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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - An Eigenmode Method with Improved Accuracy for Guided Waves
摘要： A finite difference frequency domain eigenmode method with improved accuracy for guided waves is presented. The presented method takes the conducting edge field singularity into account. The numerical experiments showed that the presented method was more accurate than the conventional method. The presented method can also be combined with the conformal method to handle more complex geometries. The numerical results showed that the combined edge singularity correction and conformal method further improved the accuracy.
关键词： conformal technique,waveguide port,FDTD,edge singularity correction,eigenmode method
更新于2025-09-04 15:30:14
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Hypercolorimetric multispectral imaging system for cultural heritage diagnostics: an innovative study for copper painting examination
摘要： The aim of this work is to test the application of a new multispectral imaging system, named Hypercolorimetric Multispectral Imaging, on two little 17th century oil paintings on copper in order to support the restoration activities. Hypercolorimetric Multispectral Imaging is a non-invasive, rapid and diagnostic technique that allows in situ accurate and reproducible spectral reflectance measurements between 300 nm and 1000 nm to obtain seven monochromatic very high spatial resolution images (36 megapixels starting from RAW format). The acquired images are transformed into radiometric and colorimetric measurements, consisting of 7 monochromatic images of spectral reflectance and one colorimetric image. All these calibrated images constitute the base for further processing performed through a dedicated software that implements a number of functions. In the present paper, a subset of those functions has been used. Specifically: Principal Component Analysis, spectral clustering, spectral mapping, multiband contrast enhancement and edge detection. Combining calibrated images of different spectral regions acquisitions, it was possible to extract relevant information about the state of conservation of the two copper paintings and further significant details were readable compared with the data coming from each single acquisition. The Hypercolorimetric Multispectral Imaging acquisition process revealed to be fast allowing to be performed during the cleaning stage of the paintings. The imaging nature of the analysis allowed to compare and map different areas of the surfaces producing degradation maps of the painting layers, which represents a precious decision-making tool for conservators.
关键词： copper painting examination,non-invasive technique,cultural heritage diagnostics,restoration support,Hypercolorimetric Multispectral Imaging
更新于2025-09-04 15:30:14
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Off-Label Use of Phakic Intraocular Lens with a “Piggyback” Technique
摘要： Purpose: We report a case of a highly myopic pseudophakic patient who received off-label placement of a phakic intraocular lens (pIOL) via a “piggyback” technique, allowing the placement of an intraocular lens (IOL) in his fellow eye, resulting in improved visual acuity and emmetropia. Case Report: A 66-year-old, highly myopic, pseudophakic male with an IOL implant in his left eye was referred for second opinion for surgical options for his phakic right eye. Given the severe myopic status of both eyes, he received off-label placement of a posterior chamber pIOL with a piggyback technique for the pseudophakic left eye followed by standard cataract surgery and intraocular lens implantation in the right eye. For the left eye, uncorrected best visual acuity improved from 20/70 to 20/25. Conclusion: This case demonstrates the successful off-label use of a phakic IOL in a pseudophakic, highly myopic patient with a piggyback technique, resulting in improved visual acuity and ultimately allowing IOL placement in the fellow eye for emmetropia. This off-label use of pIOL can offer ophthalmologists an alternative option for pseudophakic patents with severe refractive error.
关键词： Cataract surgery,Piggyback technique,Refractive error,High myopia,Phakic intraocular lens
更新于2025-09-04 15:30:14
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APPLICATION OF OPTICAL METHOD IN MEASURING MECHANICAL VIBRATIONS IN A CANTILEVER BEAM
摘要： The pertinent literature discloses a family of optical profile measuring techniques highlighting the moiré methods. The Moiré technique is based on the interference of two superimposed optical grids which produce fringe patterns which can be processed to analyze the DYNAMIC MEASUREMENT IN MATERIALS mechanical behavior. The goal of this research is to experimentally determine the mechanical displacement of a slim cantilever beam by means of Moiré technique with Phase Shift. Photomechanical experimental arrangement included a digital camera, a multimedia projector and a PC. The occurrence of oscillations has been adequately analyzed. The results showed data from which useful information can withdraw, being of great importance to support agricultural machinery projects and development.
