Training from a Better Start Point: Active Self-Semi-Supervised Learning for Few Labeled Samples

Training with fewer annotations is a key issue for applying deep models to various practical domains. To date, semi-supervised learning has achieved great success in training with few annotations. However, confirmation bias increases dramatically as the number of annotations decreases making it difficult to continue reducing the number of annotations. Based on the observation that the quality of pseudo-labels early in semi-supervised training plays an important role in mitigating confirmation bias, in this paper we propose an active self-semi-supervised learning (AS3L) framework. AS3L bootstraps semi-supervised models with prior pseudo-labels (PPL), where PPL is obtained by label propagation over self-supervised features. We illustrate that the accuracy of PPL is not only affected by the quality of features, but also by the selection of the labeled samples. We develop active learning and label propagation strategies to obtain better PPL. Consequently, our framework can significantly improve the performance of models in the case of few annotations while reducing the training time. Experiments on four semi-supervised learning benchmarks demonstrate the effectiveness of the proposed methods. Our method outperforms the baseline method by an average of 7\% on the four datasets and outperforms the baseline method in accuracy while taking about 1/3 of the training time.Comment: 12 pages, 8 figure

Visually Augmented Navigation in an Unstructured Environment Using a Delayed State History

This paper describes a framework for sensor fusion of navigation data with camera-based 5 DOF relative pose measurements for 6 DOF vehicle motion in an unstructured 3D underwater environment. The fundamental goal of this work is to concurrently sstimate online current vehicle position and its past trajectory. This goal is framed within the context of improving mobile robot navigation to support sub-sea science and exploration. Vehicle trajectory is represented by a history of poses in an augmented state Kalman filter. Camera spatial constraints from overlapping imagery provide partial observation of these posa and are used to enforce consislency and provide a mechanism for loop-closure. The multi-sensor camera+navigation framework is shown to have compelling advantages over a camera-only based approach by 1) improving the robustness of pairwise image registration, 2) setting the free gauge scale, and 3) allowing for a unconnected camera graph topology. Results are shown for a real world data set collected by an autonomous underwater vehicle in an unstructured undersea environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86055/1/reustice-32.pd

Visually Augmented Navigation for Autonomous Underwater Vehicles

As autonomous underwater vehicles (AUVs) are becoming routinely used in an exploratory context for ocean science, the goal of visually augmented navigation (VAN) is to improve the near-seafloor navigation precision of such vehicles without imposing the burden of having to deploy additional infrastructure. This is in contrast to traditional acoustic long baseline navigation techniques, which require the deployment, calibration, and eventual recovery of a transponder network. To achieve this goal, VAN is formulated within a vision-based simultaneous localization and mapping (SLAM) framework that exploits the systems-level complementary aspects of a camera and strap-down sensor suite. The result is an environmentally based navigation technique robust to the peculiarities of low-overlap underwater imagery. The method employs a view-based representation where camera-derived relative-pose measurements provide spatial constraints, which enforce trajectory consistency and also serve as a mechanism for loop closure, allowing for error growth to be independent of time for revisited imagery. This article outlines the multisensor VAN framework and demonstrates it to have compelling advantages over a purely vision-only approach by: 1) improving the robustness of low-overlap underwater image registration; 2) setting the free gauge scale; and 3) allowing for a disconnected camera-constraint topology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86054/1/reustice-16.pd

Large Area 3-D Reconstructions from Underwater Optical Surveys

Robotic underwater vehicles are regularly performing vast optical surveys of the ocean floor. Scientists value these surveys since optical images offer high levels of detail and are easily interpreted by humans. Unfortunately, the coverage of a single image is limited by absorption and backscatter while what is generally desired is an overall view of the survey area. Recent works on underwater mosaics assume planar scenes and are applicable only to situations without much relief. We present a complete and validated system for processing optical images acquired from an underwater robotic vehicle to form a 3D reconstruction of the ocean floor. Our approach is designed for the most general conditions of wide-baseline imagery (low overlap and presence of significant 3D structure) and scales to hundreds or thousands of images. We only assume a calibrated camera system and a vehicle with uncertain and possibly drifting pose information (e.g., a compass, depth sensor, and a Doppler velocity log). Our approach is based on a combination of techniques from computer vision, photogrammetry, and robotics. We use a local to global approach to structure from motion, aided by the navigation sensors on the vehicle to generate 3D sub-maps. These sub-maps are then placed in a common reference frame that is refined by matching overlapping sub-maps. The final stage of processing is a bundle adjustment that provides the 3D structure, camera poses, and uncertainty estimates in a consistent reference frame. We present results with ground truth for structure as well as results from an oceanographic survey over a coral reef.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86036/1/opizarro-12.pd

