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Escuin D.,University of Zaragoza | Millan C.,Technological Institute of Aragon | Larrode E.,University of Zaragoza
Networks and Spatial Economics | Year: 2012

The aim of the paper is to model urban distribution vehicle routing problems by means of hubs in large cities. The idea behind the urban distribution center (DC) is to provide buffer points where cargo and packages which are to be delivered to shops and businesses can be stored beforehand. At these centers, there will be other kinds of routing problems corresponding to other fairly similar distribution problems. In this paper, a new vehicle routing model (based on the known Time-Dependent Vehicle Routing Problem with Time Windows, TDVRPTW) has been carried out and a change in the traditional approach is proposed, by adopting a system in which some customers are served by urban DCs while remaining customers are served by traditional routes. This study is also motivated by recent developments in real time traffic data acquisition systems, as well as national and international policies aimed at reducing concentrations of greenhouse gases emitted by traditional vans. By using k DCs, the whole problem is now composed of k+1 problems: one special VRPTW for each DC in addition to the main problem, in which some customers and k DC are serviced. The model has been tested by simulating one real case of pharmaceutical distribution within the city of Zaragoza. © 2009 The Author(s).

Garcia J.J.T.,University of Oviedo | Alonso I.G.,University of Oviedo | De La Rua Garcia R.B.,R and D Unit | Ibor C.M.,Technological Institute of Aragon
2012 IEEE International Electric Vehicle Conference, IEVC 2012 | Year: 2012

The aim of this research is to develop a set of technologies and standards for the interoperability of an energy-efficient robotic village. Furthermore, the approach for achieving that will be done in the form of a living lab. So the research presented here will be to proof and to tune different technological standards and technologies considered "green", in a large experimental context of a Robotic Village. The research topics associated with it will be related with the increase of the energy efficiency in different daily areas and how they will contribute to the objectives of 2020 agenda from the UE, of reducing human impact on climate change. One of those research areas is the Smart Way, where technological challenges of the EV, the automation in road infrastructure building and the interoperability of road management and transportation systems will be gathered in order to boost a progressive variation of current transportation model. Concretely, the studies and developments necessary to achieve an increase in energy density and service life, reduced recharge times and price decrease will be carried out. © 2012 IEEE.

Artaso P.,Technological Institute of Aragon | Lopez-Nicolas G.,University of Zaragoza
Measurement: Journal of the International Measurement Confederation | Year: 2016

The ability of fast and automatic volume measurement of merchandise is of paramount importance in logistics. In this paper, we address the problem of volume estimation of goods stacked on pallets and transported in pallet trucks. Practical requirements of this industrial application are that the load of the moving pallet truck has to be measured in real-time, and that the measurement system should be non-invasive and non-contact, as well as robust and accurate. The main contribution of this paper is the design of simple, flexible, fast and robust algorithms for volume estimation. A significant feature of these algorithms is that they can be used in industrial environments and that they perform properly even when they use the information provided by different range devices working simultaneously. In addition, we propose a novel perception system for volume measurement consisting of a heterogeneous set of range sensors based on different technologies, such as time of flight and structured light, working simultaneously. Another key point of our proposal is the investigation of the performance of these sensors in terms of precision and accuracy under a diverse set of conditions. We also analyse their interferences and performance when they operate at the same time. Then, the analysis of this study is used to determine the final configuration of the cameras for the perception system. Real experiments proof the performance and reliability of the approach and demonstrate its validity for the industrial application considered. © 2016 Elsevier Ltd. All rights reserved.

Resano M.,University of Zaragoza | Bolea-Fernandez E.,University of Zaragoza | Mozas E.,Technological Institute of Aragon | Florez M.R.,University of Zaragoza | And 2 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2013

This work explores the possibilities of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for the direct analysis of carbon nanotubes. In particular, the simultaneous determination of Co, Fe, Ni and Pb is intended, as these elements are typically found in these samples as impurities. The results demonstrate that it is possible to find spectral (monitoring of the region between 283.168 and 283.481 nm), furnace (2500 °C for atomization; use of 100 ng Pd as a chemical modifier) and detector (use of side pixels to expand the linear range) conditions that permit the development of a fast and straightforward method for the simultaneous determination of the target elements at the levels at which they are typically found (mg g-1 for Co, Fe and Ni; μg g-1 for Pb) in carbon nanotubes. Limits of detection of 23 pg (Pb), 6 ng (Fe), 65 ng (Ni) and 86 ng (Co) were obtained, which are suitable for this type of sample. In this way, it was feasible to carry out the analysis of the samples investigated (one candidate reference material and three commercially available samples) and achieve accurate results when constructing the calibration curve with aqueous standards. Precision values for 5 solid sample replicates varied between 7 and 15% RSD in most cases. Overall, the proposed method shows important benefits for the cost-effective analysis of such complex samples in routine labs. This journal is © The Royal Society of Chemistry.

Miana M.,Technological Institute of Aragon | Cortes C.,University of Zaragoza | Pelegay J.L.,Technological Institute of Aragon | Valdes J.R.,Technological Institute of Aragon | And 2 more authors.
IEEE Transactions on Advanced Packaging | Year: 2010

This paper applies the methodology of transient thermal network modelling (TTNM) introduced in Part I to the heat transfer analysis of an electronic control unit (ECU) located in the engine enclosure of a motorcar. The complexity of the geometry, the diverse heat transfer mechanisms involved and the duration of the operating cycle prevent the use of both simple, lumped models and detailed numerical simulations. The TTNM methodology relies instead in steady, approximate heat transfer correlations and a division of the system into the largest possible isothermal elements, based on the analysis of characteristic time and length scales. The dynamic heat balance of each element is then written down, conforming the TTNM of the system, which is numerically integrated with an adequate time step. The practical aspects of the TTNM methodology (design stage) are finally demonstrated; in this particular case-study, the model reveals a very high risk of damage of electronic components due to the radiative heat load received from the exhaust pipe of the engine. A design modification consisting of a radiative shield is proposed and model-tested, achieving an appropriate reduction of heat flux and temperatures, and thus an adequate protection of critical components. © 2006 IEEE.

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