45 research outputs found
Theory of Self-maintaining Robots
This thesis proposes a theory for robotic systems that can be fully
self-maintaining. The presented design principles focus on functional survival of
the robots over long periods of time without human maintenance.
Self-maintaining semi-autonomous mobile robots are in great demand in nuclear
disposal sites from where their removal for maintenance is undesirable due to
their radioactive contamination. Similar are requirements for robots in various
defence tasks or space missions. For optimal design, modular solutions are
balanced against capabilities to replace smaller components in a robot by itself or
by help from another robot. Modules are proposed for the basic platform, which
enable self-maintenance within a team of robots helping each other. The primary
method of self-maintenance is replacement of malfunctioning modules or
components by the robots themselves. Replacement necessitates a robot teamâs
ability to diagnose and replace malfunctioning modules as needed. Due to their
design, these robots still remain manually re-configurable if opportunity arises for
human intervention. A system reliability model is developed to
describe the new theory. Depending on the system reliability model,
the redundancy allocation problem is presented and solved by a multi objective
algorithm.
Finally, the thesis introduces the self-maintaining process and transfers it to a multi robot task allocation problem with a solution by genetic algorithm
Accelerating the Translation of Nanomaterials in Biomedicine
Due to their size and tailorable physicochemical properties, nanomaterials are an emerging class of structures utilized in biomedical applications. There are now many prominent examples of nanomaterials being used to improve human health, in areas ranging from imaging and diagnostics to therapeutics and regenerative medicine. An overview of these examples reveals several common areas of synergy and future challenges. This Nano Focus discusses the current status and future potential of promising nanomaterials and their translation from the laboratory to the clinic, by highlighting a handful of successful examples
Accelerating the Translation of Nanomaterials in Biomedicine
Due to their size and tailorable physicochemical properties, nanomaterials are an emerging class of structures utilized in biomedical applications. There are now many prominent examples of nanomaterials being used to improve human health, in areas ranging from imaging and diagnostics to therapeutics and regenerative medicine. An overview of these examples reveals several common areas of synergy and future challenges. This Nano Focus discusses the current status and future potential of promising nanomaterials and their translation from the laboratory to the clinic, by highlighting a handful of successful examples
Fine-Scale Mapping of the 4q24 Locus Identifies Two Independent Loci Associated with Breast Cancer Risk
Background: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored.
Methods: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium.
Results: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 Ă 10â4; OR, 1.04; 95% confidence interval (CI), 1.02â1.07] and rs77928427 (P = 1.86 Ă 10â4; OR, 1.04; 95% CI, 1.02â1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r2 â„ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factorâbinding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue.
Conclusion: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2.
Impact: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk
Waterproof Performance of Sealing Gasket in Shield Tunnel: A Review
Rubber gaskets are commonly adopted as the waterproof component in shield tunnels for their outstanding sealing performance. The contact pressure between surfaces generated by the assembly stress ensures that the gaskets resist certain water pressure without leaking. However, with the continuous occurrence of leakage accidents, attention has been drawn to the topic of the waterproof performance of gasketed joint shield tunnels. In this article, prominent contributions to the waterproof performance of sealing gasket in shield tunnels are listed and sorted into four sections: (1) structural behavior of lining and joint; (2) material constitutive model and durability; (3) numerical simulation methods; (4) thermal-mechanical coupling analysis. First, examples of leakage are discussed and tests on gaskets are elucidated, which is followed by a summary of the progress on material mechanical properties and durability. Then, the development of the simulation methods is presented. Finally, the existing research on the thermal-mechanical coupling analysis is summarized. It is found that the contributions to gasketsâ waterproof performance are fruitful, however, with stringent construction conditions, such as the material constitutive model and aging mechanism under special conditions, such as high temperature, numerical simulation, and laboratory test methods, which need to be further explored
Co-saliency detection via similarity-based saliency propagation
In this paper, we present a method for discovering the common salient objects from a set of images. We treat co-saliency detection as a pairwise saliency propagation problem, which utilizes the similarity between each pair of images to measure the common property with the guidance of a single saliency map image. Given the pairwise co-salient foreground maps, pairwise saliency is optimized by combining the initial background cues. Pairwise co-salient maps are then fused according to a novel fusion strategy based on the focus of human attention. Finally we adopt an integrated multi-scale scheme to obtain the pixel-level saliency map. Our proposed model makes the existing single saliency model perform well in co-saliency detection and is not overly sensitive to the initial saliency model selected. Extensive experiments on two benchmark databases show the superiority of our co-saliency model against the state-of-the-art methods both subjectively and objectively
Scalable Hydrogel-Based Nanocavities for Switchable Meta-Holography with Dynamic Color Printing
Devices used for meta-optics display are currently undergoing
a
revolutionary transition from static to dynamic. Despite various tuning
strategy demonstrations such as mechanical, electrical, optical, and
thermal tunings, a longstanding challenge for their practical application
has been the achievement of a conveniently accessible real-life tuning
scheme for realizing versatile functionality dynamics outside the
laboratory. In this study, we demonstrate a practical tuning strategy
to realize a dynamic color printing with a switchable meta-holography
exhibition based on hydrogel-based nanocavities. On the basis of the
inflation sensitivity of a hydrogel to humidity alteration, its transmissive
color was notably tuned from 450 to 750 nm. More intriguingly, by
controlling the sample dry/immersed states in real time, we successfully
enabled dual-channel switchable meta-holography. With the advantages
of facile architecture, daily stimulus with large-area modulation,
and high chromaticity, our proposed hydrogel-based nanocavities provide
a promising path toward tunable display/encryption, optical sensors,
and next-generation display technology
Scalable Hydrogel-Based Nanocavities for Switchable Meta-Holography with Dynamic Color Printing
Devices used for meta-optics display are currently undergoing
a
revolutionary transition from static to dynamic. Despite various tuning
strategy demonstrations such as mechanical, electrical, optical, and
thermal tunings, a longstanding challenge for their practical application
has been the achievement of a conveniently accessible real-life tuning
scheme for realizing versatile functionality dynamics outside the
laboratory. In this study, we demonstrate a practical tuning strategy
to realize a dynamic color printing with a switchable meta-holography
exhibition based on hydrogel-based nanocavities. On the basis of the
inflation sensitivity of a hydrogel to humidity alteration, its transmissive
color was notably tuned from 450 to 750 nm. More intriguingly, by
controlling the sample dry/immersed states in real time, we successfully
enabled dual-channel switchable meta-holography. With the advantages
of facile architecture, daily stimulus with large-area modulation,
and high chromaticity, our proposed hydrogel-based nanocavities provide
a promising path toward tunable display/encryption, optical sensors,
and next-generation display technology