Localization in Wireless Networks: The Potential of Triangulation Techniques

User localization is one of the key service-enablers in broadband mobile communications. Moreover, from a different point of view, next steps towards automatic network optimization also depend upon the capability of the system to perform real-time user localization, in order to obtain the traffic distribution. The aim of this paper is to get deeper into the feasibility and accuracy of different localization mechanisms ranging from triangulation to database correlation. Call tracing data extracted from a real operating mobile network have been used to assess these algorithms after the execution of an extensive measurements campaign. Results show that enhanced triangulation offers the best performance even outperforming other more sophisticated mechanisms like fingerprinting, without introducing any change in the network and without requiring any special characteristic of the user equipment. Indeed, the lack of precision of channel estimates, which for the same position could differ up to 10 dB, introduces a large uncertainty that harms localization mechanisms based on database correlation. Finally, this paper identifies the areas for improvement in triangulation to reach its maximum potential, provides details for its implementation and analyzes the performance of the different proposed enhancements. © 2012 Springer Science+Business Media, LLC.The authors would like to thank the funding received from the Ministerio de Industria, Turismo y Comercio within the Project number TSI-020100-2010-183 and from the Generalitat Valenciana IMIDTA/2010/800 funds.Osa Ginés, V.; Matamales Casañ, J.; Monserrat Del Río, JF.; López Bayo, J. (2013). Localization in Wireless Networks: The Potential of Triangulation Techniques. Wireless Personal Communications. 68(4):1525-1538. https://doi.org/10.1007/s11277-012-0537-2S15251538684Laiho J., Wacker A., Novosad T. (2006) Radio Network Planning and Optimisation for UMTS 2nd Edn. Wiley, AmsterdamOsa V., Matamales J., Monserrat J. et al (2010) Expert systems for the automatic optimisation of 3G networks. WAVES 2: 97–105Gustafsson F., Gunnarsson F. (2005) Mobile positioning using wireless networks: Possibilites and fundamental limitations based on available wireless network measurements. IEEE Signal Processing Magazine 22(4): 41–53. doi: 10.1109/MSP.2005.1458284Gezici S. (2008) A survey on wireless position estimation. Springer Wireless Personal Communications 44(3): 263–282. doi: 10.1007/s11277-007-9375-zBahillo, A., Mazuelas, S., & Lorenzo, R.M., et al. (2010). Accurate and integrated localization system for indoor environments based on IEEE 802.11 round-trip time measurements.EURASIP Journal on Wireless Communications and Networking, 2010, Article ID 102095, p. 13. doi: 10.1155/2010/102095 .Yang Z., Liu Y. (2010) Quality of trilateration: Confidence-based iterative localization. IEEE Transactions on Parallel and Distributed Systems 21(5): 631–640. doi: 10.1109/TPDS.2009.90Zimmermann, D., et al. (2004). Database correlation for positioning of mobile terminals in cellular networks using wave propagation models. In IEEE 60th Vehicular Technology Conference (Vol. 7, pp. 4682–4686) doi: 10.1109/VETECF.2004.1404980 .Zhao Y. (2002) Standardization of mobile phone positioning for 3G systems. IEEE Communications Magazine 40(7): 108–116. doi: 10.1109/MCOM.2002.1018015Caffery J.J., Stuber G.L. (1998) Overview of radiolocation in CDMA cellular systems. IEEE Communications Magazine 36(4): 38–45. doi: 10.1109/35.667411Kaaranen H., Ahtiainen A., Laitinen L., Naghian S., Niemi V. (2005) UMTS networks: Architecture, mobility and services. Wiley, Amsterdam3GPP. (2010). TS 25.215 Physical layer; Measurements (FDD). http://www.3gpp.org/ftp/Specs/archive/25_series/25.215/25215-920.zip .3GPP. (2010). TS 25.133 Requirements for support of radio resource management. http://www.3gpp.org/ftp/Specs/archive/25_series/25.133/25133-950.zip .3GPP. (2009). TS 45.010 Radio subsystem synchronization. http://www.3gpp.org/ftp/Specs/archive/45_series/45.010/45010-900.zip .Kos, T., Grgic, M., & Sisul, G. (2006). Mobile user positioning in GSM/UMTS cellular networks. In 48th International Symposium ELMAR-2006 focused on multimedia signal processing and communications (pp. 185–188). doi: 10.1109/ELMAR.2006.329545 .Kirkpatrick S., Gelatt C. D. Jr., Vecchi M. P. (1983) Optimization by simulated annealing. Science 220(4598): 671–680. doi: 10.1126/science.220.4598.671Hepsaydir, E. (1999). Analysis of mobile positioning measurements in CDMA cellular networks. In Radio and Wireless Conference, RAWCON 99 (pp. 73–76). doi: 10.1109/RAWCON.1999.810933 .Villebrun, E., Ben Hadj Alaya, A., Boursier, Y., & Noisette, N. (2006). Indoor Outdoor user discrimination in mobile wireless networks. In Vehicular Technology Conference 2006 Fall (pp. 1–5, 25–28). doi: 10.1109/VTCF.2006.500 .Farr, T.G., et al. (2007). The shuttle radar topography mission. Reviews of geophysics, Vol. 45, RG2004, 33 pp. doi: 10.1029/2005RG000183

