Dynamical Behavior of Rumor in Online Social Networks

Hui Xie,Yongjie Yan,Yingchun Hou 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.3

As a powerful tool for phase transition analysis, the mean-field theory of rumor spreading brings us a new method for research in Online Social Networks (OSN). Based on the theory of complex networks, we simulate the complex process of rumor spreading in OSN. Using numerical simulations with focus on the information spreading threshold as well as critical behaviors, we study the Susceptible-Infected-Recovered- Susceptible (SIRS) information dynamics model in OSN with asymmetric propagation. Basic principle and structure of OSN were analyzed. We present a rumor spreading model, where the influence of the neighbor trees is treated in a more realistic way and the definition of a neighborhood can be tuned by an additional parameter. Based on the mean-field theory approach, a contact network model with scale-free property is built. It is demonstrated that the asymmetry of propagation plays important role: we could redistribute the asymmetry to balance the degree heterogeneity of the network and then to restore the information threshold to a finite value. The relationship of spreading probability, network size, infected fraction and infected ratio are showed respectively in the paper. Our model exhibits a surprisingly sharp phase transition which can be shifted by a redefinition of the neighborhood. The result shows that the SIRS model built in this paper is valid and the simulation of the information propagation is feasible.

Visual Fatigue Reduction Based on Depth Adjustment for DIBR System

( Ran Liu ),( Yingchun Tan ),( Fengchun Tian ),( Hui Xie ),( Guoqin Tai ),( Weimin Tan ),( Junling Liu ),( Xiaoyan Xu ),( Chaibou Kadri ),( Naana Abakah ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.4

A depth adjustment method for visual fatigue reduction for depth-image-based rendering (DIBR) system is proposed. One important aspect of the method is that no calibration parameters are needed for adjustment. By analyzing 3D image warping, the perceived depth is expressed as a function of three adjustable parameters: virtual view number, scale factor and depth value of zero parallax setting (ZPS) plane. Adjusting these three parameters according to the proposed parameter modification algorithm when performing 3D image warping can effectively change the perceived depth of stereo pairs generated in DIBR system. As the depth adjustment is performed in simple 3D image warping equations, the proposed method is facilitative for hardware implementation. Experimental results show that the proposed depth adjustment method provides an improvement in visual comfort of stereo pairs as well as generating comfortable stereoscopic images with different perceived depths that people desire.

Hole-filling Based on Disparity Map for DIBR

( Ran Liu ),( Hui Xie ),( Fengchun Tian ),( Yingjian Wu ),( Guoqin Tai ),( Yingchun Tan ),( Weimin Tan ),( Bole Li ),( Hengxin Chen ),( Liang Ge ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.10

Due to sharp depth transition, big holes may be found in the novel view that is synthesized by depth-image-based rendering (DIBR). A hole-filling method based on disparity map is proposed. One important aspect of the method is that the disparity map of destination image is used for hole-filling, instead of the depth image of reference image. Firstly, the big hole detection based on disparity map is conducted, and the start point and the end point of the hole are recorded. Then foreground pixels and background pixels are distinguished for hole-dilating according to disparity map, so that areas with matching errors can be determined and eliminated. In addition, parallaxes of pixels in the area with holes and matching errors are changed to new values. Finally, holes are filled with background pixels from reference image according to these new parallaxes. Experimental results show that the quality of the new view after hole-filling is quite well; and geometric distortions are avoided in destination image, in contrast to the virtual view generated by depth-smoothing methods and image inpainting methods. Moreover, this method is easy for hardware implementation.

Thermodynamic analysis of a novel adiabatic compressed air energy storage system with water cycle

Zhen Xu,Haiyang Yang,Yingchun Xie,Jinchi Zhu,Chaoqun Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

A novel water cycle compressed air energy storage system (WC-CAES) is proposed to improve the energy storage density (ESD) and round trip efficiency (RTE) of A-CAES. The new system decreases electricity consumption by recovering and reusing the hydraulic pressure of water. The thermodynamic characteristics of WC-CAES are evaluated by energy and advanced exergy analysis method. When the air storage pressure of WC-CAES is equal to the minimum storage pressure of A-CAES (4.2 MPa), the ESD and generalized storage density increase by 5.85 % and 32.41 %, respectively. When the air storage pressure increases to the same level as A-CAES (7.2 MPa), ESD and generalized storage density increase by 112 % and 162 %, respectively. In addition, the RTE increases by 1.6 % when the air storage pressure is 4.2 MPa. WC-CAES is therefore verified to be an effective way to improve the performance of conventional A-CAES.

