Horn antennas can result in good impedance matching between the waveguide and free space due to the gradual increase in the aperture size. In this paper, a novel plasmonic sectoral horn nanoantenna based on using lens in the aperture is proposed. It is investigated that in addition to improvement of the directivity, the reflection coefficient is also reduced using the proper lens structure. The...

Department of Mechanical and Aerospace Engineering, The George Washington University, Science & Engineering Hall, 800 22 Street, NW, Washington, DC 20052, USA Neurological Surgery, The George Washington University, Foggy Bottom South Pavilion, 22 Street, NW, 7 Floor, Washington, DC 20037, USA Jerome Canady Research Institute for Advanced Biological and Technological Science, 6930 Carroll Avenue...

A GIMP Retinex filtering can be used for enhancing images, with good results on foggy images, as recently discussed. Since this filter has some parameters that can be adjusted to optimize the output image, several approaches can be decided according to desired results. Here, as a criterion for optimizing the filtering parameters, we consider the maximization of the image entropy. We use, beside...

purpose: to evaluate the prevalence of contat lens wear among highschool girls and their general knowledge about contact lenses and also to evaluate the specific knowledge of contact lens wearers about the lens. methods: in a cross-sectional study, 1664 students of 22 randomly selected girl highschools were enrolled. a questionaire including questions about wearing contact lens, age of first us...

The first mention of the term chemobrain appeared in the literature in response to a steady flow of clinical reports and research articles on neurological dysfunctions and so called “foggy brain” in chemotherapy treated cancer patients [1,2]. “Foggy brain” more precisely known as a cognitive impairment of the brain is a phenomenon with a long history in psychiatry and neurology, however its pre...

A possible explanation for close following in fog is that it would allow drivers to control headway more precisely by reducing motion perception thresholds. The purpose of our experiments was to determine the motion discrimination thresholds for closing and receding under normal and foggy conditions. An experiment and a pilot study were conducted on a driving simulator in which subjects were pr...

Between AD 900 and AD 1200 Vikings, being able to navigate skillfully across the open sea, were the dominant seafarers of the North Atlantic. When the Sun was shining, geographical north could be determined with a special sundial. However, how the Vikings could have navigated in cloudy or foggy situations, when the Sun's disc was unusable, is still not fully known. A hypothesis was formulated i...

Due to environmental pollution, the climate is worsening. The fog days up to 60% of the year in inland certain segments, which it has seriously affected the marine electronic cruise normal operation and navigation safety. According to the inland video image becomes gray and lack of visibility in foggy weather conditions, and in order to remove the haze to get a clear image color and contour, th...

As light is suffered when it passes in water or in foggy area, the clarity of image or video captured under these environment is usually degraded to varying degrees. The degradation may be due to various factors like relative object-camera motion, blur due to camera misfocus, relative atmospheric turbulence and others. The clarity of image is the challenging factors in image processing. The goa...