Crosstalk in stereoscopic displays: A review

Crosstalk, also known as ghosting or leakage, is a primary factor in determining the image quality of stereoscopic three dimensional (3D) displays. In a stereoscopic display, a separate perspective view is presented to each of the observer’s two eyes in order to experience a 3D image with depth sensation. When crosstalk is present in a stereoscopic display, each eye will see a combination of the image intended for that eye, and some of the image intended for the other eye—making the image look doubled or ghosted. High levels of crosstalk can make stereoscopic images hard to fuse and lack fidelity, so it is important to achieve low levels of crosstalk in the development of high-quality stereoscopic displays. Descriptive and mathematical definitions of these terms are formalized and summarized. The mechanisms by which crosstalk occurs in different stereoscopic display technologies are also reviewed, including micropol 3D liquid crystal displays (LCDs), autostereoscopic (lenticular and parallax barrier), polarized projection, anaglyph, and time-sequential 3D on LCDs, plasma display panels and cathode ray tubes. Crosstalk reduction and crosstalk cancellation are also discussed along with methods of measuring and simulating crosstalk

Modified brinley plots: advantages and disadvantages

Accepted manuscrip

Developing compact tuning fork thermometers for sub-mK temperatures and high magnetic fields

The National High Magnetic Field Laboratory (NHMFL) High B/T facility at the University of Florida in Gainesville provides a unique combination of ultra-low temperatures below 1 mK and high magnetic fields up to 16 T for user experiments. To meet the growing user demand for calorimetric and thermal transport measurements, particularly on milligram-sized solid samples, we are developing scaleable thermometers based on quartz tuning fork resonators immersed in liquid $^3$He. We demonstrate successful thermometer operation at the combined extreme conditions available at our user facility, and discuss the feasibility of fast and compact thermal probes

Crosstalk in stereoscopic displays

Crosstalk is an important image quality attribute of stereoscopic 3D displays. The research presented in this thesis examines the presence, mechanisms, simulation, and reduction of crosstalk for a selection of stereoscopic display technologies. High levels of crosstalk degrade the perceived quality of stereoscopic displays hence it is important to minimise crosstalk. This thesis provides new insights which are critical to a detailed understanding of crosstalk and consequently to the development of effective crosstalk reduction techniques

Finding qualitative research: an evaluation of search strategies

BACKGROUND: Qualitative research makes an important contribution to our understanding of health and healthcare. However, qualitative evidence can be difficult to search for and identify, and the effectiveness of different types of search strategies is unknown. METHODS: Three search strategies for qualitative research in the example area of support for breast-feeding were evaluated using six electronic bibliographic databases. The strategies were based on using thesaurus terms, free-text terms and broad-based terms. These strategies were combined with recognised search terms for support for breast-feeding previously used in a Cochrane review. For each strategy, we evaluated the recall (potentially relevant records found) and precision (actually relevant records found). RESULTS: A total yield of 7420 potentially relevant records was retrieved by the three strategies combined. Of these, 262 were judged relevant. Using one strategy alone would miss relevant records. The broad-based strategy had the highest recall and the thesaurus strategy the highest precision. Precision was generally poor: 96% of records initially identified as potentially relevant were deemed irrelevant. Searching for qualitative research involves trade-offs between recall and precision. CONCLUSIONS: These findings confirm that strategies that attempt to maximise the number of potentially relevant records found are likely to result in a large number of false positives. The findings also suggest that a range of search terms is required to optimise searching for qualitative evidence. This underlines the problems of current methods for indexing qualitative research in bibliographic databases and indicates where improvements need to be made

Using cross-talk simulation to predict the performance of anaglyph 3-D glasses

The anaglyph 3-D method is a widely used technique for presenting stereoscopic 3-D images. Its primary advantage is that it will work on any full-color display (LCDs, plasmas, and even prints) and only requires that the user view the anaglyph image using a pair of anaglyph 3-D glasses with usually one lens tinted red and the other lens tinted cyan (blue plus green). A common image-quality problem of anaglyph 3-D images is high levels of cross-talk — the incomplete isolation of the left and right image channels such that each eye sees a “ghost” of the opposite perspective view. An anaglyph cross-talk simulation model has been developed which allows the amount of anaglyph cross-talk to be estimated based on the spectral characteristics of the anaglyph glasses and the display. The model is validated using a visual cross-talk ranking test which indicates good agreement. The model is then used to consider two scenarios for the reduction of cross-talk in anaglyph systems and finds that a considerable reduction is likely to be achieved by using spectrally pure displays. The study also finds that the 3-D performance of commercial anaglyph glasses can be significantly better than handmade anaglyph glasses

Fluoroketone inhibition of Ca(2+)-independent phospholipase A2 through binding pocket association defined by hydrogen/deuterium exchange and molecular dynamics.

