6,330 research outputs found
A Synthesis Approach for Reproducing the Response of Aircraft Panels to Turbulent Boundary Layer Excitations
Random wall-pressure fluctuations due to a Turbulent-Boundary Layer (TBL) are a feature of the air flow over an aircraft fuselage under cruise conditions, creating undesirable effects such as cabin noise annoyance. In order to test potential solutions for the reduction of TBL-induced noise, a cost-efficient alternative to in-flight measurements or wind-tunnel testing involves simulating the response of aircraft structures to TBL excitation in the laboratory. The authors have already shown that the TBL simulation using a near-field array of loudspeakers is limited to the very low frequency range due to the rapid decay of the spanwise correlation length as frequency increases. The present study addresses the problem of directly simulating the vibroacoustic response of an aircraft skin panel using a near-field array of suitably driven loudspeakers. It is compared with the use of an array of shakers and piezoelectric actuators. It is shown how the wavenumber filtering capabilities of the panel reduces the number of sources required, thus dramatically enlarging the frequency range over which the TBL vibro-acoustic response is reproduced with accuracy. Direct reconstruction of the TBL-induced panel response is found to be feasible over the hydrodynamic coincidence frequency range using a limited number of actuators driven by optimal signals. It is shown that piezoelectric actuators, which have more practical implementation than shakers, provide a more effective reproduction of the TBL response than near-field loudspeakers
The reproduction of the response of an aircraft panel to turbulent boundary layer excitation in laboratory conditions
One important topic in the aeronautic and aerospace industries is the reproduction of random pressure field, with prescribed spatial correlation characteristics, in laboratory conditions. In particular, the random-wall pressure fluctuations induced by a Turbulent Boundary Layer (TBL) excitation are a major concern for cabin noise problem, as this
excitation has been identified as the dominant contribution in cruise conditions. As in-flight measurements require
costly and time-consuming measurement campaigns, the laboratory reproduction has attracted considerable attention
in recent years. Some work has already been carried out for the laboratory simulation of the excitation pressure field
for several random fields. It has been found that TBL reproduction is very demanding in terms of number of loudspeakers per correlation length, and it should require a dense and non-uniform arrangement of acoustic sources due to
the different spanwise and streamwise correlation lengths involved. The present study addresses the problem of directly simulating the vibroacoustic response of an aircraft skin panel using a near-field array of suitably driven loudspeakers. It is compared with the use of an array of shakers and piezoelectric actuators. It is shown how the
wavenumber filtering capabilities of the panel reduces the number of sources required, thus dramatically enlarging
the frequency range over which the TBL vibro-acoustic response is reproduced with accuracy. Direct reconstruction
of the TBL-induced panel response is found to be feasible over the hydrodynamic coincidence frequency range using
a limited number of actuators driven by optimal signals. It is shown that piezoelectric actuators, which have more
practical implementation than shakers, provide a more effective reproduction of the TBL response than near-field
loudspeakers
Influence of developer factors on code quality: a data study
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Automatic source-code inspection tools help to assess,
monitor and improve code quality. Since these tools only
examine the software project’s codebase, they overlook other
possible factors that may impact code quality and the assessment of the technical debt (TD). Our initial hypothesis is that human factors associated with the software developers, like coding expertise, communication skills, and experience in the project have some measurable impact on the code quality. In this exploratory study, we test this hypothesis on two large open source repositories, using TD as a code quality metric and the data that may be inferred from the version control systems. The preliminary results of our statistical analysis suggest that the level of participation of the developers and their experience in the project have a positive correlation with the amount of TD
that they introduce. On the contrary, communication skills have
barely any impact on TD.Peer ReviewedPostprint (author's final draft
A Model of Emotion as Patterned Metacontrol
Adaptive systems use feedback as a key strategy to cope with uncertainty and change in their environments. The information fed back from the sensorimotor loop into the control architecture can be used to change different elements of the controller at four different levels: parameters of the control model, the control model itself, the functional organization of the agent and the functional components of the agent. The complexity of such a space of potential configurations is daunting. The only viable alternative for the agent ?in practical, economical, evolutionary terms? is the reduction of the dimensionality of the configuration space. This reduction is achieved both by functionalisation —or, to be more precise, by interface minimization— and by patterning, i.e. the selection among a predefined set of organisational configurations. This last analysis let us state the central problem of how autonomy emerges from the integration of the cognitive, emotional and autonomic systems in strict functional terms: autonomy is achieved by the closure of functional dependency. In this paper we will show a general model of how the emotional biological systems operate following this theoretical analysis and how this model is also of applicability to a wide spectrum of artificial systems
