169 research outputs found
Predicting stream baseflow using genetic programing
Developing reliable methods to estimate stream baseflow has been a subject of research over the past decades due to its importance in catchment response and sustainable watershed management (e.g. ground water recharge vs. extraction). Limitations and complexities of existing methods have been addressed by a number of researchers. For instance, physically based numerical models are complex, requiring substantial computational time and data which may not be always available. Artificial Intelligence (AI) tools such as Genetic Programming (GP) have been used widely to reduce the challenges associated with complex hydrological systems without losing the physical meanings. However, up to date, in the absence of complex numerical models, baseflow is frequently estimated using statistically derived empirical equations without significant physical insights. This study investigates the capability of GP in estimating baseflow for a small monitored semi-urban catchment (0.021 km2) located in Singapore. A Recursive Digital Filter (RDF) is first adopted to separate the baseflow from observed streamflow. GP is then used to derive an empirical equation to relate the filtered baseflow time series particularly with groundwater table fluctuations which are relatively easy to be measured and are physically related to baseflow generation. The equation is then validated with a longer time series of baseflow data from a groundwater numerical model. These results indicate that GP is an effective tool in determining baseflow.postprin
Combined Additive Manufacturing Techniques for Adaptive Coastline Protection Structures
Traditional reinforcement cages are manufactured in a handicraft manner and do not use the full potential of the material, nor can they map from optimised geometries. The shown research is focused on robotically-manufactured, structurally-optimised reinforcement structures which are prefabricated and can be encased by concrete through SC3DP in a combined process. Based on the reinforcement concept of “reinforcement supports concrete,” the prefabricated cages support the concrete during application in a combined AM process. To demonstrate the huge potential of combined AM processes based on the SC3DP and WAAM techniques (for example, the manufacturing of individualized CPS), the so-called FLOWall is presented here. First, the form-finding process for the FLOWall concept based on fluid dynamic simulation is explained. For this, a three-step strategy is presented, which consists of (i) the 3D modelling of the element, (ii) the force-flow analysis, and (iii) the structural validation in a computational fluid dynamics software. From the finalized design, the printing phase is divided into two steps, one for the WAAM reinforcement and one for the SC3DP wall. The final result provides a good example of efficient integration of two different printing techniques to create a new generation of freeform coastline protection structures
Dialogue Design for a Robot-Based Face-Mirroring Game to Engage Autistic Children with Emotional Expressions
We present design strategies for Human Robot Interaction for school-aged autistic children with limited receptive language. Applying these strategies to the DE-ENIGMA project (large EU project addressing emotion recognition in autistic children) supported development of a new activity for in facial expression imitation whereby the robot imitates the child’s face to encourage the child to notice facial expressions in a play-based game. A usability case study with 15 typically-developing children aged 4–6 at an English-language school in the Netherlands was performed to observe the feasibility of the setup and make design revisions before exposing the robot to autistic children
Reading hertz's own dipole theory
Basic knowledge in electromagnetic theoryIn this demonstration the plot depicts the time evolution of the lines of force of the electric field around a Hertzian dipole.Thus it recomputes Hertz's famous figures that he had created for several instants of time in the interval[0,3/8 T] , T being the period of short dipole electric oscillationsComponente Curricular::Educação Superior::Ciências Exatas e da Terra::Físic
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