Abstract We study the parameterized complexity of winner determination problems for three prevalent k -committee selection rules, namely minimax approval voting (MAV), proportional (PAV), and Chamberlin–Courant’s (CCAV). It is known that these are computationally hard. Although they have been studied from point view with respect to several natural parameters, many them turned out be -hard or -h...

In the research into the mechanism of brake squeal, minimal models with two degrees of freedom (DoFs) are widely used. Compared with the finite element method, the minimal model is more concise and efficient, making it easier to analyze the effect of parameters. However, how to accurately determine its kinetic parameters is rarely reported in the literature. In this paper, firstly, the finite e...

– In this Letter we investigate the density of states ΩN (E,M) of twoand threedimensional Ising models with N spins as a function of energy E and magnetization M . For a fixed energy lower than a critical value Ec,N the density of states exhibits two sharp maxima at M = ±Msp(E) which define the spontaneous magnetization. An analysis of the form Msp(E) ∝ (Ec,∞ − E) βε yields very good results fo...