Identification of levels of sustainable consciousness of teachers in training through an e-portfolio
The contents of Education for Sustainable Development should be included in teachers’ initial and advanced training programs. A sustainable consciousness is one of the main foundations for determining the key competences for sustainability. However, there are not many empirical studies that deal with consciousness from education. In this context, the e-portfolio appears as a tool that promotes reflection and critical thinking, which are key competences for consciousness development. This work intends to propose a categorization system to extract types of consciousness and identify the levels of consciousness of teachers in training. For this research work, which is of an eminently qualitative nature, we have selected 25 e-portfolios of students (teachers in pre-service training) in the last year
of the School of Education at the University of Macerata (Italy). The qualitative methodological procedure that was followed enabled deducing three bases that shape the consciousness of teachers in training: thinking, representation of reality, and type of consciousness. We concluded that the
attainment of a sustainable consciousness in teachers requires activating and developing higher levels of thinking, as well as a projective and macrostructural representation of reality
Consciousness, Meaning and the Future Phenomenology
Phenomenological states are generally considered sources of intrinsic motivation for autonomous biological agents. In this paper we will address the issue of exploiting these states for robust goal-directed systems. We will provide an analysis of consciousness in terms of a precise definition of how an agent “understands” the informational flows entering the agent. This model of consciousness and understanding is based in the analysis and evaluation of phenomenological states along potential trajectories in the phase space of the agents. This implies that a possible strategy to follow in order to build autonomous but useful systems is to embed them with the particular, ad-hoc phenomenology that captures the requirements that define the system usefulness from a requirements-strict engineering viewpoint
Élite tucumana, cuestión regional y proyecto universitario para el norte argentino (1907-1929)
El trabajo aborda la creación de la Universidad de Tucumán, uno de los proyectos más ambiciosos de la élite reformista liberal de la provincia. Esta fundación se sustentó en un pensamiento de corte regional que cuestionaba el “monopolio universitario” de Buenos Aires y Córdoba y propiciaba la descentralización cultural de la República. Sostenía que esta institución contribuiría a restablecer el equilibrio regional alterado por el crecimiento vertiginoso del área pampeana y afirmaría la estructura política federal del Estado argentino. La élite tucumana asumió el liderazgo de esta empresa que recibió el respaldo de los sectores medios de la ciudad de San Miguel de Tucumán.The foundation of the University was one of the most ambitious projects of the liberal reformist elite of the province of Tucumán. This creation had his base in a regional oriented thinking that defied the “university monopoly” of Buenos Aires and Córdoba and promoted the cultural decentralization of the Argentine Republic. It maintain that this institution would contribute to re-establish the regional balance disturbed by the very rapid development of the area of the pampas and would strengthen the federal political structure of the national State. The Tucumán elite take on the leadership of this enterprise which received the support of the middle classes of the city of San Miguel de Tucumán
El consejo de administración y la reputación corporativa: un análisis empírico
Purpose – The purpose of this paper is to test the association between board of director characteristics and corporate reputation. Design/methodology/approach – Logistic and multivariate regressions are performed to analyse whether the board of director characteristics are associated with the level of corporate reputation. The sample is composed of listed companies in the Madrid Stock Exchange (Índice General de la Bolsa de Madrid)atleastonceduringtheperiod2004-2010.Corporategovernancedataweremanuallyextracted from governance reports released by Spanish companies. The data for the design of a corporate reputation measure were obtained from the Monitor Español de Reputación Corporativa (MERCO) institute web site. Findings – Results from the empirical analysis show that Spanish companies that appear high up in terms of ranking in the reputation index provided by MERCO tend to have a higher percentage of independent directors as well as more female directors on their board. Firm size and the image of the president of a firm are also linked to corporate reputation. Originality/value – The results have direct implications for the management of corporate governance mechanisms by shareholders who should take into account their role in the creation and maintenance of corporate reputation.Objetivo
El objetivo de este trabajo es analizar la asociación entre las características de los consejos de administración y la reputación corporativa.
