Universal Privacy Gurantees for Smart Meters

Smart meters (SMs) provide advanced monitoring of consumer energy usage, thereby enabling optimized management and control of electricity distribution systems. Unfortunately, the data collected by SMs can reveal information about consumer activity, such as the times at which they run individual appliances. Two approaches have been proposed to tackle the privacy threat posed by such information leakage. One strategy involves manipulating user data before sending it to the utility provider (UP); this approach improves privacy at the cost of reducing the operational insight provided by the SM data to the UP. The alternative strategy employs rechargeable batteries or local energy sources at each consumer site to try decouple energy usage from energy requests. This thesis investigates the latter approach. Understanding the privacy implications of any strategy requires an appropriate privacy metric. A variety of metrics are used to study privacy in energy distribution systems. These include statistical distance metrics, differential privacy, distortion metrics, maximal leakage, maximal $\alpha$-leakage and information measures like mutual information. We here use mutual information to measure privacy both because its well understood fundamental properties and because it provides a useful bridge to adjacent fields such as hypothesis testing, estimation, and statistical or machine learning. Privacy leakage under mutual information measures has been studied under a variety of assumptions on the energy consumption of the user with a strong focus on i.i.d. and some exploration of markov processes. Since user energy consumption may be non-stationary, here we seek privacy guarantees that apply for general random process models of energy consumption. Moreover, we impose finite capacity bounds on batteries and include the price of the energy requested from the grid, thus minimizing the information leakage subject to a bound on the resulting energy bill. To that aim we model the energy management unit (EMU) as a deterministic finite-state channel, and adapt the Ahlswede-Kaspi coding strategy proposed for permuting channels to the SM privacy setting. Within this setting, we derive battery policies providing privacy guarantees that hold for any bounded process modelling the energy consumption of the user, including non-ergodic and non-stationary processes. These guarantees are also presented for bounded processes with a known expected average consumption. The optimality of the battery policy is characterized by presenting the probability law of a random process that is tight with respect to the upper bound. Moreover, we derive single letter bounds characterizing the privacy-cost trade off in the presence of variable market price. Finally it is shown that the provided results hold for mutual information, maximal leakage, maximal-alpha leakage and the Arimoto and Sibson channel capacity

Las prácticas sociales de modelación y la emergencia de lo exponencial

El presente trabajo se inserta en la línea de investigación que intenta explicar las relaciones entre las prácticas sociales y la construcción social del conocimiento. Sostenemos que es en el ejercicio de las prácticas sociales donde los actores construyen herramientas que han de constituirse en su conocimiento y éstas a su vez modifican las prácticas. En este trabajo hemos elegido a las prácticas sociales de modelación y su relación con la construcción de lo exponencial como herramienta. Modelando el enfriamiento del silicón los actores construyen modelos y con ellos realizan predicciones, articulando los diferentes modelos con el fenómeno. Se hace énfasis en el análisis epistemológico y como es que lo exponencial se construye al ejercer la modelación

