951 research outputs found

    Convergent Aeronautics Solutions (CAS) Project Overview

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    Transonic turbine blade cascade testing facility

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    NASA LeRC has designed and constructed a new state-of-the-art test facility. This facility, the Transonic Turbine Blade Cascade, is used to evaluate the aerodynamics and heat transfer characteristics of blade geometries for future turbine applications. The facility's capabilities make it unique: no other facility of its kind can combine the high degree of airflow turning, infinitely adjustable incidence angle, and high transonic flow rates. The facility air supply and exhaust pressures are controllable to 16.5 psia and 2 psia, respectively. The inlet air temperatures are at ambient conditions. The facility is equipped with a programmable logic controller with a capacity of 128 input/output channels. The data acquisition system is capable of scanning up to 1750 channels per sec. This paper discusses in detail the capabilities of the facility, overall facility design, instrumentation used in the facility, and the data acquisition system. Actual research data is not discussed

    BEHAVIOR ANALYSIS OF TAEKWONDO ATHLETES ACCORDING TO THE ROUNDS OF THE CHAMPIONSHIP

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    The purpose of this study was to analyse the technical and tactical behaviour of taekwondo athletes in a university level taekwondo championship according to the round. A total of 169 matches, consisting of 1088 performances were videotaped. The results showed that athletes when compete in a final and semifinal round performed more direct actions, simultaneous counterattacks, linear kicks, actions to the chest, and with left leg than when competing in prior rounds, whose technical-tactical behavior is characterized by perform more anticipatory actions than competitors in the final and semifinals. This information serves to focus taekwondo training in direct attacks to the chest and perform simultaneous counterattacks, imitating the final round competitors’ behavior

    Potencial turístico de la finca AraL, municipio El Tuma La Dalia, departamento de Matagalpa, durante ll Semestre, 2016

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    El potencial turístico en los municipios del departamento de Matagalpa, durante el ll semestre, 2016, tiene como propósito evaluar el potencial que posee finca AraL, ubicada en la comunidad San José de Wasaka del municipio El Tuma La Dalia. Es importante evaluar el potencial ya que mediante las oportunidades turísticas del territorio, permite superar obstáculos, aporta beneficios directamente al propietario y a la comunidad. De esta manera se determina si la finca cuenta con los recursos necesarios para desarrollarse turísticamente. Conviene señalar que la muestra para las encuestas fue de 10 turistas, de igual manera para la entrevista se aplicó al propietario de la finca. Mediante el método científico se analizó, sintetizó y dedujo la información adquirida a través de consultas a diferentes fuentes bibliográficas. Como conclusión se caracterizó la finca mediante la posición geográfica y su reseña histórica, así mismo se identificaron seis recursos naturales y un único recurso socioeconómico como parte de la oferta. La demanda potencial se determinó mediante el análisis del perfil de los turistas, a su vez se seleccionaron dos lugares como competencia, comparando y analizando sus fortalezas y debilidades, para así definir las oportunidades que tiene la finca, según las características del municipio se seleccionaron cinco tendencias principales que pueden incidir en la finca AraL, cabe señalar que se elaboró una propuesta de desarrollo turístico para la finc

    Private set intersection: A systematic literature review

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    Secure Multi-party Computation (SMPC) is a family of protocols which allow some parties to compute a function on their private inputs, obtaining the output at the end and nothing more. In this work, we focus on a particular SMPC problem named Private Set Intersection (PSI). The challenge in PSI is how two or more parties can compute the intersection of their private input sets, while the elements that are not in the intersection remain private. This problem has attracted the attention of many researchers because of its wide variety of applications, contributing to the proliferation of many different approaches. Despite that, current PSI protocols still require heavy cryptographic assumptions that may be unrealistic in some scenarios. In this paper, we perform a Systematic Literature Review of PSI solutions, with the objective of analyzing the main scenarios where PSI has been studied and giving the reader a general taxonomy of the problem together with a general understanding of the most common tools used to solve it. We also analyze the performance using different metrics, trying to determine if PSI is mature enough to be used in realistic scenarios, identifying the pros and cons of each protocol and the remaining open problems.This work has been partially supported by the projects: BIGPrivDATA (UMA20-FEDERJA-082) from the FEDER Andalucía 2014– 2020 Program and SecTwin 5.0 funded by the Ministry of Science and Innovation, Spain, and the European Union (Next Generation EU) (TED2021-129830B-I00). The first author has been funded by the Spanish Ministry of Education under the National F.P.U. Program (FPU19/01118). Funding for open access charge: Universidad de Málaga/CBU

    Positive mass and Dirac operators on weighted manifolds and smooth metric measure spaces

