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Forgery of paper invoices and certificates negatively causes huge economic loss every year. In the molding process of paper, plant fibres inside will distribute randomly and form the unique microscopic surface. Accordingly, forensic researchers have presented many techniques to build its feature descriptor for paper anti-counterfeiting. Among those methods, normal vector field and reconstructed surface based on multi-view photos captured by mobile camera have indicated incredibly effectiveness and practicality. However, the inefficiency of existing models using mobile camera is the neck in real time detection scenarios. In this paper, we focus on the efficient microstructure orientation estimation of paper surface for authentication. To address this problem, we investigate the reflection characteristics of rough surface and quantify the light attenuation accurately. Then, we model the entire propagation path of light emitted by flash, and exploit single photo captured by mobile camera to reconstruct microscopic inclination based on beam energy loss. Reduction of required pictures significantly enhances forensics efficiency. Through comparison experiments, we demonstrate that our proposed method can be used for paper discrimination effectively with speedy feature extraction.

Based on the inversion of reasonable calculation parameters from an indoor test, Midas GTS was used to establish a three-dimensional numerical model for double-row round anti-slide piles. Under the premise that the pile spacing and row spacing were three times the pile diameter, the influence of plane layout type adopts parallel/quincunx and pile top with/without connecting beam on the pile internal force and soil stress were studied. The study showed that the plane layout mainly affects the bending moment of the anchored section of the pile body. The quincuncial layout can play an anchoring role better than the parallel layout, and the front row piles play a greater performance than the back row piles. The restraint of the pile top connecting beam mainly affects the loaded section of the pile. The connecting beam can reduce the range of soil stress concentration between rows and increase the force integrity of the loaded section as well as the overall rigidity of the structure; among the four types of piles studied in this paper, the quincuncial layout double-row round piles with connecting beam on the top of the pile have better anti-sliding performance.

Islanding of photovoltaic grid-connected power system have an adverse impact on power quality and utility equipment. Islanding detection is a key consideration for photovoltaic grid-connected system. In this paper, a new passive islanding detection method is proposed, which can achieve non-destructive islanding detection by extracting the higher harmonic components of the voltage of point of common coupling (PCC) using wavelet transformation. The rate of PCC voltage fluctuations is taken as the islanding characteristic index. This method can eliminate non-detection zone (NDZ). Based on IEEE Std.1547, theoretical analysis and simulation for the proposed method are accomplished. When PCC voltage and frequency are within a normal range, this method can fast and accurately detect the islanding and identify the pseudo islanding caused by voltage sages and loads switching. The result of simulation can prove the simplicity, accuracy and practicability of the proposed method.

Low earth orbit (LEO) satellite communication systems suffer a large and fast-varying Doppler shift which has to be estimated and compensated before any demodulation processing. In this paper, a novel Doppler shift estimation and compensation method is proposed. A cascading algorithm consisting of a time-vary Burg (TV-Burg) spectral analyzer and an alpha-beta filter is designed to provide a Doppler estimate at each sampling point recursively. Doppler compensation is then applied to each data sample using the corresponding estimate. The proposed method has the following two main characteristics. Firstly, neither satellite ephemerides nor training sequences is required for estimating the Doppler frequency. That is, it is a blind estimation method. Secondly, all processing units of this method are time-recursive, and they can update the outputs whenever a new data sample is received. As a result, the proposed method is able to track the fast time-varying Doppler shift continuously, thus reducing the processing budget at each sampling point and making it hardware-efficient. Simulation results demonstrate the effectiveness of the proposed method in a low SNR environment. Furthermore, the proposed method has been implemented on the Xilinx ZYNC-7100 FPGA and verified on a general-purpose

Fan-out Wafer level package technologies particularly provide an innovative and effective way in 3D packaging arena. This paper designs a fan-out package model based on the technology of Jiangyin Changdian Advanced Packaging Co., Ltd (JCAP). According to IO complexity of the chip requirements (four-channel transceiver SoC chip), 2P2M(2 PI layers and 2 metal layers) structure is selected to optimize the high frequency performance of chip. The simulation results show a good performance of S-parameters in the bandwidth from 75GHz to 85GHz, which verifies the prospects of its application in 5G communication and Millimeter wave automotive radar.

