9,285 research outputs found

    Regulations and robust low-carbon buildings

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    Building regulations and associated calculation methods have been rapidly evolving, driven in Europe by the European Union Energy Performance of Buildings Directive. As an example, the current UK regulations are explored in relation to buildings that are naturally ventilated, mechanically ventilated, or mechanically ventilated and cooled. The UK regulatory energy and carbon calculation methods are investigated using a standard office design with typical, best practice, and advanced building fabric and systems applied. The criteria and calculations for demonstrating avoidance of excessive temperatures in buildings that have no mechanical cooling are also explored. Observations are made on how the regulations may influence future adoption of mechanical cooling. Current regulatory methods can be subjective and limited in scope. For example, they do not include adaptive comfort criteria or uncertainties in parameters such as occupant behaviour, climate, internal gains from equipment, etc. A design methodology is proposed that addresses these issues and provides a capability parameter to quantify robustness. This capability parameter allows comparison of design options and provides an indication to building users of the limitations to a building's use beyond which mitigating action would have to be taken for performance to be maintained

    A Robust Adaptive Hydraulic Power Generation System for Jet Engines

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    The paper presents an innovative hydraulic power generation system able to enhance performance, reliability and survivability of hydraulic systems used in military jet engines, as well as to allow a valuable power saving. This is obtained by a hydraulic power generation system architecture that uses variable pressure, smart control, emergency power source and suitable health management procedures. A key issue is to obtain all these functions while reducing to a minimum the number of additional components with respect to the conventional hydraulic power generation systems. The paper firstly presents the state-of-art of these systems and their critical issues, outlines the alternative solutions, and then describes architecture, characteristics and performance of the hydraulic power generation system that was eventually defined as a result of a research activity aimed at moving beyond the present state-of-art in this fiel

    Review of Development Stages in the Conceptual Design of an Electro Hydrostatic Actuator for Robotics

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    The design of modern robotic devices faces numerous requirements and limitations which are related to optimization and robustness. Consequently, these stringent requirements have caused improvements in many engineering areas and lead to development of new optimization methods which better handle new complex products designed for application in industrial robots. One of the newly developed methods used in industrial robotics is the concept of a self-contained power device, an Electro-Hydrostatic Actuator (EHA). EHA devices were designed with a central idea, to avoid the possible drawbacks which were present in other types of actuators that are currently used in robotic systems. This paper is a review of the development phases of an EHA device for robotic applications. An overview of the advantages and disadvantages related to current EHA designs are presented, and finally possible ideas for future developments are suggested

    Advanced control designs for output tracking of hydrostatic transmissions

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    The work addresses simple but efficient model descriptions in a combination with advanced control and estimation approaches to achieve an accurate tracking of the desired trajectories. The proposed control designs are capable of fully exploiting the wide operation range of HSTs within the system configuration limits. A new trajectory planning scheme for the output tracking that uses both the primary and secondary control inputs was developed. Simple models or even purely data-driven models are envisaged and deployed to develop several advanced control approaches for HST systems

    Greater response variability in adolescents is associated with increased white matter development.

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    Adolescence is a period of learning, exploration, and continuous adaptation to fluctuating environments. Response variability during adolescence is an important, understudied, and developmentally appropriate behavior. The purpose of this study was to identify the association between performance on a dynamic risky decision making task and white matter microstructure in a sample of 48 adolescents (14-16 years). Individuals with the greatest response variability on the task obtained the widest range of experience with potential outcomes to risky choice. When compared with their more behaviorally consistent peers, adolescents with greater response variability rated real-world examples of risk taking behaviors as less risky via self-report. Tract-Based Spatial Statistics (TBSS) were used to examine fractional anisotropy (FA) and mean diffusivity (MD). Greater FA in long-range, late-maturing tracts was associated with higher response variability. Greater FA and lower MD were associated with lower riskiness ratings of real-world risky behaviors. Results suggest that response variability and lower perceived risk attitudes of real-world risk are supported by neural maturation in adolescents

    Control of a Solar Energy Systems

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    8th IFAC Symposium on Advanced Control of Chemical ProcessesThe International Federation of Automatic Control Singapore, July 10-13This work deals with the main control problems found in solar power systems and the solutions proposed in literature. The paper first describes the main solar power technologies, its development status and then describes the main challenges encountered when controlling solar power systems. While in other power generating processes, the main source of energy can be manipulated, in solar energy systems, the main source of power which is solar radiation cannot be manipulated and furthermore it changes in a seasonal and on a daily base acting as a disturbance when considering it from a control point of view. Solar plants have all the characteristics needed for using industrial electronics and advanced control strategies able to cope with changing dynamics, nonlinearities and uncertainties.Ministerio de Ciencia e Innovación PI2008-05818Ministerio de Ciencia e Innovación DPI2010-21589-C05-01/04Junta de Andalucía P07-TEP-0272
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