ViC-MAE: Self-Supervised Representation Learning from Images and Video with Contrastive Masked Autoencoders

We propose ViC-MAE, a model that combines both Masked AutoEncoders (MAE) and contrastive learning. ViC-MAE is trained using a global featured obtained by pooling the local representations learned under an MAE reconstruction loss and leveraging this representation under a contrastive objective across images and video frames. We show that visual representations learned under ViC-MAE generalize well to both video and image classification tasks. Particularly, ViC-MAE obtains state-of-the-art transfer learning performance from video to images on Imagenet-1k compared to the recently proposed OmniMAE by achieving a top-1 accuracy of 86% (+1.3% absolute improvement) when trained on the same data and 87.1% (+2.4% absolute improvement) when training on extra data. At the same time ViC-MAE outperforms most other methods on video benchmarks by obtaining 75.9% top-1 accuracy on the challenging Something something-v2 video benchmark . When training on videos and images from a diverse combination of datasets, our method maintains a balanced transfer-learning performance between video and image classification benchmarks, coming only as a close second to the best supervised method.Comment: More results on Video an Image datasets, ViC-MAE now supports training on videos and image

Sistema de costos de producción y su influencia en la determinación del costo y precio de las comidas de la empresa el Paisa E.I.R.L. Distrito de Cusco. Periodo Agosto - Octubre del 2016

La empresa EL PAISA E.I.R.L. de la ciudad del Cusco, dedicada al rubro gastronómico, actualmente carece de un sistema de costos adecuado, que le permita un mejor control sobre los elementos del costo de producción, brindar información oportuna para la toma de decisiones y para generar más ganancia a través de la correcta fijación de precios. Por este motivo se plantea el presente trabajo de investigación titulado: SISTEMA DE COSTOS DE PRODUCCIÓN Y SU INFLUENCIA EN LA DETERMINACIÓN DEL COSTO Y PRECIO DE LAS COMIDAS DE LA EMPRESA EL PAISA E.I.R.L., DISTRITO DE CUSCO, PERÍODO AGOSTO-OCTUBRE DEL 2016; el cual, tiene como objetivo principal demostrar que, al diseñar y aplicar un sistema de costos de producción, se mejora la determinación del costo y precio de las principales comidas vendidas en el restaurant El Paisa. En el diseño y aplicación del Sistema de Costos, se realizó un estudio de la situación inicial de la empresa, en lo que respecta a su proceso productivo, aplicando instrumentos como: entrevistas al personal operativo y observación de documentos internos; para lo cual, se estableció el Sistema de Costos propuesto, realizando la clasificación adecuada de materia prima directa, mano de obra directa y costos indirectos de fabricación. Los resultados obtenidos luego de aplicar el sistema de Costos, fueron: determinar de forma objetiva el costo de producción y precio actual de las comidas; así mismo, comparar el sistema en que se encontraba la empresa y el sistema propuesto, señalando las mejoras que se obtuvieron en el estado de resultados. Podemos concluir que, luego de aplicar la variable independiente el restaurant El Paisa, hoy en día, cuenta con una herramienta de gestión que le va a permitir tomar decisiones apropiadas en busca de mejorar los resultados de su gestión.The company EL PAISA E.I.R.L. of the city of Cusco, dedicated to gastronomy, currently lacks an adequate cost system, which allows a better control over the elements of the cost of production; provide timely information for decision making and to generate more profit through the correct pricing. For this reason the present research work is presented entitled: SYSTEM OF PRODUCTION COSTS AND ITS INFLUENCE IN THE DETERMINATION OF THE COST AND PRICE OF THE FOODS OF THE COMPANY THE PAISA E.I.R.L., CUSCO DISTRICT, AUGUST-OCTOBER PERIOD, 2016; Which has as main objective to demonstrate that, in designing and applying a system of production costs, the determination of the cost and price of the main meals sold in the El Paisa restaurant is improved. In the design and application of the Cost System, a study of the initial situation of the company was carried out, with regard to its production process, applying instruments such as: interviews with operating personnel and observation of internal documents; For which, the proposed Cost System was established, making the appropriate classification of direct raw material, direct labor and indirect manufacturing costs. The results obtained after applying the cost system were: to objectively determine the cost of production and current price of meals; Likewise, to compare the system in which the company and the proposed system were located, indicating the improvements obtained in the income statement. We can conclude that, after applying the independent variable El Paisa restaurant, today, it has a management tool that will allow it to make appropriate decisions in order to improve the results of its management

A fast multi-object tracking system using an object detector ensemble

Multiple-Object Tracking (MOT) is of crucial importance for applications such as retail video analytics and video surveillance. Object detectors are often the computational bottleneck of modern MOT systems, limiting their use for real-time applications. In this paper, we address this issue by leveraging on an ensemble of detectors, each running every f frames. We measured the performance of our system in the MOT16 benchmark. The proposed model surpassed other online entries of the MOT16 challenge in speed, while maintaining an acceptable accuracy.Comment: 5 pages, 4 figures, 1 table, published in 2019 IEEE Colombian Conference on Applications in Computational Intelligence (ColCACI