In this paper, a feasible control method to solve a class of second-order output tracking systems with uncertain perturbations is introduced and described in detail, no matter whether the disturbances are matched or not. Based on the classical sliding mode control algorithm, we further investigated the adaptive super-twisting sliding mode control theory by combining with the nonlinear disturbance observer (NDOB) technique. At the same time, integrated with the back-stepping design procedure, a rigorous adaptive sliding mode controller design steps is achieved. Combined with the Lyapunov theory, we demonstrated the stability of the control system carefully. Finally, an example of numerical simulation is employed to prove that whether the proposed method can obtain well disturbance rejection ability under the influence of matched and mismatched uncertain perturbations. All results are not unexpected and confirmed the efficacy of the controller design approach on the other hand

With the rapid development of Internet of Things and communication technology and the arrival of the era of big data, the construction of Intelligent Tourism is no longer an unrealistic slogan. The construction of smart tourism destination is in line with the strategic objective of China's tourism development. User behavior interest data are simulated artificially. Then, the features of tourist attractions, tourist routes and user behavior interest are extracted in the tourism field, and the user interest feature model is established. This paper briefly analyzes the application of big data in the tourism industry, promoting the effective application of big data in the tourism industry, further promoting the vigorous development of the tourism industry.

In order to improve the positioning accuracy of multi-robot cooperative localization with range-only measurement in Wireless Sensor Network (WSN), a framework to describe mobile agents and WSN nodes is introduced. Based on this framework, a Multi-Robot and Utral Wideband (MR-UWB) cooperative localization approach with range-only measurement is proposed. Proper agents are selected to cooperate with UWB anchors to obtain global position measurement by the minimum covariance criterion, and EKF is used to fuse encoder data, relative distance and global position measurement for accurate positioning of robot team. Simulation experiments are carried out, and the results show that MR-UWB cooperative localization approach has higher positioning accuracy than traditional multi-robot cooperative localization and UWB positioning system based on relative distance, which verifies the superiority of proposed approach.

The heat exchanger has the advantages of good IP protection effect, high heat dissipation efficiency and low cost. It is widely used as a heat dissipation device in outdoor communication power supply, but it also has some shortcomings, such as large size, which limits its in small equipment. In this paper, a miniaturized heat exchange device is proposed in this paper. In addition to the characteristics of good heat protection of the heat exchanger, the structure is simpler, the cost is lower, and the heat dissipation effect is slightly better. This miniaturized design approach can also be applied to other scenarios such as direct ventilation.

In recent years, with the growing population of people swarmed into urban city, supercapacitor tram has been a promising candidate for the current urban rail transportation. However, the series-connection of cells will typically lead to the cell imbalance and dispersion because of the different individual cell properties such as capacitance, internal resistance, self-discharge rate, and environmental conditions. In this paper, a voltage equalization scheme based on an advanced isolated converter topology that utilizes a multi-winding transformer is proposed for onboard supercapacitors of catenary-free trams. Voltage equalization is essential for series-connected supercapacitors in the energy storage system because of the system sustainability and maximizes the available storage energy. An equalizer algorithm based on sliding mode observer is designed. The balancing approach provides both excellent performance and good reliability. Analysis and experiment results are provided to illustrate the effectiveness of the design.

–Ultracapacitors are novel energy storage devices with high power density and long cycle life. For practical applications, numerous ultracapacitor monomers need to be connected in series or parallel to form modules, in which the voltage imbalance among monomers induced by technological parameter dispersion would damage ultracapacitors. It is an important issue to achieve the voltage balance with lower energy cost. Instead of designing cell balancing systems to minimize the voltage imbalance, this paper proposes a method for optimized ultracapacitor permutation and combination using Rejected Monte Carlo algorithm. This method not only reduces voltage difference, but also decreases balancing current and energy loss of the equalization circuit. Simulation results are provided to illustrate the effectiveness of the proposed method.