Large Area 3D Reconstructions from Underwater Surveys

Robotic underwater vehicles can perform vast optical surveys of the ocean floor. Scientists value these surveys since optical images offer high levels of information and are easily interpreted by humans. Unfortunately the coverage of a single image is limited hy absorption and backscatter while what is needed is an overall view of the survey area. Recent work on underwater mosaics assume planar scenes and are applicable only to Situations without much relief. We present a complete and validated system for processing optical images acquired from an underwater mbotic vehicle to form a 3D reconstruction of the wean floor. Our approach is designed for the most general conditions of wide-baseline imagery (low overlap and presence of significant 3D structure) and scales to hundreds of images. We only assume a calibrated camera system and a vehicle with uncertain and possibly drifting pose information (e.g. a compass, depth sensor and a Doppler velocity Our approach is based on a combination of techniques from computer vision, photogrammetry and mhotics. We use a local to global approach to structure from motion, aided by the navigation sensors on the vehicle to generate 3D suhmaps. These suhmaps are then placed in a common reference frame that is refined by matching overlapping submaps. The final stage of processing is a bundle adjustment that provides the 3D structure, camera poses and uncertainty estimates in a consistent reference frame. We present results with ground-truth for structure as well as results from an oceanographic survey over a coral reef covering an area of appmximately one hundred square meters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86037/1/opizarro-33.pd

Propuesta de una herramienta de valoración por los métodos de descuento de flujos de efectivo y valoración relativa. Caso Banco Bac San José, S.A.

Proyecto de Graduación (Maestría en Administración de Empresas con énfasis Finanzas) Instituto Tecnológico de Costa Rica. Escuela de Administración de Empresas, 2017.The dynamism seen in the Costa Rican baking sector in terms of mergers and acquisitions (M&A) deals in the last decade coupled with the increased presence of global banks in Costa Rica, which could lead to more deals, motivated this research project. The research is about a proposal of a valuation model involving the valuation methods of discounted cash flows and relative valuation, which was validated with the case of Banco Bac José, S.A. (Bac San José). This model is intended to be used in the event of a M&A deal. It is based on Bac San José´s audited financial statements as well as data on reference interest rates. The data was analyzed through vertical and horizontal analysis aiming to identify historical associations and trends that facilitate the forecast of Bac San José´s future cash flows and profits which are required for the valuation methods. The forecasts also reflect the analysis of Bac San José´s current and future strategy as well as the analysis of expectations of future interest rates in colones and dollars- The valuation methods suggested different values for Bac San José although similar. The discounted cash flows suggested a value of nearly USD1.550 million while the relative valuation suggested a value of around USD1.480 million, with a difference close to USD70 million. Nevertheless, the results of both methods should be considered and therefore in the event of a real M&A deal the price of Bac San José should be somewhere between USD1.480 million and USD1.550 million

Análisis y diseño estructural del complejo deportivo del distrito de Pueblo Nuevo, provincia de Ferreñafe, departamento de Lambayeque utilizando estructuras especiales

