152 research outputs found
Reviving floodplain in Miami
This is a thesis carried out in three phases. Phase 1 and Phase 2 are research-based, and Phase 3 is exploring the future design schemes under the principles and criteria that have been set up in Phase 1 and 2.
Phase 1 is focused on understanding the water dynamics and major issues in Miami, questions like why Miami is so vulnerable to flooding, and where the water comes from are answered. The conclusions of this phase are scientific principles of how water behaves and how water is managed in the South Florida region. Moreover, critical issues caused by flooding and sea level rise are identified.
Phase 2 is more specific research and analysis of the conditions along the canals in Miami area. Sea level rise will cause flooding not just coastal but also inland along the canals. Inspired by the historical conditions of the Everglades, the author defines the concept of this thesis to revive floodplain in Miami, to bring back floodplain structures in urban area and let flooding express its dynamic, thus to make the city more resilient. This phase includes research and information that would help the author narrow down time scope and site to design with.
Phase 3 is systematic analysis and schematic design showing how the thesis concept is realized in space. Case studies are carried out to examine what has been done in precedent projects. Detailed landscape design is the focus to express how the author’s intentions are displayed in the physical landscape
A Technical Report on the Evaluation of Autonomous Driving with Artificial Intelligence
Ever since the advent of Artificial Intelligence, massive revolution of scientific and technological society has occurred. Under the application of Artificial Intelligence, several relevant technologies have acquired unprecedented rapid development. One of the prominent examples is Autonomous Driving technology, which implements that vehicles can be controlled without humans to travel on roads. This essay aims to introduce the Autonomous Driving technology’s operating principles, then evaluate this technology from two criteria, security and accuracy, and finally provide some recommendations to solve issues. The primary research method is referring to some kinds of academic literature from the library, such as professional journals and books. It is found that the implementation of Autonomous Driving technology has a great possibility in theory. Meanwhile, it is no doubt that there are still some weaknesses existing, such as wrong signal’s interference to sensors, external attacks to computer and not optimistic adaptation for complex environments. However, these difficulties may be overcome when the technology becomes mature in the future
MECHANICAL PROPERTIES OF HUMAN INCUDOSTAPEDIAL JOINT AND TYMPANIC MEMBRANE IN NORMAL AND BLAST-DAMAGED EARS
The human ear consists of outer ear, middle ear and inner ear. The mechanical properties of the incudostapedial joint (ISJ) and tympanic membrane (TM) are critical to the sound transmission function of the ear because the transformation of the acoustic pressure to the mechanical vibration relies on the TM while the vibration of the ossicles transmits through ISJ into the cochlea. However, the dynamic properties of ISJ have not been reported in previous studies. Moreover, injuries in the TM and ISJ have been observed in ears exposed to blast overpressure. The structural and functional changes in the ISJ and TM during and after blast exposure were not investigated. In addition, the sound transfer function of the middle ear has not been characterized under blast overpressure. The absence of these mechanical properties and data obtained from function tests of the human ear impedes the improvement of the accuracy of the finite element (FE) model of the human ear which was designed to simulate the response of the ear to the blast overpressure.
In this study, biomechanical measurements were conducted on TM and ISJ specimens harvested from human cadaveric temporal bones (TB). The dynamic properties of the ISJ were measured using dynamic mechanical analyzer (DMA) at frequencies from 1 to 80 Hz at three temperatures of 5, 25 and 37 °C. The frequency-temperature superposition (FTS) principle was used to extrapolate the complex moduli of the ISJ specimens to 8 kHz. Then, the mechanical properties of ISJ under high-strain-rate deformation were measured by split Hopkinson tension bar. FE simulations on ISJ demonstrated that the behavior of the joint under harmonic and impulse loads was closely related to the structure and the mechanical properties of the joint components.
For biomechanical measurement of the TM, the full-field surface motion of human TMs was measured by scanning laser Doppler vibrometry (SLDV) over a frequency range from 1 to 8 kHz under normal and post-blast conditions. An FE model of the human TM with multilayer microstructure and orthogonal fiber network was built and successfully characterized the features of the surface motion measured from the normal and damaged ears. The consistency between the experimental data and model simulation suggested that the blast-induced damage to the collagen fibers in the TM.
To investigate the mechanism of the induction of the damage, a dual laser setup was established to capture the real-time motion of the TM in the period of time during which the blast waves were propagating through the ear. The motion of the TM umbo within 5 ms after the blast exposure arrived was measured and normalized by the blast pressure levels. The response of the ear was simulated by an FE model of human ear by applying the same input pressure at the entrance of the ear canal. The TM movement and pressure showed good consistency between the results the FE model prediction and the experimental data. The nonlinear behavior of the human middle ear under blast overpressure was observed.
In this dissertation, the behavior of the human ISJ and TM in the normal and blast-damaged was characterized through a series of biomechanical measurements. The quantitative data can be used as input for FE models of the human ear to improve their accuracy on predicting the behavior of the ear under both normal and blast conditions. The methods used in this series of studies provide novel approaches for micron-level biomechanical measurement under dynamic or impulse loads
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