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An optimization scheme for Location-Assisted On-demand Routing protocol is proposed in order to improve its robustness. The simulation shows that proposed scheme can improve the robustness and reduce the routing cost of LEO routing system.

In this paper, a resource reservation algorithm based on ARIMA model with balanced performance (RABP) is proposed. The algorithm uses Auto Regressive Integrated Moving Average (ARIMA) model to predict the change trend of future on-board traffic to reserve reasonable spectrum resources in advance and evaluate the impact of resource allocation scheme on system performance. The simulation results show that the performance of resource utilization and communication blocking rate are improved.

Routing and wavelength assignment algorithms for Low Earth Orbit (LEO) satellite communication are studied in this paper. Based on intersatellite hops and wavelength utilization, the calculation model of path weight is established. In order to achieve the optimal allocation of routing and wavelength resources in Software Defined Network (SDN) network architecture, path selection and wavelength allocation are completed from the perspective of path weight. Finally, the proposed algorithm is compared with the existing algorithms. The simulation results show that the proposed algorithm can reduce the blocking rate and improve the wavelength utilization.

A spectrum allocation algorithm for satellite applications based on the characteristics of satellite elastic optical network and various conditions is proposed in this paper. Compared with the random fit (RF) and first fit (FF) spectrum allocation algorithms, the routing and spectrum allocation algorithm (RSA) based on link spectrum resource assessment set can allocate spectrum more accurately for services, reduce the generation of spectrum fragments, and improve the spectrum utilization of satellite elastic optical network.

Adaptive forwarding routing algorithm is proposed in order to solve the problem that the traditional routing algorithm is insensitive to the dynamic change of satellite network state. This algorithm mainly uses the real-time perception of local network state, to realize load balancing. The simulation results show that it achieves shorter end-to-end delay and lower packet loss rate.

The fault diagnosis of the gearbox is a complex and important work. In this paper, a multilayer gated recurrent unit (MGRU) method is proposed for spur gear fault diagnosis, that is, three-layer gated recurrent unit (GRU). The vibration signals are firstly monitored on the test bench, and then extracted in both time domain and time-frequency domain. Finally, MGRU is used to learn representation and classification. The MGRU can improve the representation of information and identify the features of fault types more precisely with the increasing number of layers. The proposed method was tested by two spur gears with 10 state modes. To evaluate the method's classification accuracy, four methods were utilized for comparison, i.e., the GRU, long short-term memory (LSTM), multilayer LSTM (MLSTM), and support vector machine (SVM), respectively. In addition, the separability and robustness analysis are also discussed for the proposed MGRU performance. All of the results exhibited that the proposed MGRU approach is effective for spur gear fault diagnosis.

To improve the convergence speed of routing and wavelength assignment (RWA) algorithm of satellite network, the Fast Convergence RWA based on Ant Colony Algorithm (ACO-FC RWA) is proposed. The results show the better network performance.

In order to improve the resilience of the satellite network and increase the communication success rate when the node fails, an intelligent backup multi-path ant colony routing algorithm (IMB-ACR) is proposed. In this algorithm, the parameter of betweenness centrality is used to evaluate the importance of satellite nodes, and use it to determine whether to calculate a backup routes, which means the backup routes will be calculated if and only if there are key nodes in the original routes. This is what distinguishes IMB-ACR from traditional multipath routing algorithms, as a consequence of the distinguishing feature, we can improve the anti-destructive and resilient ability of satellite network while reduce time overhead. The simulation results show that, compared with the KACR algorithm, the communication success rate of the IMB-ACR algorithm increases by 3%; when the number of failed nodes climbs to 4, IMB-ACR is twice as resilient as K-ACR which based on resilient slope; In addition, the time cost of the IMB-ACR algorithm is 0.3028s, which is lower than that of the K-ACR algorithm. Thus it can be seen that IMB-ACR algorithm still performs well in terms of communication success rate and resilient recovery ability under the condition of low time overhead.

