Matching with Waiting Times: The German Entry-Level Labour Market for Lawyers

We study the allocation of German lawyers to different regional courts for their compulsory legal traineeship. The number of applicants exceeds the number of available positions in a given time period in some regions, so that not all lawyers can be matched simultaneously. As a consequence some lawyers have to wait before they obtain a position. First, we analyse the currently used Berlin mechanism and demonstrate that it is unfair and that it does not respect improvements. Second, we introduce a matching with contracts model, using waiting time as the contractual term, for which we suggest an appropriate choice function for the courts that respects the capacity constraints of each court for each period. Despite the failure of the unilateral substitutes condition, under a weak assumption on lawyers preferences, a lawyer-optimal stable allocation exists. Using existing results, we can show that the resulting mechanism is strategy-proof, fair and respects improvements. Third, we extend our proposed mechanism to allow for a more flexible allocation of positions over time

On the origin of extrusion instabilities: Linear stability analysis of the viscoelastic die swell

It is well-known that, increasing the flow rate in polymer extrusion, the flow becomes unstable and the smooth extrudate surface becomes wavy and disordered to an increasing degree. In order to investigate the mechanisms responsible for these instabilities we perform a linear stability analysis of the steady extrusion of a viscoelastic fluid flowing through a planar die under creeping flow conditions. We consider the Phan-Thien-Tanner (PTT) model to account for the viscoelasticity of the material. We employ the mixed finite element method combined with an elliptic grid generator to account for the deformable shape of the interface. The generalized eigenvalue problem is solved using Arnoldi’s algorithm. We perform a thorough parametric study in order to determine the effects of all material properties and rheological parameters. We investigate in detail the effect of the interfacial tension and the presence of a deformable interface. It is found that the presence of a finite surface tension destabilizes the flow as compared to the case of the stick-slip flow. We recognize two modes, which become unstable beyond a critical value of the Weissenberg number and perform an energy analysis to examine the mechanisms responsible for the destabilization of the flow and compare against the mechanisms that have been suggested in the literature

Simulation of incompressible viscous flows around moving objects by a variant of immersed boundary-Lattice Boltzmann method

A variant of immersed boundary-lattice Boltzmann method (IB-LBM) is presented in this paper to simulate incompressible viscous flows around moving objects. As compared with the conventional IB-LBM where the force density is computed explicitly by Hook's law or the direct forcing method and the non-slip condition is only approximately satisfied, in the present work, the force density term is considered as the velocity correction which is determined by enforcing the non-slip condition at the boundary. The lift and drag forces on the moving object can be easily calculated via the velocity correction on the boundary points. The capability of the present method for moving objects is well demonstrated through its application to simulate flows around a moving circular cylinder, a rotationally oscillating cylinder, and an elliptic flapping wing. Furthermore, the simulation of flows around a flapping flexible airfoil is carried out to exhibit the ability of the present method for implementing the elastic boundary condition. It was found that under certain conditions, the flapping flexible airfoil can generate larger propulsive force than the flapping rigid airfoil

CFD Modelling coupled with Floating Structures and Mooring Dynamics for Offshore Renewable Energy Devices using the Proteus Simulation Toolkit

This is the author accepted manuscript. The final version is available from EWTEC via the link in this record.In this work, the coupling of novel opensource tools for simulating two-phase incompressible flow problems with fluid-structure interaction and mooring dynamics is presented. The open-source Computational Fluid Dynamics (CFD) toolkit Proteus is used for the simulations. Proteus solves the twophase Navier-Stokes equations using the Finite Element Method (FEM) and is fully coupled with an Arbitrary Lagrangian-Eulerian (ALE) formulation for mesh motion allowing solid body motion within the fluid domain. The multi-body dynamics solver, Chrono, is used for calculating rigid body motion and modelling dynamics of complex mooring systems. At each time step, Proteus computes the forces from the fluid acting on the rigid body necessary to find its displacement with Chrono which will be used as boundary conditions for mesh motion. Several verification and validation cases are presented here in order to prove the successful coupling between the two toolkits aforementioned. These test cases include wave sloshing in a tank, floating body dynamics under free and wave-induced motion for different degrees of freedom (DOFs), and mooring dynamics using beam element theory coupled with rigid body dynamics and collision detection. The successful validation of each component shows the potential of the coupled methodology to be used for assisting the design of offshore renewable energy devices.Support for this work was given by the Engineer Research and Development Center (ERDC) and HR Wallingford through the collaboration agreement (Contract No. W911NF-15-2-0110). The authors also acknowledge support for the IDCORE program from the Energy Technologies Institute and the Research Councils Energy Programme (grant number EP/J500847/)

