Evaluation of crowdsourcing Wi-Fi radio map creation in a real scenario for AAL applications

Indoor location at room level plays a key role for providing useful services for Ambient Assisted Living (AAL) applications. Wi-Fi fingerprinting indoor location methods are extensively used due to the widespread availability of WiFi infrastructures. A main drawback of Wi-Fi fingerprinting methods is the temporal cost involved in creating the radio maps. Crowdsourcing strategies have been presented as a way to minimize the cost of radio map creation. In this work, we present an extensive study of the issues involved when using crowdsourcing strategies for that purpose. Results provided by extensive experiments performed in a real scenario by three users during two weeks are presented. The main conclusions are: i) crowdsourcing data improves accuracy location in most studied cases; ii) accuracy of Wi-Fi fingerprinting methods decay along time; iii) device diversity is an important issue even when using the same device model

Harmonic-by-harmonic time delay compensation Method for PHIL simulation of low impedance power systems

In PHIL simulations different time delays are introduced. Although it can be reduced, there is always some time delay. As a consequence, when the device under test is part of a low impedance power system such as: microgrids, marine or aero power systems, the simulation process becomes challenging due to the poor accuracy of the results achieved by the introduction of the time delay. Therefore, in order to accurately compensate for the inherent time delay introduced in Power Hardware in the Loop (PHIL) simulations, a method based on phase-shifting the reference voltage signal harmonic-by-harmonic and phase-by-phase is proposed. In this manner the time delay compensation will not affect to the system topology and therefore the dynamic behaviour of the original system will stay as it originally was in terms of power angles and V-I phase relationships for all the harmonics processed. In this paper, an experiment where the reference voltage is altered with 5th and 7th harmonics shows that the accuracy of PHIL simulations after the application of this compensation method is greatly improved compared with traditional methods. As a result, low impedance power systems are now able to experience an accurate PHIL simulation

Controller HIL testing of real-time distributed frequency control for future power systems

With the evolution of power system components and structures driven mainly by renewable energy technologies, reliability of the network could be compromised with traditional control methodologies. Therefore, it is crucial to thoroughly validate and test future power system control concepts before deployment. In this paper, a Controller Hardware in the Loop (CHIL) simulation for a real-time distributed control algorithm concept developed within the ELECTRA IRP project is performed. CHIL allows exploration of many real-world issues such as noise, randomness of event timings, and hardware design issues that are often not present on a simulation-only system. Octave has been used as the programming language of the controller in order to facilitate the transition between software simulation and real-time control testing. The distributed controller achieved frequency restoration with a collaborative response between different controllers very fast after the unbalanced area is located

Dolor abdominal crónico en la infancia : Hacia la consulta de alta resolución en Atención Primaria

El dolor abdominal crónico genera multitud de visitas tanto en Atención Primaria como en el hospital. El trabajo muestra cómo puede ser enfocado este proceso en la consulta de Atención Primaria. Nosotros planteamos pautas diagnósticas del dolor abdominal crónico mediante analítica y estudios de imagen individualizados según las indicaciones. Nuestro objetivo es iniciar el diagnóstico y el tratamiento del dolor abdominal crónico, convirtiendo la consulta de Atención Primaria en consulta de alta resolución para esta patología.Chronic abdominal pain causes constant visits of patients in primary and hospital care. This work shows how to approach this process in Primary Care. We show the diagnosis of abdominal pain in children with individualized laboratory testing and imagine studies according to indication. Our purpose is to begin the diagnosis and the management, changing Primary Care into a high resolution form of pediatric healthcare for this [email protected]

Characterization of time delay in power hardware in the loop setups

The testing of complex power components by means of power hardware in the loop (PHIL) requires accurate and stable PHIL platforms. The total time delay typically present within these platforms is commonly acknowledged to be an important factor to be considered due to its impact on accuracy and stability. However, a thorough assessment of the total loop delay in PHIL platforms has not been performed in the literature. Therefore, time delay is typically accounted for as a constant parameter. However, with the detailed analysis of the total loop delay performed in this article, variability in time delay has been detected as a result of the interaction between discrete components. Furthermore, a time delay characterization methodology (which includes variability in time delay) has been proposed. This will allow for performing stability analysis with higher precision as well as to perform accurate compensation of these delays. The implications on stability and accuracy that the time delay variability can introduce in PHIL simulations has also been studied. Finally, with an experimental validation procedure, the presence of the variability and the effectiveness of the proposed characterization approach have been demonstrated

