TG-SPSR: A Systematic Targeted Password Attacking Model

( Mengli Zhang ),( Qihui Zhang ),( Wenfen Liu ),( Xuexian Hu ),( And Jianghong Wei ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.5

Identity authentication is a crucial line of defense for network security, and passwords are still the mainstream of identity authentication. So far trawling password attacking has been extensively studied, but the research related with personal information is always sporadic. Probabilistic context-free grammar (PCFG) and Markov chain-based models perform greatly well in trawling guessing. In this paper we propose a systematic targeted attacking model based on structure partition and string reorganization by migrating the above two models to targeted attacking, denoted as TG-SPSR. In structure partition phase, besides dividing passwords to basic structure similar to PCFG, we additionally define a trajectory-based keyboard pattern in the basic grammar and introduce index bits to accurately characterize the position of special characters. Moreover, we also construct a BiLSTM recurrent neural network classifier to characterize the behavior of password reuse and modification after defining nine kinds of modification rules. Extensive experimental results indicate that in online attacking, TG-SPSR outperforms traditional trawling attacking algorithms by average about 275%, and respectively outperforms its foremost counterparts, Personal-PCFG, TarGuess-I, by about 70% and 19%; In offline attacking, TG-SPSR outperforms traditional trawling attacking algorithms by average about 90%, outperforms Personal-PCFG and TarGuess-I by 85% and 30%, respectively.

Load Forecasting Research of Power System Based on Fuzzy Sets Algorithm

Qihui Wang,Yuhuai Wang,Huixi Zhang,Yaping Sun 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.6

In this paper, adjust the system parameters back-propagation algorithm based on fuzzy similarity interval type proposed by the fuzzy rule base to streamline redundant fuzzy sets, we can also merge with the means to reduce the number of redundant fuzzy rules, then singular value decomposition method is preferred fuzzy rules. The algorithm can effectively eliminate the adverse effects caused by redundant fuzzy rule, which improve the interpretability of fuzzy rules to reduce the computational complexity of the fuzzy reasoning process, and to improve the approximation accuracy of the system. Based on the long-term and short-term load power load characteristics analysis, to identify the influence of the load itself changes and related factors, gray system theory, neural network model and chaotic time series methods, models and methods for forecasting power load range were research. Examples verified, interval prediction has better precision, demonstrate the effectiveness of the interval prediction algorithm, the research results can be used in power market analysis and forecasting systems, power system operation and provide scientific basis for management decisions.

Optimal Opportunistic Spectrum Access with Unknown and Heterogeneous Channel Dynamics in Cognitive Radio Networks

( Yuli Zhang ),( Yuhua Xu ),( Qihui Wu ),( Alagan Anpalagan ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.8

We study the problem of optimal opportunistic spectrum access with unknown and heterogeneous channel dynamics in cognitive radio networks. There is neither statistic information about the licensed channels nor information exchange among secondary users in the respective systems. We formulate the problem of maximizing network throughput. To achieve the desired optimization, we propose a win-shift lose-stay algorithm based only on rewards. The key point of the algorithm is to make secondary users tend to shift to another channel after receiving rewards from the current channel. The optimality and the convergence of the proposed algorithm are proved. The simulation results show that for both heterogeneous and homogenous systems the proposed win-shift lose-stay algorithm has better performance in terms of throughput and fairness than an existing algorithm.

Opportunistic Spectrum Access with Dynamic Users: Directional Graphical Game and Stochastic Learning

( Yuli Zhang ),( Yuhua Xu ),( Qihui Wu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.12

This paper investigates the channel selection problem with dynamic users and the asymmetric interference relation in distributed opportunistic spectrum access systems. Since users transmitting data are based on their traffic demands, they dynamically compete for the channel occupation. Moreover, the heterogeneous interference range leads to asymmetric interference relation. The dynamic users and asymmetric interference relation bring about new challenges such as dynamic random systems and poor fairness. In this article, we will focus on maximizing the tradeoff between the achievable utility and access cost of each user, formulate the channel selection problem as a directional graphical game and prove it as an exact potential game presenting at least one pure Nash equilibrium point. We show that the best NE point maximizes both the personal and system utility, and employ the stochastic learning approach algorithm for achieving the best NE point. Simulation results show that the algorithm converges, presents near-optimal performance and good fairness, and the directional graphical model improves the systems throughput performance in different asymmetric level systems.

Optimal Cooperation and Transmission in Cooperative Spectrum Sensing for Cognitive Radio

( Xian Zhang ),( Qihui Wu ),( Xiaoqiang Li ),( Zi Yun ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.2

In this paper, we study the problem of designing the power and number of cooperative node (CN) in the cooperation phase to maximize the average throughput for secondary user (SU), under the constraint of the total cooperation and transmission power. We first investigate the scheme of cooperative spectrum sensing without a separated control channel. Then, we prove that there indeed exist an optimal CN power when the number of CNs is fixed and an optimal CN number when CN power is fixed. The case without the constraints of the power and number of CN is also studied. Finally, numerical results demonstrate the characteristics and existences of optimal CN power and number. Meanwhile, Monte Carlo simulation results match to the theoretical results well.

