USFSP Digital Archive
Not a member yet
132282 research outputs found
Sort by
Evaluating the Fault Tolerance of a Parallel Manipulator Based on Relative Manipulability Indices
No full textIn this article, the authors investigate the fault tolerance of manip- ulators in their nominal configuration. In this work, fault tolerance is measured in terms of the worst case relative manipulability index. While this approach is applicable to both serial and parallel mechanisms, it is especially applicable to parallel mechanisms with a limited workspace. It is first shown that the relative manipulability indices are characterized by the null space of the manipulator Jacobian. This motivates the problem of determining the class of manipulator Jacobians with a prescribed null space. This approach can be used to find optimally fault-tolerant manipulators. It is then shown through dimensional arguments that there are limits to the amount of redundancy for this problem to be solvable. The authors use these limits to prove that a previously derived inequality for the worst case relative manipulability index is generally not achieved for fully spatial manipulators and that the concept of optimal fault tolerance to multiple failures is more subtle than previously indicated. After presenting an example of a seven degree- of-freedom mechanism that is optimally fault-tolerant to single failure, the authors consider the problem of finding a manipulator Jacobian that is optimally fault tolerant to multiple failures. It is shown that optimal solutions cannot be equally fault tolerant
Xanthus: Self-Reconfigurable Modular Robot
No full textSecond generation self-reconfigurable modular robotic system Xanthus developed at FIU is presented in this paper. The robot is capable of self-reconfiguring its mechanical structure for efficient walking and crawling as the previous version. In addition, the current version is able to reconfigure and roll conforming to the terrain. In both versions, changing modes is accomplished without human intervention. This work addresses mechanical design, hardware, control and software development for all- terrain navigation. Algorithms for quadruped walking, crawling and rolling are generated and tested on the prototype
A Double Claw Robotic End-Effector Design
No full textA new robotic gripper was designed and constructed for Activities of Daily Living (ADL) to be used with the new Wheelchair- Mounted Robotic Arm developed at USF. Two aspects of the new gripper made it unique; one is the design of the paddles, and the other is the design of the actuation mechanism that produces parallel motion for effective gripping. The paddles of the gripper were designed to grasp a wide variety objects with different shapes and sizes that are used in every day life. The driving mechanism was designed to be simple, light, effective, safe, self content, and independent of the robotic arm attached to it
Implementing NIMS: Lessons Learned from the Boston Marathon Bombing
No full textMany opportunities to learn from the 2013 Boston Marathon bombing have not been capitalized on. The terrorist attack was launched in the heart of Boston, a densely populated urban area with a population of approximately 670,000. Those numbers are amplified by the hundreds of thousands of spectators that line the streets along the Marathon route, with most at the finish line on Boylston Street. Two pressure cooker bombs were detonated in the finish line area, killing three and injuring 264. Among the injured were 16 who suffered traumatic amputations. Numerous reviews of the response and investigation identified positive aspects to be expanded upon and others needing improvement. This monograph presents lessons learned within the context of the National Incident Management System. Individuals that responded to and investigated the attack provide insights into what went well and, more importantly, what didn’t, in the days and weeks following the attack. How would the proper implementation of Unified Command have improved outcomes? Find out from those who were there, have separated from service, and are now free to speak. The lessons presented provide critical guidance for the proper preparation for and response to terrorist attacks in urban environments
Play-Based Pedagogies in Saudi Kindergartens: Examining Teachers’ Perceptions and Practices
No full textIn this study, I explored three Saudi kindergarten teachers’ play-based pedagogies. I conducted a qualitative case study (Stake, 1994) in order to examine these teachers’ perceptions of play and describe the ways they incorporated play into their classrooms. My research questions were: How do three Saudi kindergarten teachers perceive play-based learning? In what ways do three Saudi kindergarten teachers implement play-based learning? Participants taught kindergarten in a large private school that served early childhood, elementary, middle, and high school students in Saudi Arabia. Classroom observations and interviews with the teachers were the central data sources. To analyze the data, I conducted a thematic analysis following Clark and Braun’s (2013) process. I found that teachers believed in the benefits of play for children’s learning and development and believed in the influence of their involvement in children’s learning and play. The teachers indicated that a purposeful play which targets academic learning would also promote children’s developmental skills. Further, teachers expressed hopes to develop the education of early childhood to enhance children\u27s learning outcomes and to enhance their practices in the field. Implications and recommendations for future research from the study findings were discussed
Do Industries\u27 Political Profiles Affect Their Portfolio Return Performance?