关键词： Deformation,Agricultural Machinery,Moiré Technique,Strain,Material Mechanical Behavior Analysis
更新于2025-09-04 15:30:14
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Monitoring FO-PMD and SO-PMD over Time with Respect to Environmental Conditions
摘要： Environmental conditions affect the birefringence of an optical fibre which in turn leads to fluctuations in its Polarization mode dispersion (PMD). Fluctuations in PMD make compensation for it in optical fibres very complicated. In this paper, fluctuations of first-order polarization mode dispersion (FO-PMD), FO-PMD coefficients and second-order polarization mode dispersion (SO-PMD) are monitored over time and also with respect to the environmental conditions. Long term measurements of FO-PMD have been done before by Mudau (2008) using the Generalized Interferometry Technique (GINTY) only. However, in this current study the FO-PMD coefficients and SO-PMD fluctuations were also monitored in addition to making a comparison between the measurements obtained using the Single-ended Dispersion Analyzer (FTB-5700) and the GINTY. These measurements were made on a 14.8 km long deployed aerial optical fibre that links St. Albans to Rockland transmission stations in Port Elizabeth, South Africa. The weather information was obtained from the Kestrel 4500 pocket weather tracker that was set up at St. Albans transmission station. So, for good PMD compensation, PMD should be monitored for a very long period of time or use an instrument that can accurately measure it even when the optical fibre is exposed to harsh environmental conditions.
关键词： Second-order PMD,First-order PMD,Generalized Interferometry Technique,Single-ended Dispersion Analyzer
更新于2025-09-04 15:30:14
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Comprehensive Remote Sensing || Land Surface Temperature Product Development for JPSS and GOES-R Missions
摘要： Land surface temperature (LST) is defined by the International LST and Emissivity Working Group as a measure of how hot or cold the surface of the Earth would feel to the touch. For ground-based, airborne, and space-borne remote sensing instruments it is the aggregated radiometric surface temperatures of all components within the sensor’s field of view in the direction of observation, or 'ensemble directional radiometric temperature.' As one of the most important parameters in the weather and climate system controlling surface heat and water exchange between the land and the atmosphere (Yu et al., 2012), LST has recently been listed as one of the Essential Climate Variables (ECVs) by the Global Climate Observation System (GCOS) of the World Meteorological Organization (WMO). Knowledge of the LST provides information on the temporal and spatial variations of the surface equilibrium state and is of fundamental importance in many applications (Li et al., 2013). This thermodynamic variable has been widely used in a variety of fields such as numerical weather prediction models and data assimilation systems (Meng et al., 2009; Zheng et al., 2012; Trigo et al., 2015), evapotranspiration evaluation (Sun et al., 2012; Galleguillos et al., 2011), irrigation and hydrological cycle particularly agricultural drought monitoring (Anderson et al., 2011, 2012; Karnieli et al., 2010), and urban heat island monitoring (Rajasekar and Weng, 2009; Weng et al., 2004).
关键词： ABI,LST Retrieval,Satellite LST Assessment,Land Surface Temperature,GOES-R,Split-Window Technique,Remote Sensing,VIIRS,JPSS
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Computational Photography (ICCP) - Pittsburgh, PA (2018.5.4-2018.5.6)] 2018 IEEE International Conference on Computational Photography (ICCP) - ADP: Automatic differentiation ptychography
摘要： Ptychography is an imaging technique which aims to recover the complex-valued exit wavefront of an object from a set of its diffraction pattern magnitudes. Ptychography is one of the most popular techniques for sub-30 nanometer imaging as it does not suffer from the limitations of typical lens based imaging techniques. The object can be reconstructed from the captured diffraction patterns using iterative phase retrieval algorithms. Over time many algorithms have been proposed for iterative reconstruction of the object based on manually derived update rules. In this paper, we adapt automatic differentiation framework to solve practical and complex ptychographic phase retrieval problems and demonstrate its advantages in terms of speed, accuracy, adaptability and generalizability across different scanning techniques.