On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications

[EN] Poly(lactic acid) (PLA) is the most used biopolymer for food packaging applications. Several strategies have been made to improve PLA properties for extending its applications in the packaging field. Melt blending approaches are gaining considerable interest since they are easy, cost-effective and readily available processing technologies at the industrial level. With a similar melting temperature and high crystallinity, poly(hydroxybutyrate) (PHB) represents a good candidate to blend with PLA. The ability of PHB to act as a nucleating agent for PLA improves its mechanical resistance and barrier performance. With the dual objective to improve PLAPHB processing performance and to obtain stretchable materials, plasticizers are frequently added. Current trends to enhance PLA-PHB miscibility are focused on the development of composite and nanocomposites. PLA-PHB blends are also interesting for the controlled release of active compounds in the development of active packaging systems. This review explains the most relevant processing aspects of PLA-PHB based blends such as the influence of polymers molecular weight, the PLA-PHB composition as well as the thermal stability. It also summarizes the recent developments in PLA-PHB formulations with an emphasis on their performance with interest in the sustainable food packaging field. PLA-PHB blends shows highly promising perspectives for the replacement of traditional petrochemical based polymers currently used for food packaging.This research was performed within the framework of the project MAT2014-59242-C2-1-R supported by the Spanish Ministry of Economy and Competitiveness (MINECO). Marina Patricia Arrieta is a recipient of Juan de la Cierva Post-Doctoral Contract (FJCI-2014-20630) from the MINECO.Arrieta, MP.; Samper, M.; Aldas-Carrasco, MF.; López-Martínez, J. (2017). On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications. 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Production and characterization of PLA_PBS biodegradable blends reinforced with cellulose nanocrystals extracted from hemp fibres. Industrial Crops and Products, 93, 276-289. doi:10.1016/j.indcrop.2016.01.045González-Ausejo, J., Sánchez-Safont, E., Lagarón, J. M., Balart, R., Cabedo, L., & Gámez-Pérez, J. (2017). Compatibilization of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-poly(lactic acid) blends with diisocyanates. Journal of Applied Polymer Science, 134(20). doi:10.1002/app.44806Arrieta, M. P., Fortunati, E., Dominici, F., Rayón, E., López, J., & Kenny, J. M. (2014). PLA-PHB/cellulose based films: Mechanical, barrier and disintegration properties. Polymer Degradation and Stability, 107, 139-149. doi:10.1016/j.polymdegradstab.2014.05.010Ljungberg, N., & Wesslén, B. (2005). Preparation and Properties of Plasticized Poly(lactic acid) Films. Biomacromolecules, 6(3), 1789-1796. doi:10.1021/bm050098fFerri, J. M., Fenollar, O., Jorda-Vilaplana, A., García-Sanoguera, D., & Balart, R. (2016). Effect of miscibility on mechanical and thermal properties of poly(lactic acid)/ polycaprolactone blends. Polymer International, 65(4), 453-463. doi:10.1002/pi.5079Garcia-Garcia, D., Ferri, J. M., Boronat, T., Lopez-Martinez, J., & Balart, R. (2016). Processing and characterization of binary poly(hydroxybutyrate) (PHB) and poly(caprolactone) (PCL) blends with improved impact properties. Polymer Bulletin, 73(12), 3333-3350. doi:10.1007/s00289-016-1659-6Khosravi-Darani, K. (2015). Application of Poly(hydroxyalkanoate) In Food Packaging: Improvements by Nanotechnology. Chemical and Biochemical Engineering Quarterly, 29(2), 275-285. doi:10.15255/cabeq.2014.2260Sánchez-Safont, E. L., González-Ausejo, J., Gámez-Pérez, J., Lagarón, J. M., & Cabedo, L. (2016). Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)/Purified Cellulose Fiber Composites by Melt Blending: Characterization and Degradation in Composting Conditions. 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P., Fortunati, E., Dominici, F., Rayón, E., López, J., & Kenny, J. M. (2014). Multifunctional PLA–PHB/cellulose nanocrystal films: Processing, structural and thermal properties. Carbohydrate Polymers, 107, 16-24. doi:10.1016/j.carbpol.2014.02.044S. de O. Patrício, P., Pereira, F. V., dos Santos, M. C., de Souza, P. P., Roa, J. P. B., & Orefice, R. L. (2012). Increasing the elongation at break of polyhydroxybutyrate biopolymer: Effect of cellulose nanowhiskers on mechanical and thermal properties. Journal of Applied Polymer Science, 127(5), 3613-3621. doi:10.1002/app.37811European Bioplasticshttp://www.european-bioplastics.org/market/Hu, Y., Sato, H., Zhang, J., Noda, I., & Ozaki, Y. (2008). Crystallization behavior of poly(l-lactic acid) affected by the addition of a small amount of poly(3-hydroxybutyrate). Polymer, 49(19), 4204-4210. doi:10.1016/j.polymer.2008.07.031Arrieta, M. P., López, J., López, D., Kenny, J. M., & Peponi, L. (2015). 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Thermal and crystallinity property studies of poly (L-lactic acid) blended with oligomers of 3-hydroxybutyrate or dendrimers of hydroxyalkanoic acids. Journal of Applied Polymer Science, 111(4), 1720-1727. doi:10.1002/app.29182Vogel, C., & Siesler, H. W. (2008). Thermal Degradation of Poly(ɛ-caprolactone), Poly(L-lactic acid) and their Blends with Poly(3-hydroxy-butyrate) Studied by TGA/FT-IR Spectroscopy. Macromolecular Symposia, 265(1), 183-194. doi:10.1002/masy.200850520Arrieta, M. P., López, J., Hernández, A., & Rayón, E. (2014). Ternary PLA–PHB–Limonene blends intended for biodegradable food packaging applications. European Polymer Journal, 50, 255-270. doi:10.1016/j.eurpolymj.2013.11.009Ohkoshi, I., Abe, H., & Doi, Y. (2000). Miscibility and solid-state structures for blends of poly[(S)-lactide] with atactic poly[(R,S)-3-hydroxybutyrate]. Polymer, 41(15), 5985-5992. doi:10.1016/s0032-3861(99)00781-8Tri, P. N., Domenek, S., Guinault, A., & Sollogoub, C. (2013). Crystallization behavior of poly(lactide)/poly(β-hydroxybutyrate)/talc composites. Journal of Applied Polymer Science, 129(6), 3355-3365. doi:10.1002/app.39056Zhang, L., Xiong, C., & Deng, X. (1996). Miscibility, crystallization and morphology of poly(β-hydroxybutyrate)/poly(d,l-lactide) blends. Polymer, 37(2), 235-241. doi:10.1016/0032-3861(96)81093-7Musioł, M., Sikorska, W., Adamus, G., Janeczek, H., Kowalczuk, M., & Rydz, J. (2015). (Bio)degradable polymers as a potential material for food packaging: studies on the (bio)degradation process of PLA/(R,S)-PHB rigid foils under industrial composting conditions. European Food Research and Technology, 242(6), 815-823. doi:10.1007/s00217-015-2611-yBartczak, Z., Galeski, A., Kowalczuk, M., Sobota, M., & Malinowski, R. (2013). Tough blends of poly(lactide) and amorphous poly([R,S]-3-hydroxy butyrate) – morphology and properties. 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Thermo-Mechanical and Morphological Characterization of Plasticized Poly[(R)-3-hydroxybutyric acid]. Macromolecular Symposia, 169(1), 157-164. doi:10.1002/masy.200451416Janigová, I., Lacı́k, I., & Chodák, I. (2002). Thermal degradation of plasticized poly(3-hydroxybutyrate) investigated by DSC. Polymer Degradation and Stability, 77(1), 35-41. doi:10.1016/s0141-3910(02)00077-0Erceg, M., Kovačić, T., & Klarić, I. (2005). Thermal degradation of poly(3-hydroxybutyrate) plasticized with acetyl tributyl citrate. Polymer Degradation and Stability, 90(2), 313-318. doi:10.1016/j.polymdegradstab.2005.04.048Wang, L., Zhu, W., Wang, X., Chen, X., Chen, G.-Q., & Xu, K. (2007). Processability modifica