An elastic bandwidth allocation algorithm for Low Earth Orbit (LEO) satellite optical network is proposed in this paper. The algorithm runs in a centralized software defined network architecture and serves hybrid requests including Immediate Reservation (IR) and Advanced Reservation (AR) requests. The bandwidth allocated to each request is two-dimensional, which refers to the wavelength and the time range occupying the wavelength, so the flexible time window of AR requests can be more fully utilized. Besides, according to the dynamic topological characteristics of satellite optical network, the bandwidth allocation algorithm is based on snapshot periods, and the look-ahead time of allocating is always limited to a snapshot period. Finally, the proposed algorithm is evaluated by simulations in terms of the network blocking rate, the wavelength utilization, and the average communication delay. Simulation results show that the blocking rate can be reduced by 8.7% by the proposed algorithm.

There is a growing need for efficient bandwidth allocation in broadband satellite communication system. Firstly, a cross-layer bandwidth framework is constructed by considering information exchange between application layer, medium access control (MAC) layer and physical layer. Then, in order to allocate bandwidth resources, a utility function is established with modified factor by optimized bee colony algorithm. In the bee colony optimization-based cross layer dynamic bandwidth allocation algorithm (BO-CL-DBA), important channel factors including modulation order, coding efficiency, transmission rate and quality of service (QoS) priority for different users are considered and analyzed. Furthermore, a simulation model is developed to evaluate performance such as utility value, user satisfaction and throughput. The result demonstrates high allocation efficiency which meets multi QoS requirements.

Given the unintuitive and nonquantitative analysis of traditional artificial detection results of aero-engine blades, a characterization evaluation technique has been carried out based on ultrasonic defect point cloud. 3-D reconstruction display model of ultrasonic point cloud was completed by ultrasonic C-Scan imaging principle, spatial surface display technology, and 3-D visualization technology. A hybrid reconstruction method based on Delaunay triangulation and mesh growth algorithm was proposed, which achieved the 3-D reconstruction of a defect point cloud of regional discretization, the obtained results exhibited the spatial distribution of defect area, which intuitively provided the comprehensive view of 3-D defect model. Furthermore, the defect area was calculated via the vertex coordinates of each triangle in the reconstruction mesh. Taking flat-bottom holes as an example, an experimental model for quantitative evaluation was established based on the method. The quantization error of defect size is less than ±10% with comparison of the prefabricated defect size, so the feasibility and accuracy of the method are verified, which provides a convenient and effective way to quantitatively characterize the defects of curved components with immersion ultrasonic testing.

Wireless Sensor Networks (WSNs) are mainly used to collaboratively sense and process information in the monitoring area. Sensor nodes have limited energy and are inconvenient to be replaced when the monitoring area is remote or dangerous. That makes the energy consumption an important problem for WSNs. For heterogeneous network, where sensor nodes have different energy, existing clustering methods only consider single factor, heterogeneity of node energy, for head selection. This paper applies fuzzy logic to consider multiple factors for clustering with the purpose of prolonging the lifetime of the network. Important factors, such as relative density of nodes in the network and the relative distance from the nodes to the base station, are considered together with the initial energy to select the cluster head dynamically. Simulation results demonstrated that proposed clustering algorithm can balance the energy consumption of the nodes in network and effectively prolong the survival time of the network, thus ensuring the accuracy of data aggregation.

With the rapid development of Internet of Things (IoT) technology, the number of nodes in wireless sensor networks (WSNs) is explosively increasing, and the scale of network is increased gradually. Traditional single-layer non-clustering network is no longer suitable for current WSNs, which results in high maintenance cost and fast deterioration of network performance. By analyzing the impact of existing static and dynamic clustering schemes on network performance, it is concluded that additional factors need to be considered to improve the overall performance of the network, such as residual energy of nodes, number of neighbor nodes and load balancing. Therefore, an adaptive multi-layer clustering networking strategy based on capability weights is proposed. Based on the real-time changes of each cluster density, node load and residual energy, the node capacity weights are updated dynamically according to the actual network performance, then the cluster heads are renewed adaptively. By comparing the performance metrics in the experiments, proposed strategy can effectively reduce the load of key nodes such as cluster head, and improves the network performance metrics such as average transmission delay, average transmission hops and load balancing.