No full textThe political profiles of an industry influence its performance due to its impact on industry-level investor sentiment and idiosyncratic risk. I form eight comprehensive political profile portfolios after double sorting on industry-level: (1) political geography proxied by political alignment, (2) corporate political strategies (CPS), proxied by donations to political action committees & lobbying expenditures, (3) and government interference, proxied by dependence on procurement contracts & federal regulations, and exhibit that an industries’ political profiles impact its returns. Industries with high political alignment, concentrated corporate political strategies, and low government interference, deemed the high-performance portfolio, earn an annualized alpha of 10.3428%, significantly out-performing the market. The results hold in a cross-sectional setting, as industries in the high-performance portfolio, earn a 10.338% higher return than the base group. Mispricing is reduced in the short-term in the high-performance portfolio, but prices revert in the medium and long-term. Industries in the high-performance portfolio are more likely to experience positive earnings surprises, and investors tend to under-react to the bad news of firms in the high-performance portfolio. In addition, investor sentiment and idiosyncratic risk is substantially higher for those industries. The political profile impact on stock returns is distinct and substantially stronger than other political factors known to predict returns
Untangling the Phenomenon of Teacher Anxiety During the COVID-19 Pandemic: Voices of Secondary ELA Teachers
No full textHybrid simultaneous teaching, surgical masks, Lysol wipes, and uncertainty capture the zeitgeist of teaching during COVID-19. This study builds on teachers’ daily stressors in the classroom. Many shifts in education that never seemed possible created angst and anxiety in the classroom (Cupido, 2018; Dubey and Pandey, 2020; El Rizaq & Sarmini, 2021; Zuo et al., 2020; Garcia and Piotrowski, 2022). Teachers entered the 2020-2021 school year having to learn many firsts.The purpose of this study was to understand the interplay of work-life lived experiences of secondary English teachers with moments of anxiety during the COVID-19 pandemic. Using a post-intentional phenomenological approach, I framed my study using the philosophies from Vagle, Van Manen, Schön, and Seidman. The following questions guided this study: (1) What was it like to teach secondary English with moments of anxiety during COVID-19? and (2) How does teaching during COVID-19 affect your teaching pedagogy? The participants are teachers of English in the United States teaching in grades 6-12 (secondary) from ages 20-69 years old. Participants in this study taught English during COVID-19 while experiencing moments of anxiety. This study had a unique way of identifying specific moments that caused anxiety for my secondary ELA participants. Each participant engaged in this study, and I found the following from my three participants: (1): Teaching English during Covid was exhausting and created anxiety; (2): Teaching ELA was Ineffective and Caused Anxiety; (3) Teaching English during Covid was overwhelming, and (4): Changes during Covid created moments of anxiety; (5) Stakeholders produced moments of anxiety while teaching English, and (6): ELA assessments were anxiety-producing. The experiences shared by my three participants shed light on the voices within the classroom, which created moments of anxiety. The experiences and findings from each of my participants it was clear that there were specific moments that were more anxiety-producing, which led me to my implications of how we can better support the needs of teachers. The following implications were discovered from this study: (a) Stakeholders need to be empathetic and supportive; (b) ELA teachers need better support; and (c) Changes should happen in stages. This study did not generalize to a larger demographic; however, other ELA teachers might be able to connect and relate to the findings and stories of this study
Spatial Pattern and Environmental and Social Factors of Monkeypox in the Contiguous United States
No full textMonkeypox is a rare viral disease that is usually transmitted to humans through contact with infected animals, such as rodents or primates. Although its symptoms are similar to those of smallpox, monkeypox is generally less severe and rarely fatal. In recent years, however, there has been an uptick in the number of reported cases, with a large outbreak occurring in several parts of the world in May 2022. This has raised concerns among public health officials and researchers, who are working to better understand the factors that contribute to the spread of the disease. One promising approach to studying the epidemiology of monkeypox is through the use of geographic information systems (GIS). By mapping the spatial distribution of the disease and analyzing its relationship to various environmental and socioeconomic factors, researchers can gain valuable insights into how monkeypox is transmitted and what measures can be taken to prevent its spread. In this study, we collected data on a range of socioeconomic, environmental, and demographic factors and used GIS to identify patterns in the incidence of monkeypox. We found that monkeypox outbreaks show strong spatial autocorrelation and were mainly concentrated in the northeastern United States. Socio-economic factors such as per capita income, the proportion of same-sex families, race, population density, and age structure all had a significant impact on the incidence of the disease. This information could be used to develop targeted interventions aimed at reducing the spread of monkeypox in affected areas
A Cross-national Study of Multilevel Determinants on Public Fully Vaccination Against COVID-19
No full textThe pandemic caused by SARS-CoV-2 (COVID-19) has impacted the world for close to three years and led to substantial costs to public well-being. To mitigate the pandemic\u27s damage, the most effective approach lies in the vaccine. This study aims to investigate multilevel predictors of the public decision to become fully vaccinated against COVID-19. Data from a cross-national survey on representative samples are merged with country-level indicators. Multilevel logistic regression models are estimated on populations from 15 countries. Findings show that people who agree the government handles the pandemic well, believe the health officials would provide an effective vaccine, perceive the virus\u27s danger, and are older are more likely to get fully vaccinated than their counterparts. Meanwhile, the national case rate and vaccination rate also affect one\u27s decision to become fully vaccinated. Furthermore, there are significant cross-level interactions as people are more inclined to become fully vaccinated if they agree with the government\u27s performance, perceive the virus\u27s danger, and also reside in countries with higher case and vaccination rates. This study shows cross-national evidence regarding multilevel determinants of public vaccine uptake. Knowing the profiles among populations who have become fully vaccinated or not helps public health experts leverage factors and maximize vaccination
