Forces Applied on the Ground in Roller Skating

Walking, running, cycling, skating are just some examples of the many possibilities available to man for his own motion. Most of these activities have been widely studied both from a physiological as well as biomechanic viewpoint. On the contrary, few researches and experiments are available as regards skating, particularly roller-skating. In this sport the athlete wears a special pair of shoes fitted with four little wheels, each one of which is able to spin freely on a axis of its own. The analysis of the techniques used in roller-skating (as to how, when and where the propulsive force is applied and of the most appropriate length and frequency of each step) can provide some valuable information for a more thorough development of this sport activity. In order to have the opportunity to study and evaluate at least some of these parameters, some special force transducers were built and applied to each of the wheel fitted on a pair of skates. Furthermore, front and back weight-force detectors were also installed

Coherent video reconstruction with motion estimation at the decoder

In traditional predictive video coding the block matching is performed at the encoder. The obtained motion field is then transmitted to the decoder, together with the prediction residue. Nevertheless, if the motion field is not provided it can be reconstructed, as long as the decoder manages to exploit some correlated information. This paper presents an algorithm for the motion estimation at the decoder side, given the prediction residue only. The main novelty of this algorithm relies on the contextual reconstruction of a frame region composed of several blocks. Simulation results show that taking into account a whole row can improve significantly the results obtained with an algorithm that reconstructs each block separately

GHG emissions of supply chains from different retail systems in Europe

An approach has been developed to collect data and measure energy use and GHG emissions from logistics activities for product supply chains. This approach has been used to assess the GHG efficiency of several supply chains of the same product marketed through different types of retail systems in Europe. The retail types considered are hyper and supermarkets, corner shops, open-air markets, producer's basket direct sale, farm shops and e-commerce; Their GHG efficiencies are quantified and compared for food products, considering whole supply chains from the farm gate where they are grown to the consumer's home. This supply chain efficiency approach highlights the importance of the various operations carried out within the supply chains, such as transport, warehousing, the shop itself, and even consumer behaviour for the last mile. While supermarkets in towns, shops included in a delivery system, or open air markets in town centre appears to be very efficient, rural area and independent shops with lower turnover are less favourable. Indeed, the outcomes of an online consumer survey show large differences amongst the GHG efficiency values for all these retail systems. Therefore, potential logistics choices for improving the supply chain performance could be identified

Comparison of depth-averaged and full-3D model for the benchmarking exercise on landslide runout

Two models, with fundamental differences in their approaches, are used for modeling benchmarking exercise. The first, RASH3D, is based on a set of depth-averaged equation, solved in an Eulerian framework. The second, HYBIRD, employs a 3D Lattice-Boltzmann Model (LBM), i.e. the conservation equations are not depth-averaged and therefore multiple velocity measures are available over the depth. The model output are compared for what concerns the Yu-Tung debris flow back-analysis. Two additional cases are then analyzed using RASH3D

From depth-averaging to fully three-dimensional modelling of debris-flow dynamics

Two numerical codes, with fundamental differences in their approaches, are used for modeling the Yu Tung debris flow, which occurred in Hong Kong in 2008. The first code, RASH3D, is based depthaveraged St. Venant equations, solved in an Eulerian framework. The second code, HYBIRD, is fully 3D and based on Lattice-Boltzmann Model (LBM), i.e. the conservation equations are not depth-averaged and therefore multiple velocity measures are available over the depth. The two model output are compared and discussed

Decarbonising Urban Freight Transport: Experimentations in European Research Projects

One of the objectives of European research programs is to decarbonize freight transport while maintaining its competitiveness and economic strength, reduce negative externalities such as pollutant emissions, congestion and accidents, and foster innovation. Multiple initiatives have started in Europe to reach these objectives and this paper reviews some of these schemes in the field of urban freight transport. It is based mainly on 3 EC-funded projects (BESTFACT (2016), SOLUTION (2015) and SMARTFUSION (2016)). These 3 projects are either testing (Smartfusion) or examining and disseminating European ‘new solutions’ or ‘best practices’ in freight transport. The paper mainly focuses on the most decarbonizing solutions

Energy efficiency and greenhouse gas emissions of different supply chains: a comparison of French, UK and Belgian cases

Freight transportation system is critical to economic activity but it carries significant environmental costs, notably GHG emissions and climate change : energy use and corresponding CO2 emissions is increasing faster in freight transport than in other sectors and this increase is primarily the result of increased trade. This paper compares the transport activities, associated energy consumption and CO2 emissions of different supply chains for a range of products in three countries: Belgium, France and United Kingdom. Among the products considered are furniture and ‘fruits & vegetables’. For each of these products, different supply chains, involving more or less transport activity and associated energy consumption are analysed in each country. The comparison highlights some of the main factors that influence GHG emissions for different supply chains and illustrates how they vary according to product and country of final distribution. In more detail, the paper addresses the main differences between the supply chains of these products namely, the origin of their sourcing, the logistical organisation between production and retail and different types of retail outlet. The origin of the sourcing impact is mainly related to distance. The impact of the logistical organisation between raw material and retail on GHG emissions is linked to the mode and vehicle choice and to the load factor. As for retail, the consumer trip emissions, between his home and the retail outlet, are also an important part of the whole supply chain emissions. It is worthwhile to notice that our goal in this project is to consider the whole supply chain, from production to consumption. Therefore a particular focus is put on the mobility behaviours of consumers purchasing the studied products during their shopping and dropping back home activities related to these products. Especially a web based survey has been conducted and the gathered results offer an opportunity for drawing a more detailed picture of the associated CO2 emissions. This paper uses the results of an ongoing research on supply chain energy efficiency, funded by ADEME (the French Energy Agency) through the French program on transport research (PREDIT). This research is based on a comprehensive review of the various approaches to quantifying the environmental impacts of supply chains together with data collection from a range of organisations including manufacturers, retailers and transport companies. We will first present the developed methodologies, then the results corresponding to each studied product will be described. A discussion of the potential application of the research approach to the wider debate about the environmental impact of freight transport and the scope for GHG emissions reduction targets to be achieved will be included

Error Resilience Performance Evaluation of a Distributed Video Codec

Distributed Video Coding (DVC), one of the most active research field in the video coding community, is based on the combination of Slepian-Wolf coding techniques with the idea of performing the prediction at the decoder side rather than at the encoder side. Besides its main property, which is flexible allocation of computational complexity between encoder and decoder, the distributed approach has other interesting properties. One of the most promising DVC characteristics is its intrinsic robustness to transmission errors. In this work we have evaluated the error resilience performance of a video codec based on the DVC scheme proposed by Stanford, and we have carried out a preliminary comparison with traditional H.264 encoding, showing that at high error probabilities and high bitrates the distributed approach can also outperform the traditional one

Study of the influence of baffles on an artificial debris flow through back-analysis simulations

In this work, we explore the applicability of a novel approach to the full-scale simulation of debris flows, the Lattice-Boltzmann Method (LBM). The main novelty lies in eliminating the need for depthintegrating the conservation equations, which is still a dominant approach in the field. A full 3D model, both for the topography and for the flow itself is therefore developed and employed. The 3D nature of the model allows to accurately reproduce structural countermeasures. An artificial debris flow, generated in real-scale at an experimental site in Korea, provides the basis for a cross comparison of results. The effects of two arrays of baffles were also tested in the experiment. The flow scale is intermediate between the large natural flows that are usually reported in the literature and a typical experimental apparatus. It is therefore an ideal candidate for an explorative application of the numerical metho