Fault Diagnosis of Wind Turbine Generator with Stacked Noise Reduction Autoencoder Based on Group Normalization

In order to improve the condition monitoring and fault diagnosis of wind turbines,a stacked noise reduction autoencoding network based on group normalization is proposed in this paper.The network is based on SCADA data of wind turbine operation,firstly,the group normalization(GN)algorithm is added to solve the problems of stack noise reduction autoencoding network training and slow convergence speed,and the RMSProp algorithm is used to update the weight and the bias of the autoenccoder,which further optimizes the problem that the loss function swings too much during the update process.Finally,in the last layer of the network,the softmax activation function is used to classify the results,and the output of the network is transformed into a probability distribution.The selected wind turbine SCADA data was substituted into the pre-improved and improved stacked denoising autoencoding(SDA)networks for comparative training and verification.The results show that the stacked denoising autoencoding network based on group normalization is more accurate and effective for wind turbine condition monitoring and fault diagnosis,and also provides a reference for wind turbine fault identification.

A Combining Call Admission Control and Power Control Scheme for D2D Communications Underlaying Cellular Networks

As device-to-device(D2D) communications usually reuses the resource of cellular networks, call admission control(CAC) and power control are crucial problems. However in most power control schemes, total data rates or throughput are regarded as optimization criterion. In this paper, a combining call admission control(CAC) and power control scheme under guaranteeing QoS of every user equipment(UE) is proposed. First, a simple CAC scheme is introduced. Then based on the CAC scheme, a combining call admission control and power control scheme is proposed. Next, the performance of the proposed scheme is evaluated. Finally, maximum DUE pair number and average transmitting power is calculated. Simulation results show that D2 D communications with the proposed combining call admission control and power control scheme can effectively improve the maximum DUE pair number under the premise of meeting necessary QoS.

A Trusted Multi-Task Distribution Mechanism for Internet of Vehicles Based on Smart Contract

In this paper,a trusted multi-task distribution mechanism for Internet of Vehicles based on smart contract is proposed to improve the security and efficiency for the task distribution in Internet of Vehicles.Firstly,a three-tier trusted multi-task distribution framework is presented based on smart contract.The smart contract will be triggered by the task request.As the important part of the smart contract,the task distribution algorithm is stored on the blockchain and run automatically.In the process of the task distribution,the cost of the task distribution and the system stability play a critical role.Therefore,the task distribution problem is formulated to minimize the cost of the task distribution whilst maintaining the stability of the system based on Lyapunov theorem.Unfortunately,this problem is a mixed integer nonlinear programming problem with NP-hard characteristics.To tackle this,the optimization problem is decomposed into two sub problems of computing resource allocation and task distribution decision,and an effective task distribution algorithm is proposed.Simulation results show that the proposed algorithm can effectively improves system performance.

Vibration Characteristics Analysis and Structure Optimization of Catenary Portal Structure on Four-Wire Bridge

The portal structure is the support equipment in the catenary,which bears the load of contact suspension and support equipment.In practical work,with the change of external forces,the support equipment bears complex and changeable loads,so it has higher requirements for its reliability and safety.In order to study the dynamic characteristics of catenary portal structure on continuous beam of four-way bridge,taking the catenary portal structure on Dshaping four-way bridge as the research object,the portal structure simulation model of bridgenetwork integration was established in Midas Civil.The maximum point of deformation and stress was determined by finite element analysis of catenary hard span equipment,and the frequency and mode of natural vibration of hard span were obtained by modal analysis.Secondly,through the field dynamic stress acquisition test,combined with the results of finite element analysis,the fault location is determined,and the vibration characteristics are analyzed.Finally,based on the results of modal analysis and vibration analysis,the method that the vibration of portal structure beam is affected by structural stiffness and vibration frequency amplitude is proposed.The torsional vibration of the portal structure beam was suppressed by increasing the stiffness of the beam and reducing the vibration conduction between the trolley and the beam,and the hard cross beam was optimized by strengthening the hanging column and the connecting beam and adding diagonal support between the pillar and the portal structure beam.By comparing the values of shear,bending moment,displacement and dynamic stress on the hard span before and after optimization,the amplitude peak after structural optimization is reduced by about 25%,and the application of oblique support and reinforcement of the beam can significantly improve the portal structure vibration.

Metabolic engineering of Bacillus amyloliquefaciens for efficient production ofα-glucosidase inhibitor1-deoxynojirimycin

Owing to the feature of strongα-glucosidase inhibitory activity,1-deoxynojirimycin(1-DNJ)has broad application prospects in areas of functional food,biomedicine,etc.,and this research wants to construct an efficient strain for 1-DNJ production,basing on Bacillus amyloliquefaciens HZ-12.Firstly,using the temperature-sensitive shuttle plasmid T2(2)-Ori,gene ptsG in phosphotransferase system(PTS)was weakened by homologous recombination,and non-PTS pathway was strengthened by deleting its repressor gene iolR,and 1-DNJ yield of resultant strain HZ-S2 was increased by 4.27-fold,reached 110.72 mg/L.Then,to increase precursor fructose-6-phosphate(F-6-P)supply,phosphofructokinase was weaken,fructose phosphatase GlpX and 6-phosphate glucose isomerase Pgi were strengthened by promoter replacement,moreover,regulator gene nanR was deleted,1-DNJ yield was further increased to 267.37 mg/L by 2.41-fold.Subsequently,promoter of 1-DNJ synthetase cluster was optimized,as well as 5′-UTRs of downstream genes in synthetase cluster,and 1-DNJ produced by the final strain reached 478.62 mg/L.Last but not the least,1-DNJ yield of 1632.50 mg/L was attained in 3 L fermenter,which was the highest yield of 1-DNJ reported to date.Taken together,our results demonstrated that metabolic engineering was an effective strategy for 1-DNJ synthesis,this research laid a foundation for industrialization of functional food and drugs based on 1-DNJ.

Image recoloring using geodesic distance based color harmonization

In this paper, we present a computationally simple yet effective image recoloring method based on color harmonization. Our method permits the user to obtain recolored results interactively by rotating a harmonious template after completing color harmonization. Two main improvements are made in this paper. Firstly, we give a new strategy for finding the most harmonious scheme, in terms of finding the template which best matches the hue distribution of the input image. Secondly, in order to achieve spatially coherent harmonization, geodesic distances are used to move hues lying outside the harmonious sectors to inside them. Experiments show that our approach can produce higher-quality visually pleasing recolored images than existing methods. Moreover, our method is simple and easy to implement, and has good runtime performance.

Network Coding-Aware Routing Protocol in Wireless Mesh Networks

Network coding mechanisms, such as COPE, can improve network throughput effectively in Wireless Mesh Networks（WMN）. While the Hybrid Wireless Mesh Protocol（HWMP） is suitable for WMN, its extension with COPE does not provide any added benefits; specifically, HWMP cannot establish paths with more coding opportunities. As a result, the advantages of network coding cannot be exploited sufficiently. This paper proposes improvements upon HWMP with a new, network Coding-Aware routing protocol（CAHWMP） for WMN. In the CAHWMP protocol, we propose a coding criterion based on data streams to devise an algorithm for actively detecting coding opportunities during path discovery. CAHWMP subsequently establishes paths using the codingaware routing metric, which can balance channel resource consumption and the gain due to sharing resources introduced by network coding. Simulation results show that CAHWMP can establish paths with more coding opportunities; as a result, it improves network performance such as network throughput.