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TDRHN : A Threshold Sensitive Dynamic Responsive Hybrid Network Protocol based on CTP
Xingming Sun,Chengju Xue,Baowei Wang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.2
The protocols of Wireless Sensor Networks (WSNs) can be categorized into two classes: proactive network protocol like CTP and reactive network protocol like TEEN. The former periodically collects data, working well in the applications of collecting data persistently. However, it can’t dynamically alter the transmission frequency and the routing selecting strategy. The latter can react to the environment change, so it is widely used in the applications requiring nodes to be reactive to some emergencies. But it only works in reactive networks without collecting data under normal circumstance. We find that dynamically altering the transmission frequency and the routing selecting strategy according to the environment change is very effective and significant. For the reasons above, this paper presents TDRHN protocol. It periodically collects data in normal situation and can not only take faster transmission frequency but also alter the routing selecting strategy when it detects some emergencies. So TDRHN can effectively work in hybrid networks combining proactive networks and reactive networks. Finally, we evaluate TDRHN on the testbed with TelosB motes in real deployment. The concluded results of the experiments demonstrate that TDRHN has some particular advantages.
Privacy-preserving Multi-keyword Ranked Search over Encrypted Cloud Data Supporting Dynamic Update
Xingming Sun,Lu Zhou,Zhangjie Fu,Jin Wang 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.6
With the development of cloud computing, the sensitive information of outsourced data is at risk of unauthorized accesses. To protect data privacy, the sensitive data should be encrypted by the data owner before outsourcing, which makes the traditional and efficient plaintext keyword search technique useless. Hence, it is an especially important thing to explore secure encrypted cloud data search service. Considering the huge number of outsourced data, there are three problems we are focused on to enable efficient search service: multi-keyword search, result relevance ranking and dynamic update. In this paper, we propose a practically efficient and flexible searchable encrypted scheme which supports both multi-keyword ranked search and dynamic update. To support multi-keyword search and result relevance ranking, we adopt Vector Space Model (VSM) to build the searchable index to achieve accurate search result. To improve search efficiency, we design a tree-based index structure which supports insertion and deletion update well without privacy leakage. We propose a secure search scheme to meet the privacy requirements in the threat model. Finally, experiments on real-world dataset are implemented to demonstrate the overall performance of the proposed scheme, which show our scheme is efficient.
Investigation of the interstitial oxygen behaviors in vanadium alloy: A first-principles study
Xingming Zhang,Yifan Li,Qiaoling He,Ruilian Li,Lei Deng,Liang Wang,Xunlin Liu,Jianfeng Tang,Huiqiu Deng,Wang-Yu Hu 한국물리학회 2018 Current Applied Physics Vol.18 No.2
This study aims at characterizing the interstitial Oxygen (O) behaviors in the Vanadium (V) Alloy by means of the first-principles calculations. For this, the interations between vacancy (Vac) and O interstitil atom are studied in detail to obtain the binding energies and stable structures of the complexes. It can be seen that monovacancy binding with two O atoms occupied the opposing octahedral stie are particularly stable, and is liable to form VacO2 cluster in the V alloys. According to the mass action analysis, the predicted temperature dependence of the concentration for VacOn complexes are presented. Apart from monovacancy, we also consider the trapping behavior of vacancy cluster on the O atoms. The results also prove that one vacancy can trap two O atoms in the V alloys. Based the diffusion theory, we obtain the diffusion coefficients as a function of temperature with or without the vacancy effect in the V alloys. The predicted O diffusion coefficients in defect-free V alloys from our first-principles calculations are in excellent ageement with the experimental data, meanings that the vacancy-limited mechanism does not play the key role for O diffusion in V alloys. Regarding the interactions between vacancy, solutes and O atom, combining with the diffusion barriers of O affected by vacancy and solute, we infer the formation mechanism of the precipitates in the V alloys.
Proteomic Analysis of Shigella Virulence Effectors Secreted under Different Conditions
( Xingming Liu ),( Lilan Lu ),( Xinrui Liu ),( Xiankai Liu ),( Chao Pan ),( Erling Feng ),( Dongshu Wang ),( Chang Niu ),( Li Zhu ),( Hengliang Wang ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.1
A series of novel effector molecules secreted by the type three secretion system (T3SS) of Shigella spp. have been reported in recent years. In this study, a proteomic approach was applied to study T3SS effectors systematically. First, proteins secreted by the S. flexneri wildtype strain after Congo Red induction were separated and identified using two-dimensional electrophoresis to display the relative abundance of all kinds of early effectors for the first time. Then, a gene deletion mutant of known virulence repressor (OspD1) and a gene overexpressed mutant of two known virulence activators (MxiE and IpgC) were constructed and analyzed to discover potential late effectors. Furthermore, the supernatant proteins of gene deletion mutants of two known translocators (IpaB and IpaD), which would constantly secrete effectors, were also analyzed. Among all of the secreted proteins identified in our study, IpaH1.4, IpaH_5, and IpaH_7 have not been reported before. These proteomics data of the secreted effectors will be valuable to understand the pathogenesis of S. flexneri.
Xingming Sun,Yachao Hu,Baowei Wang,Jian Zhang,Tao Li 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.8
Localization systems have been identified as key issues in the development and operation of wireless sensor networks. The global positioning system (GPS) solves the problem about localization, but it is not suitable for wireless sensor networks. Due to range-free localization approaches requiring low equipped hardware and easy to implement, it is widely used in WSNs localization system. When the node communication radius increases, the accuracy of area-based localization is reduced. It is important to improve the localization accuracy in this situation. In this paper, to improve the accuracy of the node localization, we propose a new range-free localization using Voronoi diagrams based approximate point-in-triangulation test (APIT) algorithm. We compare our algorithm with APIT. Simulation results show that the VPIT improved the precision of localization by narrowing the node's geometry region.
ACTP : An Advanced Data Collection Protocol based on CTP
Xingming Sun,Lei Gao,Baowei Wang,Jian Zhang 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.9
In wireless sensor networks, the main work of nodes is for data collection and transmission. CTP (Collected Tree Protocol) had been widely applied, and proved to be reliable, robust, efficient data collection protocol. Its independent with hardware and the data delivery rate is relatively high, but CTP also has some shortcomings: the protocol only relied on the ETX value of next hop node selection, there need other factors to consider. In the original CTP protocol, the energy consumption of a node with a better ETX value was too fast. It would cause the whole network time decreased quickly. Then, the node with better ETX value may have low package rate, and would affect the delivery rate of the whole networks. This paper was aimed at this two aspects of CTP, based on the original CTP, the probability of selection mechanism was introduced, proposed ACTP, lead the node load equilibrium and improved the delivery rate. Through the experimental data of TelosB nodes in real analysis, we had improved the whole network time and increased the number of successful packets delivery.