Feasible Use of Recycled Concrete Aggregates with Alumina Waste in Road Construction

The management of different industrial by-products, such as recycled aggregates from construction and demolition waste and alumina by-products, as well as the reduction of landfill deposits by incorporating these products in a second life cycle, were the focus of this work. The aim of this study was to demonstrate the technical viability of using these waste and by-product as a material for road pavement base layers. For this purpose, a real-scale application was carried out, and the behavior of three types of materials, applied on a section of an experimental road under real vehicle traffic conditions, was studied and compared. Three materials were used in these sections applied in the road sub-bases. First, a control material composed of a type of artificial gravel was used to be compared with the rest of materials; the second material was composed of recycled aggregates, and the third was composed of a mix of recycled aggregates and alumina waste. The results concluded that the effectiveness of the sections built using recycled aggregates and alumina waste was very positive and similar those constructed using natural aggregates.Isolux-Corsan Constructio

Commercial gilthead seabream (Sparus aurata L.) from the Mar Menor coastal lagoon as hotspots of microplastic accumulation in the digestive system

This paper presents the results on the presence and characterization of microplastics (MP) in the gastrointestinal tract of gilthead seabream (Sparus aurata L.), a species of commercial interest from the Mar Menor coastal lagoon in Southeast Spain. This is the first time that microplastic ingestion is recorded in any species from this semi-enclosed bay. Stomach and intestine from a total of 17 specimens captured by local fishermen were processed, and microplastic particles and fibers found in all of them were displayed. Overall, 40.32% (279/692) of total isolated microparticles proved to be microplastics; i.e., <5 mm, as identified by FTIR spectroscopy. The average value by fish was 20.11 _ 2.94 MP kg1, corresponding to average concentrations of 3912.06 _ 791.24 and 1562.17 _ 402.04 MP by kg stomach and intestine, respectively. Four MP forms were isolated: fiber (71.68%), fragment (21.15%), film (6.81%), and microbead (0.36%), with sizes ranging from 91 _m to 5 mm, an average of 0.83 _ 0.04 mm, and no statistically significant differences between mean sizes in stomach and intestine samples (F-test = 0.004; p = 0.936). Nine polymer types were detected, although most of fibers remained unidentified because of their small size, the presence of polymer additives, or closely adhered pollutants despite the oxidizing digestion carried out to eliminate organic matter. No significant correlation was found between main biological parameters and ingested microplastics, and high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene polypropylene (PEP), and polyvinyl (PV) were identified as the most abundant polymers. The average microplastic ingestion in this study area was higher than those reported in most studies within the Mediterranean Sea, and closely related to microplastic pollution in the surrounding area, although with a predominance of fiber form mainly due to fishery activities.This work was financed by Project 5345/18IQA (Technical University of Cartagena). Analyses carried out by Sonia Olmos were supported by a grant from Fundación Séneca (20268/FPI/17)

