Shandong Institute of Business and Technology

About: Shandong Institute of Business and Technology is a education organization based out in Yantai, China. It is known for research contribution in the topics: Computer science & Artificial neural network. The organization has 1487 authors who have published 1433 publications receiving 8915 citations.

A novel index of functional connectivity: phase lag based on Wilcoxon signed rank test

Abstract: Phase synchronization has been an effective measurement of functional connectivity, detecting similar dynamics over time among distinct brain regions. However, traditional phase synchronization-based functional connectivity indices have been proved to have some drawbacks. For example, the phase locking value (PLV) index is sensitive to volume conduction, while the phase lag index (PLI) and the weighted phase lag index (wPLI) are easily affected by noise perturbations. In addition, thresholds need to be applied to these indices to obtain the binary adjacency matrix that determines the connections. However, the selection of the thresholds is generally arbitrary. To address these issues, in this paper we propose a novel index of functional connectivity, named the phase lag based on the Wilcoxon signed-rank test (PLWT). Specifically, it characterizes the functional connectivity based on the phase lag with a weighting procedure to reduce the influence of volume conduction and noise. Besides, it automatically identifies the important connections without relying on thresholds, by taking advantage of the framework of the Wilcoxon signed-rank test. The performance of the proposed PLWT index is evaluated on simulated electroencephalograph (EEG) datasets, as well as on two resting-state EEG datasets. The experimental results on the simulated EEG data show that the PLWT index is robust to volume conduction and noise. Furthermore, the brain functional networks derived by PLWT on the real EEG data exhibit a reasonable scale-free characteristic and high test-retest (TRT) reliability of graph measures. We believe that the proposed PLWT index provides a useful and reliable tool to identify the underlying neural interactions, while effectively diminishing the influence of volume conduction and noise.

Mixed H 2 / H ∞ control for a class of nonlinear networked control systems

Abstract: In this paper, the mixed H 2/H ∞ control problem is investigated for a class of nonlinear discrete-time networked control systems with random network-induced delays, stochastic packet dropouts and probabilistic sensor faults. The packet dropouts process is modeled as a homogeneous Markov chains taking values in a finite state space. Network-induced delays occur in a random way with known upper bound. A set of stochastic variables are exploited to describe sensor faults with different probabilistic density functions. By using a delay-dependent Lyapunov functional, a mode-dependent mixed H 2/H ∞ controller is designed to guarantee both stochastic stability of the closed-loop system and the prescribed H2, H¥ control performances. Sufficient conditions for the existence of the mixed H 2/H ∞ controller are presented in terms of a series of LMIs. If these LMIs are feasible, then the modedependent mixed H 2/H ∞ controller can be obtained. A numerical example is given to demonstrate the effectiveness of the developed method.

The number of spanning trees of a graph with given matching number

Abstract: The number of spanning trees of a graph G is the total number of distinct spanning subgraphs of G that are trees. In this paper, we present sharp upper bounds for the number of spanning trees of a graph with given matching number.

Study on Overburden Stability and Development Height of Water Flowing Fractured Zone in Roadway Mining with Cemented Backfill

Abstract: In order to explore the stability of overburden rock and the development height of water flowing fractured zone in roadway filling mining, based on the movement and deformation mechanism of overburden rock, the mechanical analysis of overburden stability and failure was carried out, and the mechanical model of main roof rock beam was established, and the ultimate span and limit deflection of rock beam fracture were deduced. Combined with the mechanical model of the main roof fractured rock, the basis for the judgment of overburden failure developing to fractured zone is given in this paper. Taking a coal mine roadway backfill under water-bearing stratum as an example, based on the equivalent mining height, the theoretical calculation and analysis are carried out on the stability of overburden rock and the height of water flowing fractured zone. The reliability of the theoretical analysis is verified compared with the empirical formula and the numerical simulation results. The results showed that the water flowing fractured zone developed to the bottom of no. 7 glutenite, with a height of 32.5 m, slightly less than the calculation result of the empirical formula. The thickness of the waterproof coal pillar was 39.8 m, which was much less than the distance from the aquifer to the coal seam and can be mined safely.

Blockchain Based Big Data Security Protection Scheme

Abstract: As the key platform to deal with big data, Hadoop cannot fully protect data security of users by relying on a single Kerberos authentication mechanism. In addition, the single Namenode has disadvantages such as single point failure, performance bottleneck and poor scalability. To solve these problems, a big data security protection scheme is proposed. In this scheme, blockchain technology is adopted to deploy distributed Namenode server cluster to take joint efforts to safeguard the metadata and to allocate access tasks of users. We also improved the heartbeat model to collect user behavior so as to make a faster response to Datanode failure. The smart contract conducts reasonable allocation of user role through the judgment of user tag and risk value. It also establishes a tracking chain of risk value to monitor user behavior in real time. Experiments show that this scheme can better protect data security in Hadoop. It has the advantage of metadata decentralization and the data is hard to be tampered.