Search results for "VISION"
showing 10 items of 5066 documents
Service Provisioning and User Association for Heterogeneous Wireless Railway Networks
2017
In addition to comforting passengers' journey, the modern railway system is responsible to support a variety of on-board Internet services to meet the passenger's demands on seamless service provisioning. In order to provide wireless access to the train, one idea attracting increasing attention is to deploy a series of track-side access points (TAPs) with high-speed data rates along the rail lines dedicated to the broadband mobile service provisioning on board. Due to the heavy data traffic flushing into the base stations (BSs) of the cellular networks, TAPs act as a complement to the BSs in data delivery. In this paper, we focus on the TAP association problem for service provisioning in a …
A fully automatic method for biological target volume segmentation of brain metastases
2016
Leksell Gamma Knife is a mini-invasive technique to obtain a complete destruction of cerebral lesions delivering a single high dose radiation beam. Positron Emission Tomography (PET) imaging is increasingly utilized for radiation treatment planning. Nevertheless, lesion volume delineation in PET datasets is challenging because of the low spatial resolution and high noise level of PET images. Nowadays, the biological target volume (BTV) is manually contoured on PET studies. This procedure is time expensive and operator-dependent. In this article, a fully automatic algorithm for the BTV delineation based on random walks (RW) on graphs is proposed. The results are compared with the outcomes of…
Prevision de los gastos de educacion primaria en el ano 2000 en les paises en desarrollo
1991
International audience
An exploratory study of gazing behavior during live performance
2009
It is known that the visual information given by performers during a performance works as a useful channel of communication to the audience. In my previous studies, many performers referred to the importance of gazing behavior or eye contact. The purpose of this research is to explore the role of gaze during live performance by measuring the timing and direction of gazing. The hypotheses are as follows: [1] Gazing behavior depends on the musical structure. [2] Gazing behavior is used for the communication between performers which is necessary during performance. [3] Performers set their gazing direction in order to contribute to the audience’s understanding of the music. This research was e…
AUTOMATIC RETINA EXUDATES SEGMENTATION WITHOUT A MANUALLY LABELLED TRAINING SET
2011
International audience; Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, two new methods for the detection of exudates are presented. The methods do not require a lesion training set so the need to ground-truth data is avoided with significant time savings and independence from human error. We evaluate our algorithm with a new publicly available dataset from various ethnic groups and levels of DME. Also, we compare our results with two recent exudate segmentation algorithms on the same dataset. In all of …
Video display terminal use and dry eye: preventive measures and future perspectives
2022
Background: Dry eye disease (DED) is a common cause of ocular pain and discomfort. Dry eye disease (DED) stems from a loss-of-tear film homeostasis and is frequently seen in video display terminal (VDT) users. Video display terminal (VDT) use reduces blink rates and increases incomplete blinks, leading to tear film instability and ocular inflammation, promoting DED. Purpose: To assess and evaluate the methods for preventing VDT-associated DED and ocular discomfort. Methods: Studies were found using PubMed and Embase with the search terms: (digital visual terminal* OR computer use OR screen use OR smartphone OR display OR visual display terminal* OR computer vision syndrome OR tablet OR phon…
<title>Selective filters for improvement of color discrimination</title>
2003
Colored filters have been used as possible aids for perception in case of congenital color vision abnormalities. Higher stimulation for L cones in one eye (red filter) and for M cones (green) in other eye acts as a simple method to interfere in human color vision processing. Influence on subjective and objective vision performances as binocular functions, fusion, stereopsis and color vision has been tested. Special colored glasses have been created, taking into account each subjects refraction for distance and tested for the 5 months adaption time. No negative influence on binocular functions, no changes of heterophoria and lowering in fusion ability and stereopsis have been stated due to u…
Color induction via non-opponent lateral interactions in the human retina
1992
Retinal connections causing colors in Benham's top (pattern induced flicker colors, PIFCs) are investigated by psychophysical experiments. PIFCs are still seen when stimuli to different cones are demodulated selectively, indicating the involvement of non-opponent channels. PIFCs also occur on retinal areas next to those affected by modulated stimuli; further, both monochromat and dark-adapted trichromats perceive PIFCs which are achromatic. These additional findings point to horizontal cells as neuronal mediators of modulated excitation leading to PIFCs. The unspecifity of the postulated connection with respect to cone types agrees with anatomic findings of Boycott, B. B., Hopkins, J. M. an…
Motion detection in goldfish investigated with the optomotor response is “color blind”
1996
AbstractThe action spectrum of the optomotor response in goldfish was measured to investigate which of the four cone types involved in color vision contributes to motion detection. In the dark-adapted state, the action spectrum showed a single maximum in the range of 500–520 nm, and resembled the rod spectral sensitivity function. Surprisingly, the action spectrum measured in the light-adapted state also revealed a single maximum only, located in the long wavelength range between 620 and 660 nm. A comparison with spectral sensitivity functions of the four cone types suggests that motion detection is dominated by the L-cone type. Using a two colored, “red-green” cylinder illuminated with two…
Visual fields in a chloroquine treatment
2014
Purpose: In this study, we describe contrast sensitivity losses in the visual field of a patient affected by chloroquine toxicity, measured with stimuli favoring different visual mechanisms. We have compared these results with those of other, usual clinical tests. Methods: The vision of a patient who underwent ten years of chloroquine treatment was analyzed by a battery of clinical tests: visual acuity (VA), Amsler’s grid, Farnsworth–Munsell 100-hue test, spectral domain optical coherence tomography, multifocal electroretinogram (ERG), white-on-white and red-on-white Humphrey perimetries, chromatic and achromatic contrast sensitivity perimetry tests, and fluorescein angiography. Measurement…