Johannes Kepler University of Linz

About: Johannes Kepler University of Linz is a education organization based out in Linz, Oberösterreich, Austria. It is known for research contribution in the topics: Computer science & Thin film. The organization has 6605 authors who have published 19243 publications receiving 385667 citations.

Tax Morale and Compliance Behavior: First Evidence on a Causal Link

Abstract: Recent literature on tax evasion emphasizes the importance of moral considerations to explain compliance behavior. As a consequence scholars aim to identify factors that shape this so-called tax morale. However, the causal link between tax morale and actual compliance behavior is not established yet. Exploiting exogenous variation in tax morale - given by the inherited part of tax morale of American-born from their ancestors' country of origin - our instrumental variable analysis provides first evidence on a causal effect of tax morale on the size of the underground production.

Low Driving Voltage and High Mobility Ambipolar Field-Effect Transistors with PbS Colloidal Nanocrystals

Abstract: PbS colloidal nanocrystals (NCs) are promising materials for optoelectronic devices, due to their size-tunable properties. However, there is still minimal understanding of their charge transport mechanism. Through a combination of ligand selections, ambipolar transistor structure optimization, and electrochemical gating usage, high carrier mobility is achieved. The outstanding device characteristics open possibility to investigate the intrinsic transport properties of PbS NCs.

RUDDER: Return Decomposition for Delayed Rewards

Abstract: We propose RUDDER, a novel reinforcement learning approach for delayed rewards in finite Markov decision processes (MDPs). In MDPs the Q-values are equal to the expected immediate reward plus the expected future rewards. The latter are related to bias problems in temporal difference (TD) learning and to high variance problems in Monte Carlo (MC) learning. Both problems are even more severe when rewards are delayed. RUDDER aims at making the expected future rewards zero, which simplifies Q-value estimation to computing the mean of the immediate reward. We propose the following two new concepts to push the expected future rewards toward zero. (i) Reward redistribution that leads to return-equivalent decision processes with the same optimal policies and, when optimal, zero expected future rewards. (ii) Return decomposition via contribution analysis which transforms the reinforcement learning task into a regression task at which deep learning excels. On artificial tasks with delayed rewards, RUDDER is significantly faster than MC and exponentially faster than Monte Carlo Tree Search (MCTS), TD(λ), and reward shaping approaches. At Atari games, RUDDER on top of a Proximal Policy Optimization (PPO) baseline improves the scores, which is most prominent at games with delayed rewards.

Semiconductor quantum dots as an ideal source of polarization-entangled photon pairs on-demand: a review

Abstract: More than 80 years passed since the first publication on entangled quantum states. In this period of time the concept of spookily interacting quantum states became an emerging field of science. After various experiments proving the existence of such non-classical states, visionary ideas were put forward to exploit entanglement in quantum information science and technology. These novel concepts have not yet come out of the experimental stage, mostly because of the lack of suitable, deterministic sources of entangled quantum states. Among many systems under investigation, semiconductor quantum dots are particularly appealing emitters of on-demand, single polarization-entangled photon-pairs. Although, it was originally believed that quantum dots must exhibit a limited degree of entanglement related to numerous decoherence effects present in the solid-state. Recent studies invalidated the premise of unavoidable entanglement degrading effects. We review the relevant experiments which have led to these important discoveries and discuss the remaining challenges for the anticipated quantum technologies.

The 2010 Eurobarometer on the life sciences

Abstract: Since 1991, the triennial Eurobarometer survey has assessed public attitudes about biotech and the life sciences in Europe. The latest 2010 Eurobarometer survey on the Life Sciences and Biotechnology (http://ec.europa.eu/research/science-society/document_library/pdf_06/europeans-biotechnology-in-2010_en.pdf), based on representative samples from 32 European countries, hints at a new era in the relations between science and society. We see less criticism of technology based on distrust in government and industry; more enthusiasm for novel technologies; and a more sophisticated appraisal of what technologies offer in terms of benefits, safety and sustainability. Europeans want regulation in the public interest and want a voice in such regulation when social values are at stake; we highlight an emerging European landscape of social value differences that shape people's views of technologies.