MAG3D and its application to internal flowfield analysis

MAG3D (multiblock adaptive grid, 3D) is a 3D solution-adaptive grid generation code which redistributes grid points to improve the accuracy of a flow solution without increasing the number of grid points. The code is applicable to structured grids with a multiblock topology. It is independent of the original grid generator and the flow solver. The code uses the coordinates of an initial grid and the flow solution interpolated onto the new grid. MAG3D uses a numerical mapping and potential theory to modify the grid distribution based on properties of the flow solution on the initial grid. The adaptation technique is discussed, and the capability of MAG3D is demonstrated with several internal flow examples. Advantages of using solution-adaptive grids are also shown by comparing flow solutions on adaptive grids with those on initial grids

The nonlinear Bernstein-Schr\"odinger equation in Economics

In this paper we relate the Equilibrium Assignment Problem (EAP), which is underlying in several economics models, to a system of nonlinear equations that we call the "nonlinear Bernstein-Schr\"odinger system", which is well-known in the linear case, but whose nonlinear extension does not seem to have been studied. We apply this connection to derive an existence result for the EAP, and an efficient computational method.Comment: 8 pages, submitted to Lecture Notes in Computer Scienc

NASA Workshop on future directions in surface modeling and grid generation

Given here is a summary of the paper sessions and panel discussions of the NASA Workshop on Future Directions in Surface Modeling and Grid Generation held a NASA Ames Research Center, Moffett Field, California, December 5-7, 1989. The purpose was to assess U.S. capabilities in surface modeling and grid generation and take steps to improve the focus and pace of these disciplines within NASA. The organization of the workshop centered around overviews from NASA centers and expert presentations from U.S. corporations and universities. Small discussion groups were held and summarized by group leaders. Brief overviews and a panel discussion by representatives from the DoD were held, and a NASA-only session concluded the meeting. In the NASA Program Planning Session summary there are five recommended steps for NASA to take to improve the development and application of surface modeling and grid generation

Right inferior frontal gyrus damage is associated with impaired initiation of inhibitory control, but not its implementation

Inhibitory control is one of the most important control functions in the human brain. Much of our understanding of its neural basis comes from seminal work showing that lesions to the right inferior frontal gyrus (rIFG) increase stop-signal reaction time (SSRT), a latent variable that expresses the speed of inhibitory control. However, recent work has identified substantial limitations of the SSRT method. Notably, SSRT is confounded by trigger failures: stop-signal trials in which inhibitory control was never initiated. Such trials inflate SSRT, but are typically indicative of attentional, rather than inhibitory deficits. Here, we used hierarchical Bayesian modeling to identify stop-signal trigger failures in human rIFG lesion patients, non-rIFG lesion patients, and healthy comparisons. Furthermore, we measured scalp-EEG to detect β-bursts, a neurophysiological index of inhibitory control. rIFG lesion patients showed a more than fivefold increase in trigger failure trials and did not exhibit the typical increase of stop-related frontal β-bursts. However, on trials in which such β-bursts did occur, rIFG patients showed the typical subsequent upregulation of β over sensorimotor areas, indicating that their ability to implement inhibitory control, once triggered, remains intact. These findings suggest that the role of rIFG in inhibitory control has to be fundamentally reinterpreted

Bacterial populations on silicone hydrogel and hydrogel contact lenses after swimming in a chlorinated pool

Purpose: A number of reports have indicated an association between swimming with contact lenses and subsequent eye infection. This study tests whether a hydrophilic contact lens worn while swimming accumulates bacteria present in the water. It was of interest to determine if lens type (silicone hydrogel versus hydrogel) affected the result. Methods: Fifteen healthy non-contact lens wearers swam for 30 minutes with a silicone hydrogel lens (Purevision) on one eye and a hydrogel lens (Acuvue 2) on the other. Lenses were removed aseptically and placed in sterile vials five minutes after the subjects left the water. Microbial growth was enumerated for total numbers of colonies and categorized by species present. Numbers of colonies were compared between the two lens groups, and with a water sample taken from the pool at the time of the experiment. Eight of the subjects returned on a different day and wore new lenses for thirty minutes under normal room conditions. Results: Two lenses were lost while swimming. 27 of the remaining 28 lenses worn while swimming showed colonization, principally with Staphylococcus epidermidis, which was also by far the most common species identified from the water itself. Small numbers of Staphylococcus aureus and Streptococcus salivarus were also present in both the water and on the lenses. Numbers of colonies varied among subjects (range 0-230), but no differences were observed between the two lens groups. Lenses removed after thirty minutes of wear without swimming were mostly sterile, with 3 of the 16 lenses showing just two colonies each. Conclusion: It appears that wearing a hydrophilic lens while swimming allows accumulation of microbial organisms on, or in, the lens, regardless of lens material. Swimmers should be advised to wear tight fitting goggles if lenses are worn while swimming, and thorough disinfection of the lenses prior to overnight wear seems prudent

Influence of Deformed Metal Decking Composite Floors to Beam-column Connections

A series of tests designed to investigate the interaction of a variety of different steel beam to column connection details with a composite metal deck floor is described. The main emphasis is on assessing the connections\u27 moment capacity, rotational stiffness and rotation capacity. The full details of the experimental behaviour of the flush end plate and partial depth end plate connections will be described in this paper. A simple method for moment capacity calculation based on the test results is proposed herein

Characterization of an Improved, Real-Time MEMS-Based Phase-Shifting Interferometer

We describe and present detailed performance characterizations for an enhanced version of our MEMS-Based Phase-Shifting Interferometer (MBPSI) that achieves 13 times denser motion reconstruction than our original system. We measure the noise level to be ≤±6 nm λ for a 660 nm laser), and the frequency-resolution to be ≤ 0.03Hz for 31Hz motion captured at 300Hz. We have successfully tracked a piezo-based actuator, driven with an arbitrary waveform composed of transients ≤10Hz