Synthesis and Characterization of pH and Temperature Sensitive Hydrogel Based on Poly(N-isopropylacrylamide), Poly(ε-caprolactone), Methylacrylic Acid, and Methoxyl Poly(ethylene glycol)

Xu Xu,Jia Song,Ke Wang,YingChun Gu,Feng Luo,XiaoHai Tang,Ping Xie,ZhiYong Qian 한국고분자학회 2013 Macromolecular Research Vol.21 No.8

In this paper, a novel biodegradable and pH/thermo-sensitive hydrogel based on poly(ε-caprolactone),methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide was prepared by UV-initiated free radical polymerization. The hydrogels were characterized by Fourier transforms infrared ray. The thermal responsibility was investigated with the help of differential scanning calorimetry. Swelling behavior in aqueous medium with different pH value was studied in detail. When the pH value of the aqueous medium was increased from 1.2 to 7.2,the swelling ratio of the hydrogels increased accordingly. The morphology was observed by scanning electron microscopy, and the hydrolytic degradation behavior in different aqueous media (pH 1.2 and pH 7.2) was also investigated in detail. The prepared biodegradable pH/thermo-sensitive hydrogel based on poly(ε-caprolactone), methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide hold great promise in the development of a smart drug delivery system.

Enhancing Tensile Properties of Wire-Arc Additively Manufactured Ti-6Al-4 V Deposits Via Cryogenic Vaporised Ar Shielding/Cooling

Peng Han,Jia Lin,Wen Wang,Zhihao Liu,Yating Xiang,Ting Zhang,Qiang Liu,Xiaohu Guan,Ke Qiao,Yingchun Xie,Kuaishe Wang 대한금속ᆞ재료학회 2023 METALS AND MATERIALS International Vol.29 No.2

The high-entropy alloy particles reinforced 6061Al composite was prepared by cold spray (CS) and then modified by frictionstir processing (FSP). The microstructure evolutions, corrosion, and wear behaviors of the composites were investigated. Results showed that numerous micro-pores and cracks were distributed in the Al matrix due to adiabatic shear instability andinsufficient deformation of the deposited particles for CSed samples. The average size of uniformly distributed HEA particleswas ~ 24 μm, and the geometric necessary dislocation (GND) density reached 17.1 × 1015m−2 due to large plastic deformationduring CS. Comparatively, the micro-pores and cracks were eliminated, and many fragmented HEA particles dispersed inthe Al matrix with an average size of ~ 4 μm for FSPed sample. Note that the GND density reduced to 9.8 × 1015m−2 due todynamic recrystallization during FSP. The formation rate of the oxide film was gradually greater than that of the dissolutionrate with the samples immersion in 3.5 wt% NaCl solution from 12 to 36 h, and the main corrosion mechanism was particledissolution around micro-pores and pitting for CSed and FSPed samples, respectively. In the polarization process, the FSPedsamples exhibited low corrosion tendency and high corrosion rate due to the dense and uniform microstructure, low GNDdensity, and dispersed HEA particles. The FSPed samples had better wear resistance than the CSed samples at 25 °C and200 °C. The dominant wear mechanisms of CSed and FSPed samples were abrasion at 25 °C, while the wear mechanismsof these samples were adhesion accompanied by abrasion at 200 °C.

Friction Stir Processing of Cold-Sprayed High-Entropy Alloy Particles Reinforced Aluminum Matrix Composites: Corrosion and Wear Properties

Peng Han,Jia Lin,Wen Wang,Zhihao Liu,Yating Xiang,Ting Zhang,Qiang Liu,Xiaohu Guan,Ke Qiao,Yingchun Xie,Kuaishe Wang 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.3

The high-entropy alloy particles reinforced 6061Al composite was prepared by cold spray (CS) and then modified by frictionstir processing (FSP). The microstructure evolutions, corrosion, and wear behaviors of the composites were investigated. Results showed that numerous micro-pores and cracks were distributed in the Al matrix due to adiabatic shear instability andinsufficient deformation of the deposited particles for CSed samples. The average size of uniformly distributed HEA particleswas ~ 24 μm, and the geometric necessary dislocation (GND) density reached 17.1 × 1015m−2 due to large plastic deformationduring CS. Comparatively, the micro-pores and cracks were eliminated, and many fragmented HEA particles dispersed inthe Al matrix with an average size of ~ 4 μm for FSPed sample. Note that the GND density reduced to 9.8 × 1015m−2 due todynamic recrystallization during FSP. The formation rate of the oxide film was gradually greater than that of the dissolutionrate with the samples immersion in 3.5 wt% NaCl solution from 12 to 36 h, and the main corrosion mechanism was particledissolution around micro-pores and pitting for CSed and FSPed samples, respectively. In the polarization process, the FSPedsamples exhibited low corrosion tendency and high corrosion rate due to the dense and uniform microstructure, low GNDdensity, and dispersed HEA particles. The FSPed samples had better wear resistance than the CSed samples at 25 °C and200 °C. The dominant wear mechanisms of CSed and FSPed samples were abrasion at 25 °C, while the wear mechanismsof these samples were adhesion accompanied by abrasion at 200 °C.