Effect of Microwave Frying on Acrylamide Generation, Mass Transfer, Color, and Texture in French Fries

[EN] The objective of this work was to evaluate the effect of microwave power on acrylamide generation, as well as moisture and oil fluxes and quality attributes of microwave-fried potatoes. Concretely, 25 g of potato strips, in 250 mL of fresh oil (at room temperature), were subjected to three different microwave powers (315, 430, and 600 W) in a conventional microwave oven. Microwave frying resulted in an acrylamide reduction ranged from 37 to 83% compared to deep-oil frying. Microwave-fried French fries presented lower moisture and higher fat content than deep-oil fried potatoes. Concretely, microwave-fried potatoes presented values of moisture and texture more similar to potato chips than French fries, nonetheless with lower fat levels (less than 20 g/100 g wb) and acrylamide content (lower than 100 ¿g/kg wb) at the reference time. This study presents an alternative way of frying to address the production of healthier potato chips.The authors would like to thank the Universitat Politecnica de Valencia for the PhD scholarship given to Mariola Sansano Tomas.Sansano, M.; De Los Reyes Cánovas, R.; Andrés Grau, AM.; Heredia Gutiérrez, AB. (2018). Effect of Microwave Frying on Acrylamide Generation, Mass Transfer, Color, and Texture in French Fries. Food and Bioprocess Technology. 11(10):1934-1939. doi:10.1007/s11947-018-2144-zS193419391110AACC. (1995). Approved methods of the American association of cereal chemists (9th ed.). St. Paul: The Association.Adedeji, A. A., Ngadi, M. O., & Raghavan, G. S. V. (2009). Kinetics of mass transfer in microwave precooked and deep-fat fried chicken nuggets. Journal of Food Engineering, 91(1), 146–153.Ahrné, L., Andersson, C.-G., Floberg, P., Rosén, J., & Lingnert, H. (2007). Effect of crust temperature and water content on acrylamide formation during baking of white bread: steam and falling temperature baking. LWT-Food Science and Technology, 40(10), 1708–1715.Amrein, T. M., Limacher, A., Conde-Petit, B., Amadò, R., & Escher, F. (2006). Influence of thermal processing conditions on acrylamide generation and Browning in a potato model system. Journal of Agricultural and Food Chemistry, 54(16), 5910–5916.Andrés, A., Arguelles, Á., Castelló, M. L., & Heredia, A. (2013). Mass transfer and volume changes in French fries during air frying. Food and Bioprocess Technology, 6(8), 1917–1924.Barutcu, I., Sahin, S., & Sumnu, G. (2009). Acrylamide formation in different batter formulations during microwave frying. LWT - Food Science and Technology, 42(1), 17–22.Belgin Erdoǧdu, S., Palazoǧlu, T. K., Gökmen, V., Şenyuva, H. Z., & Ekiz, H. İ. (2007). Reduction of acrylamide formation in French fries by microwave pre-cooking of potato strips. Journal of the Science of Food and Agriculture, 87(1), 133–137.Biedermann, M., Noti, A., Biedermann-Brem, S., Mozzetti, V., & GROB, K. (2002). Experiments on acrylamide formation and possibilities to decrease the potential of acrylamide formation in potatoes. Mitteilungen aus Lebensmitteluntersuchung und Hygiene, 93(6), 668–687.Bråthen, E., & Knutsen, S. H. (2005). Effect of temperature and time on the formation of acrylamide in starch-based and cereal model systems, flat breads and bread. Food Chemistry, 92(4), 693–700.Buffler, C. R. (1993). Microwave cooking and processing: Engineering fundamentals for the food scientist. (A. Books, Ed.). New York: Van Nostrand Reinhold.Datta, A. K. (1990). Heat and mass transfer in the microwave processing of food. Chemical Engineering Progress, 86(6), 47–53.Datta, A. K. (2001). Handbook of microwave technology for food application. CRC Press.De los Reyes, R., Heredia, A., Fito, P., De los Reyes, E., & Andrés, A. (2007). Dielectric spectroscopy of osmotic solutions and osmotically dehydrated tomato products. Journal of Food Engineering, 80(4), 1218–1225. 2.Granda, C., & Moreira, R. G. (2005). Kinetics of acrylamide formation during traditional and vacuum frying of potato chips. Journal of Food Process Engineering, 28(5), 478–493.Lizhi, H., Toyoda, K., & Ihara, I. (2008). Dielectric properties of edible oils and fatty acids as a function of frequency, temperature, moisture and composition. Journal of Food Engineering, 88(2), 151–158.Oztop, M. H., Sahin, S., & Sumnu, G. (2007). Optimization of microwave frying of potato slices by using Taguchi technique. Journal of Food Engineering, 79(1), 83–91.Parikh, A., & Takhar, P. S. (2016). Comparison of microwave and conventional frying on quality attributes and fat content of potatoes. Journal of Food Science, 81(11), E2743–E2755.Pedreschi, F., & Moyano, P. (2005). Oil uptake and texture development in fried potato slices. Journal of Food Engineering, 70(4), 557–563.Sahin, S., Sumnu, G., & Oztop, M. H. (2007). Effect of osmotic pretreatment and microwave frying on acrylamide formation in potato strips. Journal of the Science of Food and Agriculture, 87(15), 2830–2836. https://doi.org/10.1002/jsfa.3034 .Sansano, M., Juan-Borrás, M., Escriche, I., Andrés, A., & Heredia, A. (2015). Effect of pretreatments and air-frying, a novel technology, on acrylamide generation in fried potatoes. Journal of Food Science, 80(5), 1120–1128.Sansano, M., Heredia, A., Peinado, I., & Andrés, A. (2017). Dietary acrylamide: What happens during digestion. Food Chemistry, 237, 58–64.Schiffmann, R. (2017). 7 - Microwave-assisted frying. In The microwave processing of foods (2nd edn, pp. 142–151). Sawston: Woodhead Publishing.Tang, J., Feng, H., & Lau, M. (2002). Microwave heating in food processing. In X.Young, J. Tang, C. Zhang, & W. Xin (Eds.), Advances in Agricultural Engineering (pp. 1–44). New York: Scientific Press.Tareke, E., Rydberg, P., Karlsson, P., Eriksson, S., & Törnqvist, M. (2002). Analysis of acrylamide, a carcinogen formed in heated foodstuffs. Journal of Agricultural and Food Chemistry, 50(17), 4998–5006.Taubert, D., Harlfinger, S., Henkes, L., Berkels, R., & Schömig, E. (2004). Influence of processing parameters on acrylamide formation during frying of potatoes. Journal of Agricultural and Food Chemistry, 52(9), 2735–2739.Venkatesh, M. S., & Raghavan, G. S. V. (2004). An overview of microwave processing and dielectric properties of agri-food materials. Biosystems Engineering, 88(1), 1–18

