316 research outputs found
Recent Labour Market Trends in the Visegrad Group Countries
The large declines in the Slovak and Czech employment appeared because the countries' GDPs grew smaller while real wages grew bigger. Shorter working hours and limitations on labour productivity that the two countries introduced could not reverse the unfavourable employment trends that occurred during economic downturn.Duże spadki zatrudnienia w Słowacji i Czechach były związane ze słabym wzrostem PKB i silnym wzrostem płac realnych. Redukcje czasu pracy i wydajności pracy nie były w stanie odwrócić niekorzystnych tendencji w zatrudnieniu
A method for the assessment of time-varying brain shift during navigated epilepsy surgery
Image guidance is widely used in neurosurgery. Tracking systems (neuronavigators) allow registering the preoperative image space to the surgical space. The localization accuracy is influenced by technical and clinical factors, such as brain shift. This paper aims at providing quantitative measure of the time-varying brain shift during open epilepsy surgery, and at measuring the pattern of brain deformation with respect to three potentially meaningful parameters: craniotomy area, craniotomy orientation and gravity vector direction in the images reference frame
Poaching and firm-sponsored training: first clean evidence
A series of seminal theoretical papers argues that poaching of employees may hamper company-sponsored general training. However, the extent of poaching, its determinants and consequences, remains an open empirical question. We provide a novel empirical identification strategy for poaching and investigate its causes and consequences. We find that only a small number of training firms in Germany are poaching victims. Firms are more likely to poach employees during an economic downturn. Training firms respond to poaching by lowering the share of new apprentice intakes in the following years
Global Optimization Algorithms in Multidisciplinary DesignOptimization
While Multidisciplinay Design Optimization (MDO) literature focuses mainly on the development of different formulations, through the manipulation of design variables, less
attention is generally devoted to the combination of specific MDO formulations with existing nonlinear optimization algorithms.
In this paper, the focus is on the application of a Global Optimization (GO) algorithm
to an MDO problem. We first introduce and describe some MDO approaches from the
literature. Then, we consider our MDO formulation where we deal with the GO box-constrained problem
min_{a R
We assume that the solution of the latter problem requires the use of a derivative-free methods since the derivatives of f(x) are unavailable and/or the function must be treated
as a `black-box'. Within this framework we study some globally convergent modifications of
the evolutionary Particle Swarm Optimization (PSO) algorithm, suitably adapted for box-constrained optimization. Finally, we report our numerical experience. Preliminary results
are provided for a simple hydroelastic problem. Two different numerical tools are involved:
a fluid dynamic solver, to simulate the
ow around hydrofoils traveling in proximity of the
air-water interface, and a simplified torsion-flexional wing model
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