Measurement of wide frequency range structural microvibrations with a pocket digital camera and sub-pixel techniques

Analysis of vibrations and displacements is a hot topic in structural engineering. Although there is a wide variety of methods for vibration analysis, direct measurement of displacements in the mid and high frequency range is not well solved and accurate devices tend to be very expensive. Low-cost systems can be achieved by applying adequate image processing algorithms. In this paper, we propose the use of a commercial pocket digital camera, which is able to register more than 420 frames per second (fps) at low resolution, for accurate measuring of small vibrations and displacements. The method is based on tracking elliptical targets with sub-pixel accuracy. Our proposal is demonstrated at a 10 m distance with a spatial resolution of 0.15 mm. A practical application over a simple structure is given, and the main parameters of an attenuated movement of a steel column after an impulsive impact are determined with a spatial accuracy of 4 µm.

Measurement of wide frequency range structural microvibrations with a pocket digital camera and sub-pixel techniques

Analysis of vibrations and displacements is a hot topic in structural engineering. Although there is a wide variety of methods for vibration analysis, direct measurement of displacements in the mid and high frequency range is not well solved and accurate devices tend to be very expensive. Low-cost systems can be achieved by applying adequate image processing algorithms. In this paper, we propose the use of a commercial pocket digital camera, which is able to register more than 420 frames per second (fps) at low resolution, for accurate measuring of small vibrations and displacements. The method is based on tracking elliptical targets with sub-pixel accuracy. Our proposal is demonstrated at a 10 m distance with a spatial resolution of 0.15 mm. A practical application over a simple structure is given, and the main parameters of an attenuated movement of a steel column after an impulsive impact are determined with a spatial accuracy of 4 µm.

Digital Fabrication and Free Culture. One More Minor Becoming?

Diferentes autores se refieren a la fabricación digital como la Tercera Revolución Digital, después de las revoluciones de la computación y la comunicación. Como ocurriera con las dos revoluciones precedentes, se generaron grandes expectativas en torno a las virtualidades políticas de estas nuevas tecnologías para dar lugar a relaciones de producción más libres e individuos más autónomos. Sin embargo, como también ocurriera con la computación y la comunicación, lo que realmente está ocurriendo demuestra que las supuestas virtualidades no llegarán a hacerse actuales sin una intensa implicación, organización y trabajo por parte de sectores activistas técnicos y sociales. Se discute el caso de la compra corporativa de la empresa pionera de hardware libre Makerbot, como ejemplo de la situación y punto de inflexión en las expectativas de los nuevos tecno-visionarios. Para concluir se propone una serie de posibles estrategias que podrían promover el desarrollo efectivo de un ecosistema libre y open source de fabricación digital.

Conocimientos tecnológicos, pedagógicos y disciplinares del profesorado de Primaria

La emergencia de las tecnologías de información y comunicación (TIC) plantea nuevos desafíos educativos al profesorado, a los cuales puede responder desde un modelo de formación coherente. El propósito de este estudio es analizar los conocimientos tecnológicos, pedagógicos y disciplinares del profesorado de Educación Primaria, necesarios para la integración de las TIC en la labor docente. Para ello, se llevó a cabo una investigación con una metodología cuantitativa de carácter no experimental en la que participaron 224 profesores de Educación Infantil y Primaria de la provincia de Alicante. Los resultados mostraron que los docentes poseen mayores conocimientos pedagógicos y disciplinares que tecnológicos, lo que conlleva a escasos conocimientos para la integración de las TIC en la labor docente. Se constataron, además, diferencias significativas entre el género y los años de experiencia docente, y la relación entre el uso lúdico de la tecnología y los conocimientos sobre sus aspectos fundamentales. Según los resultados obtenidos, se corrobora la necesidad de una alfabetización digital del profesorado abordada no solo desde una formación tecnológica, sino también pedagógica y disciplinar de forma global. Ello responde al modelo TPACK (Technological, Pedagogical and Content Knowledge), el cual se contempla como un marco de referencia a tener en cuenta por lo que respecta al desarrollo profesional del profesorado y su vinculación a los procesos de enseñanza-aprendizaje en el aula donde las TIC estén presentes.

Implementation Feasibility of a Digital Nervous System for the Construction Industry: For Efficient and Effective Information Management across the Project Lifecycle

The construction industry has long been considered as highly fragmented and non-collaborative industry. This fragmentation sprouted from complex and unstructured traditional coordination processes and information exchanges amongst all parties involved in a construction project. This nature coupled with risk and uncertainty has pushed clients and their supply chain to search for new ways of improving their business process to deliver better quality and high performing product. This research will closely investigate the need to implement a Digital Nervous System (DNS), analogous to a biological nervous system, on the flow and management of digital information across the project lifecycle. This will be through direct examination of the key processes and information produced in a construction project and how a DNS can provide a well-integrated flow of digital information throughout the project lifecycle. This research will also investigate how a DNS can create a tight digital feedback loop that enables the organisation to sense, react and adapt to changing project conditions. A Digital Nervous System is a digital infrastructure that provides a well-integrated flow of digital information to the right part of the organisation at the right time. It provides the organisation with the relevant and up-to-date information it needs, for critical project issues, to aid in near real-time decision-making. Previous literature review and survey questionnaires were used in this research to collect and analyse data about information management problems of the industry – e.g. disruption and discontinuity of digital information flow due to interoperability issues, disintegration/fragmentation of the adopted digital solutions and paper-based transactions. Results analysis revealed efficient and effective information management requires the creation and implementation of a DNS.