The mechanism of inhibition of group VIA Ca(2+)-independent phospholipase A(2) (iPLA(2)) by fluoroketone (FK) ligands is examined by a combination of deuterium exchange mass spectrometry (DXMS) and molecular dynamics (MD). Models for iPLA(2) were built by homology with the known structure of patatin and equilibrated by extensive MD simulations. Empty pockets were identified during the simulations and studied for their ability to accommodate FK inhibitors. Ligand docking techniques showed that the potent inhibitor 1,1,1,3-tetrafluoro-7-phenylheptan-2-one (PHFK) forms favorable interactions inside an active-site pocket, where it blocks the entrance of phospholipid substrates. The polar fluoroketone headgroup is stabilized by hydrogen bonds with residues Gly486, Gly487, and Ser519. The nonpolar aliphatic chain and aromatic group are stabilized by hydrophobic contacts with Met544, Val548, Phe549, Leu560, and Ala640. The binding mode is supported by DXMS experiments showing an important decrease of deuteration in the contact regions in the presence of the inhibitor. The discovery of the precise binding mode of FK ligands to the iPLA(2) should greatly improve our ability to design new inhibitors with higher potency and selectivity

The relation between symmetry in food packaging and approach and avoidance words

Research on aesthetic science has demonstrated that people generally prefer symmetrical over asymmetrical compositions. However, it remains unclear whether and how such compositions relate to the concepts of approach and avoidance motivation, especially in consumer contexts. In addition, it is not known how symmetry may influence such concepts in contexts where objects can differ in terms of their hedonic values (symmetry/product taste congruency). In the present research, we evaluated the relation between visual symmetry of the packaging of products with different hedonic value (sweet, non-sweet, non-food) and approach and avoidance words. In two experiments, we found evidence that people associate symmetrical designs with approach words more often than asymmetrical designs. Importantly, however, we did not find evidence that such an effect is influenced by the hedonic value of the products. Our results have value for scholars and practitioners interested in the effect of aesthetic features of brand elements (such as a product’s packaging) on consumer motivation

Turbulent buoyant convection from a maintained source of buoyancy in a narrow vertical tank

We describe new experiments to examine the buoyancy-induced mixing which results from the injection of a small constant volume flux of fluid of density at the top of a long narrow vertical tank with square cross-section which is filled with fluid of density . The injected fluid vigorously mixes with the less dense fluid which initially occupies the tank, such that a dense mixed region of turbulent fluid propagates downwards during the initial mixing phase of the experiment. For an ideal source of constant buoyancy flux , we show that the height of the mixed region grows as and that the horizontally averaged reduced gravity at the top of tank increases as , where is the width of the tank. Once the mixed region reaches the bottom of the tank, the turbulent mixing continues in an intermediate mixing phase, and we demonstrate that the reduced gravity at each height increases approximately linearly with time. This suggests that the buoyancy flux is uniformly distributed over the full height of the tank. The overall density gradient between the top and bottom of the mixed region is hence time-independent for both the mixing phases before and after the mixed region has reached the bottom of the tank. Our results are consistent with previous models developed for the mixing of an unstable density gradient in a confined geometry, based on Prandtl’s mixing length theory, which suggest that the turbulent diffusion coefficient and the magnitude of the local turbulent flux are given by the nonlinear relations and , respectively. The constant relates the width of the tank to the characteristic mixing length of the turbulent eddies. Since the mixed region is characterized by a time-independent overall density gradient, we also tested the predictions based on a linear model in which the turbulent diffusion coefficient is approximated by a constant . We solve the corresponding nonlinear and linear turbulent diffusion equations for both mixing phases, and show a good agreement with experimental profiles measured by a dye attenuation technique, in particular for the solutions based on the nonlinear model

Assessing sampling of the fossil record in a geographically and stratigraphically constrained dataset: the Chalk Group of Hampshire, southern UK

Taphonomic, geological and sampling processes have been cited as biasing richness measurements in the fossil record, and sampling proxies have been widely used to assess this. However, the link between sampling and taxonomic richness is poorly understood, and there has been much debate on the equivalence and relevance of proxies. We approach this question by combining both historical and novel data: a historical fossil occurrence dataset with uniquely high spatial resolution from the Upper Cretaceous Chalk Group of Hampshire, UK, and a newly compiled 3D geological model that maps subsurface extent. The geological model provides rock volumes, and these are compared with exposure and outcrop area, sampling proxies that have often been conflated in previous studies. The extent to which exposure area (true rock availability) has changed over research time is also tested. We find a trend of low Cenomanian to high Turonian to Campanian raw richness, which correlates with, and is possibly driven by, the number of specimens found. After sampling standardization, an unexpected mid-Turonian peak diversity is recovered, and sampling-standardized genus richness is best predicted by rock volume, suggesting a species–area (or ‘genus–area’) effect. Additionally, total exposure area has changed over time, but relative exposure remains the same. Supplementary materials: A locality list, abundance matrix and all correlation and modelling results are available at https://doi.org/10.6084/m9.figshare.c.3592208