The 5th Generation mobile network is coming, and phase array antenna is one of most important applications in 5th Generation network. Power source is the root of all electric application, including antenna. Even with the best design, an application will be useless if it doesn’t have a good electricity supplying system. Phase array antenna consists of multiple antennas, and each antenna will need its own power source. Normally, people need to adjust the power supply manually. This research will focus on how to manipulate the power source by using software. We use LabVIEW’s human machine interface and NI-8451 interface to communicate with the power supply. Due to single human machine interface design, users can feel more convenient when operating it. Because we use I2C command, we no longer need to go through complex setting steps. It will also decrease the setting time to achieve the control of highly efficient power source output.

A server power supply should be able to supply high quality and stable power source. Every power supply must have done a series of tests and calibration before shipping out for fear of unstable power supplying. But the procedure of voltage calibration is complex, we need to operate a lot of instruments at the same time and connect with complex testing tools. Going through a lot of adjustment meet the requirement. However, complex working procedure and the long working time is not accepted by the production line. The goal of this project is to find the best way which is using the least man power and the more efficient way to calibrate the power supply. The aim of this study is that how to design an automatic test program. In order to reduce defective product and increase the production capacity. We use the feature of LabVIEW’s Human machine interface along with its supporting multiple communication interface and GPIB interface manipulating instruments to design this automatic test program. Operator just need to load the test profile and follow the program instruction. In addition to designing a testing file loading method to decrease the wasted time and the error rate. After each test, it will output a report to help engineers trouble shooting.

An extended pathfinding routing and wavelength assignment (RWA) algorithm based on ant colony optimization (ACO-EP) is proposed in order to enhance the global exploratory capability. The algorithm introduces heuristic function which is based on wavelength availability to solve the problem of unbalanced wavelength usage and introduces volatilization coefficient and random interference mechanism based on traffic intensity to improve the shortcoming of easily falling into local optimum. The communication success rate and transmission delay performance are simulated in the scene of Iridium satellite constellation. The results show that when traffic intensity is 138.6Erl, compared with the original ant colony algorithm, ACO-EP algorithm can improve the communication success rate by 23.56% and reduce the communication delay by 13.89%.

In order to solve the interference caused by the instability of the channel environment in Massive MIMO to the transmitted signal, this paper proposes a precoding method based on the channel condition number. In this algorithm, the channel condition number is used as the basis for judging the channel quality. Under different channel condition numbers, the transmit power is changed. At the same time, in order to reduce the hardware complexity, the algorithm uses Neumann series to replace the direct inversion of large-scale matrix, and choose the appropriate convergence factor, which can guarantee the convergence speed and reduce the number of iterations.

Satellite laser communication has high operating frequency and strong direction. It has the advantages of high transmission code rate, small antenna size and strong confidentiality. It is more suitable for high speed and large capacity communication in space. In order to solve the problem of establishing links in satellite laser communication, the paper proposes a hexagonal spiral scanning method with equal number of internal and external scanning circles. The method uses internal and external simultaneous scanning to the uncertain region of capture, and the number of scan circles of inner and outer is equal, this method shortens the time of laser scanning, improves the success rate of satellite communication link establishment, and optimizes the performance of satellite communication system. This paper establishes the theoretical model of the scanning method and verifies the correctness of the proposed model.

Massive multi-input and multi-output technology is a key technology for future 5G wireless communication. The channel feedback problem of massive mimo becomes more and more challenging as the size of the mimo channel matrix becomes larger. A supervised deep learning-based encoder-decoder scheme was proposed to improve recinstruction quality recovery channel state information.Compared with the traditional compression-based sensing algorithm, Residual Attention-Net can still maintain good performance when compression is low.

In this paper, the numerical simulation method of multilayer phase screen step-by-step transmission is used to study the influence of atmospheric turbulence on the upstream transmission of satellite-ground optical communication. The model of atmospheric turbulence laser transmission between satellite and ground is established to simulate the laser transmission between ground terminal and Low-Orbit satellite. Unequal spacing phase screen is used to simulate non-uniform turbulence. The simulation calculation of optical transmission under different turbulence conditions with different zenith angles can be realized. The simulation results of the satellite upstream optical communication verified the model.