Evaluation of physichochemical parameters influencing bulking episodes in a municipal wastewater treatment plant

A study of physicochemical parameters in a municipal wastewater treatment plant was undertaken to consider the presence of bulking phenomena by means of statistical and logistic regression analyses. There appears to be an important effect on activated sludge settleability that can be related to the temperature of wastewater. Besides, there were significant differences between the percentage of nitrogen removal from the secondary treatment with the season. The SVI increased with conductivity, meanwhile BOD5 removal decreased with this parameter. The development of logistic regression models identified two statistically significant variables that appeared to be important to the contribution of a higher SVI: season and pH

Evolution of nutritional biochemical parameters in hemodialysis patients during a one-year follow-up period

La elevada supervivencia actual del paciente en hemodiálisis (52% hasta 5 años), ha hecho que se pongan de manifiesto complicaciones crónicas como la elevada prevalencia de malnutrición en los enfermos, así como la importancia de la situación nutricional en la morbi-mortalidad que presentan. La causa de desnutrición proteico-calórica es multifactorial, aunque procesos de inflamación crónica asociada a la técnica de diálisis cobran cada vez más relevancia. Se han evaluado las variaciones de distintos parámetros bioquímicos nutricionales (proteínas totales, albúmina plasmática, transferrina y colesterol total) de 73 pacientes en hemodiálisis durante un año de seguimiento. La edad media de los pacientes era de 53,3 ± 18,69 años, con 43 varones y 30 mujeres. El tiempo en programa de hemodiálisis ha sido de 43 ± 33 meses, con una duración media de la sesión de 246 ± 24 minutos y dosis media de hemodiálisis administrada de 1,37 ± 0,27 (KT/V) (Daurgidas 2ª generación). Se ha observado un descenso en todos los parámetros bioquímicos evaluados, con diferencias estadísticamente significativas: Proteínas totales (p < 0,001), albúmina (p < 0,00001), colesterol total (p < 0,05) y transferrina (p < 0,01). La evolución de los parámetros bioquímicos nutricionales evaluados mostró un importante deterioro nutricional de los pacientes estables con el tratamiento.Current high survival in hemodialysis patients (52% at 5 years) have made the chronic manifestations to emerge such as the high hyponutrition prevalence of these patients, as well as the importance of the nutritional status in their morbimortality. The reason for protein-caloric hyponutrition is multifactorial, although chronic inflammatory conditions associated to the dialysis technique are becoming more and more relevant. The variations in several nutritional biochemical parameters (total proteins, plasma albumin, transferrin, and total cholesterol) have been assessed in 73 hemodialysis patients for one year. The mean age of the patients was 53.3 ± 18.69 years (43 males and 30 females). The average on hemodialysis program was 43 ± 33 months, with a mean session duration of 246 ± 24 minutes, and mean hemodialysis dose administered of 1.37 ± 0.27 (KT/V) (second generation Daurgidas). A decrease in all the biochemical parameters assessed has been observed, with statistically significant differences: total proteins (p < 0.001), albumin (p < 0.00001), total cholesterol (p < 0.05), and transferrin (p < 0.01). The evolution of the nutritional biochemical parameters assessed showed an important nutritional deterioration of the patients remaining stable with the therapy

Resistance of hyperhomocysteinemia in renal patients to treatment with supra-physiological doses of parenteral folic acid

