A Blind Watermarking for 3-D Dynamic Mesh Model Using Distribution of Temporal Wavelet Coefficients

Author(s):  
Min-Su Kim ◽  
Rémy Prost ◽  
Hyun-Yeol Chung ◽  
Ho-Youl Jung
2018 ◽  
Vol 25 (2) ◽  
pp. 287-303 ◽  
Author(s):  
Qi-bin Wang ◽  
Hong-bo Ma ◽  
Xian-guang Kong ◽  
Yi-min Zhang

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 739-747
Author(s):  
Liu Liu ◽  
Zhe Yang ◽  
Yingwen Liu ◽  
Gao Bo

In this study, a dynamic mesh model was proposed in the light of the actual working condition of an acoustic driver. Moreover, the structural optimization of the stack to improve the performance of thermoacoustic refrigerator was presented using response surface methodology. The analysis of variance was conducted to describe the rationality of regression model and examine the statistical significance of factors. Based on the consideration of parameters interaction, the optimized values of stack parameters suggested by response surface methodology have been predicted successfully. Results showed that optimal stack parameters group could realize the optimal cooling performance. The optimal ratios of stack spacing to stack thickness and stack length to stack position were 3.59-4 and 0.77-1, respectively. This study provides a new method for CFD modeling and optimizing the thermoacoustic refrigerator, which helps to popularize its application.


2016 ◽  
Vol 16 (02) ◽  
pp. 1650006 ◽  
Author(s):  
P. Manimehalai ◽  
P. Arockia Jansi Rani

Reversible watermarking methods are used for copyright protection and are able to recover the host image without distortion. Robust reversible watermarking technique should resist against intentional and unintentional image processing attacks. Robust reversible watermarking techniques should have three features namely imperceptibility, reversibility and robustness. In this paper, it is proposed to develop a new robust reversible blind watermarking for color images based on histogram construction of the wavelet coefficients constructed from the cover image. In the proposed approach, the red component of a host color image is decomposed into wavelet coefficients. Motivated by the excellent spatio-frequency localization properties of wavelets, this technique is proposed in the wavelet domain. The pixels are adjusted before watermark embedding such that both overflow and underflow of pixels during embedding is avoided and image is recovered without distortion. Based on histogram construction and the local sensitivity of Human Visual System (HVS) in wavelet domain, the watermark is embedded. For watermark extraction without host image, k-means clustering algorithm is proposed. The experimental results show that the proposed technique has good performance in terms of reversibility and robustness with the high quality of the watermarked image. The PSNR value of the recovered image is around 48[Formula: see text]dB which proves that the quality of the recovered image is not degraded.


2011 ◽  
Vol 320 ◽  
pp. 319-324
Author(s):  
Mao Deng ◽  
Zong Ming Wang ◽  
Chun Xue Zhang

We present an easy approach to obtain the dynamic flow field with a moving body inside. Instead of popular interface boundaries, the interior boundaries were applied as moving parts, which made separated computation volumes a default-continuum meanwhile. With the combination use of UDF and dynamic mesh model, the numerical technique was tested and validated by simulating flow through moving screen, a kind of porous material. The pressure and velocity contours obtained clearly showed the changing behaviors of the flow while passing through a moving porous material, and clarified the influence posed by the movement of its frame. The method is used for the simulation of the flow with a moving body inside.


2017 ◽  
Vol 4 (3) ◽  
pp. 234-244 ◽  
Author(s):  
Yi Zheng ◽  
Ying Li ◽  
Magesh Thiruvengadam ◽  
Hai Lan ◽  
Jerry C. Tien
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