Avoiding Flow Size Overestimation in the Count-Min Sketch with Bloom Filter Constructions

The Count-Min sketch is the most popular data structure for flow size estimation, a basic measurement task required in many networks. Typically the number of potential flows is large, eliminating the possibility to maintain a counter per flow within memory of high access rate. The Count-Min sketch is probabilistic and relies on mapping each flow to multiple counters through hashing. This implies potential estimation error such that the size of a flow is overestimated when all flow counters are shared with other flows with observed traffic. Although the error in the estimation can be probabilistically bounded, many applications can benefit from accurate flow size estimation and the guarantee to completely avoid overestimation. We describe a design of the Count-Min sketch with accurate estimations whenever the number of flows with observed traffic follows a known bound, regardless of the identity of these particular flows. We make use of a concept of Bloom filters that avoid false positives and indicate the limitations of existing Bloom filter designs towards accurate size estimation. We suggest new Bloom filter constructions that allow scalability with the support for a larger number of flows and explain how these can imply the unique guarantee of accurate flow size estimation in the well known Count-Min sketch.Ori Rottenstreich was partially supported by the German-Israeli Foundation for Scientic Research and Development (GIF), by the Gordon Fund for System Engineering as well as by the Technion Hiroshi Fujiwara Cyber Security Research Center and the Israel National Cyber Directorate. Pedro Reviriego would like to acknowledge the sup-port of the ACHILLES project PID2019-104207RB-I00 and the Go2Edge network RED2018-102585-T funded by the Spanish Ministry of Science and Innovation and of the Madrid Community research project TAPIR-CM grant no. P2018/TCS-4496

On the Practical Limitations for the Generation of Gunn Oscillations in Highly Doped GaN Diodes

Planar Gunn diodes based on doped GaN active layers with different geometries have been fabricated and characterized. Gunn oscillations have not been observed due to the catastrophic breakdown of the diodes for applied voltages around 20-25 V, much below the bias theoretically needed for the onset of Gunn oscillations. The breakdown of the diodes has been analyzed by pulsed I-V measurements at low temperature, and it has been observed to be almost independent of the geometry of the channels, thus allowing to discard self-heating effects as the origin of the device burning. The other possible mechanism for the device failure is impact-ionization avalanche due to the high electric fields present at the anode corner of the isolating trenches. However, Monte Carlo simulations using the typical value of the intervalley energy separation of GaN, ε_(1-2)=2.2 eV, show that impact ionization mechanisms are not significant for the voltages for which the experimental failure is observed. But recent experiments showed that ε_(1-2) is lower, around 0.9 eV. This lower intervalley separation leads to a much lower threshold voltage for the Gunn oscillations, not far from the experimental breakdown. Therefore, we attribute the devices failure to an avalanche process just when Gunn domains start to form, since they increase the population of electrons at the high electric field region, thus strongly enhancing impact ionization mechanisms which lead to the diode failure

Incidencia de la gestión de buenas prácticas agrícolas en vinos obtenidos en el Valle de Calamuchita de Córdoba