Estrategias didácticas para la construcción de conocimientos estadísticos

En este trabajo de investigación se presenta una guía de aprendizaje construida para utilizar una diversidad de herramientas tecnológicas y matemáticas como parte de una estrategia didáctica, estructurada en función de las necesidades de los estudiantes, donde se cuenta con una variedad de problemas contextuales y factibles, considerando una sociedad en crisis y cuya repercusión se proyecta en el proceso educativo. En la aplicación de ésta, se puede apreciar el hecho de la intencionalidad para utilizar las herramientas, las construcciones de conceptos estadísticos, la motivación del trabajo en equipo y los argumentos presentados por los estudiantes para dar significado a la media aritmética y la noción de variabilidad; como logran darle sentido a la toma de decisiones en forma empírica, basados en los efectos que presenta la inestabilidad de los datos

Deep Semi-Supervised and Self-Supervised Learning for Diabetic Retinopathy Detection

Diabetic retinopathy (DR) is one of the leading causes of blindness in the working-age population of developed countries, caused by a side effect of diabetes that reduces the blood supply to the retina. Deep neural networks have been widely used in automated systems for DR classification on eye fundus images. However, these models need a large number of annotated images. In the medical domain, annotations from experts are costly, tedious, and time-consuming; as a result, a limited number of annotated images are available. This paper presents a semi-supervised method that leverages unlabeled images and labeled ones to train a model that detects diabetic retinopathy. The proposed method uses unsupervised pretraining via self-supervised learning followed by supervised fine-tuning with a small set of labeled images and knowledge distillation to increase the performance in classification task. This method was evaluated on the EyePACS test and Messidor-2 dataset achieving 0.94 and 0.89 AUC respectively using only 2% of EyePACS train labeled images

Spin initialization of a p-doped quantum dot coupled to a bowtie nanoantenna

The spin initialization of a hybrid system consisting of a p-doped semiconductor quantum dot coupled to a gold bowtie nanoantenna is analyzed. The quantum dot is described as a four-level atom-like system using the density matrix formalism. The two lower levels are Zeeman-split hole spin states and the two upper levels correspond to positively charged excitons with a spin-up, spin-down hole pair and opposite spin electron. The gold bowtie nanoantenna is placed in close proximity to the quantum dot. A linearly polarized laser field drives two of the optical transitions of the quantum dot and produces localized surface charge oscillations in the nanoantenna which act back upon the quantum dot thus changing the effective field felt by it. The angular frequencies of those charge oscillations are very different along its two principal axes, resulting in an anisotropic modification of the spontaneous emission rates of the allowed optical transitions of the quantum dot. These changes are accounted for by using the Green tensor method, and result in a faster spin state initialization than that of the isolated quantum dot. We also show that the presence of the nanoantenna dramatically modifies the optical properties of the fluorescent photons, either in the spectral and in the time domain

Efecto De La Concentración De Albumina De Huevo Y Tiempo De Batido En Las Características Físicas De Espuma De Pulpa De Sauco (Sambucus Nigra) Con Fines De Deshidratación.