Reliable parameters information is of great importance for on-board energy management and optimal power control. In this paper, we applies the online strategy of multi-forgetting factor recursive least square algorithm to identify parameters of first-order dynamic model through cyclic operating current. The output voltage of the identified model shows a good agreement with the experimental results, and the results of comparison with curve fitting method highlight the proposed method has great accuracy and convergence.

Memristor has attracted extensive attention in recent years because of its capability to act as artificial synapse in neuromorphic network. In this paper, by combining a designed memristive synapse and a resistive synapse, a novel neural network circuit with three neurons and one operational module has been constructed. With the memristor device whose resistance can be purposely changed according to the time interval between pre- and post-spikes, the weight of the memristive synapse that connected between two neurons can be modified as required. What's more, the transmission of signal from pre-neuron to post-neuron and the adjustment of memristive resistance were carried out alternately through the coordination of different modules. Finally, the neural network simulated the Pavlov's experiment successfully, indicating that it can realize the process of associative learning and forgetting.

This paper designs a vertical-interconnect transmission structure which could be applied in PoP(Package on Package) package structure. In this model, Through Mold Via(TMV) transmission structure is utilized to realize inter-side and stacked-model interconnection. A quasi-coaxial via cluster connected to the strip line is designed for vertical RF transmission. It was found that the center distance between core via and shielding vias and diameter of those vias have great influence on performance of the transmission structure, which requires optimization specifically. The optimized size of this interconnection structure is 4mm×4mm×4mm based on ANSYS HFSS. The simulation results show a good performance of S-parameters in a large bandwidth from 1GHz to 6GHz, which verifies the prospects of its application in RF-front PoP structure.

This paper presents a new method for extracting urban roadside trees automatically from mobile laser scanning point clouds. This method mainly includes three steps. First, ground point clouds are removed by voxel-based upward growing method. Second, Euclidean distance segment method is used to cluster non-ground point clouds into certain individual objects. Then crown seeds of the initial layer is found by comparing the number of points in each layer after using the voxel modeling algorithm. Crown seeds in other layers can thereafter be detected via the upward inter-sectional analysis. Third, a crown voxel growing algorithm is used to make the crown grow in horizontal. The experimental results show that the voxel models of the individual roadside trees can be automatically and effectively extracted with our method.

Storing and retrieving problem for assembly blocks in a ship block stockyard is an important operational problem in shipyards. It affects not only the operation efficiency of stockyard but also the productivity and coordination of workshops. This paper formulates a mathematical model with the purpose of reducing unproductive moves in a stockyard. A heuristic approach is proposed combining a relocating strategy based on Tabu search structure.

In this paper, sliding mode control is designed as the controller for railway vehicle braking systems and a novel estimator is introduced to estimate the immeasurable adhesion force torque, which is based on the locomotive wheel model and a proportional integral control. Then value of adhesion force can be achieved by a simple division transformation of the estimated adhesion force torque. The value of adhesion force calculated from the estimation of adhesion force torque has three benefits. Due to the accuracy of estimated adhesion force, it can be used to calculate the reference speed and used as a necessary parameter of controller. What's more, it can be used as an input of the algorithm for calculating the optimal slip rate, which lays the foundation for future research. The simulation verifies the performance of the proposed estimator.

The Pantograph-Catenary system(PAC) is the most crucial and vulnerable part in the high-speed train. During the high-speed movement of locomotive, the conventional passive control would cause various malfunction of the PAC system. Because the passive control does not have sufficient ability to avoid the dynamic variation of the contact force between carbon-plate and catenary wire. Therefore, this paper considers the optimal reference-tracking active control algorithm based on explicit model predictive control (EMPC) to stabilize the contact force of PAC and set it precisely for which there exists experimentally validated model. Firstly, the nonlinear model of pantograph with one pair of ON/OFF valves is deduced to describe the correspondence between cylinder pressure and contact force. Secondly, the process of an offline computation for the state-space approximate optimal linear affine is presented. Finally, the EMPC based on the linear affine is designed. Then, the simulation and experiment result are illustrated to prove the effectiveness of the design.

