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Review on Metrics and Prediction Methods of Civil Aviation Noise
Hao Feng,Yadong Zhou,Weili Zeng,Cong Ding 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.5
Civil aviation noise is one of the main factors hindering the growth of the civil aviation industry. With the increase in global air traffic demand, the problem of aviation noise pollution will become more and more serious. It is of great significance to carry out research in aviation noise. First, by summarizing the characteristics of aviation noise metrics, this paper divides them into three categories: single event noise metrics, cumulative exposure metrics, and daily metrics. Representative metrics of each category are selected for explanation and in-depth analysis. Second, according to the principles of aviation noise prediction models, this paper classifies these existing models into three categories: best practice models, scientific models, and machine learning models. Relevant academic research results are summarized. The best practice model regards the aircraft as noise point source, and its specialty is to predict noise under complex air traffic conditions. The scientific model considers the noise from the level of aircraft components and reflects the underlying physical effects. Based on data, the machine learning model uses algorithms to mine the hidden relationship between various factors and noise to achieve the purpose of noise prediction. Then, this paper introduces two kinds of aviation noise simulation software based on the best practice and scientific models, and lists their access addresses. Finally, challenges and prospects are presented from three aspects: metrics, prediction models and simulation software.
A Novel Blind Watermarking Scheme based on Quaternion and Joint SVD Blocks
Feng Liu,Hao Feng 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.4
In this paper, a novel blind color image watermarking technique using Quaternion and Joint QSVD Blocks is proposed to protect the intellectual property rights of color images. The proposed method tries to insert the watermark in the joint blocks .In this method, the color image is considered as an array of pure quaternion numbers. Then the array of pure quaternion is divided into non-overlapping blocks and performs QSVD to the blocks. The watermarking is inserted into the S blocks by changing the 2 of S of two adjacent blocks. Besides, in the procedure of watermark insertion and extraction, ensuring higher fidelity and robustness and resilience to several possible image attacks have been considered. The experimental results showed that the proposed method performance created watermarked images with better PSNRs and more robustness versus several attacks such as JPEG, Salt &Pepper noise, Brightness adjustment, Sharpen and Blurring.
Feng, Zhi-Qiang,Yang, Xiao-Li,Ye, Yuan-Feng,Hao, Lin-Yun Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4
The design, synthesis, and structural characterization of two new palladium complexes based on Schiff base ligands is reported; $[Pd(L1)_2]$ (1) and $[Pd(L2)_2]$ (2), [HL1 = 2-((E)-(2,6-diethylphenylimino)methyl)-4,6-dibromophenol, L2 = (E)-N-benzylidene-2,6-diethylbenzenamine], which are obtained by functionalizing Schiff base ligands with or without electron-withdrawing groups. Both compounds are mononuclear structures. Comparisons are made to the compounds 1 and 2 to analyze and understand the effect of electron-withdrawing groups. Antibacterial activity studies indicate the electron-withdrawing groups on Schiff base ligands enhance antibacterial activity. Catalytic activity, however, is reduced due to the enhanced steric-hindrance of the electron-withdrawing groups. Electronic absorption and emission properties of HL1, L2, 1 and 2 are also reported.
Blind Watermarking Scheme based on U matrix Through QSVD Transformation
Feng Liu,Hao Feng,Chao Lu 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.4
In this paper, a novel blind color image watermarking technique using U matrix through QSVD transformation is proposed to protect the intellectual property rights of color images. The proposed method tries to insert the watermark through moderating the coefficient of the quaternion elements in U matrix. .In this method, the color image is considered as an array of pure quaternion numbers. Then the array of pure quaternion is divided into non-overlapping blocks and we perform QSVD to the block to get the U matrix. The watermarking is inserted into the coefficient of the quaternion elements in the first column of the U matrix. Besides, in the procedure of watermark insertion and extraction, ensuring higher fidelity and robustness and resilience to several possible image attacks have been considered. The experimental results showed that the proposed method performance created watermarked images with better PSNRs and more robustness versus several attacks such as Salt &Pepper noise, Brightness adjustment, Sharpen and Blurring and Clipping.
Hao Hong,Chang-Hao Cui,Jin-Kwang Kim,Feng-Xie Jin,Sun-Chang Kim,Wan-Taek Im 고려인삼학회 2012 Journal of Ginseng Research Vol.36 No.4
This study focused on the enzymatic biotransformation of the major ginsenoside Rb1 into Rd for the mass production of minor ginsenosides using a novel recombinant β-glucosidase from Flavobacterium johnsoniae. The gene (bglF3) consisting of 2,235 bp (744 amino acid residues) was cloned and the recombinant enzyme overexpressed in Escherichia coli BL21(DE3) was characterized. This enzyme could transform ginsenoside Rb1 and gypenoside XVII to the ginsenosides Rd and F2, respectively. The glutathione S-transferase (GST) fused BglF3 was purifi ed with GST-bind agarose resin and characterized. The kinetic parameters for β-glucosidase had apparent Km values of 0.91±0.02 and 2.84±0.05 mM and Vmax values of 5.75±0.12 and 0.71±0.01 μmol·min-1·mg of protein-1 against p-nitrophenyl-β-D-glucopyranoside and Rb1, respectively. At optimal conditions of pH 6.0 and 37°C, BglF3 could only hydrolyze the outer glucose moiety of ginsenoside Rb1 and gypenoside XVII at the C-20 position of aglycon into ginsenosides Rd and F2, respectively. These results indicate that the recombinant BglF3 could be useful for the mass production of ginsenosides Rd and F2 in the pharmaceutical or cosmetic industry.
ATF3 Activates Stat3 Phosphorylation through Inhibition of p53 Expression in Skin Cancer Cells
Hao, Zhen-Feng,Ao, Jun-Hong,Zhang, Jie,Su, You-Ming,Yang, Rong-Ya Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12
Aim: ATF3, a member of the ATF/CREB family of transcription factors, has been found to be selectively induced by calcineurin/NFAT inhibition and to enhance keratinocyte tumor formation, although the precise role of ATF3 in human skin cancer and possible mechanisms remain unknown. Methods: In this study, clinical analysis of 30 skin cancer patients and 30 normal donors revealed that ATF3 was accumulated in skin cancer tissues. Functional assays demonstrated that ATF3 significantly promoted skin cancer cell proliferation. Results: Mechanically, ATF3 activated Stat3 phosphorylation in skin cancer cell through regulation of p53 expression. Moreover, the promotion effect of ATF3 on skin cancer cell proliferation was dependent on the p53-Stat3 signaling cascade. Conclusion: Together, the results indicate that ATF3 might promote skin cancer cell proliferation and enhance skin keratinocyte tumor development through inhibiting p53 expression and then activating Stat3 phosphorylation.
Optical Properties of a Nanofiber with Metal Cladding
Guoying Feng,Hao Zhou,Guorui Zhou,Hao Yang,Guoliang Deng,Shouhuan Zhou 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.41
We present a detailed report on the linear and the nonlinear optical properties of a nanofiber with metal cladding fabricated by using a flame stretch method and a vacuum deposition method. We numerically simulated the field distribution in a tapered nanofiber with different thicknesses of silver cladding. The results show that, due to the high-index contrast between the silica core and the silver cladding, the silica waveguide allows strong optical confinement and large effective nonlinearity. The supercontinuum generation based on a nanofiber with metal cladding is investigated theoretically and experimentally.