The CLAWAR project

In Europe, there are two main thematic groups focusing on robotics, the Climbing and Walking Robots (CLAWAR) project (http://www.clawar.net) and the European Robotics Network (EURON) project (http://www.euron.org). The two networks are complementary: CLAWAR is industrially focused on the immediate needs, and EURON is focused more on blue skies research. This article presents the activities of the CLAWAR project

The comparison and evaluation of different mathematical models for deformation analysis

Bibliography: pages 124-125.In the analysis of deformations using geodetic techniques, the errors in point positions due to observation errors must be distinguished from movements due to actual deformation. A number of models are available, which offer solutions to this problem. In this study, four of such methods are described and compared: 1. Method using Invariant Functions. 2. Method using Direct Comparison of Co-ordinates. 3. Method using Direct Differences. 4. Method using Niemeier's Comparison of Co-ordinates. The introduction of "false" deformations, caused by errors in translation, rotation and scale, is a very real problem which may be eliminated by processes such as the use of invariant functions (distances and angles) and the sound construction of constraint points. Niemeier's solution to this problem is the use of a free network adjustment which forces the new network into a best fit of the provisional co-ordinates, which generally would be the final co-ordinates of a previous epoch. Although the model advocated for the first three methods above is the minimum constraint adjustment, the free network adjustment may also be used. Similarly, the minimum constraints technique may be employed for Niemeier's method, subject to some necessary modifications. The four methods have thus been compared using both adjustment techniques also. The four methods using both adjustment techniques as well as some variations of methods 1. and 2. above are evaluated using a series of nine simulated test epochs, one reference and eight other, to which known deformations were applied. From the results obtained from the various epochs, the methods are examined for reliability, accuracy and suitability

Athletes as community; athletes in community: covid-19, sporting mega- events and athlete health protection

This is the author accepted manuscript. The final version is available from BMJ Publishing Group via the DOI in this recor

Elastomeric load sharing device

An elastomeric load sharing device, interposed in combination between a driven gear and a central drive shaft to facilitate balanced torque distribution in split power transmission systems, includes a cylindrical elastomeric bearing and a plurality of elastomeric bearing pads. The elastomeric bearing and bearing pads comprise one or more layers, each layer including an elastomer having a metal backing strip secured thereto. The elastomeric bearing is configured to have a high radial stiffness and a low torsional stiffness and is operative to radially center the driven gear and to minimize torque transfer through the elastomeric bearing. The bearing pads are configured to have a low radial and torsional stiffness and a high axial stiffness and are operative to compressively transmit torque from the driven gear to the drive shaft. The elastomeric load sharing device has spring rates that compensate for mechanical deviations in the gear train assembly to provide balanced torque distribution between complementary load paths of split power transmission systems

Financial Valuation of PBGC Insurance with Market-Implied Default Probabilities

In this paper, we use financial valuation techniques to measure the unfunded liabilities associated with the Pension Benefit Guaranty Corporation (PBGC) single-employer pension insurance program. This is an alternative approach to the calculations of expected future PBGC payouts in the PBGC exposure reports. The PBGC insurance is akin to an exchange option, a financial instrument that allows a party to exchange one risky asset for another. Calculating the value of this option for each PBGC-covered plan provides a measure of the fair market price of the PBGC guarantee that is consistent with the finance principles of risk-neutral pricing. That is, the market valuation method reflects the fact that bad outcomes tend to coincide with times when losses are particularly painful. The valuation we perform also reflects the fact that PBGC insurance is triggered only in the case of bankruptcy by drawing on the default probabilities implied by the credit ratings of insured plans. Under the baseline parameters, the PBGC’s insurance of the unfunded liabilities has a financial value of $358 billion, net of the estimated present value of PBGC premiums

Dynamical phase transition in the activity-biased fully-connected random field Ising model: connection with glass-forming systems

Abstract: We analyse biased ensembles of trajectories for the random-field Ising model on a fully-connected lattice, which is described exactly by mean-field theory. By coupling the activity of the system to a dynamical biasing field, we find a range of dynamical phase transitions, including spontaneous symmetry breaking into ordered states. For weak bias, the phase behaviour is controlled by extrema of the free energy, which may be local minima or saddle points. For large bias, the system tends to states of extremal activity, which may differ strongly from free energy minima. We discuss connections of these results to random first-order transition theory of glasses, which motivates an extension of the analysis to random-field Ising models where the dynamical activity is not symmetric under magnetisation reversal