skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Computational Geometry Concept Videos: A Dual-Use Project in Education and Outreach (Media Exposition)
We present a series of nine Computational Geometry Concept Videos, available on Youtube. The videos are aimed at a general audience and introduce concepts ranging from closest and farthest pairs to data structures for range searching and for point location. The video series grew out of the development of an online graduate course on computational geometry, and the beginning portions of the videos are used in the course to motivate the concept and to tie it to a "real" problem in New Orleans. Thus our videos serve a dual purpose of outreach and education.  more » « less
Award ID(s):
2107434
PAR ID:
10588587
Author(s) / Creator(s):
; ;
Editor(s):
Mulzer, Wolfgang; Phillips, Jeff M
Publisher / Repository:
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Date Published:
Volume:
293
ISSN:
1868-8969
ISBN:
978-3-95977-316-4
Page Range / eLocation ID:
88:1-88:4
Subject(s) / Keyword(s):
Computational geometry concepts videos online education Social and professional topics → Computing education Applied computing → Distance learning Theory of computation → Computational geometry
Format(s):
Medium: X Size: 4 pages; 495401 bytes Other: application/pdf
Size(s):
4 pages 495401 bytes
Right(s):
Creative Commons Attribution 4.0 International license; info:eu-repo/semantics/openAccess
Sponsoring Org:
National Science Foundation
More Like this
  1. The large introductory physics lab course at the University of Colorado Boulder, which serves primarily engineering and physical science majors, was recently completely redesigned to align with new explicit learning goals. One of the learning goals of the new course was to have students enjoy working on physics experiments and to see value in experimental physics as a discipline. Additionally, we wanted to make the student workload consistent with a one credit course. To help achieve these goals, we created custom interactive videos that were viewed by the students before the lab to help them prepare for the lab activities. We present design principles for creating these videos, as well as data regarding student engagement and perceptions of this part of the course. Physics Education Research Conference 2019 Part of the PER Conference series Provo, UT: July 24-25, 2019 
    more » « less
  2. Ahn, Hee-Kap; Sadakane, Kunihiko (Ed.)
    Visibility problems are fundamental to computational geometry, and many versions of geometric set cover where coverage is based on visibility have been considered. In most settings, points can see "infinitely far" so long as visibility is not "blocked" by some obstacle. In many applications, this may be an unreasonable assumption. In this paper, we consider a new model of visibility where no point can see any other point beyond a sight radius ρ. In particular, we consider this visibility model in the context of terrains. We show that the VC-dimension of limited visibility terrains is exactly 7. We give lower bound construction that shatters a set of 7 points, and we prove that shattering 8 points is not possible. 
    more » « less
  3. The load on wireless cellular networks is not uniformly distributed through the day, and is significantly higher during peak periods. In this context, we present MANTIS, a time-shifted prefetching solution that prefetches content during off-peak periods of network connectivity. We specifically focus on YouTube given that it represents a significant portion of overall wireless data-usage. We make the following contributions: first, we collect and analyze a real-life dataset of YouTube watch history from 206 users comprised of over 1.8 million videos spanning over a 1-year period and present insights on a typical user's viewing behavior; second, we develop an accurate prediction algorithm using a K-nearest neighbor classifier approach; third, we evaluate the prefetching algorithm on two different datasets and show that MANTIS is able to reduce the traffic during peak periods by 34%; and finally, we develop a proof-of-concept prototype for MANTIS and perform a user study. 
    more » « less
  4. Passive fluid pumping during boiling using the concept of asymmetry in the geometry of the heated surface is studied experimentally. The geometry consists of a channel that is located within a chamber filled with dielectric fluid. The channel ends (inlet and outlet) are exposed to the chamber, such that the ends of the channel have the same pressure prior to the addition of heat. Two types of asymmetry are introduced on the heated surface, and their effect is assessed on the net bubble growth and motion within the open-ended channel. The first is a millimeter-scale asymmetry caused by contouring the vertical walls of the channel into repeating 60-30-degree ratchets. The second asymmetry consists of microscale reentrant cavities, located periodically on the shallow ratchet face of the ratchet. To assess the motion of two-phase flow within the channel, visualization at various heat fluxes ranging from 0.8 – 2.6 watts per square centimeter and subcooling from 2.7 - 11.5 degrees C is performed. Videos of bubble ebullition, mergers and slug transport are analyzed to obtain growth rates, velocities, and frequency counts of slugs emanating from either end of the open-ended channel. 
    more » « less
  5. Passive fluid pumping during boiling using the concept of asymmetry in the geometry of the heated surface is studied experimentally. The geometry consists of a channel that is located within a chamber filled with dielectric fluid. The channel ends (inlet and outlet) are exposed to the chamber, such that the ends of the channel have the same pressure prior to the addition of heat. Two types of asymmetry are introduced on the heated surface, and their effect is assessed on the net bubble growth and motion within the open-ended channel. The first is a millimeterscale asymmetry caused by contouring the vertical walls of the channel into repeating 60-30-degree ratchets. The second asymmetry consists of microscale reentrant cavities, located periodically on the shallow ratchet face of the ratchet. To assess the motion of two-phase flow within the channel, visualization at various heat fluxes ranging from 0.8 – 2.6 W/cm2 and subcooling from 2.7 - 11.5 oC is performed. Videos of bubble ebullition, mergers and slug transport are analyzed to obtain growth rates, velocities, and frequency counts of slugs emanating from either end of the open-ended channel. 
    more » « less