On the Empirical Saddlepoint Approximation with Application to Asset Pricing

Presentation (2018, November 06)

FAST: A MapReduce Consensus for High Performance Blockchains

in ACM BlockSys'18 Proceedings of the 1st Workshop on Blockchain-enabled Networked Sensor Systems (2018, November 04)

Blockchain platforms when used as a database for IoT systems can resolve data reliability fault-tolerance, consistency and non-repudiation issues. However, their inherent shortcomings related to their ... [more ▼]

Blockchain platforms when used as a database for IoT systems can resolve data reliability fault-tolerance, consistency and non-repudiation issues. However, their inherent shortcomings related to their throughput in terms of processed transactions, limit their applicability in such environments in a decentralized way as the underlying network is unable to sustain high workloads. In this paper a fully decentralized high performance consensus mechanism, named FAST, is proposed for a public blockchain. FAST is based on mapreduce paradigm for aggregating and adding transactions on blockchain blocks. FAST was implemented and evaluated in a basic blockchain prototype. A light client for FAST using IPFS, was developed to bring about a reduction in the data stored locally. The obtained results from tests conducted on the prototype depict that FAST exceeds the performance of not just other existing blockchain platforms but comes very close to the throughput of traditional electronic payment networks such as Visa. [less ▲]

It's not only the game, it's also the player: The role of player personality in violent video game preference

Scientific Conference (2018, November 03)

In contrast to the effects of game content, violent video games have less been researched with regard to players' preferences for these games, and whether these preferences are related to certain ... [more ▼]

In contrast to the effects of game content, violent video games have less been researched with regard to players' preferences for these games, and whether these preferences are related to certain personality characteristics. Using a novel brief and uni-dimensional self-report measure, the present research examined the role of personality factors and preferences for violent video games. A scale of five items was administrated in two studies that involved 292 and 180 respondents, respectively. The same scale with two additional items was presented to 190 respondents in the third study, which included measures revealed by prior research to be relevant for understanding violent video game motivation and preference. More specifically, we measured participants' trait aggression, the Dark Triad traits of psychopathy, Machiavellianism, and narcissism. To test for the scale's discriminant validity, trait empathy was also included. In line with other findings in the literature (e.g., Greitemeyer, 2015), results obtained with the self-report measure indicated that players with a propensity for games featuring violent themes show callous, impulsive and exploitative attributes, whereas narcissism was not a significant predictor. However, and as already suggested by some authors (Hartmann, Möller, & Krause, 2014), a lack of empathy was found to predict violent game preferences. The present findings are important with regard to future research on video games that should focus more on the players and their gaming motivation than on the effects of playing alone. [less ▲]

Visualizing the Learning Progress of Self-Driving Cars

in 21st International Conference on Intelligent Transportation Systems (2018, November 02)

Using Deep Learning to predict lateral and longitudinal vehicle control, i.e. steering, acceleration and braking, is becoming increasingly popular. However, it remains widely unknown why those models ... [more ▼]

Using Deep Learning to predict lateral and longitudinal vehicle control, i.e. steering, acceleration and braking, is becoming increasingly popular. However, it remains widely unknown why those models perform so well. In order for them to become a commercially viable solution, it first needs to be understood why a certain behavior is triggered and how and what those networks learn from human-generated driving data to ensure safety. One research direction is to visualize what the network sees by highlighting regions of an image that influence the outcome of the model. In this vein, we propose a generic visualization method using Attention Heatmaps (AHs) to highlight what a given Convolutional Neural Network (CNN) learns over time. To do so, we rely on a novel occlusion technique to mask different regions of an input image to observe the effect on a predicted steering signal. We then gradually increase the amount of training data and study the effect on the resulting Attention Heatmaps, both in terms of visual focus and temporal behavior. [less ▲]

Competition and Workplace Bullying. The moderating role of passive avoidant leadership style.

Scientific Conference (2018, November 02)

The aim of the study was to test if competition is a potential risk factor for the occurrence of workplace bullying and if this association depends on the level of passive avoidant leadership style. We ... [more ▼]

The aim of the study was to test if competition is a potential risk factor for the occurrence of workplace bullying and if this association depends on the level of passive avoidant leadership style. We proposed that competition and passive avoidant leadership style are positive related to workplace bullying exposure and perpetration. Furthermore, we hypothesized that the effect of competition on workplace bullying exposure and perpetration is moderated through passive avoidant leadership style. An online survey design was employed and data were collected among U.S. employees. The final sample consists of 1,408 respondents. Workplace bullying exposure and perpetration were cross-sectionally assessed via self-labeling and behavioral experience method. Hierarchical regression analyses showed that competition and passive avoidant leadership style are important predictors for workplace bullying exposure and perpetration. Furthermore, the results indicated that the effect of competition on workplace bullying exposure (measured via behavioral method) and self-labeled workplace bullying exposure and perpetration is moderated through passive avoidant leadership style. However, for workplace bullying perpetration (measured via behavioral method) no moderation effect was found. The findings underline the importance of the supervisor’s behavior in the occurrence of workplace bullying. Organizations may decrease workplace bullying incidents by training their supervisors to apply a more constructive leadership style. [less ▲]