Diseño y construcción de un Holter de EKG con memoria SD

En este trabajo se describe el diseño y construcción de un Holter de EKG, el cual permite obtener las señales cardiacas de un paciente y almacenarlas en un a memoria SD, durante un tiempo relativamente largo, con el afán de permitirle hacer sus tareas diarias mientras el dispositivo realiza su objetivo. Además de esto, las señales almacenadas en la memoria serán tratadas mediante un software, para ser mostradas en una computadora para que un médico especialista las estudie y pueda emitir un diagnóstico.This project describes the EKG Holter design and construction, with this medical device you can get patients heart signals and storage them in a SD card during a relative long time and permit do the daily chores while the device work. Additionally, the stored signals will be processed with a software to be displayed in a computer in order to be studied by a cardiologist and emit a diagnostic

Implementación de un sistema solar para el calentamiento de agua en uso doméstico

Energy and its use in any of its forms, have delineated the development of human society in each of its evolutionary stages. Trough the years, humanity has perfected the use of energy, going from the simplest to the most complex methods. In the present titling work, the waste of solar energy is analyzed at San Buenaventura parish, and the selection of the solar system that allows to take advantage of it. Considering all these aspects, a water heating system for domestic use is being dimensioned and implemented to replace the conventional one, which selects the parabolic trough solar collector (CCP) and a vacuum tube solar collector (heat pipe), which are: safe, efficient, economical, long-lasting and easy to maintain. For the feasibility of this technological proposal, a solar radiation research is carried out in the sector, receiving an average value of 828 Wh / m2 with peaks greater than 1899 Wh / m2 allowing the sizing of the parabolic trough solar collector (CCP) to jointly with the solar collector of vacuum tubes achieve an average temperature higher than 26 ° C in less time, reaching an efficiency of 35% at a height of 2750 masl, data obtained for the month of February which can be seen in table 5.1. For a better use of the radiation captured in the day by the system, the hot water is stored in a selected accumulator to satisfy the need of 5 people, it has a capacity of 100 liters and keeps the hot water for 24 hours, having a 5% temperature loss, thanks to the thermal insulation layer (polyurethane foam) that allows to minimize the flow of heat to the environment. This type of heating that has a renewable energy source contributes greatly to the environment caring. Keywords: Radiation, solar collector, efficiency, thermal insulation, feasibility.La energía y su utilización en cualquiera de sus formas, han delineado el desarrollo de la sociedad humana en cada una de sus etapas evolutivas. La humanidad a lo largo de los años, ha perfeccionado el uso de la energía, pasando de los métodos más simples a los más complejos. En el presente trabajo de titulación se analiza el desaprovechamiento de la energía solar en la parroquia San Buenaventura, y la selección del sistema solar que permita aprovechar la misma. Considerando todos estos aspectos se dimensionó e implementó un sistema de calentamiento de agua para uso doméstico que reemplace al convencional, la cual se selecciona el colector solar cilindro parabólico (CCP) y un colector solar de tubos de vacío (heat pipe) los mismos que son: seguros, eficientes, económicos, de larga vida útil y de fácil mantenimiento. Para la factibilidad de esta propuesta tecnológica se realiza un estudio de radiación solar en el sector, recibiendo un valor promedio de 828 Wh/m2 con picos superiores a 1899 Wh/m2 permitiendo el dimensionamiento del colector solar cilindro parabólico (CCP) para conjuntamente con el colector solar de tubos de vacío lograr una temperatura promedio superior de 26° C en menor tiempo, alcanzando a una eficiencia del 35% a una altura de 2750 msnm, datos obtenidos del mes de febrero que se puede observar en la tabla 5.1. Para un mejor provecho de la radiación captada en el día por el sistema, el agua caliente se almacena en un acumulador seleccionado para satisfacer la necesidad de 5 personas, este tiene una capacidad de 100 litros y mantiene el agua caliente por 24 horas, teniendo una pérdida de temperatura del 5%, gracias a la capa de aislamiento térmico (espuma de poliuretano) que permite minimizar el flujo de calor hacia el ambiente

