Public Research in Regional Networks of Innovators: A Comparative Study of Four East-German Regions

Universities and public research organizations are said to be an integrative and essential element of a functioning innovation system as they play a vital role not only in the generation of new technological knowledge, but also in its diffusion. We analyse four East German local networks of innovators which differ in structure and innovative performance and investigate the characteristic role of public research within these local systems by applying methods of social network analysis. Our results show that universities and non-university institutions of public research are key actors in all regional networks of innovators both in terms of patent output and in terms of centrality of their position in the networks. Further we find the 'thicker' networks to have more central public research organizations. Higher centrality of public research compared to private actors may be due to the fact that universities are explicitly designed to give away their knowledge and that they increasingly face the need to raise external funds.Innovator Networks; Public research; R+D Cooperation; Mobility

A Finite Time Combinatorial Algorithm for Instantaneous Dynamic Equilibrium Flows

Instantaneous dynamic equilibrium (IDE) is a standard game-theoretic concept in dynamic traffic assignment in which individual flow particles myopically select en route currently shortest paths towards their destination. We analyze IDE within the Vickrey bottleneck model, where current travel times along a path consist of the physical travel times plus the sum of waiting times in all the queues along a path. Although IDE have been studied for decades, several fundamental questions regarding equilibrium computation and complexity are not well understood. In particular, all existence results and computational methods are based on fixed-point theorems and numerical discretization schemes and no exact finite time algorithm for equilibrium computation is known to date. As our main result we show that a natural extension algorithm needs only finitely many phases to converge leading to the first finite time combinatorial algorithm computing an IDE. We complement this result by several hardness results showing that computing IDE with natural properties is NP-hard.Comment: 27 pages, 11 figure

Public research in regional networks of innovators: a comparative study of four East-German regions

Universities and public research organizations are said to be integrative and essential elements of a functioning innovation system. We analyze four East German regional networks of innovators and investigate the characteristic role of public research within these networks by applying methods of social network analysis using patent data. Our results show that universities and non-university institutions of public research are key actors in all regional networks. Differences between regional innovative performance seem to be related to differences in the structural properties of the networks

Side-Constrained Dynamic Traffic Equilibria

We study dynamic traffic assignment with side-constraints. We first give a counter-example to a key result from the literature regarding the existence of dynamic equilibria for volume-constrained traffic models in the classical edge-delay model. Our counter-example shows that the feasible flow space need not be convex and it further reveals that classical infinite dimensional variational inequalities are not suited for the definition of side-constrained dynamic equilibria. We propose a new framework for side-constrained dynamic equilibria based on the concept of feasible $\varepsilon$-deviations of flow particles in space and time. Under natural assumptions, we characterize the resulting equilibria by means of quasi-variational and variational inequalities, respectively. Finally, we establish first existence results for side-constrained dynamic equilibria for the non-convex setting of volume-constraints.Comment: 57 pages, 8 figure

Deep Denoising for Hearing Aid Applications

Reduction of unwanted environmental noises is an important feature of today's hearing aids (HA), which is why noise reduction is nowadays included in almost every commercially available device. The majority of these algorithms, however, is restricted to the reduction of stationary noises. In this work, we propose a denoising approach based on a three hidden layer fully connected deep learning network that aims to predict a Wiener filtering gain with an asymmetric input context, enabling real-time applications with high constraints on signal delay. The approach is employing a hearing instrument-grade filter bank and complies with typical hearing aid demands, such as low latency and on-line processing. It can further be well integrated with other algorithms in an existing HA signal processing chain. We can show on a database of real world noise signals that our algorithm is able to outperform a state of the art baseline approach, both using objective metrics and subject tests.Comment: submitted to IWAENC 201

Dynamic Traffic Assignment for Electric Vehicles

We initiate the study of dynamic traffic assignment for electrical vehicles addressing the specific challenges such as range limitations and the possibility of battery recharge at predefined charging locations. We pose the dynamic equilibrium problem within the deterministic queueing model of Vickrey and as our main result, we establish the existence of an energy-feasible dynamic equilibrium. There are three key modeling-ingredients for obtaining this existence result: 1) We introduce a walk-based definition of dynamic traffic flows which allows for cyclic routing behavior as a result of recharging events en route. 2) We use abstract convex feasibility sets in an appropriate function space to model the energy-feasibility of used walks. 3) We introduce the concept of capacitated dynamic equilibrium walk-flows which generalize the former unrestricted dynamic equilibrium path-flows. Viewed in this framework, we show the existence of an energy-feasible dynamic equilibrium by applying an infinite dimensional variational inequality, which in turn requires a careful analysis of continuity properties of the network loading as a result of injecting flow into walks. We complement our theoretical results by a computational study in which we design a fixed-point algorithm computing energy-feasible dynamic equilibria. We apply the algorithm to standard real-world instances from the traffic assignment community illustrating the complex interplay of resulting travel times, energy consumption and prices paid at equilibrium