Automatic parameter tuning for functional regionalization methods

The methods used to define functional regions for public statistics and policy purposes need to establish several parameter values. This is typically achieved using expert knowledge based on qualitative judgements and lengthy consultations with local stakeholders. We propose to support this process by using an optimization algorithm to calibrate any regionalization method by identifying the parameter values that produce the best regionalization for a given quantitative indicator. The approach is exemplified by using a grid search and a genetic algorithm to configure the official methods employed in the UK and Sweden for the definition of their respective official concepts of local labour markets.     

Effect of asphalt thin beams mixed with three nominal maximum aggregate sizes in the bending beam rheometer on the prediction of thermal properties of bituminous material

The objective of this research is to evaluate an impact of asphalt mixture beams with varying sizes of aggregate in the Bending Beam Rheometer (BBR) for testing/predicting thermal cracking properties of asphalt pavements. The BBR test has following benefits: the equipment is cheaper, it uses smaller specimens, faster conditioning, easier availability for quality control, easier to manage, etc. However some concerns have been raised: some consider that the size of the aggregate may affect the test’s results; the other concern is that such small beams cannot represent the whole properties of the asphalt pavement. To address these criticisms, imaging techniques, statistical analysis, and viscoelastic modeling are used. Asphalt thin beams prepared with three different nominal maximum aggregate size (NMAS) (12.5mm, 9.5 mm, and 4.75 mm) were tested at three different temperatures (-18°C, -24°C, and -30°C). Based on results from statistical analyses and viscoelasticity, the ratio of asphalt binders and voids and stiffness differences among the three NMAS specimens are not significant, meaning that the impact of asphalt thin beams prepared with the three NMAS on the prediction of thermal cracking is minimal and can be neglected.