El presente trabajo de investigación tuvo por objetivo evaluar el efecto de la concentración de albumina de huevo y tiempo de batido en las características físicas de la espuma (estabilidad, expansión) de pulpa de sauco (Sambucus nigra) para fines de deshidratación, para lo cual se empleó albumina de huevo como agente espumante; a concentraciones de 5-15% y tiempos de batido de 5-15% como niveles mínimos y máximos. Se realizó 13 tratamientos provenientes del diseño experimental de superficie de respuesta con diseño central compuesto rotacional. Se aplicó un análisis de varianza (ANOVA) encontrándose diferencia significativa (p<0,05), se obtuvo un R2 de 88.44% para la variable expansión y un R2 76.27% para la variable estabilidad, de lo cual se observa que el modelo sólo describe el fenómeno producido por la expansión de espuma. Dicha variable se optimizó para obtener los mejores resultados. Para expansión de espuma se tomaron como valores óptimos en concentración de albumina 16.58 % p/p y en tiempo de batido 10.94 min. La predicción para la óptima combinación fue de 415.25 % de expansión de espuma; dado que en estadística se trabaja con un intervalo de confianza del 95% tendremos dos límites: el inferior de 381. 29 % y el superior de 449.22 % de expansión de espuma. Finalmente mediante una prueba experimental se logró confirmar dichas predicciones validando correctamente la variable expansión de espuma

Diseño de un portal de venta de boletos para solucionar la falta de automatización para una agencia de viajes

"Autobuses México Puebla Estrella Roja (ER) tiene la necesidad de venta de boletos mediante un canal de distribución que no es propio de la empresa, este canal de venta se le denomina agencia de viaje, el proceso de venta en estas agencias de viaje se lleva a cabo utilizando un procedimiento manual de generación de boleto, registro y seguimiento de ventas, generando falsificación de boletos por parte de los clientes a los que se les venden los boletos y haciendo que los ciclos de trabajo sean más largos impactando negativamente en el rendimiento de la gestión de ventas. Este documento describe el desarrollo e implementación de un sistema basado en una plataforma web que permite la venta de boletos sin solicitar un método de pago, y efectúa la venta e impresión del boleto, buscando mejorar los procesos de negocios como el proceso de venta para cubrir todas estas necesidades se decidió crear una aplicación WEB el cual sea capaz de llevar a cabo el proceso de venta con las siguientes características: • Registro de usuarios • Visualización de boletos vendidos al usuario • Venta sin solicitar un método de pago • Emisión de boleto con los estándares de Estrella Roja"

Fasciolosis en vicuñas (vicugna vicugna) en el distrito de Paccha, provincia de Yauli – Junín

El objetivo del presente estudio fue determinar la presencia de huevos de Fasciola hepatica en vicuñas en el distrito de Paccha, provincia de Yauli – Junín, así como, estimar la frecuencia y determinar la asociación con las variables sexo y estrato etario; además determinar la carga parasitaria (hpg). Considerando que se tratan de animales silvestres, se tomaron muestras del mayor número de vicuñas posibles provenientes de un chaccu realizado durante la época de esquila en el mes de setiembre del 2010. Las muestras de heces fueron tomadas directamente del recto de los animales, siendo almacenadas y conservadas en refrigeración a 4ºC para su traslado y evaluación en el Laboratorio de Parasitología de la Facultad de Medicina Veterinaria de la Universidad Nacional Mayor de San Marcos. El diagnóstico de la frecuencia de F. hepatica se realizó mediante la técnica de sedimentación rápida y la determinación de la carga parasitaria, huevos por gramo de heces (hpg), mediante el método de Mc Master modificado. Se encontró una frecuencia de F. hepatica del 32.9%. Respecto a la variable sexo, se halló frecuencias en macho y hembra del 35.8 y 29% respectivamente, y respecto a la variable estrato etario, las frecuencias en cría, juvenil y adulto fueron de 5.6, 45.7 y 33.3 % respectivamente. No se encontró diferencia significativa (p<0.05%) entre las variables sexo, sin embargo, hubo asociación significativa con la variable estrato etario, donde los animales juveniles presentaron un alta frecuencia. La carga promedio fue de 23.7 hpg.Tesi