An Improved Random Key Predistribution Scheme for Wireless Sensor Networks Using Deployment Knowledge

Lina Zhu,Zuochang Zhang,Jianhua Li,Renjie Zhou 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.5

Key management is the basis of many security mechanisms and services in wireless sensor networks (WSN). Random key predistribution scheme is widely considered as the most practical for WSN. However, this scheme faces the challenge that it cannot achieve the ideal security connectivity and strong resilience against node capture simultaneously. To address this limitation, an improved random key predistribution scheme using deployment knowledge is proposed in this paper. Firstly, sensor nodes are divided into different groups according to their location expected. And the key pool is grouped into key pool subsets accordingly. To realize the communication between adjacent groups, the corresponding key pool subsets have a certain degree of overlapping. For all keys, there is no limitation on key reuse. Neighboring nodes sharing q common keys will establish secure link with high probability. Moreover, our scheme inherits the advantage of q-composite random key predistribution scheme that it can maintain security even if some nodes are captured. Theoretical analysis and simulation experiments show that the improved scheme performs well on network connectivity and resilience.

Multi-dimensional Network Security Situation Assessment

Lina Zhu,Guoen Xia,Zuochang Zhang,Jianhua Li,Renjie Zhou 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.11

Network security situation awareness is vital important for network security supervision. In order to obtain the network security situation effectively, a multi-dimensional assessment method is proposed in this paper. The method is composed of three dimensions at different levels, namely vulnerability, threat and basic operation, with quantitative calculation method for each index. In the service layer, CVSS standard is adopted to assess the vulnerability situation, and simplified DREAD model is chosen for the threat situation. In the node layer, the vulnerability situation in the service layer is added with a weight, the threat situation in the service layer is accumulated according to attack paths based on Markov model, and the basic operation situation is evaluated by D-S evidence fusion of several host and network performance index. In the network layer, each situation equals to weighted summation of corresponding situation in the node layer. Experimental results show the ease of use of this method, and multi-dimensional situation depicts the overall safety evolution process of network system accurately and intuitively.

Dynamic Response of Lunar Soil Caused by Landing Impact

Ailan Che,Renjie Zhu,Mingjing Jiang 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.11

In recent years, there is an increasing interest on lunar exploration and future utilization of lunar resources. Technology of landing is a key in order to establish frequent access to the lunar surface. For a lunar lander, one of the major tasks is to accurately determine the loads and energy absorption capability during the landing event. On the other hands, it should be paid special attention on the study of wave propagation phenomenon in lunar soil and its dynamic response and dissipated energy by the lunar soil. A series of model tests for the simulated lunar soil model with plane and slope are conducted. The model tests are performed to study on the regularity of wave propagation and its attenuation in lunar soil. The waveform of acceleration, velocity and earth pressure in the model are observed. The research focuses on the analysis of the phenomenon through numerical methods. The wave propagation characteristics of the lunar soil model with plane and slope is assessed by means of dynamic FEM analyses in three dimensions. The analysis is obtained in the time domain and allows the consideration of multiple wave reflections between layers. It is concluded that the wave field propagation in lunar soil during landing impact mainly shows Rayleigh wave along axial of impact pads, and repeatedly superimposing occur between impact pads. The predominant frequency of the landing impact is over 100 Hz. The response is quickly attenuated in lunar soil and its propagation distance is very limited. Moreover, according to the numerical results and the model test results, it can be found that a small input wave velocity (< 1 m/s) has a great impact on the maximum acceleration and displacement. Furthermore, when it reaches a certain value, the maximum acceleration and displacement reach the maximum value. The plastic strain zone increases rapidly with the increasing input wave peak velocity, when the plastic strain is > 0.05, and when input wave velocity is 4 m/s, the ground floor of the landing pad is in plastic.

Experimental study on the axial bearing capacity of built-up cold-formed thin-walled steel multi-limb-section columns

Wentao Qiao,Yuhuan Wang,Renjie Zhu,Ruifeng Li,Mingshan Zhao 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.6

To solve the shortcomings of single-limb or double-limb cold-formed thin-walled steel column easy to buckling failure and low bearing capacity, a new cross-shaped built-up cold-formed thin-walled steel multi-limb-section is proposed for columns. The structure is composed of several single-limb cold-formed thin-walled steel C-channel sections. The flanges and webs are connected by self-drilling screws. In order to assess the mechanical properties of this built-up multi-limb-section column and the influence of the slenderness ratio on the column behavior, the axial loading tests were carried out. Three kinds of single-limb column and built-up multi-limb-section column with different ratio of slenderness were tested. The deformation process, failure mode and bearing capacity were analyzed. The SC specimens failed with local buckling and distorted buckling, while the MC and LC specimens failed with local buckling and global instability. For the built-up multi-limb-section column, the section combination multiple is 12. Compared to the section combination multiple, the bearing capacity combination multiple is much higher. The SQ specimens’ combination factor is about 1.1, the combination factor of MQ specimens and LQ specimens are about 1.4 and 3.0, respectively. It is concluded that the overall combined-performance and structural efficiency of the specimens is proportional to the combination factor.