Effectiveness evaluation model based on ambient fuzzy operator is proposed for laser/microwave satellite communication system (L/MSCS), in order to evaluate the effectiveness of L/MSCS more scientifically. In this paper, the model establishes an ambient parameter system, and selects the ambient state according to the actual situation of L/MSCS, and then selects the ambient fuzzy operator according to the state. The effectiveness of L/MSCS is simulated by this model and compared with the basic fuzzy analytic hierarchy process (fuzzy-AHP). The research results show that the proposed model is closer to the actual situation and more scientific than fuzzy-AHP.

A recursive neural network based BBU pool resource allocation scheme in C-RAN is proposed. Simulation results indicate the proposed scheme achieves lower power consumption and blocking rate with higher total throughput compared with traditional network.

In this paper, a novel Cross-layer Dynamic Bandwidth Allocation Algorithm Based on Convex Optimization Theory(CO-CDBA) in Digital Video Broadcast-Return Channel via Satellite system is proposed. A novel utility function by taking application layer, Data Link Layer and physical layer(PHY) parameters into account is established. The Dynamic Bandwidth Allocation(DBA) problem is converted to a convex optimization problem with constraints, which can be solved by using a fast interval iterative algorithm. The allocation result, utility value, users' fairness performance and allocation procedure based on CO-CDBA are simulated. Results show that CO-CDBA can reduce computational complexity and efficiently allocate bandwidth for each user. Fairness and utility are significantly improved compared with Max-Min and water-filling model.

In order to solve the problem of instability clustering in Ad Hoc Networks with complex and changeable node motion, this paper proposes a weighted clustering algorithm based on node stability(SA-WCA). In this algorithm, we propose a node stability factor based on node received power, which does not need to calculate the specific distance between nodes and can only judge the relative motion between the nodes according to the transmitting power and the received power of the node. The newly defined factors have a more scientific evaluation on the stability of the nodes. The Simulation studies the performance of the clustering algorithm such as the number of clusters reconstruction, the change rate of nodes and the load balance factor and compared with the Lowest ID algorithm (LOWID), the Highest degree algorithm (HIGHD) and the Weighted clustering algorithm (WCA). The results show that the proposed algorithm is superior to other algorithms in improving the stability of cluster structures.

As in-line interference between geostationary(GEO) and Non-Geostationary(NGEO) systems is becoming more and more serious. We propose an efficient utilisation of the adaptive modulation and coding (AMC) scheme for spectral coexistence of GEO and NGEO satellites to mitigate in-line interference. Results of Simulation show that the proposed scheme can improve the performance of the NGEO system in comparison with the traditional method of mitigating the co-channel interference.

In this paper we consider a novel design of space-time block code combined with pre-coding module transmission system. Theory of orthogonal designs has shown that such code cannot be simultaneously orthogonal, of rate 1, with full diversity order, for more than 2 transmit antennas. We propose in this paper a new way to overcome this limitation by adding a pre-coding module before transmitting space-time block signals, this scheme is a rate 1 coding scheme with full diversity, and is also an orthogonal one thanks to the new adding pre-coding weights.

Aiming to solve the problems of lacking quality element dynamics prediction in Kano model, considering the advantages of grey theory in coping with irregular data, a quality element dynamics prediction method based on GM(1,1) model is proposed. In view of the strong subjectivity of traditional Kano model, propose a fuzzy Kano model to classify the quality elements more objectively. Furthermore, for GM(1,1) model's ability to deal with small data, inadequate information and high prediction precision, it is widely used to study the dynamics prediction of Kano quality elements. Finally, an empirical study in express industry is provided to illustrate the feasibility and availability of the proposed method.

Hundreds of millions of webusers access to or use a variety of network services via various digital identity credentials every day. Network security issues such as Identity authentication, privacy and information sharing have become focuses of IT industry. To strengthen network security management and risk prevention, some of China's large-scale sites have launched real name registration policy, indicating that digital identity gradually stepping into normalization. This paper intends to explore ways of encouraging the establishment of digital identity authentication system.

