1,728 research outputs found
Program and Data for 'Cat and Mouse Search' paper
No full textHillstrom, Anne P., Segabinazi, Joice D., Godwin, Hayward J., Liversedge, Simon P. and Benson, Valerie (2017) Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search. Philosophical Transactions of The Royal Society B Biological Sciences, 372, (1714), 1-9. (doi:10.1098/rstb.2016.0106 ). (PMID:28044017). The programme was written using Experiment Builder, software from SR-Research Ltd.</span
A one-step synthesis towards new ligands based on aryl-functionalised thiazolo[5,4-d]thiazole chromophores
No full textA general synthesis of disubstituted thiazolo[5,4-d]thiazoles was achieved by condensing two equivalents of an aryl aldehyde with dithiooxamide in nitrobenzene at 130 °C for 24 h. The method is tolerant to a range of aromatic aldehydes including derivatives of pyridine, quinoline, mono- and dihydroxybenzene. An X-ray crystal structure of 2,5-bis(2-hydroxy-3,5-di-tert- butylphenyl)thiazolo[5,4-d]thiazole was obtained confirming the proposed formulation, together with supporting spectroscopic data that suggests that for the 2-hydroxyphenyl derivatives intramolecular hydrogen bonding exists in both solution and solid states. © 2010 Elsevier Ltd. All rights reserved
Investigating eye movement acquisition and analysis technologies as a causal factor in differential prevalence of crossed and uncrossed fixation disparity during reading and dot scanning
No full textPrevious studies examining binocular coordination during reading have reported conflicting results in terms of the nature of disparity (e.g. Kliegl, Nuthmann, & Engbert (Journal of Experimental Psychology General 135:12-35, 2006); Liversedge, White, Findlay, & Rayner (Vision Research 46:2363-2374, 2006). One potential cause of this inconsistency is differences in acquisition devices and associated analysis technologies. We tested this by directly comparing binocular eye movement recordings made using SR Research EyeLink 1000 and the Fourward Technologies Inc. DPI binocular eye-tracking systems. Participants read sentences or scanned horizontal rows of dot strings; for each participant, half the data were recorded with the EyeLink, and the other half with the DPIs. The viewing conditions in both testing laboratories were set to be very similar. Monocular calibrations were used. The majority of fixations recorded using either system were aligned, although data from the EyeLink system showed greater disparity magnitudes. Critically, for unaligned fixations, the data from both systems showed a majority of uncrossed fixations. These results suggest that variability in previous reports of binocular fixation alignment is attributable to the specific viewing conditions associated with a particular experiment (variables such as luminance and viewing distance), rather than acquisition and analysis software and hardware.<br/
Simulations of Dynamic Interaction Between a Bluff Body and Installation Vessel During Launch and Recovery in Rough Seas
No full textSimulation of marine operations for launch and recovery of bluff bodies such as autonomous underwater vehicles (AUV), remotely operated vehicles (ROV) or subsea templates is traditionally performed in calm to moderate sea conditions. The reason for doing so is partly due to the interaction between the complex dynamic response of an installation vessel, a moving bluff body and the wave kinematics of the rough sea condition. This is in addition to the need for accurate hydrodynamic coefficients that would enable proper simulation and modelling of the launch and recovery process. The key objective of the current methodology is to minimize risks of damage to the vessel and total loss of assets during the deployment and recovery process for marine operations in rough sea conditions.
The aim of this paper is to present the results of experimental and numerical investigation on the prediction of dynamic response of a bluff body during launch and recovery from a surface vessel in rough sea condition. Experimental measurements of hydrodynamic coefficients and responses of a large scale bluff body using a scaled model were completed. Further studies using a time-domain numerical tool have been undertaken to measure the response characteristic of bluff bodies in rough seas. The study also predicted the contributions of vessel motion in rough seas to the dynamic response of the bluff bodies. The results obtained have shown that simulation of launch and recovery operations in rough seas can be carried out efficiently if their hydrodynamic coefficients through the wave active regions of the rough seas are predicted and then adequately implemented in the simulations.</jats:p
Mono- and dimeric complexes of an asymmetric heterotopic P,CNHC,pyr ligand
No full textAn asymmetric heterotopic ligand (S-NMeCP) containing a central bicyclic, expanded-ring NHC with one pyridyl and one phosphine exo-substituent has been synthesised and its coordination chemistry with selected late transition metals investigated. The amidinium precursor [S-NMeCHP]PF6 shows variable coordination modes with Ag(I), Cu(I) and Au(I) depending on the L : M ratio. The reaction of two mols of [S-NMeCHP]PF6 with [Cu(MeCN)4]BF4, AgBF4 or Au(THT)Cl gives the bis-ligand complexes [Cu(?-P-NMeCHP)2(CH3CN)2]BF4·(PF6)2, 1, and [M(?-P-NMeCHP)2]X·(PF6)2 (3: M = Ag, X = BF4; 6: M = Au, X = Cl) respectively. The 1 : 1 reaction of [S-NMeCHP]PF6 with AgOTf gave the head-to-tail dimer H,T-[Ag2(?-N,P-NMeCHP)2(?-OTf)2](PF6)2, 2, whereas the analogous reaction with Au(THT)Cl gave monomeric [Au(?-P-NMeCHP)Cl]PF6, 5. Complex 2 was converted to H,T-[Ag2(?-C,P-NMeCP)2](PF6)2, 4, upon addition of base, while 6 gave [Au(?-C-NMeCP)2]Cl, 8, when treated likewise. Reaction of [S-NMeCHP]PF6 with Ni(1,5-COD)2 gave the oxidative addition/insertion product [Ni(?3-N,C,P-NMeCP)(?3-C8H13)]PF6, 9, which converted to [Ni(?3-N,C,P-NMeCP)Cl]PF6, 10, upon exposure of a CHCl3 solution to air. Complex 10 showed conformational isomerism that was also present in [Rh(?3-N,C,P-NMeCP)(CO)]PF6, 14, prepared from the precursor complex [Rh(?-P-NMeCHP)(acac)(CO)]PF6, 13, upon heating in C6H5Cl. [Pt(?3-N,C,P-NMeCP)(Cl)]PF6, 12, derived from trans-[Pt(?-P-NMeCHP)2(Cl)2](PF6)2, 11, was isolated as a single conformer
Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search
No full textWe explored the influence of early scene analysis and visible object characteristics on eye movements when searching for objects in photographs of scenes. On each trial, participants were shown sequentially either a scene preview or a uniform grey screen (250 ms), a visual mask, the name of the target and the scene, now including the target at a likely location. During the participant's first saccade during search, the target location was changed to: (i) a different likely location, (ii) an unlikely but possible location or (iii) a very implausible location. The results showed that the first saccade landed more often on the likely location in which the target re-appeared than on unlikely or implausible locations, and overall the first saccade landed nearer the first target location with a preview than without. Hence, rapid scene analysis influenced initial eye movement planning, but availability of the target rapidly modified that plan. After the target moved, it was found more quickly when it appeared in a likely location than when it appeared in an unlikely or implausible location. The findings show that both scene gist and object properties are extracted rapidly, and are used in conjunction to guide saccadic eye movements during visual search
Student Response System and Learning: Perceptions of the Student
No full textAbstract
Date Presented 3/30/2017
Student perceptions of a student response system (SRS) were examined. Students were surveyed to determine perceptions of the impact the SRS has on learning. Results indicate that using an SRS may help support engagement and learning by using pedagogical methods perceived by the learner as current and familiar.
Primary Author and Speaker: Meredith Taylor
Additional Authors and Speakers: Jeryl D. Benson, Kimberly Szucs</jats:p
Measurement of the D+/- production asymmetry in 7 TeV pp collisions
No full textThe asymmetry in the production cross-section \sigma of D+/- mesons, A_P = (\sigma(D+) - \sigma(D-))/(\sigma(D+) + \sigma(D-)), is measured in bins of pseudorapidity \eta and transverse momentum p_T within the acceptance of the LHCb detector. The result is obtained with a sample of D+ -> K_S pi+ decays corresponding to an integrated luminosity of 1.0 fb^-1, collected in pp collisions at a centre of mass energy of 7 TeV at the Large Hadron Collider. When integrated over the kinematic range 2.0 K_S pi+ decay is negligible. No significant dependence on \eta or p_T is observed
Hydrodynamic Characteristics of ROVs During Deployment Through Wave-Affected Zones
No full textThe prediction of wave-induced loads on Remotely Operated Vehicles (ROVs) during deployment through the splash zone is an important requirement to the design of a launch and recovery system. This paper presents the results of numerical and experimental hydrodynamic analysis of the motion response and wave-induced loads on a subsea trencher ROV during its deployment through the splash zone. The main focus of the study is to determine the maximum wave-induced loads and also to establish the maximum range of sea conditions in which the ROV can be operated safely. The numerical measurement of the hydrodynamic responses is completed using a 3D potential theory-based solver. The results obtained are compared with the predicted experimental responses measured using a 1/12 scale model of the ROV in a wave tank. A further comparison of the numerical responses with a box-shaped model of approximately similar overall dimensions to the ROV is performed in order to establish the validity of using a simplified shape to represent the actual ROV in various modelling scenarios. The result of this comparison shows that using a box-shaped model grossly over-predicts the responses and can lead to overly conservative load prediction.</p
The Dynamic Behaviour of an ROV in Wave Affected Zones
No full textWe present a method to directly predict the hydrodynamic response of a Remotely Operated Vehicle (ROV) as it transitions through the wave-affected splash zone during launch or recovery. ROVs are commonly used in offshore operations and for many different purposes. They are usually deployed from a purpose built Launch and Recovery System (LARS) located on the open deck of a surface ship. Current industry practice used for LARS design is to use a pre-defined dynamic amplification factor (DAF) together with high factors of safety. However, this does not properly account for the influence of different sea states and operational profiles. We therefore propose an improved method to directly predict the hydrodynamic response of an ROV as it transitions through the wave-affected splash zone.We apply the approach to a trencher ROV and validate using physical experiments completed in a wave tank. We demonstrate the need to for an accurate definition of the added mass and damping characteristics of the ROV. The method is incorporated into OrcaFlex for direct use within the design and analysis of a LARS system.</p
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