Privacy Protection Method for Sensitive Weighted Edges in Social Networks

( Weihua Gong ),( Rong Jin ),( Yanjun Li ),( Lianghuai Yang ),( Jianping Mei ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.2

Privacy vulnerability of social networks is one of the major concerns for social science research and business analysis. Most existing studies which mainly focus on un-weighted network graph, have designed various privacy models similar to k-anonymity to prevent data disclosure of vertex attributes or relationships, but they may be suffered from serious problems of huge information loss and significant modification of key properties of the network structure. Furthermore, there still lacks further considerations of privacy protection for important sensitive edges in weighted social networks. To address this problem, this paper proposes a privacy preserving method to protect sensitive weighted edges. Firstly, the sensitive edges are differentiated from weighted edges according to the edge betweenness centrality, which evaluates the importance of entities in social network. Then, the perturbation operations are used to preserve the privacy of weighted social network by adding some pseudo-edges or modifying specific edge weights, so that the bottleneck problem of information flow can be well resolved in key area of the social network. Experimental results show that the proposed method can not only effectively preserve the sensitive edges with lower computation cost, but also maintain the stability of the network structures. Further, the capability of defending against malicious attacks to important sensitive edges has been greatly improved.

Joint Space-time Coding and Power Domain Non-orthogonal Multiple Access for Future Wireless System

( Jin Xu ),( Hanqing Ding ),( Zeqi Yu ),( Zhe Zhang ),( Weihua Liu ),( Xueyan Chen ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.1

According to information theory, non-orthogonal transmission can achieve the multiple-user channel capacity with an onion-peeling like successive interference cancellation (SIC) based detection followed by a capacity approaching channel code. However, in multiple antenna system, due to the unideal characteristic of the SIC detector, the residual interference propagated to the next detection stage will significantly degrade the detection performance of spatial data layers. To overcome this problem, we proposed a modified power-domain non-orthogonal multiple access (P-NOMA) scheme joint designed with space-time coding for multiple input multiple output (MIMO) NOMA system. First, with proper power allocation for each user, inter-user signals can be separated from each other for NOMA detection. Second, a well-designed quasi-orthogonal space-time block code (QO-STBC) was employed to facilitate the SIC-based MIMO detection of spatial data layers within each user. Last, we proposed an optimization algorithm to assign channel coding rates to balance the bit error rate (BER) performance of those spatial data layers for each user. Link-level performance simulation results demonstrate that the proposed time-space-power domain joint transmission scheme performs better than the traditional P-NOMA scheme. Furthermore, the proposed algorithm is of low complexity and easy to implement.

Optimizations of Multi-hop Cooperative Molecular Communication in Cylindrical Anomalous-Diffusive Channel

Xuancheng Jin,Zhen Cheng,Zhian Ye,Weihua Gong 한국인터넷정보학회 2024 KSII Transactions on Internet and Information Syst Vol.18 No.4

In this paper, the optimizations of multi-hop cooperative molecular communication (CMC) system in cylindrical anomalous-diffusive channel in three-dimensional enviroment are investigated. First, we derive the performance of bit error probability (BEP) of CMC system under decode-and-forward relay strategy. Then for achieving minimum average BEP, the optimization variables are detection thresholds at cooperative nodes and destination node, and the corresponding optimization problem is formulated. Furthermore, we use conjugate gradient (CG) algorithm to solve this optimization problem to search optimal detection thresholds. The numerical results show the optimal detection thresholds can be obtained by CG algorithm, which has good convergence behaviors with fewer iterations to achieve minimized average BEP compared with gradient decent algorithm and Bisection method which are used in molecular communication.

Morphology Transitions of Linear A₁B₁A₂B₂ Tetrablock Copolymers at Symmetric Overall Volume Fraction

Ahn, Seonghyeon,Kim, Jin Kon,Zhao, Bin,Duan, Chao,Li, Weihua American Chemical Society 2018 Macromolecules Vol.51 No.11

<P>We investigated morphology transitions of linear tetrablock copolymers of polystyrene-<I>block</I>-polyisoprene-<I>block</I>-polystyrene-<I>block</I>-polyisoprene (S<SUB>1</SUB>I<SUB>1</SUB>S<SUB>2</SUB>I<SUB>2</SUB>) by varying volume fraction of PI<SUB>1</SUB> block (<I>f</I><SUB>PI1</SUB>), while maintaining the symmetric volume fraction of total PS blocks and PI blocks (<I>f</I><SUB>PS1</SUB>+<I>f</I><SUB>PS2</SUB>:<I>f</I><SUB>PI1</SUB>+<I>f</I><SUB>PI2</SUB> ≈ 1:1). An interesting sequence of morphology transitions was observed as <I>f</I><SUB>PI1</SUB> was increased: lamellae (L) → asymmetric lamellae (aL) → hexagonally packed PI-cylinders (C<SUB>PI</SUB>) → double gyroid with PI-network domains (G<SUB>PI</SUB>) → short-period lamellae (sL). The domain spacing of sL was nearly half that of L, while aL had asymmetric lamellar width of PS and PI microdomains. It is particularly interesting that cylindrical and gyroid morphologies were observed in linear block copolymers with symmetric overall volume fraction at intermediate segregation. The experimentally observed morphologies are in good agreement with the predicted equilibrium phases by self-consistent field theory (SCFT).</P> [FIG OMISSION]</BR>

Analysis on Steering Capability of a New Bogie with Independently Rotating Wheels

CHI Maoru,ZENG Jing,GUO Wenhao,ZHANG Weihua,JIN Xuesong 한국철도학회 2009 International Journal of Railway Vol.2 No.4

A new scheme about a coupled bogie with Independently Rotating Wheels was put forward firstly. And then it is fund by theoretic analysis that the bogie takes on prominent radial capability on curved track and splendiferous restoring capability on tangent track. Lastly, a dynamic calculating model of the coupled bogie with independently rotating wheels has been established and a dynamic simulation analysis on steering capability of the bogie was made and the simulation results can inosculate foregoing theoretic analysis, which illuminates that the coupled bogie can solve drastically the difficulty about steering problem of independently rotating wheel.

Mangiferin loaded magnetic PCEC microspheres: preparation, characterization and antitumor activity studies in vitro

WenJing Xiao,Jun Hou,Jie Ma,BoTao Yu,JianDong Ren,WeiHua Jin,Juan Wu,DeZhi Zheng,KaiHua Fan 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.8

Mangiferin is a promising effective chemopreventiveagent against various tumors. However, itsclinical use is limited by poor water solubility and lowbioavailability. In this article, mangiferin loaded magneticPCEC microspheres (MG-MS) were designed, characterizedand the antitumor activity of MG-MS was evaluatedin vitro. The magnetic nanoparticles (MNP) were synthesizedvia the high-temperature reaction of ironacetylacetonate in phenyl ether in the presence of oleic acidand oleylamine. Poly (ε-caprolactone)-poly (ethyleneglycol)-poly (ε-caprolactone) (PCL-PEG-PCL, PCEC)copolymers were formed by ring-opening copolymerizationof ε-CL initiated by PEG-diol using Sn(Oct)2 as acatalyst and MG-MS were prepared by solvent diffusionmethod. MNP, PCEC copolymer, and MG-MS werecharacterized by GPC, TEM, XRD, FT-IR, 1H-NMP andMalvern Laser Particle Sizer. Meanwhile, the antiproliferativeactivity in vitro and in vitro release behavior of thismicrospheres were studied in detail. The results indicatethat the obtained magnetic microspheres might have greatpotential as an effective carrier for mangiferin used incancer chemotherapy.