De-cloaking Malicious Activities in Smartphones Using HTTP Flow Mining

( Xin Su ),( Xuchong Liu ),( Jiuchuang Lin ),( Shiming He ),( Zhangjie Fu ),( Wenjia Li ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.6

Android malware steals users` private information, and embedded unsafe advertisement (ad) libraries, which execute unsafe code causing damage to users. The majority of such traffic is HTTP and is mixed with other normal traffic, which makes the detection of malware and unsafe ad libraries a challenging problem. To address this problem, this work describes a novel HTTP traffic flow mining approach to detect and categorize Android malware and unsafe ad library. This work designed AndroCollector, which can automatically execute the Android application (app) and collect the network traffic traces. From these traces, this work extracts HTTP traffic features along three important dimensions: quantitative, timing, and semantic and use these features for characterizing malware and unsafe ad libraries. Based on these HTTP traffic features, this work describes a supervised classification scheme for detecting malware and unsafe ad libraries. In addition, to help network operators, this work describes a fine-grained categorization method by generating fingerprints from HTTP request methods for each malware family and unsafe ad libraries. This work evaluated the scheme using HTTP traffic traces collected from 10778 Android apps. The experimental results show that the scheme can detect malware with 97% accuracy and unsafe ad libraries with 95% accuracy when tested on the popular third-party Android markets.

Optimized Iterative Algorithm for Energy-Efficient Power Allocation in Two-tier Heterogeneous Networks

Wang Junliang,Li Wenjia,Liu Haitao 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.12

In heterogeneous networks, the issue of interference between femtocells and macrocells should be carefully considered. Resource allocation schemes with cognitive technologies have been a key challenge to manage interference. In this paper, we investigate price-based power allocation strategies with the energy efficiency criterion for a spectrum-sharing heterogeneous cognitive network from the aspect of energy efficiency, and provide the utility function of macrocell and femtocells based on a non-cooperative Stackleberg game model. We build a combination of price vector and power allocation values by standard Lagrangian method and propose an improved iteration algorithm based on price updating to obtain the Stackleberg equilibrium solution. The simulation results verify the proposed method can improve energy efficiency and achieve better utility.

The effect of various sandblasting conditions on surface changes of dental zirconia and shear bond strength between zirconia core and indirect composite resin

Su, Naichuan,Yue, Li,Liao, Yunmao,Liu, Wenjia,Zhang, Hai,Li, Xin,Wang, Hang,Shen, Jiefei The Korean Academy of Prosthodonitics 2015 The Journal of Advanced Prosthodontics Vol.7 No.3

PURPOSE. To measure the surface loss of dental restorative zirconia and the short-term bond strength between an indirect composite resin (ICR) and zirconia ceramic after various sandblasting processes. MATERIALS AND METHODS. Three hundred zirconia bars were randomly divided into 25 groups according to the type of sandblasting performed with pressures of 0.1, 0.2, 0.4 and 0.6 MPa, sandblasting times of 7, 14 and 21 seconds, and alumina powder sizes of 50 and $110{\mu}m$. The control group did not receive sandblasting. The volume loss and height loss on zirconia surface after sandblasting and the shear bond strength (SBS) between the sandblasted zirconia and ICR after 24-h immersion were measured for each group using multivariate analysis of variance (ANOVA) and Least Significance Difference (LSD) test (${\alpha}$=.05). After sandblasting, the failure modes of the ICR/zirconia surfaces were observed using scanning electron microscopy. RESULTS. The volume loss and height loss were increased with higher sandblasting pressure and longer sandblasting treatment, but they decreased with larger powder size. SBS was significantly increased by increasing the sandblasting time from 7 seconds to 14 seconds and from 14 seconds to 21 seconds, as well as increasing the size of alumina powder from $50{\mu}m$ to $110{\mu}m$. SBS was significantly increased from 0.1 MPa to 0.2 MPa according to the size of alumina powder. However, the SBSs were not significantly different with the sandblasting pressure of 0.2, 0.4 and 0.6 MPa. The possibilities of the combination of both adhesive failure and cohesive failure within the ICR were higher with the increases in bonding strength. CONCLUSION. Based on the findings of this study, sandblasting with alumina particles at 0.2 MPa, 21 seconds and the powder size of $110{\mu}m$ is recommended for dental applications to improve the bonding between zirconia core and ICR.