A Hydrogel-based First-Aid Tissue Adhesive with Effective Hemostasis and Anti-bacteria for Trauma Emergency Management

Dongjie Zhang,Li Mei,Yuanping Hao,Bingcheng Yi,Jilin Hu,Danyang Wang,Yaodong Zhao,Zhe Wang,Hailin Huang,Yongzhi Xu,Xuyang Deng,Cong Li,Xuewei Li,Qihui Zhou,Yun Lu 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Clinical tissue adhesives remain some critical drawbacks for managing emergency injuries, such as inadequate adhesive strength and insufficient anti-infection ability. Herein, a novel, self-healing, and antibacterial carboxymethyl chitosan/polyaldehyde dextran (CMCS/PD) hydrogel is designed as the first-aid tissue adhesive for effective trauma emergency management. Methods We examined the gel-forming time, porosity, self-healing, antibacterial properties, cytotoxicity, adhesive strength, and hemocompatibility. Liver hemorrhage, tail severance, and skin wound infection models of rats are constructed in vivo, respectively. Results Results demonstrate that the CMCS/PD hydrogel has the rapid gel-forming (~ 5 s), good self-healing, and effective antibacterial abilities, and could adhere to tissue firmly (adhesive strength of ~ 10 kPa and burst pressure of 327.5 mmHg) with excellent hemocompatibility and cytocompatibility. This suggests the great prospect of CMCS/ PD hydrogel in acting as a first-aid tissue adhesive for trauma emergency management. The CMCS/PD hydrogel is observed to not only achieve rapid hemostasis for curing liver hemorrhage and tail severance in comparison to commercial hemostatic gel (Surgiflo ®) but also exhibit superior anti-infection for treating acute skin trauma compared with clinical disinfectant gel (Prontosan ®). Conclusions Overall, the CMCS/PD hydrogel offers a promising candidate for first-aid tissue adhesives to manage the trauma emergency. Because of the rapid gel-forming time, it could also be applied as a liquid first-aid bandage for mini-invasive surgical treatment.

Outage Analysis of CRNs with SC Diversity Over Nakagami-m Fading Environment

( Zongsheng Zhang ),( Qihui Wu ),( Xueqiang Zheng ),( Jinlong Wang ),( Lianbao Li ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.12

In this paper, we investigate the outage performance of a cognitive relay network. We consider mutual interference in an independent, non-identically distributed Nakagmai-m fading environment. We first derive the close-form outage probability expression, which provides an efficient means to evaluate the effects of several parameters. This allows us to study the impact of several parameters on the network`s performance. We then derive the asymptotic expression and reveal that the diversity order is strictly determined by the fading severity of the cognitive system. It is not affected by the primary network. Moreover, the primary network only affects the coding gain of the cognitive system. Finally, Monte Carlo simulations are provided, which corroborate the analytical results.

Irreversible phase transition characteristic of 0.91Pb(Zn1/3Nb2/3) O3-0.09PbTiO3 single crystals by domain observation

Rongfeng Zhu,Qihui Zhang,Bijun Fang,Jianning Ding,Xiangyong Zhao,Haosu Luo 한국물리학회 2016 Current Applied Physics Vol.16 No.12

In situ temperature dependent ferroelectric domains dynamic evolution of the (001)pc oriented 0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3 (PZNT91/9) single crystals was observed by polarized light microscopy (PLM) and real time synchrotron-radiation (SR) X-ray white-beam topography. Intricate domain structures including monoclinic phase are distinguished by PLM at room temperature, and irreversible domain configuration dynamic evolution upon thermal cycling is observed by both methods. Such irreversible domain evolution combined with coexistence of multi-phases and polarization rotation may be related to the extraordinary piezoelectric performance in the ferroelectric single crystals with the morphotropic phase boundary (MPB) compositions.

Improved Particle Swarm Optimization Algorithm for Optimization of Power Communication Network

Yuhuai Wang,Qihui Wang,Huixi Zhang,Kang An,Xia Ye,Yaping Sun 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.1

Based on particle swarm optimization (PSO) algorithm and its power system reactive power optimization method to in-depth study and research proposed a new hybrid particle swarm optimization algorithm (HPSO). Algorithm combines the differential evolution algorithm and simulated annealing algorithm and particle swarm optimization algorithm, in particle searching optimal except for tracking individual and global, and tracks produced by particle information difference of the three value. At the same time, when the particle search space of one dimension speed lower than the setting value will be re initialized the dimensional particle velocity and the particle of differential evolution mutation. For the crossover and mutation operations, new solution may be worse than the original solution to, the introduction of simulated annealing algorithm, the metropolis rule in a certain extent accept bad solutions, allows the target function in a certain degree of deterioration, practical calculation is not according to the probability to choose the poor solution, but rather the judgment target function difference is less than allows the target function deterioration range. Hybrid particle swarm optimization algorithm combines the advantages of particle swarm optimization algorithm, differential evolution algorithm and simulated annealing algorithm, to maintain the diversity of particles, has very strong practicability.

Research on the Management Strategy of the Last Level Cache Sharing Multi-Core Processor

Yuhuai Wang,Huixi Zhang,Yaping Sun,Qihui Wang 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.5

Effective allocation of shared resources limited is a key problem for chip multiprocessors. As the processor core growth in the scale, multi thread for the shared resource limited system competition will become more intense, the performance of the system will also be more significant. In order to alleviate this problem, a fair and effective multi thread shared resources allocation scheduling algorithm is important. In all kinds of shared resources, the largest effect on the system performance is the shared cache and DRAM system. There are essential differences between the last level cache and a cache. The goal of a cache design is to provide fast data processor which requires high access speed. However, the object of the last level cache is to save data in the chip as much as possible, and the access speed requirements are not too high, it is more subject to the plate number of available transistors. Management level cache LRU strategy and its approximate algorithm are not applicable to the large capacity last level cache for traditional. It may cause destructive interference between threads, cache thrashing of stream media program lead, which will lead to a decline in the performance of processor. This paper focuses on the analysis of some hot problems of the last level cache management in the process of the large capacity of multi-core platform sharing, and puts forward the corresponding costs less.