Fil: Faillaci, S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Bertozzi, J. Universidad Tecnológica Nacional – Facultad Villa María; Argentina.Fil: Giordano, J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Vanella, O. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Lorenzo Izquierdo, M. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Fil: Reyes Linares, A. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Fil: Vasallo Sordo, M. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Fil: Blanco Carvajal, I. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.En la elaboración del vino la calidad de la materia prima impacta de manera determinante en el producto final por lo que es necesario asegurar la inocuidad desde un proceso que comienza con la plantación de la cepa, la realización de injertos y la poda; el arado del suelo y los tratamientos anuales con agentes químicos que intentan evitar las enfermedades, y sigue con la recolección de la uva y el comienzo del proceso de la primera transformación. Este trabajo tuvo como objetivo establecer e implementar las buenas prácticas agrícolas (BPA) en los primeros emprendimientos vitivinícolas que se han comenzado a establecer como actividad no tradicional en el Valle de Calamuchita de Córdoba, Argentina. Primeramente se realizó un diseño de las plantaciones observando las escorrentías y diseñándose un sistema de riego por goteo libre de agentes químicos asegurando la poda y recolección manual. Para establecer la eficacia de la implementación de la gestión de la inocuidad se realizaron tres tipos seguimientos: 1. determinaciones de residuos de pesticidas organoforforados y organoclorados para asegurarse la no incidencia de posibles contaminantes de zonas aledañas en aguas de napas, suelos y producto final de una finca tomada como modelo; 2. comparaciones en la presencia de metales pesados: arsénico, cadmio y plomo entre una finca modelo y otra no sometida a tratamiento; 3. perfiles de compuestos volátiles mediante cromatografía gaseosa- espectrometría de masa en los vinos finales. Los resultados demuestran que el vino obtenido bajo BPA no manifestó presencia de compuestos organofosforados ni organoclorados; registró un tercio de la concentración de arsénico (0.00264 mg/l vs 0.00757 mg/l) y de la concentración de plomo ( 0.0035 mg/l vs 0.0139 mg/l) – aunque ambos estuvieron bajo los límites aceptables- y presentó menores valores en alcohol isoamílico que puede inducir a enrarecimiento en el sabor durante el almacenamiento.Fil: Faillaci, S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Bertozzi, J. Universidad Tecnológica Nacional – Facultad Villa María; Argentina.Fil: Giordano, J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Vanella, O. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Lorenzo Izquierdo, M. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Fil: Reyes Linares, A. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Fil: Vasallo Sordo, M. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Fil: Blanco Carvajal, I. ICIDCA- Centro de Referencia de Alcoholes y Bebidas; Cuba.Otras Ingeniería Químic

New horizons in geriatric medicine education and training: the need for pan-European education and training standards

The ageing population ought to be celebrated as evidence for the efficacy of modern medicine, but the challenge that this demographic shift presents for 21st century healthcare systems, with increasing numbers of people living with multi-morbidity and frailty, cannot be ignored. There is therefore a need to ensure that all healthcare professionals grasp the basic principles of care of older people. In this paper, we make a case for the development of pan-European education and training standards for the field of geriatric medicine. Firstly, the challenges which face the implementation and delivery of geriatric medicine in a systematic way across Europe are described – these include, but are not limited to; variance in geriatric medicine practice across Europe, insecurity of the specialty in some countries and significant heterogeneity in geriatric medicine training programs across Europe. The opportunities for geriatric medicine are then presented and we consider how engendering core geriatric medicine competencies amongst nongeriatricians has potential to bridge existing gaps in service provision across Europe. Finally, we consider how work can proceed to teach sufficient numbers of doctors and health professionals in the core knowledge, skills and attitudes required to do this. To safeguard the future of the specialty across Europe, we contend that there is a need to strive towards harmonisation of post-graduate geriatric medicine training across Europe, through the establishment of pan-European education and training standards in the specialty

Assaying Total Carotenoids in Flours of Corn and Sweetpotato by Laser Photoacoustic Spectroscopy

This study describes the application of the laser photoacoustic spectroscopy (PAS) for quantification of total carotenoids (TC) in corn flours and sweetpotato flours. Overall, thirty-three different corn flours and nine sweetpotato flours were investigated. All PAS measurements were performed at room temperature using 488-nm argon laser radiation for excitation and mechanical modulation of 9 and 30 Hz. The measurements were repeated within a run and within several days or months. The UV–Vis spectrophotometry was used as the reference method. The concentration range that allows for the reliable analysis of TC spans a region from 1 to 40 mg kg−1 for corn flours and from 9 to 40 mg kg−1 for sweetpotato flours. In the case of sweetpotato flours, the quantification may extend even to 240 mg kg−1 TC. The estimated detection limit values for TC in corn and sweetpotato flours were 0.1 and 0.3 mg kg−1, respectively. The computed repeatability (n = 3–12) and intermediate precision (n = 6–28) RSD values at 9 and 30 Hz are comparable: 0.1–17.1% and 5.3–14.7% for corn flours as compared with 1.4–9.1% and 4.2–23.0% for sweetpotato flours. Our results show that PAS can be successfully used as a new analytical tool to simply and rapidly screen the flours for their nutritional potential based on the total carotenoid concentration