Improving Interfacial Interactions of CF/PEEK Composites with Sulfonated Polyether Sulfone

Tianning Ren,Guangming Zhu,Xiaoming Ren,Renjie Tian,Ben Li 한국섬유공학회 2021 Fibers and polymers Vol.22 No.1

Due to the limitation of surface inertness and wettability of carbon fibers (CF), the adhesion between Poly(etherether-ketone) (PEEK) resin matrix and CF is poor, which reduces the mechanical properties of CF/PEEK composites. Inorder to improve the interfacial performance between PEEK matrix and carbon fiber fabric, sulfonated-polyether-sulfone (s-PSF) was coated as a sizing agent on the surface of the carbon fiber to construct CF/PEEK composite interface. On one hand,the formation of hydrogen bonds between s-PSF and activated CF increases the adhesion between s-PSF and fibers. On theother hand, Good compatibility between S-PSF and PEEK, which improves the interface performance between PEEK andCF. The results showed that the mechanical properties and interface properties of CF/PEEK composite prepared by modifiedCF were improved to some extent. The flexural strength, flexural modulus, impact strength and interlaminar shear strength ofthe materials were increased by 57.5 %, 16.7 %, 44.2 % and 39.7 %, respectively. By introducing s-PSF as sizing agent intoCF/PEEK composite interface, the comprehensive properties of the material were effectively improved.

LINC00703 Acts as a Tumor Suppressor via Regulating miR-181a/KLF6 Axis in Gastric Cancer

Yang, Haiyang,Peng, Minqi,Li, Yanjiao,Zhu, Renjie,Li, Xiang,Qian, Zhengjiang The Korean Gastric Cancer Association 2019 Journal of gastric cancer Vol.19 No.4

Purpose: Long noncoding RNA 00703 (LINC00703) was found originating from a region downstream of Kruppel-like factor 6 (KLF6) gene, having 2 binding sites for miR-181a. Since KLF6 has been reported as a target of miR-181a in gastric cancer (GC), this study aims to investigate whether LINC00703 regulates the miR-181a/KLF6 axis and plays a functional role in GC pathogenesis. Materials and Methods: GC tissues, cell lines, and nude mice were included in this study. RNA binding protein immunoprecipitation (RIP) and pull-down assays were used to evaluate interaction between LINC00703 and miR-181a. Quantitative real-time polymerase chain reaction and western blot were applied for analysis of gene expression at the transcriptional and protein levels. A nude xenograft mouse model was used to determine LINC00703 function in vivo. Results: We revealed that LINC00703 competitively interacts with miR-181a to regulate KLF6. Overexpression of LINC00703 inhibited cell proliferation, migration/invasion, but promoted apoptosis in vitro, and arrested tumor growth in vivo. LINC00703 expression was found to be decreased in GC tissues, which was positively correlated with KLF6, but negatively with the miR-181a levels. Conclusions: LINC00703 may have an anti-cancer function via modulation of the miR-181a/KLF6 axis. This study also provides a new potential diagnostic marker and therapeutic target for GC treatment.

LINC00703 Acts as a Tumor Suppressor via Regulating miR-181a/KLF6 Axis in Gastric Cancer

Zhengjiang Qian,Haiyang Yang,Minqi Peng,Yanjiao Li,Renjie Zhu,Xiang Li 대한위암학회 2019 Journal of gastric cancer Vol.19 No.4

Purpose: Long noncoding RNA 00703 (LINC00703) was found originating from a region downstream of Kruppel-like factor 6 (KLF6) gene, having 2 binding sites for miR-181a. Since KLF6 has been reported as a target of miR-181a in gastric cancer (GC), this study aims to investigate whether LINC00703 regulates the miR-181a/KLF6 axis and plays a functional role in GC pathogenesis. Materials and Methods: GC tissues, cell lines, and nude mice were included in this study. RNA binding protein immunoprecipitation (RIP) and pull-down assays were used to evaluate interaction between LINC00703 and miR-181a. Quantitative real-time polymerase chain reaction and western blot were applied for analysis of gene expression at the transcriptional and protein levels. A nude xenograft mouse model was used to determine LINC00703 function in vivo. Results: We revealed that LINC00703 competitively interacts with miR-181a to regulate KLF6. Overexpression of LINC00703 inhibited cell proliferation, migration/invasion, but promoted apoptosis in vitro, and arrested tumor growth in vivo. LINC00703 expression was found to be decreased in GC tissues, which was positively correlated with KLF6, but negatively with the miR-181a levels. Conclusions: LINC00703 may have an anti-cancer function via modulation of the miR-181a/KLF6 axis. This study also provides a new potential diagnostic marker and therapeutic target for GC treatment.