Metodología
La metodología empleada se basa en el uso de regresiones logísticas y multivariantes. Nuestra muestra se compone de las empresas que cotizaron en el Índice General de la Bolsa de Madrid (IGBM) durante el período 2004-2010. Los datos sobre gobierno corporativo se obtuvieron manualmente a partir de los informes de gobierno corporativo publicados por las empresas españolas. La información para diseñar la medida de la reputación corporativa se obtuvo de la página web de MERCO (Monitor Español de Reputación Corporativa).
Resultados
Los resultados del análisis empírico muestran que las empresas españolas que aparecen en las posiciones más altas del ranking de reputación corporativa proporcionado por MERCO tienden a tener un mayor porcentaje de directores independientes y de mujeres en sus consejos de administración. El tamaño de la empresa y la reputación del presidente también están relacionados con la reputación corporativa.
Originalidad
Los resultados tienen implicaciones directas para la gestión de los mecanismos de gobierno corporativo por parte de los accionistas, que deberían considerar el papel de los consejos de administración en la creación y mantenimiento de la reputación corporativa
The development of the digital teaching competence from a sociocultural approach
En la actualidad, la competencia digital docente trasciende de la formación individual del profesorado en materia TIC. El marco europeo DigCompEdu incide en que el profesorado tiene que capacitar al alumnado en la aplicación de las tecnologías digitales de forma crítica y responsable en cuanto a información, comunicación, generación de contenido, bienestar y resolución de problemas. Pese a las buenas intenciones para sistematizar un modelo común de desarrollo de la competencia digital, se detecta que las propuestas carecen de un enfoque pedagógico que sirva de base teórica de los mismos. Este trabajo propone un modelo de desarrollo de la competencia digital docente basado en el enfoque sociocultural mediante cuatro constructos: Dominio, Preferencia, Reintegración y Apropiación. Para ello, se elaboró una escala ad hoc para registrar la competencia digital docente a través del desarrollo de esta en sus estudiantes, aportando evidencias empíricas. Se plantea un diseño de tipo cuestionario. La muestra se compone de 1.881 estudiantes de educación obligatoria de Andalucía. Para el análisis de datos se utilizó SPSS. Los resultados promedios generales por cada una de las dimensiones estudiadas revelan un nivel medio de desarrollo de la competencia digital. Se concluye que aún existe mucho por hacer en cuanto a la formación del profesorado en materia TIC, siendo necesario facilitarles estrategias para el desarrollo de esta en sus estudiantes.Abstract
Many Nowadays, digital teaching competence transcends the individual training of teachers in ICT. The European framework DigCompEdu, highlights that teachers must train students in the application of digital technologies in a critical and responsible way, in terms of information, communication, content generation, wellbeing and problem solving. Despite the good intentions to systematize a common model of development of digital competence, it is detected that the proposals lack a pedagogical approach that serves as a theoretical
© COMUNICAR, 61 (2019-4); e-ISSN: 1988-3293; Preprint DOI: 10.3916/C61-2019-02
framework for them. This paper proposes a development model of the digital teaching competence based on the sociocultural approach through four constructs: Command, Preference, Reintegration and Appropriation. For this study, an ad hoc scale is created to record the digital teaching competence through the development of this in their students and empirical evidences are provided. A survey type design is proposed. The sample consists of 1,881 students of compulsory education in Andalusia (Spain). SPSS is used to analyse data. The average general results for each of the dimensions studied reveal a medium level of development of digital competence. It is concluded that there is still too much to be done in terms of teacher training in ICT, being necessary to provide them strategies for the development of this in their students
El Ius Honorum en la antigua Roma
[Resumen] En la Roma clásica, se estableció una estructura jerarquizada de magistraturas que se encargarían de distintos aspectos de la administración romana. Nosotros analizamos en el presente artículo las características comunes a todas ellas, así como el cometido preciso de cada una de las magistraturas existentes. El cursus honorumobligaba a un itinerario determinado para acceder a un determinado cargo, con plazos temporales, al margen de la necesaria capacidad para el ejercicio del cargo.[Abstract] In classical Rome, was established a hierarchical structure of magistrates would be responsible for various aspects of Roman administration. We analyze in this article the common characteristics to all, as well as the precise role each of the existing magistrates. The cursus honorum forced to a specific course to access a particular charge, with time limits, regardless of the required capacity for the exercise of office
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