Adaptive self-calibrating image rejection receiver

An adaptive self-calibrating image rejection receiver is described, containing a modified Weaver image rejection mixer and a Digital Image Rejection Processor (DIRP). The blind source-separation-based DIRP eliminates the I/Q errors improving the Image Rejection Ratio (IRR) without the need for trimming or use of power-hungry discrete components. Hardware complexity is minimal, requiring only two complex coefficients; hence it can be easily integrated into the signal processing path of any receiver. Simulation results show that the proposed approach achieves 75-97 dB of IRR.

Design and low-power implementation of an adaptive image rejection receiver

This paper deals with and details the design and implementation of a low-power; hardware-efficient adaptive self-calibrating image rejection receiver based on blind-source-separation that alleviates the RF analog front-end impairments. Hybrid strength-reduced and re-scheduled data-flow, low-power implementation of the adaptive self-calibration algorithm is developed and its efficiency is demonstrated through simulation case studies. A behavioral and structural model is developed in Matlab as well as a low-level architectural design in VHDL providing valuable test benches for the performance measures undertaken on the detailed algorithms and structures.

Self-esteem mediates the relationship between connectedness to nature and body appreciation in women, but not men

Connectedness to nature (i.e., an affective and experiential connection to nature) is known to have a positive effect on psychological well-being, but its specific associations with body image have not been fully examined. To attend to this oversight, we conducted a preliminary investigation of associations between connectedness to nature and body appreciation. A total of 380 British adults completed measures of connectedness to nature, body appreciation, and self-esteem. Bivariate correlations revealed significant positive associations between all variables in women. In men, body appreciation was significantly correlated with self-esteem, but not connectedness to nature. Mediation analysis showed that, in women, self-esteem fully mediated the relationship between connectedness to nature and body appreciation. In men, body appreciation was significantly associated with self-esteem, but not connectedness to nature. These results point to a potential route for improving body image among women through connectedness to nature and self-esteem, but further research is necessary.

Renouncing the Single Image: Photography and the Realism of Abstraction

This essay addresses the issue of the relationship between abstraction and realism that it argues is at stake in the rejection of any primacy accorded to the single image, in favour of a sequencing of photographs according to certain, often novelistic and epic ideas of narrative form. Setting out from the opening text of Allan Sekula’s Fish Story, the article explores the competing tendencies towards what Georg Lukács termed ‘narration’ and ‘description’ as these are traced throughout Sekula's project (in part through a comparison with the contrasting works of Andreas Gursky). The essay concludes by suggesting the ways in which it is the irreducible actuality of abstraction within the concrete everydayness of capitalism's social world that means that all photographic ‘realism’ is intrinsically ‘haunted’ by a certain spectre of that ‘self-moving substance in the ‘shape of money’, as Marx calls it, or of the abstract form of capital itself.

Bodies in Nature: Associations between Exposure to Nature, Connectedness to Nature, and Body Image

Here, we sought to replicate previous work showing a relationship between connectedness to nature and body appreciation, and extend it by examining associations between exposure to natural environments and other body image-related variables. An online sample of 399 U.S. women and men (Mage = 34.55 years) completed measures of body appreciation, connectedness to nature, nature exposure, appearance investment, sociocultural attitudes toward appearance, and self-esteem. Path analysis showed that nature exposure and connectedness to nature, respectively, were associated with body appreciation in women and men, both directly and indirectly via self-esteem. Connectedness to nature also mediated the link between nature exposure and body appreciation. In men, but not women, the link between connectedness to nature and body appreciation was also mediated by appearance investment and internalisation of a muscular ideal. These results may point to novel methods for promoting more positive body image in adults through engagement with nature.