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  1. Abstract Birds morph their wing shape to accomplish extraordinary manoeuvres 1–4 , which are governed by avian-specific equations of motion. Solving these equations requires information about a bird’s aerodynamic and inertial characteristics 5 . Avian flight research to date has focused on resolving aerodynamic features, whereas inertial properties including centre of gravity and moment of inertia are seldom addressed. Here we use an analytical method to determine the inertial characteristics of 22 species across the full range of elbow and wrist flexion and extension. We find that wing morphing allows birds to substantially change their roll and yaw inertia but has a minimal effect on the position of the centre of gravity. With the addition of inertial characteristics, we derived a novel metric of pitch agility and estimated the static pitch stability, revealing that the agility and static margin ranges are reduced as body mass increases. These results provide quantitative evidence that evolution selects for both stable and unstable flight, in contrast to the prevailing narrative that birds are evolving away from stability 6 . This comprehensive analysis of avian inertial characteristics provides the key features required to establish a theoretical model of avian manoeuvrability.
    Free, publicly-accessible full text available March 24, 2023
  2. de Vries, E. (Ed.)
    Historically, learning for young students has occurred in formal, in-person classroom environments. But in just a matter of weeks, children were mandated to transition to a completely new mode of learning, facing new learning challenges with heightened anxieties. To this end, we aim to better understand how our learning experience design (LXD) efforts support or hinder children’s engagement while participating in an online, video-based math course. This study operationalized LXD through the integration of e-learning instructional design (ID) as a lever for promoting students’ situational interest (SI), emphasis on human-centered design to support students’ user experience (UX), and the combination of SI and UX to foster student engagement in an online environment. Results provide practical implications for how we can intentionally iterate our designs to sustain children’s online engagement as we prepare for future instances of traditional, online and even hybrid models of instruction.
  3. A formidable challenge for global change biologists is to predict how natural populations will respond to the emergence of conditions not observed at present, termed novel climates. Popular approaches to predict population vulnerability are based on the expected degree of novelty relative to the amplitude of historical climate fluctuations experienced by a population. Here, we argue that predictions focused on amplitude may be inaccurate because they ignore the predictability of environmental fluctuations in driving patterns of evolution and responses to climate change. To address this disconnect, we review major findings of evolutionary theory demonstrating the conditions under which phenotypic plasticity is likely to evolve in natural populations, and how plasticity decreases population vulnerability to novel environments. We outline key criteria that experimental studies should aim for to effectively test theoretical predictions, while controlling for the degree of climate novelty. We show that such targeted tests of evolutionary theory are rare, with marine systems being overall underrepresented in this venture despite exhibiting unique opportunities to test theory. We conclude that with more robust experimental designs that manipulate both the amplitude and predictability of fluctuations, while controlling for the degree of novelty, we may better predict population vulnerability to climate change.
  4. With a call in recent years to increase safety and enhance the value of emerging high-rise building clusters, skybridges as linking systems are attacking interest by urban designers and could play a key role in the development of our future cities. While the functional and economic benefits of the skybridges are realized, the effects of skybridges on structural systems are not widely understood. Researchers and practitioners in both academia and industry have been investigating the potential of the skybridge serving to increase the resiliency and sustainability of the connected structures. However, there is a gap between engineering science in academia and engineering practice in industry, which has previously limiting the research outcomes from becoming built realities. Partnering with an industry expert in high-rise building design, Skidmore, Owings & Merrill LLP, this study sought to better understand how coupling behaviors between high-rise structures using a skybridge affect various aspects of the individual and the linked structures. In this study, parametric data, including modal information, displacement, shear, and overturning moment were gathered from realistic high-rise structure models to evaluate the structural performance under static and dynamic loading when the skybridge is installed at various locations of the structures.