458 research outputs found
Women in the War: A Gendered Analysis of Media Coverage of the Russian-Ukraine War
In recent years several commentators have observed the trend of mainstream media ignoring and distorting women’s perspectives and experiences in armed conflicts. Both in the reporting and the wider discourse about conflicts, women tend to be cast less as political actors and more as helpless victims, often paired with children in accounts of war incidents. Carolina Marques de Mesquita (2016), in her study of media coverage of recent wars and conflicts, observed that while major media outlets tend to represent the scale of violence in a conflict through the harm and death inflicted on women, they are otherwise often neglected. This contention sets the backdrop for our study that aims to explore the Russian-Ukraine War from a gendered lens. We examine the coverage of the ongoing conflict in four news outlets to see whether or not they reflect the established pattern of gendered representations of war. Our analysis reveals, by and large, persistence in the pattern of coverage of the war that corroborates the charge that media reportage of conflict tends to underrepresent women and distort their involvement in wars through narrow role characterizations
The research of 3D small-field imaging system based on fringe projection technique
This paper presents a 3D small-field imaging system by using the color fringe projection technique to measure the small
objects having large slopes and/or discontinuous surface. A stereo microscope is used to generate a small-field projecting
field and to capture the deformed fringe patterns on the measured small objects, respectively. Three fringe sets having
the optimum fringe numbers are coded into one major color channel to generate color fringe patterns having the
maximum fringe contrast of the captured fringe images. Through one channel of the stereo microscope, a DLP (Digital
Light Processing) projector projects these generated color fringe pattern images onto the measured objects surface. From
another channel, the fringe patterns are deformed with regard to the object surface and captured by a color CCD camera.
The absolute phase of each pixel can be calculated from the captured fringe patterns by using the optimum three-fringe
numbers selection method. Experimental results on measuring 3D shape of small objects show the accuracy and
availability of the developed 3D imaging system
Distinct composition and amplification dynamics of transposable elements in sacred lotus (Nelumbo nucifera Gaertn.)
Sacred lotus (Nelumbo nucifera Gaertn.) is a basal eudicot plant with a unique lifestyle, physiological features, and evolutionary characteristics. Here we report the unique profile of transposable elements (TEs) in the genome, using a manually curated repeat library. TEs account for 59% of the genome, and hAT (Ac/Ds) elements alone represent 8%, more than in any other known plant genome. About 18% of the lotus genome is comprised of Copia LTR retrotransposons, and over 25% of them are associated with non-canonical termini (non-TGCA). Such high abundance of non-canonical LTR retrotransposons has not been reported for any other organism. TEs are very abundant in genic regions, with retrotransposons enriched in introns and DNA transposons primarily in flanking regions of genes. The recent insertion of TEs in introns has led to significant intron size expansion, with a total of 200 Mb in the 28 455 genes. This is accompanied by declining TE activity in intergenic regions, suggesting distinct control efficacy of TE amplification in different genomic compartments. Despite the prevalence of TEs in genic regions, some genes are associated with fewer TEs, such as those involved in fruit ripening and stress responses. Other genes are enriched with TEs, and genes in epigenetic pathways are the most associated with TEs in introns, indicating a dynamic interaction between TEs and the host surveillance machinery. The dramatic differential abundance of TEs with genes involved in different biological processes as well as the variation of target preference of different TEs suggests the composition and activity of TEs influence the path of evolution
Projector calibration method based on optical coaxial camera
This paper presents a novel method to accurately calibrate a DLP projector by using an optical coaxial camera to capture
the needed images. A plate beam splitter is used to make imaging axis of the CCD camera and projecting axis of the DLP
projector coaxial, so the DLP projector can be treated as a true inverse camera. A plate having discrete markers on the
surface will be designed and manufactured to calibrate the DLP projector. By projecting vertical and horizontal
sinusoidal fringe patterns on the plate surface from the projector, the absolute phase of each marker’s center can be
obtained. The corresponding projector pixel coordinate of each marker is determined from the obtained absolute phase.
