking faults is assumed to arise under the influence of sodium ion movement through a high electric field across the SiN_x anti‐reflective layer, resulting in PID. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)