Distributed negotiation in future power networks : rapid prototyping using multi-agent system

Technologies like multi-agent system (MAS) have the capability to deal with future power grid requirements such as frequency management and voltage control under a flexible, intelligent and active feature. Based on web of cells (WoC) architecture proposed by European Liaison on Electricity Committed Towards longer-term Research Activity Integrated Research Programme (ELECTRA IRP), a distributed MAS with distributed negotiation ability for future distributed control (including frequency management and voltage control) is proposed. Each cell is designed as an intelligent agent and is investigated in case studies with constraints, where each agent can only communicate with its neighbouring agents. The interaction logic among agents is according to the distributed negotiation algorithm under consideration by the authors. Simulation results indicate that the WoC architecture could negotiate resources in a distributed manner and achieve successful exchange of resources by coordinating distributed agents. Moreover, the prototype reported in this paper can be extended further for future grids' distributed control regimes. The option of MAS to be exploited for the support of the development and integration of novel power system concepts is explored

Analysis of responsibilization within primary frequency control

The emerging need to prioritize remedial frequency control measures closer to the source of an imbalance event, referred to as responsibilization, is being acknowledged. As responsibilization is inherent within secondary frequency control, novel primary frequency control (PFC) approaches to incorporate responsibilization are being proposed in literature. This contribution is aimed to enhance the understanding of responsibilization to enable further improvement and development of the concept. To this end, this paper extends the knowledge-base by presenting an analysis of responsibilization within conventional PFC and a responsibilizing PFC reported in literature. The analysis is undertaken by means of real-time simulation conducted on a six-area reduced model of the Great Britain power system

A novel decentralized responsibilizing primary frequency control

There is an emerging need to prioritize remedial frequency control measures closer to the source of an imbalance event. This approach, referred to herein as responsibilization, is challenging to achieve within the conventional operating times of Primary Frequency Control (PFC) and therefore novel methods are sought. In this letter, a novel decentralized PFC is proposed which relies on transient phase offset to achieve fast responsibilization autonomously. The effectiveness of the proposed control is demonstrated by real-time simulations and its stability assessed by small-signal analysis. This development will lead to increased system resilience during imbalance events