33,216 research outputs found
A versatile scanning photocurrent mapping system to characterize optoelectronic devices based on 2D materials
The investigation of optoelectronic devices based on two-dimensional
materials and their heterostructures is a very active area of investigation
with both fundamental and applied aspects involved. We present a description of
a home-built scanning photocurrent microscope that we have designed and
developed to perform electronic transport and optical measurements of
two-dimensional materials based devices. The complete system is rather
inexpensive (<10000 EUR) and it can be easily replicated in any laboratory. To
illustrate the setup we measure current-voltage characteristics, in dark and
under global illumination, of an ultra-thin PN junction formed by the stacking
of an n-doped few-layer MoS2 flake onto a p-type MoS2 flake. We then acquire
scanning photocurrent maps and by mapping the short circuit current generated
in the device under local illumination we find that at zero bias the
photocurrent is generated mostly in the region of overlap between the n-type
and p-type flakes.Comment: 9 pages, 3 figures, 1 table, supporting informatio
Fusion of Multispectral Data Through Illumination-aware Deep Neural Networks for Pedestrian Detection
Multispectral pedestrian detection has received extensive attention in recent
years as a promising solution to facilitate robust human target detection for
around-the-clock applications (e.g. security surveillance and autonomous
driving). In this paper, we demonstrate illumination information encoded in
multispectral images can be utilized to significantly boost performance of
pedestrian detection. A novel illumination-aware weighting mechanism is present
to accurately depict illumination condition of a scene. Such illumination
information is incorporated into two-stream deep convolutional neural networks
to learn multispectral human-related features under different illumination
conditions (daytime and nighttime). Moreover, we utilized illumination
information together with multispectral data to generate more accurate semantic
segmentation which are used to boost pedestrian detection accuracy. Putting all
of the pieces together, we present a powerful framework for multispectral
pedestrian detection based on multi-task learning of illumination-aware
pedestrian detection and semantic segmentation. Our proposed method is trained
end-to-end using a well-designed multi-task loss function and outperforms
state-of-the-art approaches on KAIST multispectral pedestrian dataset
Iranian cashes recognition using mobile
In economical societies of today, using cash is an inseparable aspect of
human life. People use cashes for marketing, services, entertainments, bank
operations and so on. This huge amount of contact with cash and the necessity
of knowing the monetary value of it caused one of the most challenging problems
for visually impaired people. In this paper we propose a mobile phone based
approach to identify monetary value of a picture taken from cashes using some
image processing and machine vision techniques. While the developed approach is
very fast, it can recognize the value of cash by average accuracy of about 95%
and can overcome different challenges like rotation, scaling, collision,
illumination changes, perspective, and some others.Comment: arXiv #13370
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