skip to main content

Search for: All records

Creators/Authors contains: "Liu, Z"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Free, publicly-accessible full text available May 1, 2024
  2. Free, publicly-accessible full text available April 1, 2024
  3. Free, publicly-accessible full text available March 1, 2024
  4. Although the professional learning opportunities for teachers to introduce computational thinking (CT) into K-12 education are increasing, it remains challenging to support teachers in integrating CT into their everyday classroom practices. In this study, we have identified six elementary teachers who showed evident eagerness or reluctance in a CT integration professional learning experience. We further analyzed the emerging verbal and non-verbal participation patterns of eagerness and reluctance and the challenges teachers have encountered in the professional learning experience. The results shed light on how to better understand and address the challenges in creating sustainable and effective professional learning.
    Free, publicly-accessible full text available April 1, 2024
  5. The article develops an impact-resilient aerial robot (s-ARQ) equipped with a compliant arm to sense contacts and reduce collision impact and featuring a real-time contact force estimator and a non-linear motion controller to handle collisions while performing aggressive maneuvers and stabilize from high-speed wall collisions. Further, a new collision-inclusive planning method that aims to prioritize contacts to facilitate aerial robot navigation in cluttered environments is proposed. A range of simulated and physical experiments demonstrate key benefits of the robot and the contact-prioritized (CP) planner. Experimental results show that the compliant robot has only a 4% weight increase but around 40% impact reduction in drop tests and wall collision tests. s-ARQ can handle collisions while performing aggressive maneuvers and stabilize from high-speed wall collisions at 3.0 m/s with a success rate of 100%. Our proposed compliant robot and contact-prioritized planning method can accelerate computation time while having shorter trajectory time and larger clearances compared to A* and RRT* planners with velocity constraints. Online planning tests in partially-known environments further demonstrate the preliminary feasibility of our method to apply in practical use cases.
    Free, publicly-accessible full text available January 1, 2024
  6. Free, publicly-accessible full text available February 1, 2024
  7. Free, publicly-accessible full text available December 1, 2023
  8. Free, publicly-accessible full text available December 1, 2023
  9. Free, publicly-accessible full text available November 1, 2023
  10. Free, publicly-accessible full text available December 1, 2023