Erratum - The effect of various sandblasting conditions on surface changes of dental zirconia and shear bond strength between zirconia core and indirect composite resin

Naichuan Su,Li Yue,Yunmao Liao,Wenjia Liu,Hai Zhang,Xin Li,Hang Wang,Jiefei Shen 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.6

The effect of various sandblasting conditions on surface changes of dental zirconia and shear bond strength between zirconia core and indirect composite resin

Jiefei Shen,Xin Li,Naichuan Su,Wenjia Liu,Yunmao Liao,Li Yue,Hang Wang,Hai Zhang 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.3

PURPOSE To measure the surface loss of dental restorative zirconia and the short-term bond strength between an indirect composite resin (ICR) and zirconia ceramic after various sandblasting processes. MATERIALS AND METHODS Three hundred zirconia bars were randomly divided into 25 groups according to the type of sandblasting performed with pressures of 0.1, 0.2, 0.4 and 0.6 MPa, sandblasting times of 7, 14 and 21 seconds, and alumina powder sizes of 50 and 110 µm. The control group did not receive sandblasting. The volume loss and height loss on zirconia surface after sandblasting and the shear bond strength (SBS) between the sandblasted zirconia and ICR after 24-h immersion were measured for each group using multivariate analysis of variance (ANOVA) and Least Significance Difference (LSD) test (α=.05). After sandblasting, the failure modes of the ICR/zirconia surfaces were observed using scanning electron microscopy. RESULTS The volume loss and height loss were increased with higher sandblasting pressure and longer sandblasting treatment, but they decreased with larger powder size. SBS was significantly increased by increasing the sandblasting time from 7 seconds to 14 seconds and from 14 seconds to 21 seconds, as well as increasing the size of alumina powder from 50 µm to 110 µm. SBS was significantly increased from 0.1 MPa to 0.2 MPa according to the size of alumina powder. However, the SBSs were not significantly different with the sandblasting pressure of 0.2, 0.4 and 0.6 MPa. The possibilities of the combination of both adhesive failure and cohesive failure within the ICR were higher with the increases in bonding strength. CONCLUSION Based on the findings of this study, sandblasting with alumina particles at 0.2 MPa, 21 seconds and the powder size of 110 µm is recommended for dental applications to improve the bonding between zirconia core and ICR.

The association between glaucoma and all-cause mortality in middle-aged and elderly Chinese people: results from the China Health and Retirement Longitudinal Study

Xiaoxu Huang,Mengqiao Xu,Minwen Zhou,Wenjia Liu,Xiaohuan Zhao,Xiaodong Sun 한국역학회 2023 Epidemiology and Health Vol.45 No.-

OBJECTIVES: This population-based, prospective cohort study investigated the association between glaucoma and mortality in older adults. METHODS: Participants aged 45 years or older at baseline (47.9% male) were enrolled in 2011 for the China Health and Retirement Longitudinal Study (CHARLS). All-cause mortality was observed during 7 years of follow-up. The baseline data were collected in the 2011 CHARLS, and participants were followed up for 7 years (until 2018). The risk of all-cause mortality was investigated using Cox proportional-hazards regression with age as the time scale, adjusting for significant risk factors and comorbid conditions. RESULTS: Among the 14,803 participants included, the risk of all-cause death was significantly higher among people with glaucoma than among those without glaucoma, after adjustment for other confounders (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.04 to 2.03). In a subgroup analysis based on the mean age of death, among those who were 75 years and older (n=1,231), the risk of all-cause death was significantly higher in patients with glaucoma than in those without glaucoma (HR, 1.89; 95% CI, 1.24 to 1.89). CONCLUSIONS: Participants with glaucoma had a higher risk of all-cause mortality, especially those aged 75 years and above. Our findings revealed potential mechanisms underlying an association between glaucoma and all-cause mortality. They also highlighted the importance of glaucoma management to prevent premature death in middle-aged and older adults.

The association between obesity and glaucoma in older adults: evidence from the China Health and Retirement Longitudinal Study

Zhao Xiaohuan,Bo Qiyu,Sun Junran,Chen Jieqiong,Li Tong,Huang Xiaoxu,Zhou Minwen,Wang Jing,Liu Wenjia,Sun Xiaodong 한국역학회 2023 Epidemiology and Health Vol.45 No.-

Objectives: This study evaluated the association between obesity and glaucoma in middle-aged and older people. A population-based retrospective cohort study was conducted using data from the China Health and Retirement Longitudinal Study.Methods: Glaucoma was assessed via self-reports. Multivariate logistic regression analysis and a Cox proportional hazards model were used to assess the relationship between obesity and glaucoma risk.Results: Older men living in urban areas who were single, smokers, and non-drinkers were found to have a significantly higher incidence of glaucoma (all P<0.05). Diabetes, hypertension, and kidney disease were also associated with higher glaucoma risk, while dyslipidemia was associated with lower risk (all P<0.05). After the model was adjusted for demographic, socio-economic, and health-related variables, obesity was significantly associated with a 10.2% decrease in glaucoma risk according to the Cox proportional hazards model (hazard ratio, 0.898; 95% CI, 0.829-0.973) and an 11.8% risk reduction in the multivariate logistic regression analysis (odds ratio, 0.882; 95% CI, 0.803-0.968). A further subgroup analysis showed that obesity was associated with a reduced risk of glaucoma in people living in rural areas, in smokers, and in those with kidney disease (all P<0.05). Obesity also reduced glaucoma risk in people with diabetes, hypertension, or dyslipidemia more than in healthy controls (all P<0.05).Conclusions: This cohort study suggests that obesity was associated with a reduced risk of glaucoma, especially in rural residents, smokers, and people with kidney disease. Obesity exerted a stronger protective effect in people with diabetes, hypertension, or dyslipidemia than in healthy people.