This paper reports a digital decimation filter chip for real-time signal processing of micro-air-vehicles (MAVs), which is composed of cascade integrator comb (CIC) filter, half-band filter and CIC compensation filter. To obtain low power, low hardware cost and efficient area, optimization was performed at behavioral level modeling and register transfer level (RTL) design. A mathematical framework was presented to perform parameters optimization of different filters. The layout was designed based on SMIC 0.18 µ m process library. The verification results show that the chip achieves a signal to noise ratio (SNR) of 54.40dB. The chip area occupies 1.69mm2 and dissipates only 2.95mW power. Area and power are well satisfied with the separation point detection of MAVs' boundary layer.

Cheng’s refined theory is extended to investigate the thermoelastic plate posting inside Winkler Foundation under steady temperature, and the refined analyses for the thermoelastic plates posting inside the Winkler Foundation under steady temperature is deduced systematically and directly from linear thermoelastic theory and Lur’e method. Expressions are introduced for all the displacements and stress components in term of the mid-plane displacement and its derivatives. From boundary conditions, the refined equations of thermoelastic plates posting inside the Winkler Foundation under steady temperature are given without ad hoc assumptions. Using Taylor Series of the trigonometric functions and then dropping all the terms associated with the higher-order terms, we obtain the approximate expressions of random precision. To illustrate the application of the theory developed, one example is examined.

To solve the problem of spectrum deviation brought about by existing AR parameter estimation methods in engineering application, this paper proposed an improved and optimized estimation method for parameters of the AR model with constant parameters. The method was figured out as followed. Firstly, the initial estimation of AR parameters was derived according to LS criteria; Secondly, through the parametric spectrum estimation formula and the consecutive function's extreme theorem, the mathematical constraint formula was derived with which a combined objective function was constructed under the guidance of punishment function idea; Lastly, the Genetic Algorithm was adopted to optimize the LS estimation of AR parameters. The method proposed was used to estimate spectrum of the vertical vibration acceleration voltage data in turning condition. The results demonstrated that the method proposed overcome such problem as the spectral spectrum deviation, characteristics extraction was more precise and inhibited side-lobes well.

In this report, an OTA which is used in fully differential pipelined ADC was described. Using gain-boost architecture with current-mode single-ended amplifier, this OTA reduce parasitic taking by gain-boost amplifier to achieve high-gain and high-speed. Besides, a dual phase SC-CMFB circuit is introduced, and some methods are concerned to improve the performance. Then, by optimization the layout design, OTA's mismatch was reduced. This design was using SMIC 0.35um CMOS process and simulation both schematic and layout in Cadence. The result of the simulation shows that the OTA has a gain up to 105dB, a unity gain bandwidth of about 937MHz for a 2pF load, a settling time of about 4.4ns, a Common-Mode Range is 0.6V∼3.3V, a output swing is 0.6V∼3.1V, with the power supply of 3.3V, the dissipation is 39mW. This amplifier was used in a 10bit 100MHz pipelined ADC.

The refined theory and the decomposed theorem of plates are converted into the refined theory of the torsional deformation of transversely isotropic piezoelectric circular shaft by using Bessel Function's Operator Method from equation of transversely isotropic piezoelasticity for torsional problem without ad hoc assumptions. Firstly, the problem of deducing one-dimensional theory from three-dimensional theory for transversely isotropic piezoelastic shaft is investigated. Expressions are obtained for all the displacements and stress components in term of one function on the neutral axis. Secondly, based on the refined theory of piezoelectric circular shaft, the exact equations for homogeneous boundary conditions are derived, which consist of two governing differential equations: 2-orders equation and the transcendental equation. Lastly, the approximate governing equations are accurate up to the high-order terms with respect to radius of shaft in the case of non-homogenous boundary conditions.

Non-traditional safety-critical systems are widely used in transportation control, banking and financial systems, and the management of water systems, which have different characteristics with traditional safety-critical systems. In those systems, tasks cannot be determined as critical or non-critical apparently but a few failures of some tasks are acceptable. This paper establishes a new schedule model for Non-traditional safety-critical systems and proposes a non-preemptive fuzzy classification (NFC) algorithm. NFC is consisted of two phrases, called initialized step and execution step. Afterwards, NFC and MUF are compared based on sample tasks abstracted from an existing financial system. It is concluded that NFC has fewer failed tasks and similar performance.