Age constraints for the mineralization of the metamorphosed Kutemajärvi gold deposit using the single-grain U-Pb dating method of accessory minerals

The metamorphosed Kutemajärvi gold deposit is located near the town of Orivesi, at the eastern flank of the Tampere Schist Belt, which constitutes part of the Svecofennian domain of southern Finland, and it is hosted in the volcanic rocks of the Koskuenjärvi formation. Previous isotopic studies have mainly focused on the igneous and metamorphic rocks of the Tampere Schist Belt and only a few of them have presented ages for the area of Kutemajärvi. This study aims to shed light on the timing of mineralization by employing the single-grain U-Pb dating method of monazite and zircon, in order to evaluate the relationship between the ore and its host rocks. Based on the results from the SEM mineral identification, monazite grains are divided into metamorphic and hydrothermal grains. In the case of zircon grains, a third magmatic type has been identified. Results from U-Pb dating of single monazite and zircon grains are well constrained and document four distinct stages of geodynamic evolution in the region. Ages older than 1.91 Ga represent detrital material transported during the stage of rifting that led to the opening of the Tampere basin. Subsequent subduction resulted in active volcanism which is expressed with the extrusion of the Koskuenjärvi formation at 1904 Ma. At the late stages of subduction or at the outset of the collision stage, the subvolcanic Pukala porphyry intruded into the volcanic sequence of the Tampere Schist Belt at 1890 Ma, which provides the maximum mineralization age. Release of hydrothermal fluids, due to the crystallization of the Pukala intrusion caused pervasive hydrothermal alteration of the Kutemajärvi host rocks and deposition of epithermal gold and other elements. However, the participation of hydrothermal fluids, released by high-temperature metamorphism of the lower crust, cannot be ruled out. Ages between 1890‒1878 Ma record the syn-collision stage, during which the deposit, the Pukala intrusion and its adjoining rocks were deformed and metamorphosed at greenschist to lower-amphibolite facies. The majority of ages fall within the 1880‒1878 Ma time-interval, characterizing the metamorphic peak that marks the culmination of the Svecofennian orogeny and provides a minimum age of the mineralization. This major orogenic event is partly overlapped by the collision of the Central Svecofennian Arc Complex with the Southern Svecofennian Arc Complex that transpired at 1880‒1860 Ma, as indicated by ample age data. Monazite and zircon also yield lower ages (<1860 Ma), which record retrograde metamorphic and subordinate cooling events, and resonate recurring tectonothermal activity, associated with the syn- and post-collisional magmatism of Southern Svecofennia and the emplacement of rapakivi intrusions in southern Finland. Single-grain U-Pb dating of monazite and zircon from polished thin sections, in tandem with collation of the obtained ages with earlier published data, establishes a spatial and temporal framework with respect to the tectonometamorphic evolution of the Kutemajärvi gold deposit and the Tampere Schist Belt. Precise temporal constraints substantiate the intricate geological history of the area and can be used to discriminate magmatic, metamorphic and hydrothermal events, with a view to breaking ground on the exploration of other epithermal deposits in the metamorphic terranes of southern Finland

Between Chaos and Cosmic Order: The Ambivalent Disposition of Matter in Middle Platonism

In&nbsp;Timaeus (30a ff.), Plato presents matter as a passive principle, inherently predisposed to disorder, subject to mechanistic necessity, and apparently devoid of any volition or predisposition towards the Demiurge. This cosmological framework, however, is not uniformly embraced by Middle Platonists. Instead, three divergent conceptions of matter emerge: one aligned with Plato’s notion of passivity, another in which matter resists the Demiurge with malevolence, and a third where it actively seeks union with the intelligible realm. This study pursues two primary objectives: first, to explore the ontological status and disposition of matter in relation to the intelligible within Middle Platonic thought; second, to elucidate why matter assumes such antithetical attributes

