A Robust Watermarking Scheme Based on Least Significant Bit and Discrete Cosine Transform

Zhou Fu-an 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.4

In this paper, an image watermarking scheme is presented, in which Least Significant Bit and discrete cosine transform are used. The discrete cosine transform is performed on the original host image, and the secret watermark image is embedded into the coefficient of discrete cosine transform, which will replace the least significant bit. The embedded secret watermark bit will cause minimal distortion of the original host image, but we cannot find the difference of the original host image and the watermarked image. The experiment based on this algorithm demonstrates that the watermarking is robust to the common signal processing techniques, including noise attack, JPEG Compression attack and so on.

Phishing Sites and Prevention Measures

Zhou Fu-an 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

With the growing number of Internet users in online transactions, the number of phishing sites is also increasing rapidly, the threat of malicious attack front is extended, the means are ever-changing, which gives great economic losses to China's Internet users and businesses, and caused a serious impediment to online financial services and the healthy development of e-business applications. Facing of the growing phishing epidemic, the initiative alone to enhance awareness of Internet users to avoid "phishing" is not enough. This paper analyzes phishing sites based on deception trick, focusing on the Internet user side, made several recommendations to strengthen their resistance to phishing sites.

Distribution and Properties of Shear Stress in Elastic Beams with Variable Cross Section: Theoretical Analysis and Finite Element Modelling

Man Zhou,Huiyang Fu,Lin An 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

It was found that additional shear stress arising from the bending moment should be involved in the formulation due to the effect of variable cross section, which is quite different from the conventional method of analysis for the prismatic members. This paper focuses on the analytical formulation, properties and distribution regularity of the shear stress for the elastic tapered beams with rectangular cross-section. Currently, an analytical expression for the shear stress in elastic tapered beams is derived theoretically based on the theory of elasticity. Most notably, it is strictly proved in mathematics that the additional shear stresses arising from bending moment are self-balanced which only change the distribution of shear stress in the section but will not affect the shear stress resultant. This new finding will be beneficial to promoting the development and consummation of non-prismatic beam theory. The correctness of the theoretical formula have been verified through comparisons with finite element (FE) results of two groups with a total of 12 three-dimensional FE models. The validity of self-balanced properties of additional shear stress in tapered beams under pure bending is additionally verified by using Free Body Cuts in ABAQUS program.

Impacts of Ownership Balance and Nonexecutive Directors on Bank Performance and Risk Taking: Evidence from City Commercial Banks in China

Fangzhao Zhou,Yajing Fu,Yunbi An,Jun Yang 연세대학교 동서문제연구원 2019 Global economic review Vol.48 No.1

This paper investigates the impacts of nongovernmental stake, ownership balance, and nonexecutive directors on bank performance and risk taking in city commercial banks (CCBs) in China. We find that ownership balance can improve CCBs’ financial performance and reduce their bankruptcy risk as well as nonperforming loan level. Nonexecutive directors can help reduce bankruptcy risk, but have no significant effect on performance or nonperforming loans. The impacts of ownership balance and nonexecutive directors become more prominent when the nongovernmental stake is relatively high, suggesting that mixed ownership reform can promote bank performance and risk control via these two avenues.

Therapeutic inhibition of SGK1 suppresses colorectal cancer

Xuchun Liang,Chunling Lan,Guanming Jiao,Wencheng Fu,Xuesha Long,Yu An,Kejin Wang,Jinzhe Zhou,Ting Chen,Yongqin Li,Jiahong Xu,Qi Huang,Bin Xu,Junjie Xiao 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Colorectal cancer (CRC) is one of the leading causes of death worldwide. Thus, the development of new therapeutic targets for CRC treatment is urgently needed. SGK1 is involved in various cellular activities, and its dysregulation can result in multiple cancers. However, little is known about its roles and associated molecular mechanisms in CRC. In present study, we found that SGK1 was highly expressed in tumor tissues compared with peri-tumor samples from CRC patients. In vitro experiments revealed that SGK1 overexpression promoted colonic tumor cell proliferation and migration and inhibited cell apoptosis induced by 5-fluorouracil (5-FU), while SGK1 shRNA and inhibitors showed the inverse effects. Using CRC xenograft mice models, we demonstrated that knockdown or therapeutic inhibition of SGK1 repressed tumor cell proliferation and tumor growth. Moreover, SGK1 inhibitors increased p27 expression and promoted p27 nuclear accumulation in colorectal cancer cells, and p27 siRNAs could attenuate the repression of CRC cell proliferation induced by SGK1 inhibitors. Collectively, SGK1 promotes colorectal cancer development via regulation

Effective adsorption of phenols using nitrogen-containing porous activated carbon prepared from sunflower plates

Zhengguo Zhang,Xiaoqin Feng,Xiao-Xia Yue,Fu-Qiang An,Wen-Xia Zhou,Jian-Feng Gao,Tuo-Ping Hu,Chin-Chuan Wei 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.8

Nitrogen-containing porous carbons, the 800SP-NH3, were synthesized using sunflower plates as the major carbon source carbonized at 800 oC and activated with concentrated aqueous ammonia at the same temperature. The porous carbons were characterized by nitrogen physical adsorption-desorption, surface area analyzer, FT-IR, and SEM. The adsorption properties of the porous carbons towards phenols were also investigated by batch methods. The test results show that the average pore diameter of porous carbon is smaller than 2 nm, and nitrogen-containing chemical groups are formed on its surface. The adsorption capacity for phenol, 4-chlorophenol, and p-nitrophenol is 316.5mg/g, 330.24mg/g and 387.62mg/g due to its developed pore structure and nitrogen-containing chemical groups. The adsorption isotherm data greatly obey the Langmuir model.

Effect of six sugars on the longevity, oviposition performance and nutrition accumulation in an endoparasitoid, Meteorus pulchricornis (Hymenoptera: Braconidae)

Sheng Sheng,Xiaorui Zhang,Yu Zheng,Jiao Wang,Yu Zhou,Chengwu Liao,Jun Wang,Fu-an Wu 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

The effects of six sugar resources (fructose, glucose, sucrose, trehalose, raffinose and honey) on the longevity, oviposition performance and nutrition levels of Meteorus pulchricornis, a thelytokous larval endoparasitoid of the common cutworm Spodoptera litura were examined under laboratory conditions. Female adults of M. pulchricornis fed 1 M fructose, glucose, trehalose or sucrose solutions survived longer than those fed on other sugar solutions or water. When provided with honey or sucrose solutions, the female parasitoids laid more offspring than those fed other sugar diets or the control. The body size of offspring driven from honey-, fructose-, sucrose-, and glucose-fed females, along with water-fed group, were larger than the trehalose- and raffinose-fed females. However, the emergence rates of all offspring generated from different sugars- and water-fed females were similar. When separately given honey, sucrose or fructose, M. pulchricornis females accumulated fructose at a higher level than the other groups. Parasitoid wasps fed trehalose solution accumulated the highest level of total sugar. Glycogen levels and lipid content were highest at emergence and then decreased across all diets. In addition, females fed on trehalose had the highest level of glycogen compared to other sugar diets and water control regardless of emergency level. Females fed trehalsoe, fructose, and glucose solutions had a higher level of lipid than those fed other sugar solutions and water at life end. The outcome of this study can benefit both laboratory rearing and management interventions that improve sugar sources for the parasitoid in the field.