24 research outputs found
Theoretical Investigation of Carrier-selective Contacts Featuring Tunnel Oxides by Means of Numerical Device Simulation
AbstractRecently, a variety of different n-type Si solar cells with carrier-selective contacts featuring tunnel oxides achieving remarkable cell results has been presented. Theoretical investigations on this topic are rare, especially simulations actually accounting for tunneling through the oxide interlayer. In this work we investigate the influence of different parameters affecting the passivation quality and thus the device performance by means of numerical device simulation. Thereby, a fundamental understanding of solar cells with carrier-selective contacts featuring tunnel oxides is generated which is essential to further develop this promising technology
Study of the Potts Model on the Honeycomb and Triangular Lattices: Low-Temperature Series and Partition Function Zeros
We present and analyze low-temperature series and complex-temperature
partition function zeros for the -state Potts model with on the
honeycomb lattice and on the triangular lattice. A discussion is given
as to how the locations of the singularities obtained from the series analysis
correlate with the complex-temperature phase boundary. Extending our earlier
work, we include a similar discussion for the Potts model with on the
honeycomb lattice and with on the kagom\'e lattice.Comment: 33 pages, Latex, 9 encapsulated postscript figures, J. Phys. A, in
pres
Die Deutung des Unbewegten Bewegenden im Lichte biologischer Phänomene.
Zu Aristoteles gibt es eine große Anzahl von Interpretationen. Sie beziehen sich meist auf einzelne Werke: Physik, Ethik oder noch kleinere Einheiten. Es gibt selbstverständlich auch Interpretationen zur Metaphysik und zur Biologie wie es auch heute nichts ungewöhnliches mehr ist, Biologie und Metaphysik, insbesondere die Eidoslehre, in Beziehung zu setzen. Meiner Kenntnis nach gibt es mehrere Autoren, die eine Verbindung von Biologie und Unbewegtem Bewegenden gezogen haben: J. M. Le Blond, H. v. Arnim, Klaus Oehler und Anthony Preus. Aus sprachlichen Gründen ist der Autor bei Le Blond auf eine indirekte Kenntnis aus den Bemerkungen anderer Autoren angewiesen. Er scheint sich aber primär auf die Argumentationsmethode zu beziehen, die er in der Physik als "technisch", in der Metaphysik als "biologisch" bezeichnet. Abgesehen davon, daß eine solche Trennung bei Aristoteles unangemessen ist, weil er seine Technikvorstellung aus der Medizin und an biologischen Beispielen entwickelt, ist die hier vertretene Ansicht weitreichender: Sie behauptet einen genetischen und inhaltlichen Zusammenhang. Genetisch ist dieser Zusammenhang insofern, als die Konstruktion des Unbewegten Bewegenden durch die biologischen Erkenntnisse bewirkt wurde, die er während seiner Wanderjahre gewonnen hat, insbesondere die Zurückführung der Selbstbewegung der Tiere auf interne und externe Vorgänge, womit auch die Selbstbewegung des ersten Himmels fällt. Inhaltlich wird hier ein Zusammenhang vertreten, der darin besteht, daß das Unbewegte Bewegende als absolute Negentropie die Existenz der bewegten Welt und damit besonders der belebten, biologischen Welt gewährleistet
Exoskeletons: Productivity and ergonomics in logistics:a systematic review
Purpose: Exoskeletons are robotic wearables that have the potential to positively support employees during physical working operations. However, the technology is rather young, and long-term studies that could positively influence exoskeletons with respect to health, productivity, and ROI (and thereby support investment in it) are lacking. Accordingly, logistics companies are cautious about investing in exoskeletons. This paper identifies the research gaps that should be addressed in further research to change this situation. Methodology: Based on an extensive literature review following the systematic approach of vom Brocke et al. (2009), this paper surveys current research regarding the impact of exoskeletons in intralogistics with respect to productivity and health. Findings: Since exoskeletons in industrial contexts have been used mainly in pilot trials so far, few findings from long-term studies are available. Accordingly, the sustainable positive influence of exoskeletons on productivity and health cannot be empirically proved. Originality: This paper identifies research gaps for a novel technology that could transform a sector which is characterized by a high proportion of manual labor, a high age average, a shortage of skilled workers, and beside increasing complexity
Computing Approximate Nash Equilibria in Network Congestion Games
We consider the problem of computing ε-approximate Nash equilibria in network congestion games. The general problem is known to be PLS-complete for every ε> 0, but the reductions are based on artificial and steep delay functions with the property that already two players using the same resource cause a delay that is significantly larger than the delay for a single player. We consider network congestion games with delay functions such as polynomials, exponential functions, and functions from queuing theory. We analyse which approximation guarantees can be achieved for such congestion games by the method of randomised rounding. Our results show that the success of this method depends on different criteria depending on the class of functions considered. For example, queuing theoretical functions admit good approximations if the equilibrium load of every resource is bounded away appropriately from its capacity