Lossless information hiding scheme for two-dimensional CAD engineering graphics based on coordinate modification

Author(s):  
Zhengqiao Lei
2012 ◽  
Vol 229-231 ◽  
pp. 1798-1801
Author(s):  
Ze Rong Li ◽  
Bi Ru Li ◽  
Li Qin ◽  
Jian Chun Gong

This article analyses the development history of Engineering graphics, researches on modern engineering graphics, and puts forward the problem of modern engineering graphics, as drawing and interpreting drawings all need special training. For the problem this article puts forward the new structure of pattern: using three-dimensional pattern to replace traditional two- dimensional pattern, expressing the inside and outside structure shape of parts, by the profile and rotation of three-dimensional pattern. the three-dimensional is more directer and visualer than the two-dimensional patterns as the same method to express the structure and shape of objects. use three-dimensional to express to avoid the two conversions from three-dimensional to two-dimensional(drawing) or from two-dimensional to three- dimensional(interpret drawings).


2012 ◽  
Vol 605-607 ◽  
pp. 1402-1407
Author(s):  
Fan Zeng ◽  
Jing Jun Lou ◽  
Shi Jian Zhu

This paper introduces the characteristics of SolidWorks software and process of modeling and design of giant magnetostrictive actuator. Parts designing, formation of assembly body, sports simulation, and two-dimensional engineering graphics are completed on the way of giant magnetostrictive actuator structure with SolidWorks software. In the process of the giant magnetostrictive actuators modeling, the interference and clearance of assembly bady is found and revised in time to ensure the design more reasonable.


2013 ◽  
Vol 655-657 ◽  
pp. 349-354
Author(s):  
Xiaoli Tu ◽  
Xue Mei Jiang ◽  
Xiao Mei Zhang

With the development of digital design and processing and the explosive growth of the demand for two-dimensional CAD engineering graphics, more attention has been paid on the security and the copyright issues of engineering graphics. In this paper, an improved reversible watermarking algorithm in wavelet domain for two-dimensional CAD engineering graphics is proposed. Firstly, the watermark information is preprocessed by compound chaos sequence. And then, block the graphic and extract all vertexes in each blocks of the 2D CAD engineering graphics, Log-polar Mapping (LPM) and wavelet transform are done to them respectively to achieve the invariance of affine transform. Finally, the encrypted watermark is embedded into detailed coefficients by using improved quantization index modulation (IQIM) scheme. Compared with the original previous algorithm, theoretical analysis and experimental results show that the proposed algorithm has not only good visibility and good reversibility, but also stronger robust against the attacks such as transformation, rotation, equal scaling and entity deleting, tampering or adding etc.


1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


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