Purcell magneto-elastic swimmer controlled by an external magnetic field

International audienceThis paper focuses on the mechanism of propulsion of a Purcell swimmer whose segments are magnetized and react to an external magnetic field applied into the fluid. By an asymptotic analysis, we prove that it is possible to steer the swimmer along a chosen direction when the control functions are prescribed as an oscillating field. Moreover, we discuss what are the main obstructions to overcome in order to get classical controllability result for this system

C-SAIL Year 3 Convening: Implementation Study Presentation

Laura Desimone presents Year 2 findings from the Implementation Study at C-SAIL\u27s second annual A Conversation on College- and Career-Readiness Standards in Washington, D.C. on April 27, 2018. This PowerPoint presentation corresponds to a presentation video available at c-sail.org/videos

Airline Schedule Recovery after Airport Closures: Empirical Evidence Since September 11th

Since the September 11, 2001 terrorist attacks, repeated airport closures due to potential security breaches have imposed substantial costs on travelers, airlines, and government agencies in terms of flight delays and cancellations. Using data from the year following September 11th, this study examines how airlines recover flight schedules upon reopening of airports that have been closed for security reasons. As such, this is the first study to examine service quality during irregular operations. Our results indicate that while outcomes of flights scheduled during airport closures are difficult to explain, a variety of factors, including potential revenue per flight and logistical variables such as flight distance, seating capacity and shutdown severity, significantly predict outcomes of flights scheduled after airports reopen. Given the likelihood of continued security-related airport closings, understanding the factors that determine schedule recovery is potentially important.

Internal Audit and Financial Reporting Quality in the Public Sector

Using a unique set of hand-collected data, this study investigates the association of (1) the presence of an Internal Audit Function (IAF) and (2) the use of quality assurance programs for the IAF with financial reporting quality in public sector organizations. Specifically, I examine if the presence of IAFs and the use of quality assessments therein is associated with the presence of financial statement audit reportable conditions and restatements in municipalities in the U.S. Results indicate that both the presence of an IAF and use of external quality programs therein are positively associated with financial statement audit reportable conditions related to internal control (significant deficiencies). Findings also suggest that the presence of an IAF is negatively associated with restatements in U.S. municipalities with populations over 100,000 at significant levels. The use of quality assurance programs for the IAF has no effect on the occurrence of restatements. The study’s findings provide insights on IAF influence over financial statement reporting quality in the public sector and suggest further research is necessary. Results should be of interest to standard setters, regulators, and pubic-sector leadership as they attempt to improve governmental financial reporting quality and transparency

Does School Choice Increase School Quality?

Federal No Child Left Behind' legislation, which enables students of low-performing schools to exercise public school choice, exemplies a widespread belief that competing for students will spur public schools to higher achievement. We investigate how the introduction of school choice in North Carolina, via a dramatic increase in the number of charter schools across the state, affects the performance of traditional public schools on statewide tests. We find test score gains from competition that are robust to a variety of specifications. The introduction of charter school competition causes an approximate one percent increase in the score, which constitutes about one quarter of the average yearly growth.

The Effect of Facial Attractiveness on Recognition Memory

The ability to recognize the faces of others has been significant throughout human history. The in-group and out-group bias show that humans remember more faces of people in their own group in most circumstances. This study focused on gender of perceiver and target effects in recognition when faces vary in attractiveness. There were 15 white male and 15 white female participants who engaged in a facial recognition task with a manipulation of target attractiveness. This consisted of the participant encoding 15 male and 15 female computer generated faces for future recognition. The participants saw the same 30 faces randomly mixed with 15 new male and 15 new female faces making a total of 60 faces. They were asked to recognize the faces that they saw in the first set and rate how confident they felt about their answers. The faces used ranged from highly attractive, average, and highly unattractive for both male and female faces. The findings supported the hypothesis that the more attractive or unattractive the faces, the more they will be remembered. Also the findings showed a gender difference in the recognition of faces of the same and other gender

C-SAIL Year 2 Convening: Implementation Study Presentation

Laura Desimone presents Year 1 findings from the Implementation Study at C-SAIL\u27s first annual A Conversation on College- and Career-Readiness Standards in Washington, D.C. on November 18, 2016. This PowerPoint presentation corresponds to a presentation video available at c-sail.org/videos