Inverse transformed encoding models - A solution to the problem of correlated trial-by-trial parameter estimates in fMRI decoding

Techniques of multivariate pattern analysis (MVPA) can be used to decode the discrete experimental condition or a continuous modulator variable from measured brain activity during a particular trial. In functional magnetic resonance imaging (fMRI), trial-wise response amplitudes are sometimes estimated from the measured signal using a general linear model (GLM) with one onset regressor for each trial. When using rapid event-related designs with trials closely spaced in time, those estimates are highly variable and serially correlated due to the temporally extended shape of the hemodynamic response function (HRF). Here, we describe inverse transformed encoding modelling (ITEM), a principled approach of accounting for those serial correlations and decoding from the resulting estimates, at low computational cost and with no loss in statistical power. We use simulated data to show that ITEM outperforms the current standard approach in terms of decoding accuracy and analyze empirical data to demonstrate that ITEM is capable of visual reconstruction from fMRI signals

A comparison between the MEXE and Pippard's methods of assessing the load carrying capacity of masonry arch bridges

The Military Engineering eXperimental Establishment (MEXE) method is a long established system of masonry arch load carrying capacity assessment. It has been subject to review in recent years and some shortcomings have been identified. There is now growing consensus that the current version of MEXE overestimates the load carrying capacity of short span bridges, but for spans over 12m it becomes increasingly conservative. In this paper Pippard’s elastic method and the MEXE method are used to investigate the significance of factors such as fill cover, ring thickness and effective width of arch barrel, and their effect upon the load-carrying capacity predictions in short and long span arches. Conclusions are drawn which establish directions of new research and offer guidance to assessors of short and long span masonry arch bridges

Sonic impedance technique detects flaws in polyurethane foam spray-on insulation

Sonic impedance testing detects voids and unbonded regions as small as 1 inch in diameter by 0.03 inch thick. Measurements are made manually or by automatic scanning and the readout is made by meter or recorder

Generating Equidistributed Meshes in 2D via Domain Decomposition

In this paper we consider Schwarz domain decomposition applied to the generation of 2D spatial meshes by a local equidistribution principle. We briefly review the derivation of the local equidistribution principle and the appropriate choice of boundary conditions. We then introduce classical and optimized Schwarz domain decomposition methods to solve the resulting system of nonlinear equations. The implementation of these iterations are discussed, and we conclude with numerical examples to illustrate the performance of the approach

A study of the probability of depositing viable organisms on Mars during the Mariner 1964 mission

Probability of depositing viable organisms on Mars during 1964 Mariner missio

Genuine lab experiences for students in resource constrained environments: The RealLab with integrated intelligent assessment.

Laboratory activities are indispensable for developing engineering skills. Computer Aided Learning (CAL) tools can be used to enhance laboratory learning in various ways, the latest approach being the virtual laboratory technique that emulates traditional laboratory processes. This new approach makes it possible to give students complete and genuine laboratory experiences in situations constrained by limited resources in the provision of laboratory facilities and infrastructure and/or where there is need for laboratory education, for large classes, with only one laboratory stand. This may especially be the case in countries in transition. Most existing virtual laboratories are not available for purchase. Where they are, they may not be cost friendly for resource constrained environments. Also, most do not integrate any form of assessment structure. In this paper, we present a very cost friendly virtual laboratory solution for genuine laboratory experiences in resource constrained environments, with integrated intelligent assessment

A Schwarz Method for the Magnetotelluric Approximation of Maxwell's equations

The magnetotelluric approximation of the Maxwell's equations is used to model the propagation of low frequency electro-magnetic waves in the Earth's subsurface, with the purpose of reconstructing the presence of mineral or oil deposits. We propose a classical Schwarz method for solving this magnetotelluric approximation of the Maxwell equations, and prove its convergence using maximum principle techniques. This is not trivial, since solutions are complex valued, and we need a new result that the magnetotelluric approximations satisfy a maximum modulus principle for our proof. We illustrate our analysis with numerical experiments.Comment: 9 pages, 3 figure

Ultrasonic scanning system for in-place inspection of brazed tube joints

A miniaturized ultrasonic scanning system for nondestructive in-place, non-immersion testing of brazed joints in stainless-steel tubing is described. The system is capable of scanning brazed tube joints, with limited clearance access, in 1/4 through 5/8 inch union, tee, elbow and cross configurations. The system has the capability to detect defective conditions now associated with material density changes in addition to those which are depended upon density variations. The system includes a miniaturized scanning head assembly that fits around a tube joint and rotates the transducer around and down the joint in a continuous spiral motion. The C-scan recorder is similar in principle to conventional models except that it was specially designed to track the continuous spiral scan of the tube joint. The scanner and recorder can be operated with most commercially available ultrasonic flaw detectors

Ultrasonic scanning system for in-place inspection of brazed-tube joints

System detects defects of .051 cm in diameter and larger. System incorporates scanning head assembly including boot enclosed transducer, slip ring assembly, drive mechanism, and servotransmitter. Ultrasonic flaw detector, prototype recorder, and special recorder complete system

Community pharmacy type 2 diabetes risk assessment: demographics and risk results

Objectives: To determine the demographics and risk results of patients accessing a community pharmacy diabetes risk assessment service. Method: Participating patients underwent an assessment using a validated questionnaire to determine their 10-year risk of developing type 2 diabetes. Patients were given appropriate lifestyle advice or referred to their general practitioner if necessary. Key findings: In total, 21 302 risk assessments were performed. Nearly one-third (29%) of 3427 risk assessments analysed yielded a result of moderate or high chance of developing the condition. Conclusions: Community pharmacies can identify a significant number of patients at risk of developing type 2 diabetes in the next 10 years. Further follow-up work needs to be done to determine the cost-effectiveness of such a service and the consequences of receiving a risk assessment