Guter wân und Wahnsinn der Liebe – Vom Motiv des klassischen Minnesangs zur spätmittelalterlichen Schelte des Liebesnarren

Speeches/Talks (2018)

A survey: The usage of Augmented Reality in Industry

in Robotix-Academy Conference for Industrial Robotics 2018 (2018, November 01)

Human-Robot-Interaction technologies in industry 4.0 and modern manufacturing are more and more growing. Using off-line robot programming methods such as Augmented Reality (AR) could gain time and money ... [more ▼]

Human-Robot-Interaction technologies in industry 4.0 and modern manufacturing are more and more growing. Using off-line robot programming methods such as Augmented Reality (AR) could gain time and money as well as improve programming and repair tasks. This paper is a study of the use of AR in smart factories. [less ▲]

The Reflection of Data-Driven Value Creation in the 2018 OECD and EU Proposals

in EC Tax Review (2018), 27(6), 325-334

Is the current corporate tax system fit for the digitalized economy? The 2018 interim report of the OECD and the proposals of the European Commission on the introduction of significant digital presence ... [more ▼]

Is the current corporate tax system fit for the digitalized economy? The 2018 interim report of the OECD and the proposals of the European Commission on the introduction of significant digital presence and a digital services tax give new insights into policymakers’ perception of ‘value creation’ and income generation in digitalized business models. Although the right way to tax digitalized business models seems disputed with regard to the diverging outcomes of the OECD’s and European Commission’s work so far, it seems to be of common understanding that user data are susceptible of establishing a taxable nexus. In a first step, this article aims at analysing how the collection and processing of user data may create such genuine link between an income generating activity and a state territory enabling this state to exercise its taxing right. In that respect, the concept of value creation, a driving concept in the discussion on how to tax digitalized businesses, is critically reviewed and an attempt to understand its real meaning is presented. In a second step, the article analyses to which extent the long- and short-term proposals of the European Commission reflect such data-driven (taxable) value creation, critically highlighting their main characteristics and flaws. [less ▲]

Evidence for the homothetic scaling of urban forms

in Environment and Planning B: Urban Analytics and City Science (2018)

The size and form of cities influence their social and environmental impacts. Whether cities have the same form irrespective of their size is still an open question. We analyse the profile of artificial ... [more ▼]

The size and form of cities influence their social and environmental impacts. Whether cities have the same form irrespective of their size is still an open question. We analyse the profile of artificial land and population density, with respect to the distance to their main centre, for the 300 largest European cities. Our analysis combines the GMES/Copernicus Urban Atlas 2006 land use database at 5 m resolution for 300 larger urban zones with more than 100,000 inhabitants and the Geostat population grid at 1 km resolution. We find a remarkable constancy of radial profiles across city sizes. Artificial land profiles scale in the two horizontal dimensions with the square root of city population, while population density profiles scale in three dimensions with its cube root. In short, cities of different size are homothetic in terms of land use and population density, which challenges the idea that larger cities are more parsimonious in the use of land per capita. While earlier literature documented the scaling of average densities (total surface and population) with city size, we document the scaling of the whole radial distance profile with city size, thus liaising intra-urban radial analysis and systems of cities. Our findings also yield homogenous spatial definitions of cities, from which we can re-question urban scaling laws and Zipf’s law for cities. [less ▲]

Systemic network analysis identifies XIAP and IkappaBalpha as potential drug targets in TRAIL resistant BRAF mutated melanoma.

in NPJ systems biology and applications (2018), 4

Metastatic melanoma remains a life-threatening disease because most tumors develop resistance to targeted kinase inhibitors thereby regaining tumorigenic capacity. We show the 2nd generation hexavalent ... [more ▼]

Metastatic melanoma remains a life-threatening disease because most tumors develop resistance to targeted kinase inhibitors thereby regaining tumorigenic capacity. We show the 2nd generation hexavalent TRAIL receptor-targeted agonist IZI1551 to induce pronounced apoptotic cell death in mutBRAF melanoma cells. Aiming to identify molecular changes that may confer IZI1551 resistance we combined Dynamic Bayesian Network modelling with a sophisticated regularization strategy resulting in sparse and context-sensitive networks and show the performance of this strategy in the detection of cell line-specific deregulations of a signalling network. Comparing IZI1551-sensitive to IZI1551-resistant melanoma cells the model accurately and correctly predicted activation of NFkappaB in concert with upregulation of the anti-apoptotic protein XIAP as the key mediator of IZI1551 resistance. Thus, the incorporation of multiple regularization functions in logical network optimization may provide a promising avenue to assess the effects of drug combinations and to identify responders to selected combination therapies. [less ▲]