La utilización de distintos materiales en las estructuras requiere de un análisis en función a sus características mecánicas. Las estructuras tensadas son una alternativa sofisticada para cubrir espacios de grandes áreas, su análisis y diseño no es común hoy en día y debe ser estudiado previendo fallas. El material bambú, ingresado recientemente a la normativa peruana, es una solución ecológica y armoniosa con el ambiente, solicita en su diseño, muy similar a la madera, tener en cuenta características naturales del material. El beneficio del uso del bambú es el liviano peso que posee, su uso es aplicable a elementos estructurales tales como vigas, columnas y en armaduras para cubiertas. Por ser un material relativamente nuevo, su diseño se basa en el método de esfuerzos admisibles (ASD). También existen en el proyecto estructuras de concreto armado y acero, ambos ya estudiados en cuanto a su análisis y diseño a nivel internacional. Se utiliza el método del diseño por factores de carga y resistencia (LRFD). El uso de estos materiales está presente en el coliseo, el auditorio, losas deportivas y en otras estructuras adicionales que permiten el correcto funcionamiento y brindan serviciabilidad para los propósitos del proyecto

USALSIM: Learning, Professional Practices and Employability in a 3D Virtual World

Int. J. Technology Enhanced Learning, Vol. 5, Nos. 3/4, 2013 pp. 307-321 http://www.inderscience.com/info/inarticletoc.php?jcode=ijtel&year=2013&vol=5&issue=3/4[EN] USALSIM is a project developed by the University of Salamanca as a response to the policy changes of learning and work placements in the new European Space for Higher Education, funded by the Spanish Ministry of Education and inscribed within an innovation programme regarding the employability of university students (CAIE059). The contribution of USALSIM is concerned with how to face the increase in the number of students who will participate in the different university work placement programmes and the increasing number of companies and institutions necessary to host and train theses students. This project uses a 3D virtual environment (a work placement simulator) that creates a virtual representation of different work environments and allows students to acquire professional skills. Representing a professional workspace such as a laboratory, for example, the student can simulate common tasks through active learning. This virtual world is focused on a constructive pedagogy, whereby students are directly involved in their formative development, establishing professional relationships, developing transversal and technical competencies, and evaluating their knowledge

Influencia del mejoramiento vial del Jr. Moquegua, tramo: Jr. Bolognesi - Av. La Marina, para los habitantes del distrito de el Tambo- Huancayo-Junín

El desarrollo del presente Informe Técnico tuvo como problema general: ¿De qué manera influye el Mejoramiento vial del Jr. Moquegua Tramo: Jr. Bolognesi – Av. La Marina, para los habitantes del distrito de El Tambo- Huancayo- Junín?, el Objetivo General fue: Desarrollar el mencionado proyecto, influirá significativamente en sus habitantes. El tipo de estudio del presente informe fue aplicado, de nivel descriptivo y de diseño cuasi experimental. La población fue comprendida por los residentes del distrito de El Tambo comprendidos entre las 8 cuadras del Jr. Moquegua y la muestra está comprendida por 727 beneficiarios directos. La conclusión importante de este informe técnico fue que, con la ejecución y desarrollo del mejoramiento vial del Jr. Moquegua, se ha subsanado problemas de transitabilidad, saneamiento urbano, salubridad, contaminación ambiental y otros que afectan las condiciones de vida.Trabajo de suficiencia profesiona

Contrataciones menores o iguales a 8 Unidades Impositivas Tributarias y principios de contrataciones del Estado en una municipalidad distrital-región Lambayeque

La presente investigación busca analizar la relación entre las contrataciones públicas inferiores o iguales a 8 Unidades Impositivas Tributarias y los principios de contrataciones del estado en una municipalidad distrital de la región Lambayeque. Se desarrolla bajo un diseño no experimental de tipo transversal con un alcance correlacional, la población fue de 61 trabajadores y al tratarse de una cantidad pequeña se utiliza un estudio censal, es decir, la muestra es la población. La técnica utilizada para la recopilación de información es la encuesta mediante la aplicación del instrumento denominado cuestionario. La validez de los instrumentos se llevó a cabo a través del juicio de expertos. Se plantea la hipótesis de la existencia de relación entre las contrataciones inferiores o iguales a 8 UIT y los principios de contrataciones en la municipalidad distrital de la región Lambayeque concluyendo que no existe correlación estadística como resultado, obteniendo un valor de significancia p=0.072 para el objetivo general debido a la independencia los procesos administrativos que integran las contrataciones inferiores con respecto a los principios, sin embargo, la supervisión de los mismos es importante en el desarrollo contractual de las contrataciones públicas en general