Doped elements in alloys significantly impact their performance.Conventional methods usually sputter the surface material of the sample,or their performance is limited to the surface of alloys owing to their poor pene...Doped elements in alloys significantly impact their performance.Conventional methods usually sputter the surface material of the sample,or their performance is limited to the surface of alloys owing to their poor penetration ability.The X-ray K-edge subtraction(KES)method exhibits great potential for the nondestructive in situ detection of element contents in alloys.However,the signal of doped elements usually deteriorates because of the strong absorption of the principal component and scattering of crystal grains.This in turn prevents the extensive application of X-ray KES imaging to alloys.In this study,methods were developed to calibrate the linearity between the grayscale of the KES image and element content.The methods were aimed at the sensitive analysis of elements in alloys.Furthermore,experiments with phantoms and alloys demonstrated that,after elaborate calibration,X-ray KES imaging is capable of nondestructive and sensitive analysis of doped elements in alloys.展开更多
A new method of back propagation learning with respect to the problem of image restora- tion which is named as greyscale based learning in back propagation neural networks （BPNN） is in- vestigated. It is observed th...A new method of back propagation learning with respect to the problem of image restora- tion which is named as greyscale based learning in back propagation neural networks （BPNN） is in- vestigated. It is observed that by using this method the value of mean square error （MSE） decreases significantly. In addition, this method also gives good visual results when it is applied in image resto- ration problem. This method is also useful to tackle the inherited drawback of falling into local mini- ma by reducing its effect on overall system by bifurcating the learning locally different for different grey scale values. The performance of this algorithm has been studied in detail with different combi- nations of weights. In short, this algorithm provides much better results especially when compared with the simple back propagation algorithm with any further enhancements and without going for hy- brid solutions.展开更多
This document describes the use of grayscale mapping and GIS for identification of historical irrigated lands. Historical irrigated lands form the basis for water rights—a private property right in New Mexico that is...This document describes the use of grayscale mapping and GIS for identification of historical irrigated lands. Historical irrigated lands form the basis for water rights—a private property right in New Mexico that is bought and sold on the open market. Identification of irrigated land on historical photography is both a science and an art. Grayscale mapping of historic black and white photographs can aid in the identification of irrigated lands. GIS allows historical images to be geo-referenced and area computations to be performed on polygons that define the irrigated lands.展开更多
There are many detectors for the least significant bit(LSB)steganography which is broadly used in hiding information in the digital images.The length of the hidden information is one of the most important parameters i...There are many detectors for the least significant bit(LSB)steganography which is broadly used in hiding information in the digital images.The length of the hidden information is one of the most important parameters in detecting steganographic information.Using 2-D gradient of a pixel and the distance between variables the proposed method gives the length of hidden information in natural grayscale images without original image.Extensive experimental results show good performance even at low embedding rate compared with other methods.Furthermore,the proposed method also works well disregarding the status of the embedded information.展开更多
Structural color from artificial structures,due to its environmental friendliness and excellent durability,represents a route for color printing applications.Among various physical mechanisms,the Fabry–Perot(F–P)cav...Structural color from artificial structures,due to its environmental friendliness and excellent durability,represents a route for color printing applications.Among various physical mechanisms,the Fabry–Perot(F–P)cavity effect provides a powerful way to generate vivid colors in either the reflection or transmission direction.Most of the previous F–P type color printing works rely on electron beam grayscale lithography,however,with this technique it is challenging to make large-area and low-cost devices.To circumvent this constraint,we propose to fabricate the F–P type color printing device by the laser grayscale lithography process.The F–P cavity consists of two thin silver films as mirrors and a photoresist film with a spatially variant thickness as the spacer layer.By controlling the laser exposure dose pixel by pixel,a centimeter-scale fullcolor printing device with a spatial resolution up to 5μm×5μm is demonstrated.The proposed large area color printing device may have great potential in practical application areas such as color displays,hyperspectral imaging,advanced painting,and so on.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2017YFA0403801,2017YFA0206004,2018YFC1200204)the National Natural Science Foundation of China(NSFC)(Nos.81430087,11775297,U1932205).
