66,234 research outputs found
High Dynamic Range Imaging for Preserving Chromaticity Information of Architectural Heritage
This proposal seeks to enhance the documentation of architectural heritage. Precise color information (i.e. chromaticity, excluding lighting effects) as an intrinsic property of materials has not been accurately documented in the scale of large surfaces for historical buildings. Every day the materials of historical buildings are decaying and their colors are fading. The colors we can see today will not be the same as future generations can see if we cannot preserve the chromaticity information. We propose to develop a method to assist in recording the chromaticity of historical buildings with low cost and high efficiency based on the emerging High Dynamic Range Imaging technology. The significance of it lies in that by recording the chromaticity information, we can achieve more complete documentation for historical buildings and can detect color change of the buildings when measurements are done in a regular basis, which will provide important information for preservation planning
Cylindrical Superlens by a Coordinate Transformation
Cylinder-shaped perfect lens deduced from the coordinate transformation
method is proposed. The previously reported perfect slab lens is noticed to be
a limiting form of the cylindrical lens when the inner radius approaches
infinity with respect to the lens thickness. Connaturality between a
cylindrical lens and a slab lens is affirmed by comparing their eigenfield
transfer functions. We numerically confirm the subwavelength focusing
capability of such a cylindrical lens with consideration of material
imperfection. Compared to a slab lens, a cylindrical lens has several
advantages, including finiteness in cross-section, and ability in lensing with
magnification or demagnification. Immediate applications of such a cylindrical
lens can be in high-resolution imaging and lithography technologies. In
addition, its invisibility property suggests that it may be valuable for
non-invasive electromagnetic probing.Comment: Minor changes to conform with the published versio
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