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    We establish a weighted positive mass theorem which unifies and generalizes results of Baldauf--Ozuch and Chu--Zhu. Our result is in fact equivalent to the usual positive mass theorem, and can be regarded as a positive mass theorem for smooth metric measure spaces. We also study Dirac operators on certain warped product manifolds associated to smooth metric measure spaces. Applications of this include, among others, an alternative proof for a special case of our positive mass theorem, eigenvalue bounds for the Dirac operator on closed spin manifolds, and a new way to understand the weighted Dirac operator using warped products.Comment: 19 pages; references added, edited for readabilit

    Convergent Aeronautics Solutions Project

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    NASA is committed to transforming our aviation system to best meet demands and opportunities of the future. With a vision of safe, efficient, flexible, and environmentally sustainable air transportation, the NASA Aeronautics Research Mission Directorate is conducting research and development to address future needs of the aviation community, the Nation, and the world. While our NASA Aeronautics vision and strategy reaches into the next 25 years and beyond, we recognize that our vision and strategy must be responsive to new discoveries and emerging markets. For this reason, we are empowering our research community to redefine the future of aviation by dreaming up convergent/transformative ideas and studying if those ideas are possible. By modeling the new NASA Aeronautics' Convergent Aeronautics Solutions (CAS) Project after the venture capital community, we created opportunities for teams of intrapreneurs to mature their ideas into concepts through rapid feasibility studies. The CAS Project expects teams to consider the complexities and potential benefits of multi-disciplinary solutions and to leverage technology advances from outside the field of aeronautics. We also expect teams to explore their concepts in a rapid, iterative manner that allows them to learn and adjust their research approach. Within a year or two, teams are responsible for reporting on the feasibility of their concept. The findings inform NASA Aeronautics strategic planning and further investment. This presentation will give an overview of CAS

    Cost/Performance Ratio Achieved by Using a Commodity-Based Cluster

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    Researchers at the NASA Glenn Research Center acquired a commodity cluster based on Intel Corporation processors to compare its performance with a traditional UNIX cluster in the execution of aeropropulsion applications. Since the cost differential of the clusters was significant, a cost/performance ratio was calculated. After executing a propulsion application on both clusters, the researchers demonstrated a 9.4 cost/performance ratio in favor of the Intel-based cluster. These researchers utilize the Aeroshark cluster as one of the primary testbeds for developing NPSS parallel application codes and system software. The Aero-shark cluster provides 64 Intel Pentium II 400-MHz processors, housed in 32 nodes. Recently, APNASA - a code developed by a Government/industry team for the design and analysis of turbomachinery systems was used for a simulation on Glenn's Aeroshark cluster

    Augmented Active-Bending Formwork for Concrete, A Manufacturing Technique for Accessible Local Construction of Structural Systems

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    This research introduces Augmented Reality (AR) for manufacturing concrete structures through an open platform for autonomous construction. The study was developed under the following scopes: computational algorithms for bending simulations, materiality tests, system implementation, and a set of Augmented Reality (AR) tools. AR devices offer a technological tool that allows for a self-built environment through holographic guidance, allowing the untrained workforce to participate in the process. This technology can help users select the system to construct through an Open-Source platform, reducing the gap between complex computational geometries and construction processes. The research aims to investigate a building system that could benefit the UN Objectives SDG 10 by increasing the access to technology in undeveloped communities, SDG 11 and SDG 12 by promoting a self-sustainable method of construction based on local resources and material efficiency. In conjunction with the development of the AR Platform and augmented manufacturing, a 1:1 prototype was built in Quito, Ecuador, with the help of seven people with no previous knowledge of digital tools or construction. Presenting a novel, fast, and affordable concrete formwork connected with AR assisted assembly methods that facilitate access to more efficient and advanced building technology

    Power Assessment in Road Cycling: A Narrative Review

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    Nowadays, the evaluation of physiological characteristics and training load quantification in road cycling is frequently performed through power meter data analyses, but the scientific evidence behind this tool is scarce and often contradictory. The aim of this paper is to review the literature related to power profiling, functional threshold testing, and performance assessment based on power meter data. A literature search was conducted following preferred reporting items for review statement (PRISMA) on the topic of {"cyclist" OR "cycling" AND "functional threshold" OR "power meter"}. The reviewed evidence provided important insights regarding power meter-based training: (a) functional threshold testing is closely related to laboratory markers of steady state; (b) the 20-min protocol represents the most researched option for functional threshold testing, although shorter durations may be used if verified on an individual basis; (c) power profiling obtained through the recovery of recorded power outputs allows the categorization and assessment of the cyclist''s fitness level; and (d) power meters represent an alternative to laboratory tests for the assessment of the relationship between power output and cadence. This review elucidates the increasing amount of studies related to power profiling, functional threshold testing, and performance assessment based on power meter data, highlighting the opportunity for the expanding knowledge that power meters have brought in the road cycling field
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