The brake linkage of a hoisting machine is a very important component determining the safety of

the hoisting machine’s entire braking system. It is subject to weekly inspections. However, an efficiency

test of brake performance is carried out every 6 months. Once every 3 years, a test must be carried out by

an appraiser who pays particular attention to the executive and control components of the brakes as well

as the strain - brake system and brake release components. The legal provisions regulating the testing

of braking system linkages are not precise. So far, the control has been based on random measurement

of strains using electrical resistance strain gauges stuck to the surface of the linkage. A new method

for measuring the strains of the linkage has been proposed in the work. It is based on fibre optic strain

sensors with Fibre Bragg Gratings (FBG). They are mounted using specially designed and tested holders

for mounting on the brake linkage. They provide quick assembly and the measurement of strain in the

direction parallel to the axis of the linkage. The structure of the holder also allows for the measurement

in 4 positions turned every 90 relative to one another. Such a measurement enables a comprehensive

analysis of strains and stresses in the brake linkage. In the work, it was shown that there is a complex

state of strain and stress in the brake linkage. The previous procedures for linkage testing are inadequate

in relation to this condition. An experimental and numerical method was proposed to assess the state

of linkage stress. It should constitute the basis for the decision of the appraiser to allow the linkage for

further use. The method proposed in the work also allows for continuous measurements of linkage strains

as well as dynamic braking tests.

A new double stator permanent magnet machine having two sets of alternating current (AC) windings in separate stators is proposed in this study. The proposed machine is appropriate for low-speed direct-drive applications. 2D- and 3D-finite element analysis (FEA) is adopted in the result predictions. The considered machine elements are: coil and phase flux linkage, coil and phase induced-electromotive force (EMF), copper loss, current density and torque characteristics. The analysis shows that the studied permanent magnet (PM) machine has better electromagnetic performance than its single-stator equivalent. Moreover, the proposed machine has potential for higher reliability if the separate stators are used independently. The effect of design parameters on open-circuit flux linkage and induced-electromotive force, as well as on the average electromagnetic torque of the proposed double stator machine is also presented. It is observed that for each of the investigated design variables, there is a need to select the optimal value in order to achieve the best average torque. The investigated design parameters are: the split ratio, magnet thickness, rotor radial thickness, inner stator tooth-width, rotor inner and outer iron-width/pitch ratio, and stator yoke size.

Voting power methodology offers insights to understand coalition building in collective decision making. This paper proposes a new measure of voting power inspired from Banzhaf (1965) accounting for the proximity between voters by capturing how often they appear in winning coalitions together. Using this proximity index, we introduce a notion of relative linkages among coalition participants as determinant of coalition building. We propose an application to the governance structure of the International Monetary Fund, with linkages being represented by bilateral volumes of trade between voters. The results are able to explain several important features of the functioning of this particular voting body, and may be useful for other applications in international politics.

We examined the male-female collaboration practices of all internationally visible Polish university professors (N = 25,463) based on their Scopus-indexed publications from 2009–2018 (158,743 journal articles). We merged a national registry of 99,935 scientists with the Scopus publication database, using probabilistic and deterministic record linkage. Our database (“The Polish Science Observatory”) included all professors with at least a doctoral degree employed in 85 researchinvolved universities. We determined an “individual publication portfolio” for every professor. The gender homophily principle (publishing predominantly with scientists of the same sex) was found to apply to male scientists — but not to females. The majority of male scientists collaborate solely with males; most female scientists, in contrast, do not collaborate with females at all. Gender homophily in research-intensive institutions proved stronger for males than for females. Finally, we used a multi-dimensional fractional logit regression model to estimate the impact of gender and other individual-level and institutional-level independent variables on gender homophily in research collaboration.