关键词： Imaging Technique,Ptychography,Automatic Differentiation,Phase Retrieval,Sub-30 Nanometer Imaging
更新于2025-09-04 15:30:14
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Surgical management of proximal coronary arteriovenous fistulas using intraoperative fluorescence imaging
摘要： We report the use of intraoperative fluorescence imaging to assist in the surgical management of proximal coronary arteriovenous fistulas in four patients.
关键词： coronary arteriovenous fistula,fluorescence imaging,surgical technique
更新于2025-09-04 15:30:14
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Dual-Channel Photoelectrochemical Ratiometric Aptasensor with Up-converting Nanocrystals Using Spatial-Resolved Technique on Homemade 3D Printed Device
摘要： A near-infrared light (NIRL)-activated ratiometric photoelectrochemical (PEC) aptasensor was fabricated for detection of carcinoembryonic antigen (CEA) coupling with upconversion nanoparticles (UCNPs)-semiconductor nanocrystals-based spatial-resolved technique on a homemade 3D printing device in which a self-regulating integrated electrode was designed for dual signal readout. The as-prepared NaYF4:Yb, Er UCNPs@CdTe nanocrystals were initially assembled on two adjacent photoelectrodes, then CEA aptamer 1 (A1) and capture DNA (CA) were modified onto two working photoelectrodes (WP1 and WP2) through covalent binding, respectively, and then gold nanoparticle-labeled CEA aptamer 2 (Au NP-A2) were immobilized on the surface of functional WP2 for the formation of double-stranded DNA. Upon target CEA introduction, the various concentrations of CEA were captured on the WP1, whereas the binding of the CEA with Au NP-A2 could be released from the WP2 thanks to the highly affinity of CEA toward A2. The dual signal readout with the 'signal-off' of WP1 and 'signal-on' of WP2 were employed for the spatial-resolved PEC (SR-PEC) strategy to detect CEA as an analytical model. Combining NaYF4:Yb, Er UCNPs@CdTe nanocrystals with spatial-resolved model on 3D printing device, the PEC ratiometric aptasensor based on steric hindrance effect and exciton-plasmon interactions (EPI) exhibited a linear range from 10.0 pg mL-1 to 5.0 ng mL-1 with a limit of detection of 4.8 pg mL-1 under 980 nm illumination. The SR-PEC ratiometric strategy showed acceptable stability and reproducibility with a superior anti-interference ability. This approach can provide the guidance for the design of ratiometric, multiplexed and point-of-care biosensors.
关键词： 3D printing device,upconversion nanoparticles,Photoelectrochemical biosensor,ratiometric,spatial-resolved technique,carcinoembryonic antigen
更新于2025-09-04 15:30:14
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A spectral domain approach for the calculation of the scattering of the stratified uniaxial electric anisotropic media under point source excitation with arbitrary orientation
摘要： A method for the calculation of the scattering of the strati?ed uniaxial electric anisotropic media (UEAM) under point source excitation with arbitrary orientation is presented. In this method, the total ?eld is decomposed into three parts, the radiated ?eld of the point source in free space, the re?ected ?eld from the top interface of the UEAM and the transmitted ?eld after multiple re?ections in the anisotropic layer. The three parts are derived in spectral domain respectively and can be expressed by using Fourier transform. Then the saddle point technique (SPT) is introduced to obtain an asymptotic solution of the scattered ?eld. Results from the asymptotic solution are compared with the results calculated by the method of moments (MOM) and the comparison shows good agreement.
关键词： uniaxial electric anisotropic,scattering,spectral domain method,Point source,saddle point technique
更新于2025-09-04 15:30:14