Los pacientes en hemodiálisis presentan un aumento de homocisteína plasmática (Hcy), debido a la alteración en la metilación causada por la uremia y déficit de los cofactores necesarios (vitamina B, ácido fólico). Esto se correlaciona con un mayor desarrollo de la enfermedad vascular prematura. El tratamiento, no está consensuado, siendo escasa la respuesta a la administración oral de dosis convencionales de ácido fólico. En este trabajo valoramos la respuesta de la hiperhomocisteinemia de 73 pacientes en programa de hemodiálisis periódica tras la administración de 50 mg de ácido folínico parenteral durante 18 meses. La homocisteína plasmática de los pacientes en el momento de inicio del estudio presentaba unos valores medios de 22,67 (μmol/l). Durante el primer año de suplementación mantuvieron el valor medio de 20 μmol/l. A partir del primer año de tratamiento, y hasta finalizar los 18 meses de observación, los niveles medios de homocisteína fueron de 19,58 μmol/l. Aunque con el tiempo de tratamiento encontramos una clara tendencia al descenso de sus valores plasmáticos, no existieron diferencias estadísticamente significativas. Los valores de homocisteína no se normalizaron en ninguno de los pacientes tratados.Hemodialysis patients present an increase in plasma homocysteine (Hcy) due to methylation impairment caused by uremia and the deficiency of the co-factors needed (vitamin B, folic acid). This correlates with a more common development of premature vascular disease. There is no consensus on the therapy, with a poor response to oral administration of conventional doses of folic acid. In this work, we assessed the response of hyperhomocysteinemia in 73 regular hemodialysis patients after the administration of 50 mg of parenteral folinic acid for 18 months. Plasma homocysteine of the patients at the time of the study beginning presented mean values of 22.67 (μmol/L). During the first year of supplementation the mean value was kept at 20 μmol/L. From the first year to the end of the 18-months observation period the mean homocysteine levels were 19.58 μmol/L. Although we found a clear trend towards a decrease in plasma homocysteine levels during the treatment period, there were no significant differences. Homocysteine levels did not come back to normal in none of the patients treated

A nationwide monitoring of atmospheric microplastic deposition

8 Pág.Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 μm to 398 μm, with a median value of 71 μm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition.The authors acknowledge the support provided by Spanish Network of Plastics in the Environment, EnviroPlaNet (www.enviroplanet.net) and the financial support provided by the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22. The authors would like to thank the Interdepartmental Investigation Research Service of the Universidad Autónoma de Madrid (SIDI-UAM and Segainvex) for the use of their infrastructures and their technical support. J.G.S. thanks ACIISI for the contract from the Viera y Clavijo program at the University of La Laguna (85 % co-financed by the European Social Fund).Peer reviewe

Izaña Atmospheric Research Center. Activity Report 2019-2020

Editors: Emilio Cuevas, Celia Milford and Oksana Tarasova.[EN]The Izaña Atmospheric Research Center (IARC), which is part of the State Meteorological Agency of Spain (AEMET), is a site of excellence in atmospheric science. It manages four observatories in Tenerife including the high altitude Izaña Atmospheric Observatory. The Izaña Atmospheric Observatory was inaugurated in 1916 and since that date has carried out uninterrupted meteorological and climatological observations, contributing towards a unique 100-year record in 2016. This reports are a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues.[ES]El Centro de Investigación Atmosférica de Izaña (CIAI), que forma parte de la Agencia Estatal de Meteorología de España (AEMET), representa un centro de excelencia en ciencias atmosféricas. Gestiona cuatro observatorios en Tenerife, incluido el Observatorio de Izaña de gran altitud, inaugurado en 1916 y que desde entonces ha realizado observaciones meteorológicas y climatológicas ininterrumpidas y se ha convertido en una estación centenaria de la OMM. Estos informes resumen las múltiples actividades llevadas a cabo por el Centro de Investigación Atmosférica de Izaña. El liderazgo del Centro en materia de investigación y desarrollo con respecto a las técnicas de medición, calibración y validación de última generación, así como la cooperación internacional, le han otorgado una reputación sobresaliente en lo que se refiere al tiempo, el clima, la hidrología y otros temas ambientales afines