Fully Synthetic Longitudinal Real-World Data From Hearing Aid Wearers for Public Health Policy Modeling

Here, we share the first outcome of EVOTION (www.h2020evotion.eu) in the form of a data-set to inspire, encourage, and motivate a data-driven analytical approach to evidence-based healthcare policy modeling using real-world longitudinal data. The data-set includes information relating to patterns of real-world hearing aid usage and sound environment exposure. Undoubtedly, many such data-sources will be available for researchers and policy-makers in the future, and the data-set presented here can act as a first step of building and testing potential statistical model

Identifying Epileptogenic Brain Tissue by Automated Detection of Biomarkers in Electrophysiological Recordings in Epilepsy Patients

In selected patients with drug-resistant focal epilepsy, epilepsy surgery is the treatment of choice and may eliminate the occurrence of seizures completely. High frequency oscillations (HFOs) might have the potential to be a clinical asset for delineating epileptogenic brain areas and have been proposed as a new biomarker of the epileptogenic zone (EZ). The main objective of this thesis was to evaluate the detectability of HFOs and validate the clinical relevance of HFOs as epileptogenic brain tissue biomarkers using intracranial electrophysiological recordings. As a second objective of this thesis, I focused on understanding which brain areas generate high rate of physiological HFOs .These brain areas should not be taken into account in the definition of pathological HFOs. I evaluated the detectability of HFOs by means of signal-to-noise ratio and recording electrodes. I then investigated the direction of information flow between hippocampus and sensory cortices during a working memory task to understand brain networks that might generate high rate of physiological HFOs. Further, I validated a pipeline that is centered on the fully automated and robust detection of clinically relevant HFO in independent and multicenter patient cohorts, which have the potential to guide surgery planning and may improve post-surgical seizure outcomes in patients with drug-resistant focal epilepsy. I contributed to the detectability of HFOs in a clinical setting by developing an algorithm to optimize the SNR calculation in intraoperative SEP recordings that facilitated the recording of evoked HFOs. I also showed that the noise reduction offered by low impedance electrodes might facilitate detection of fast ripple oscillations that are discussed as biomarkers for epileptogenic brain tissue. I then contributed to the understanding of potential physiological HFO networks by showing that the sensory cortices (i.e. auditory and occipital cortex) encoded memory items in high gamma frequency range (&gt;80 Hz). This high frequency activity may act as confounder for the pathological HFOs and thus the delineation of the EZ. Finally, I contributed to the validation of the clinical relevance of prospectively defined and automatically detected HFOs while I was blinded to the seizure outcome. I showed that the complete resection of the brain tissue generating HFOs lead to post-surgical seizure freedom in 1) a cohort from an independent epilepsy center and 2) a large cohort of 160 patients from eight independent epilepsy centers. My research may improve surgical planning, leading to a more favorable seizure outcome for patients with drug resistant focal epilepsy. Automated HFO analysis has the potential to improve epilepsy diagnosis and treatment, as well as the post-operative patient outcomes

The cooperative parallel: A discussion about run-time schedulers for nested parallelism

Nested parallelism is a well-known parallelization strategy to exploit irregular parallelism in HPC applications. This strategy also fits in critical real-time embedded systems, composed of a set of concurrent functionalities. In this case, nested parallelism can be used to further exploit the parallelism of each functionality. However, current run-time implementations of nested parallelism can produce inefficiencies and load imbalance. Moreover, in critical real-time embedded systems, it may lead to incorrect executions due to, for instance, a work non-conserving scheduler. In both cases, the reason is that the teams of OpenMP threads are a black-box for the scheduler, i.e., the scheduler that assigns OpenMP threads and tasks to the set of available computing resources is agnostic to the internal execution of each team. This paper proposes a new run-time scheduler that considers dynamic information of the OpenMP threads and tasks running within several concurrent teams, i.e., concurrent parallel regions. This information may include the existence of OpenMP threads waiting in a barrier and the priority of tasks ready to execute. By making the concurrent parallel regions to cooperate, the shared computing resources can be better controlled and a work conserving and priority driven scheduler can be guaranteed.Peer ReviewedPostprint (author's final draft