The internal and external parameters of the DLP projector are calibrated by the corresponding point pair between the
projector coordinate and the world coordinate of discrete markers. Experimental results show that the proposed method
accurately obtains the parameters of the DLP projector. One advantage of the method is the calibrated internal and
external parameters have high accuracy because of uncalibrating the camera. The other is the optical coaxes geometry
gives a true inverse camera, so the calibrated parameters are more accurate than that of crossed-optical-axes, especially
the principal points and the radial distortion coefficients of the projector lens
Full-field calibration and compensation of lateral chromatic aberration based on unwrapped phase
Lateral chromatic aberration (CA) of color cameras has great effects on the imaging quality. This paper presents a novel
method to full-field calibrate lateral CA between color channels by using unwrapped phase data. Closed circle sinusoidal
fringe patterns having the optimum three-fringe numbers are generated and displayed on a liquid crystal screen
consecutively through red, green and blue channels. These closed fringe patterns are captured by a color camera. The
wrapped phase and unwrapped phase of each pixel can be calculated by using four-step phase shifting algorithm and
optimum three-fringe number method, respectively. The pixel deviations produced by lateral CA are computed by
comparing the obtained absolute phase data between red, blue, and green channels in polar coordinate system and
calibration is accomplished in Cartesian coordinate system. Lateral CA between color channels of the color camera can
be compensated by using the calibrated data. Simulated and experimental results show the validity of the proposed
calibration and compensation method
Full-field calibration of color camera chromatic aberration using absolute phase maps
The refractive index of a lens varies for different wavelengths of light, and thus the same incident light with different wavelengths has different outgoing light. This characteristic of lenses causes images captured by a color camera to display chromatic aberration (CA), which seriously reduces image quality. Based on an analysis of the distribution of CA, a full-field calibration method based on absolute phase maps is proposed in this paper. Red, green, and blue closed sinusoidal fringe patterns are generated, consecutively displayed on an LCD (liquid crystal display), and captured by a color camera from the front viewpoint. The phase information of each color fringe is obtained using a four-step phase-shifting algorithm and optimum fringe number selection method. CA causes the unwrapped phase of the three channels to differ. These pixel deviations can be computed by comparing the unwrapped phase data of the red, blue, and green channels in polar coordinates. CA calibration is accomplished in Cartesian coordinates. The systematic errors introduced by the LCD are analyzed and corrected. Simulated results show the validity of the proposed method and experimental results demonstrate that the proposed full-field calibration method based on absolute phase maps will be useful for practical software-based CA calibration
Recovering Sign Bits of DCT Coefficients in Digital Images as an Optimization Problem
Recovering unknown, missing, damaged, distorted or lost information in DCT
coefficients is a common task in multiple applications of digital image
processing, including image compression, selective image encryption, and image
communications. This paper investigates recovery of a special type of
information in DCT coefficients of digital images: sign bits. This problem can
be modelled as a mixed integer linear programming (MILP) problem, which is
NP-hard in general. To efficiently solve the problem, we propose two
approximation methods: 1) a relaxation-based method that convert the MILP
problem to a linear programming (LP) problem; 2) a divide-and-conquer method
which splits the target image into sufficiently small regions, each of which
can be more efficiently solved as an MILP problem, and then conducts a global
optimization phase as a smaller MILP problem or an LP problem to maximize
smoothness across different regions. To the best of our knowledge, we are the
first who considered how to use global optimization to recover sign bits of DCT
coefficients. We considered how the proposed methods can be applied to
JPEG-encoded images and conducted extensive experiments to validate the
performances of our proposed methods. The experimental results showed that the
proposed methods worked well, especially when the number of unknown sign bits
per DCT block is not too large. Compared with other existing methods, which are
all based on simple error-concealment strategies, our proposed methods
outperformed them with a substantial margin, both according to objective
quality metrics (PSNR and SSIM) and also our subjective evaluation. Our work
has a number of profound implications, e.g., more sign bits can be discarded to
develop more efficient image compression methods, and image encryption methods
based on sign bit encryption can be less secure than we previously understood.Comment: 13 pages, 8 figure
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