Academic Integrity in the Post-Truth, Fake News Era

In this guest lecture, Dr O\u27 Rourke highlights a number of new challenges in relation to academic integrity with particular reference to the global explosion of fake news

Affine actions on non-archimedean trees

We initiate the study of affine actions of groups on $\Lambda$-trees for a general ordered abelian group $\Lambda$; these are actions by dilations rather than isometries. This gives a common generalisation of isometric action on a $\Lambda$-tree, and affine action on an $\R$-tree as studied by I. Liousse. The duality between based length functions and actions on $\Lambda$-trees is generalised to this setting. We are led to consider a new class of groups: those that admit a free affine action on a $\Lambda$-tree for some $\Lambda$. Examples of such groups are presented, including soluble Baumslag-Solitar groups and the discrete Heisenberg group.Comment: 27 pages. Section 1.4 expanded, typos corrected from previous versio

A Particle Numerical Model for Wall Film Dynamics in Port-Injected Engines

To help predict hydrocarbon emissions during cold-start conditions the authors are developing a numerical model for the dynamics and vaporization of the liquid wall films formed in port-injected spark-ignition engines and incorporating this model in the KIVA-3 code for complex geometries. This paper summarizes the current status of the project and presents illustrative example calculations. The dynamics of the wall film is influenced by interactions with the impinging spray, the wall, and the gas flow near the wall. The spray influences the film through mass, tangential momentum, and energy addition. The wall affects the film through the no-slip boundary condition and heat transfer. The gas alters film dynamics through tangential stresses and heat and mass transfer in the gas boundary layers above the films. New wall functions are given to predict transport in the boundary layers above the vaporizing films. It is assumed the films are sufficiently thin that film flow is laminar and that liquid inertial forces are negligible. Because liquid Prandtl numbers are typically about then, unsteady heating of the film should be important and is accounted for by the model. The thin film approximation breaks down near sharp corners, where an inertial separation criterion is used. A particle numerical method is used for the wall film. This has the advantages of compatibility with the KIVA-3 spray model and of very accurate calculation of convective transport of the film. The authors have incorporated the wall film model into KIVA-3, and the resulting combined model can be used to simulate the coupled port and cylinder flows in modern spark-ignition engines. They give examples by comparing computed fuel distributions with closed- and open-valve injection during the intake and compression strokes of a generic two-valve engine

Behaving Optimistically: How the (Un)Desirability of an Outcome Can Bias People’s Preparations for It

Past research on the desirability bias and on bracing for bad news has focused on the potential influence of outcome desirability on people’s stated expectations. The present studies examined its influence on behavior—that is, what is done in anticipation of, or preparation for, an uncertain outcome. In five studies, the desirability of possible outcomes for an event, which was uncertain and uncontrollable by the participant, was manipulated, and preparation behavior was measured. Study 1 used a hypothetical‐events paradigm. Studies 2 and 3 involved a computer activity in which behavior was tracked on a trial‐by‐trial basis. In Studies 4 and 5, the uncertain event was the ending of a videotaped basketball game. Rather than exhibiting bracing or a reluctance to tempt fate, participants tended to behave in a manner consistent with an optimistic desirability bias. In a subset of studies, predictions and likelihood judgments were also solicited; the differential effects of outcome desirability on these measures are discussed. Copyright © 2015 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135587/1/bdm1918_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135587/2/bdm1918.pd

Sabertooth: A High Mobility Quadrupedal Robot Platform

Team Sabertooth aimed to design and realize an innovative high mobility, quadrupedal robot capable of delivering a payload over terrain impassable by wheeled vehicles at a speed of 5fps. The robot is designed to ascend and descend stairs. The robot uses a spring system in each of its legs for energy efficient locomotion. The 4\u27x3\u27x3\u27 freestanding four legged robot weighs approximately 300lbs with an additional payload capacity of 30lbs. The passive two degree of freedom body joint allows flexibility in terms of robot motion for going around tight corners and ascending stairs. The system integrates sensors for staircase recognition, obstacle avoidance, and distance calculation. A distributed control and software architecture is used for world mapping, path planning and motion control

Mjerenje direktnih i indirektnih učinaka turizma na BDP metodom TSA (satelitski račun turizma): Analiza rezultata za Sloveniju i njena najveća turistička tržišta

Turizam, brzorastuća industrija, prisutan u Sloveniji kao i u ostatku svijeta, suočava se s nepotpunim statističkim praćenjem. U većini zemalja praćenje se odvija u skladu s definiranim kriterijima statističkog praćenja. Iz tog razloga je teže jasno definirati i učinkovito prikazati brzinu kojom se industrija mijenja te njezin domet. Stoga rješenje leži u primjeni satelitskog računa turizma (TSA), koji “pruža detaljan statistički pregled i predstavlja osnovni alat ekonomskog doprinosa turističkog sektora” (TSA: RMF, 2008). Zahvaljujući postojećem trendu šire globalne primjene takvog statističkog praćenja brojnih zemalja diljem svijeta, cilj empirijskog dijela ovog članka je provjeriti učinkovitost ove metodologije u praćenju turističkih tijekova. Učinkovitost smo provjerili u Sloveniji te na njezina četiri najveća turistička tržišta (npr. u Austriji, Italiji i Njemačkoj) i predočili analizu. Prvo, dokazali smo da je dodana vrijednost izračunata pomoću satelitskog računa turizma barem 2% viša u ove četiri zemlje od dodane vrijednosti izračunate tradicionalnim statističkim metodama. Nadalje, učinkovitost ove metode pomaže dokazati učinak koji je posljednja gospodarska kriza imala na turizam. Uopće metoda i rezultati ukazuju na učinkovitost ove metode, što olakšava znnastvenicima i stručnjacima promicanje njenog daljnjeg razvoja

Affirmative Action Bans and Health Risk Behaviors

College affirmative action bans were associated with higher rates of smoking and drinking in underrepresented minority 11th and 12th graders, and these students continued to smoke at higher rates into young adulthood. Policymakers should consider unintended public health consequences of proposals, such as affirmative action bans, that may limit socioeconomic opportunities