Image enhancement using fuzzy intensity measure and adaptive clipping histogram equalization

Image enhancement aims at processing an input image so that the visual content of the output image is more pleasing or more useful for certain applications. Although histogram equalization is widely used in image enhancement due to its simplicity and effectiveness, it changes the mean brightness of the enhanced image and introduces a high level of noise and distortion. To address these problems, this paper proposes image enhancement using fuzzy intensity measure and adaptive clipping histogram equalization (FIMHE). FIMHE uses fuzzy intensity measure to first segment the histogram of the original image, and then clip the histogram adaptively in order to prevent excessive image enhancement. Experiments on the Berkeley database and CVF-UGR-Image database show that FIMHE outperforms state-of-the-art histogram equalization based methods

A novel rapid method for viewshed computation on DEM through max-pooling and min-expected height

Viewshed computation of a digital elevation model (DEM) plays an important role in a geographic information system, but the required high computational time is a serious problem for a practical application. Hitherto, the mainstream methods of viewshed computing include line-of-sight method, reference planes method, etc. Based on these classical algorithms, a new algorithm for viewshed computation is proposed in this paper: the Matryoshka doll algorithm. Through a pooling operation, the minimum expected height of the DEM is introduced as max-pooling with minimum expected height in the viewshed computing optimization. This is to increase the efficiency and adaptability of the computation of the visibility range. The experimental results demonstrate that the algorithm has obvious advantages in computing speed, but with the accuracy only slightly reduced

Camera geolocation using digital elevation models in hilly area

he geolocation of skyline provides an important application in unmanned vehicles, unmanned aerial vehicles, and other fields. However, the existing methods are not effective in hilly areas. In this paper, we analyze the difficulties to locate in hilly areas and propose a new geolocation method. According to the vegetation in hilly area, two new skyline features, enhanced angle chain code and lapel point, are proposed. In order to deal with the skyline being close to the camera, we also propose a matching method which incorporates skyline distance heatmap and skyline pyramid. The experimental results show that the proposed method is highly effective in hilly area and has a robust performance against noise and rotation effects

Design and Characterization of a Human Monoclonal Antibody that Modulates Mutant Connexin 26 Hemichannels Implicated in Deafness and Skin Disorders

Background: Mutations leading to changes in properties, regulation, or expression of connexin-made channels have been implicated in 28 distinct human hereditary diseases. Eight of these result from variants of connexin 26 (Cx26), a protein critically involved in cell-cell signaling in the inner ear and skin. Lack of non-toxic drugs with defined mechanisms of action poses a serious obstacle to therapeutic interventions for diseases caused by mutant connexins. In particular, molecules that specifically modulate connexin hemichannel function without affecting gap junction channels are considered of primary importance for the study of connexin hemichannel role in physiological as well as pathological conditions. Monoclonal antibodies developed in the last three decades have become the most important class of therapeutic biologicals. Recombinant methods permit rapid selection and improvement of monoclonal antibodies from libraries with large diversity.Methods: By screening a combinatorial library of human single-chain fragment variable (scFv) antibodies expressed in phage, we identified a candidate that binds an extracellular epitope of Cx26. We characterized antibody action using a variety of biochemical and biophysical assays in HeLa cells, organotypic cultures of mouse cochlea and human keratinocyte-derived cells.Results: We determined that the antibody is a remarkably efficient, non-toxic, and completely reversible inhibitor of hemichannels formed by connexin 26 and does not affect direct cell-cell communication via gap junction channels. Importantly, we also demonstrate that the antibody efficiently inhibits hyperative mutant Cx26 hemichannels implicated in autosomal dominant non-syndromic hearing impairment accompanied by keratitis and hystrix-like ichthyosis-deafness (KID/HID) syndrome. We solved the crystal structure of the antibody, identified residues that are critical for binding and used molecular dynamics to uncover its mechanism of action.Conclusions: Although further studies will be necessary to validate the effect of the antibody in vivo, the methodology described here can be extended to select antibodies against hemichannels composed by other connexin isoforms and, consequently, to target other pathologies associated with hyperactive hemichannels. Our study highlights the potential of this approach and identifies connexins as therapeutic targets addressable by screening phage display libraries expressing human randomized antibodies

Hunting for wealthy encounters promotes cooperation in spatial Prisoner’s Dilemma games

We consider an evolutionary Prisoner’s Dilemma game on the lattice where a parameter α is employed to determine with whom individuals aspire to interact in future iterations. Specifically, for positive α, rich environments are preferentially considered when individuals hunt for new surroundings, while for negative α, the opposite holds. When α = 0, individuals adopt ‘random move’-like migration. The results indicate that aspiring for wealthy ambience makes cooperation survive and even thrive under certain circumstances. Moreover, there exist the optimal population densities that most uphold cooperation. We also investigate the expansion of cooperators. And the discovery of utmost salience is that cooperators can spontaneously break out for the population consisting of full defectors in the presence of strategy mutation. Our results relax the requirements for cooperation to outbreak and suggest that spying into others’ strategies is not always necessary for the cooperation to burst. Finally, we deepen our studies by exploring the situation that each individual has an independent α and find that the fate of evolution is mainly determined by the population composition in this scenario

Effects of partner choice and role assignation in the spatial ultimatum game

Hitherto, there has been an increasing interest in the ultimatum game, an elegant metaphor constituted for decoding the self-organization of fair behavior. Most previous studies have been done in the context of unbiased partner selection and symmetric role assignation. However, this is not always the case. To investigate the role of partner choice and role allocation on fairness, we develop a co-evolutionary ultimatum game in which agents can dynamically choose interacting neighbors as well as allocate game roles based on the real-time feedback from interactions. By the Monte Carlo simulation, we find that the related biases always play a crucial role in transforming the evolution of fairness. More specifically, the fairness level can be strikingly promoted when agents often aspire for interactions with more successful players and frequently designate reputable ones as proposers in the ultimatum game. For other cases, however, fairness is often remarkably inhibited. Compared with weak selection, strong selection turns out to be more favorable to the evolution of fair behavior. Finally, with proper parameters we witness the spontaneous emergence of social fairness in a totally self-regarding population under the noisy condition

Effects of different aspiration thresholds on the evolution of cooperation in the PDG (a) and SG (b).

<p> corresponds to the results obtained on static networks. Based on this plot, one can conclude that the aspiration level plays a crucial role in the evolution of cooperation. Moderate aspirations are more efficient in terms of boosting cooperation. for the PDG (a), and for the SG (b). Other parameters and conditions are the same as in Fig. 1.</p