文摘Doped elements in alloys significantly impact their performance.Conventional methods usually sputter the surface material of the sample,or their performance is limited to the surface of alloys owing to their poor penetration ability.The X-ray K-edge subtraction(KES)method exhibits great potential for the nondestructive in situ detection of element contents in alloys.However,the signal of doped elements usually deteriorates because of the strong absorption of the principal component and scattering of crystal grains.This in turn prevents the extensive application of X-ray KES imaging to alloys.In this study,methods were developed to calibrate the linearity between the grayscale of the KES image and element content.The methods were aimed at the sensitive analysis of elements in alloys.Furthermore,experiments with phantoms and alloys demonstrated that,after elaborate calibration,X-ray KES imaging is capable of nondestructive and sensitive analysis of doped elements in alloys.
基金Supported by the National Natural Science Foundation of China(60772066)Higher Education Commission,Pakistan
文摘A new method of back propagation learning with respect to the problem of image restora- tion which is named as greyscale based learning in back propagation neural networks （BPNN） is in- vestigated. It is observed that by using this method the value of mean square error （MSE） decreases significantly. In addition, this method also gives good visual results when it is applied in image resto- ration problem. This method is also useful to tackle the inherited drawback of falling into local mini- ma by reducing its effect on overall system by bifurcating the learning locally different for different grey scale values. The performance of this algorithm has been studied in detail with different combi- nations of weights. In short, this algorithm provides much better results especially when compared with the simple back propagation algorithm with any further enhancements and without going for hy- brid solutions.
文摘This document describes the use of grayscale mapping and GIS for identification of historical irrigated lands. Historical irrigated lands form the basis for water rights—a private property right in New Mexico that is bought and sold on the open market. Identification of irrigated land on historical photography is both a science and an art. Grayscale mapping of historic black and white photographs can aid in the identification of irrigated lands. GIS allows historical images to be geo-referenced and area computations to be performed on polygons that define the irrigated lands.
基金The National Natural Science Foundation ofChina(No.60372076)
文摘There are many detectors for the least significant bit(LSB)steganography which is broadly used in hiding information in the digital images.The length of the hidden information is one of the most important parameters in detecting steganographic information.Using 2-D gradient of a pixel and the distance between variables the proposed method gives the length of hidden information in natural grayscale images without original image.Extensive experimental results show good performance even at low embedding rate compared with other methods.Furthermore,the proposed method also works well disregarding the status of the embedded information.
基金supported by National Natural Science Foundation of China(91950114,12161141010)Zhangjiang Laboratory,Guangdong Provincial Innovation and Entrepreneurship Project(2017ZT07C071)+1 种基金Natural Science Foundation of Shenzhen Innovation Commission(JCYJ20200109140808088)K.C.would like to thank the support from Hong Kong Research Grant Council AoE/P-02/12 and 12303019.
文摘Structural color from artificial structures,due to its environmental friendliness and excellent durability,represents a route for color printing applications.Among various physical mechanisms,the Fabry–Perot(F–P)cavity effect provides a powerful way to generate vivid colors in either the reflection or transmission direction.Most of the previous F–P type color printing works rely on electron beam grayscale lithography,however,with this technique it is challenging to make large-area and low-cost devices.To circumvent this constraint,we propose to fabricate the F–P type color printing device by the laser grayscale lithography process.The F–P cavity consists of two thin silver films as mirrors and a photoresist film with a spatially variant thickness as the spacer layer.By controlling the laser exposure dose pixel by pixel,a centimeter-scale fullcolor printing device with a spatial resolution up to 5μm×5μm is demonstrated.The proposed large area color printing device may have great potential in practical application areas such as color displays,hyperspectral imaging,advanced painting,and so on.