Optimal value of past samples for decision making in cognitive radio networks

Context: Modeling and prediction of spectrum use by PUs is an important aspect to reduce interference between SUs and PUs, and improve the performance of the spectral decision. This requires past spectral information, which allows the algorithm to model the behavior of the PU. Objective: Determine the optimal value of past samples and time to recalculate decision criteria for decision-making algorithms in cognitive radio networks. Methodology: Several simulation experiments are performed from the FFAHP algorithm, in two different approaches, real-time and best-effort, with high and low traffic, in the GSM frequency band. A statistical analysis of the data obtained is performed, varying the time range parameters, while time criteria remains constant, and vice versa. Results: For high traffic it is enough to take 1800 previous samples to calculate the initial value of the parameters and update them every 10 minutes (1800). If the traffic is low, it is enough to take 5400 previous samples to calculate the initial value of the parameters and update them every 10 minutes (1800). Conclusions: A large number of previous samples is not necessary to determine the initial value of the decision parameters to obtain a good performance of the handoff rate, nor is it necessary for updating them, for traffic corresponding to the band of GSM frequency. Funding: This work is a result of a research project funded by the Center for Research and Scientific Development of the Francisco José de Caldas District University.Contexto: El modelado y predicción del uso del espectro por parte de los PU es un aspecto importante para reducir la interferencia entre los SU y PU, y mejorar el desempeño de la decisión espectral. Lo anterior requiere de información espectral pasada, que permita al algoritmo modelar el comportamiento del PU. Objetivo: Determinar el valor óptimo de muestras pasadas y tiempo de recalculo de criterios de decisión, para los algoritmos de toma de decisiones en redes de radio cognitiva. Metodología: Se realizan varios experimentos de simulación a partir del algoritmo FFAHP, en dos diferentes enfoques, tiempo-real y mejor-esfuerzo, con tráfico alto y bajo, en la banda de frecuencia GSM. Se realiza un análisis estadístico de los datos obtenidos, variando los parámetros de time range, mientras criteria time permanece constante, y viceversa. Resultados: Para tráfico alto es suficiente con tomar 1800 muestras anteriores para calcular el valor inicial de los parámetros y actualizarlos cada 10 minutos (1800). Si el tráfico es bajo es suficiente con tomar 5400 muestras anteriores para calcular el valor inicial de los parámetros y actualizarlos cada 10 minutos (1800). Conclusiones: No es necesario un número elevado de muestras anteriores para determinar el valor inicial de los parámetros de decisión para obtener un buen desempeño de la tasa de handoff, así como tampoco lo es para la actualización de los mismos, para un tráfico correspondiente a la banda de frecuencia GSM. Financiamiento: El presente trabajo es un resultado de un proyecto de investigación financiado por el Centro de Investigaciones y Desarrollo Científico de la Universidad Distrital Francisco José de Caldas

The influence of teriparatide in induced tooth movement: a systematic review

Teriparatide is a synthetic drug similar than PTH (parathyroid hormone), which is currently used as long-term treatment option for patients with bone chronic diseases, as osteoporosis; and this drug can interfere in a positive way in orthodontic movement. Objectives: The medical literature was assessed in the present systematic review in order to determine the level of scientific evidence supporting the influence of teriparatide in induced tooth movement. The PRISMA Checklist was followed in this systematic review. Four electronic databases (PubMed; Scopus; ScienceDirect; OpenGrey) were searched without implementing restrictions of year, status, and language of publications. The inclusion criteria consisted of selecting only experimental studies comparing the influence of teriparatide in tooth movement of male Wistar rats. The exclusion criteria consisted of experiments with female rats or other experimental animals, and animals with pathologic conditions. The eligible studies were evaluated based on methodological quality. Two trained examiners performed all the research steps. The initial sample comprised 700 studies, which was reduced to 664 after the exclusion of duplicates (n=36). Three articles were selected for the final qualitative analysis. The local administration of parathyroid hormone (PTH) 1-34 or PTH 1-84 revealed major effectiveness when compared with control groups and systematic administration. Additionally, the dilution of PTH 1-34 within methyl cellulose (MC) gel increased the time range for drug release, enabling to reduce the drug concentration without decreasing the effectiveness of tooth movement. Teriparatide demonstrated potential acceleration of tooth movement in Wistar rats depending on the drug concentration; drug administration; and time for drug release

Diffusion-weighted MRI for differentiation between sialadenitis and pleomorphic adenoma

Objectives: The aim of this study was to compare apparent diffusion coefficient (ADC) values from diffusion-weighted MRI (DWI) among normal salivary glands, cases with sialadenitis and cases with pleomorphic adenoma of major salivary glands.Methods: 22 patients (totalling 44 major salivary glands) diagnosed with either unilateral sialadenitis (on either parotid or submandibular gland) or parotid gland pleomorphic adenoma were selected. Contralateral non-affected glands (normal) were also analyzed. DW images were achieved using a spin-echo pulse sequence with a 1.5-T MRI device. Mean ADC values were compared among the three groups analyzed (contralateral normal glands, sialadenitis and pleomorphic adenoma).Results: The mean ADC values were significantly higher in cases of parotid sialadenitis (p = 0.001), but not in cases of submandibular sialadenitis (p = 0.466), as compared with the contralateral non-affected glands. Cases of pleomorphic adenoma presented the highest ADC values of the study. In addition, one-way ANOVA test revealed a significant difference among the three groups of parotid glands analyzed.Conclusions: Within the limitations of this study, the present results suggest that DWI allows for differentiation between parotid sialadenitis and pleomorphic adenoma.peer-reviewe