General Techniques for Approximate Incidences and Their Application to the Camera Posing Problem

We consider the classical camera pose estimation problem that arises in many computer vision applications, in which we are given n 2D-3D correspondences between points in the scene and points in the camera image (some of which are incorrect associations), and where we aim to determine the camera pose (the position and orientation of the camera in the scene) from this data. We demonstrate that this posing problem can be reduced to the problem of computing epsilon-approximate incidences between two-dimensional surfaces (derived from the input correspondences) and points (on a grid) in a four-dimensional pose space. Similar reductions can be applied to other camera pose problems, as well as to similar problems in related application areas. We describe and analyze three techniques for solving the resulting epsilon-approximate incidences problem in the context of our camera posing application. The first is a straightforward assignment of surfaces to the cells of a grid (of side-length epsilon) that they intersect. The second is a variant of a primal-dual technique, recently introduced by a subset of the authors [Aiger et al., 2017] for different (and simpler) applications. The third is a non-trivial generalization of a data structure Fonseca and Mount [Da Fonseca and Mount, 2010], originally designed for the case of hyperplanes. We present and analyze this technique in full generality, and then apply it to the camera posing problem at hand. We compare our methods experimentally on real and synthetic data. Our experiments show that for the typical values of n and epsilon, the primal-dual method is the fastest, also in practice

The Effect of Multimedia Cases on Science Teaching Self-Efficacy Beliefs of Prospective Teachers in Kenya

This study examined the effects of multimedia cases on science teaching self-efficacy beliefs of prospective teachers in Kenya using mixed methods in data collection and analysis. Collaborating with two teacher educators at Central University, I designed and implemented two multimedia case-based intervention lessons, one with prospective chemistry teachers and the other with prospective physics teachers. I determined the changes in self-efficacy beliefs using a pretest and posttest with the Science Teaching Efficacy Beliefs Instrument (STEBI) for N=41 participants. I also collected data using a worksheet during the intervention lesson. When the prospective teachers went for their field practice, I sampled eight of them for in depth interviews to determine what they drew on from the intervention lesson during their classroom teaching. I used Roth McDuffie’s et al. (2014) framing to categorize the comments that the prospective teachers made on the worksheet into the four lenses of teacher, students, task or power and participation. I used paired sample t-test to determine the changes in self-efficacy beliefs and then developed profiles of the prospective teachers from the in depth interviews. The results revealed that prospective teachers paid more attention to the actions of the teacher and paid less attention to students’ activities. Their attention to the task was predominantly about the cognitive level of the task and almost always focused on the errors they noted. The prospective teacher noticing using the power and participation lens was not clearly delineable from the teacher lens, because most instructional activities that led to more participation were teacher actions. Science teaching efficacy beliefs has two constructs: personal science teaching efficacy (PSTE) and science teaching outcome expectancy (STOE). The PSTE scores were very high at 4.46 out of five on the pretest, and 4.41 on posttest. There was a decrease in the mean scores, but the change was not significant. There was a statistically significant increase in STOE (M=1.78, SD=5.8 t(40)=2.802 p=0.008) and an overall increase in the self-efficacy beliefs. The teacher profiles showed that prospective teachers drew from specific examples from the multimedia cases as well as learned from a gestalt interpretation of the teaching and learning activities in the clips that were shown. From these results, I discuss how prospective science teachers’ self-efficacy beliefs are altered in the process of watching multimedia cases. Their beliefs about knowledge start to change from absolute ownership to shared and co-constructed knowledge in class, as seen in the decrease in the personal teaching outcome expectancy (PSTE) and an increase in noticing of students’ role in learning

Makers Do Math! Legitimizing Informal Mathematical Practices Within Making Contexts

In this paper, we argue that making activities within non-formal learning environments (e.g., museums, libraries) provide opportunities to engage youth in what we define as mathematical practices for making, everyday mathematical practices within the context of making activities. The mathematical practices identified from two non-formal school-based contexts highlighted three mathematical practices for making: informal measurement, spatial reasoning, and curiosity. These practices are identified in prior scholarship as being beneficial and foundational for the understanding of mathematical concepts. As educators and researchers turn to non-formal and informal contexts, with an eye toward understanding ways youth engage in the activity of making, descriptions of mathematical practices for making build upon prior everyday mathematical practices and open up a new landscape of inquiry

Computer-Aided Design (CAD) Tools to Support the Human Factors Design Teams

The scope of this assessment was to develop a library of basic 1-Gravity (G) human posture and motion elements used to construct complex virtual simulations of ground processing and maintenance tasks for spaceflight vehicles, including launch vehicles, crewed spacecraft, robotic spacecraft, satellites, and other payloads. The report herein describes the task, its purpose, performance, findings, NASA Engineering and Safety Center (NESC) recommendations, and conclusions in the definition and assemblage of the postures and motions database (PMD)

The Ferguson Effect on Police Officers\u27 Culture and Perceptions in Local Police Departments

The Ferguson effect is a recent hypothesis that suggests police officers have been influenced by negative media coverage of police conduct. The problem this study addressed is how policing continues to deal with perception, civil liability, and accountability issues related to police misconduct when interacting with Latino and African-American communities. The research was conducted to examine influence the Ferguson effect may have had on the culture and perceptions of police officers in local police departments. With a phenomenological qualitative approach, the research data were collected from interviews with 7 police officers across 3 police departments. The theoretical background of Merton\u27s theory of unintended consequences offered insights into how law enforcement functions and the kinds of policies that affect police-civilian relations. Data was analyzed with NVivo 12 data analysis software. Four predominant themes emerged: (1) commitment to service, (2) police officers\u27 perception of the media, (3) impact of the Ferguson Effect, and (4) attitudes toward civil liability. The research indicates that the officers shared a strong commitment to service as well as being satisfied overall with the police department where they work. In addition, the participants acknowledged the Ferguson effect but did not believe it prevented them from performing their sworn duties. With this research study, the police officers\u27 voices can be added to the national debate regarding the Ferguson effect and their perception of its impact on their culture in local police departments, community engagement with minority citizens, and civil liability

Wildlife Population Monitoring

Wildlife management is about finding the balance between conservation of endangered species and mitigating the impacts of overabundant wildlife on humans and the environment. This book deals with the monitoring of fauna, related diseases, and interactions with humans. It is intended to assist and support the professional worker in wildlife management

Implications of Privacy Needs and Interpersonal Distancing Mechanisms for Space Station Design

The literature on privacy needs, personal space, interpersonal distancing, and crowding is reveiwed with special reference to spaceflight and spaceflight analogous conditions. A quantitative model is proposed for understanding privacy, interpersonal distancing, and performance. The implications for space station design is described