73 research outputs found
Orienting during gaze guidance in a letter-identification task
The idea of gaze guidance is to lead a viewer’s gaze through a visual display in order to facilitate the viewer’s search for specific information in a least-obtrusive manner. This study investigates saccadic orienting when a viewer is guided in a fast-paced, low-contrast letter identification task. Despite the task’s difficulty and although guiding cues were ad-justed to gaze eccentricity, observers preferred attentional over saccadic shifts to obtain a letter identification judgment; and if a saccade was carried out its saccadic constant error was 50%. From those results we derive a number of design recommendations for the process of gaze guidance
Evidence for a Structural Analysis of Target Selection in Picture Viewing
Spontaneous fixations onto shapes are driven by a structural analysis. But is such analysis also carried out during free viewing of real-world scenes? Here, we analyze how fixation locations in such scenes are related to their region using the region's symmetric axes as a reference. Each fixation location is compared with respect to its nearest symmetric-axis segment by a latitude and a longitude measure. Analyzing the distributions for the two measures we find that there exist fixation biases for L features and parallel contours, suggesting that structural analysis may play a role in saccadic target selection during free viewing
First step developing a early-warning system against corruption for sports associations
The business model of sports is based on trust, reputation and fairness. In recent years sports associations have often engaged in crime, corruption and non-compliance, which has damaged the reputation of sports. A professional compliance tool to counteract the loss of trust is still missing, an early-warning system for sports organisations could provide a solution. It simulates how they react to non-tolerable instances of corruption, doping or violations of competitive integrity. The aim of this article is to present the first step developing an early-warning system for sports associations. The approach of New Institutional Economics was chosen to be the theoretical framework to understand the characteristics of corrupt deals and from that identify indicators that uncover corruption at an early stage. To support the normative process of indicator finding a literature research and a case study were carried out. The results indicate that corrupt deals involve three phases and that the relationship between the corrupt partners is central. Regarding to the strong bonds in corrupt relationships a lack of term limitations, no rotation in leadership positions, missing systems of whistleblowing or insufficient transparency could be possible indicators for corruption and non-compliance in sports associations
Recognizing the gist of a visual scene: possible perceptual and neural mechanisms
We try to understand the basics of human image processing from a gist recognition perspective. Because the gist is only a subset of the image's information, we think that it is extracted with help of interpretation (feedback). In a perceptual section we list possible mechanisms that the interpretation process uses to determine the gist: in addition to the commonly known local-to-global perception evolvement, there is likely to be also a global-to-local evolvement direction, a coarse/fine scale, as well as a foreground/background scale. In a neural section we first summarize feedback connections that can possibly be involved in gist recognition. Second, we propose that the perceptual mechanisms are spread all over the cortex and that cortical visual computation occurs distributively rather than hierarchical
Video genre categorization and representation using audio-visual information
International audienceWe propose an audio-visual approach to video genre classification using content descriptors that exploit audio, color, temporal, and contour information. Audio information is extracted at block-level, which has the advantage of capturing local temporal information. At the temporal structure level, we consider action content in relation to human perception. Color perception is quantified using statistics of color distribution, elementary hues, color properties, and relationships between colors. Further, we compute statistics of contour geometry and relationships. The main contribution of our work lies in harnessingn the descriptive power of the combination of these descriptors in genre classification. Validation was carried out on over 91 h of video footage encompassing 7 common video genres, yielding average precision and recall ratios of 87% to 100% and 77% to 100%, respectively, and an overall average correct classification of up to 97%. Also, experimental comparison as part of the MediaEval 2011 benchmarkingn campaign demonstrated the efficiency of the proposed audiovisual descriptors over other existing approaches. Finally, we discuss a 3-D video browsing platform that displays movies using efaturebased coordinates and thus regroups them according to genre
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Mammalian deltavirus without hepadnavirus coinfection in the neotropical rodent Proechimys semispinosus.
Hepatitis delta virus (HDV) is a human hepatitis-causing RNA virus, unrelated to any other taxonomic group of RNA viruses. Its occurrence as a satellite virus of hepatitis B virus (HBV) is a singular case in animal virology for which no consensus evolutionary explanation exists. Here we present a mammalian deltavirus that does not occur in humans, identified in the neotropical rodent species Proechimys semispinosus The rodent deltavirus is highly distinct, showing a common ancestor with a recently described deltavirus in snakes. Reverse genetics based on a tandem minus-strand complementary DNA genome copy under the control of a cytomegalovirus (CMV) promoter confirms autonomous genome replication in transfected cells, with initiation of replication from the upstream genome copy. In contrast to HDV, a large delta antigen is not expressed and the farnesylation motif critical for HBV interaction is absent from a genome region that might correspond to a hypothetical rodent large delta antigen. Correspondingly, there is no evidence for coinfection with an HBV-related hepadnavirus based on virus detection and serology in any deltavirus-positive animal. No other coinfecting viruses were detected by RNA sequencing studies of 120 wild-caught animals that could serve as a potential helper virus. The presence of virus in blood and pronounced detection in reproductively active males suggest horizontal transmission linked to competitive behavior. Our study establishes a nonhuman, mammalian deltavirus that occurs as a horizontally transmitted infection, is potentially cleared by immune response, is not focused in the liver, and possibly does not require helper virus coinfection
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