Power selling by electronic management has still not been realized in the power system. Especially, smart payment terminal of state grid lacked a variety of payment means, and the users mainly paid the fees by cash. Inevitably, there were some security problems and human error in the process of reconciliation. Currently, there were some operation regulations in the management system, as well as there was lack of technological control means. Hence, it is easy to result in the loopholes in the operation business management, and then causing loss for power work. This paper put forward a new design for authentication technology in the payment terminal. Namely, the existing USB key was combined with the payment terminal, the PIN code of USB key hardware was used to execute login authentication, as well as the encryption chip of USB key was used for encryption and decryption of conversation. Simultaneously, SM2 encryption algorithm also has the authentication function, which can ensure the security of power enterprise reconciliation.

This paper proposes a synchronization control strategy based on voltage-controlled inverter and the synchronous speed is controllable. The proposed inverter can be simplified as a circuit consists of a controlled voltage source and equivalent impedance, the output voltage amplitude and frequency can be changed by adjusting the axial-regulators. The designed synchronization method has detection module and regulation module to regulate the synchronous speed. As impulse current and harmonic contents have relationships with the synchronous speed, this paper would analysis the relationships and find a suitable range of the speed.

Current sensing technology is regarded as the foundation of condition monitoring and diagnosis for power equipment. In this paper, a novel current transducer based on discrete Rogowski coils with the advantages of high precision, miniature and mass production has been researched in detail. For structural features of discrete Rogowski coils, the mutual inductance between the measured conductor and the coils has been deduced by magnetic vector potential method, and the correctness of this method has been verified by finite element method. Then, the influences of section parameters, incline and eccentricity to measurement accuracy of discrete Rogowski coil have been analyzed by Matlab software, which provides a reference for engineering application. Finally, the tests of discrete Rogowski coil have been carried out. According to the test results, the current transducer based on discrete Rogowski coils has a linear sensitivity and can be consistent with the result of magnetic vector potential method. Through interference test, the influence to measurement produced by the external current-carrying conductor has been investigated and compared with the analytical results.

It is very important for railway vehicles to have a good braking performance to avoid the phenomenon of idling and skidding, which can be implemented by looking for and keeping an optimal slip ratio. The optimal slip ratio is a value existing in the creep zone of functions between friction coefficient and slip ratio corresponding to the maximum adhesion. Controller based on the sliding mode control needs to be entered an reference slip ratio which can be used to find out the optimal control by the designer and can be tracked by actual slip ratio by the controller. Moreover, as an indispensable factor for calculating slip ratio, vehicle velocity is estimated by the proposed algorithm based on locomotive dynamic model. Then the optimal control ensures the actual slip ratio is equal to or close to the best reference slip ratio generated by extremum seeking algorithm dynamically. According to those functions, the optimal slip ratio changes dynamically once the pavement behavior changes. The simulation result demonstrates that compared with constant reference slip ratios, the proposed dynamical seeking algorithm for optimal reference slip ratio achieves the effect of real-time adjustment for braking torque, which prevents the brake torque from being too large or small and guarantees the braking performance.

In order to realize the coordinating and stable gait control for quadruped robot, this paper presents a hierarchical distributed controller structure of CPG by studying CPG-based gait control. The two output modes of the CPG network based on Kimura model are compared, and the waveform characteristics under different parameters and its effect in the practical application on gait are analyzed. Using neuron state output model to build the network connection between the CPG and joint oscillator and quadruped robot rhythmic crawl gait is realized with mapping function. Experiment results show that the controller structure can achieve coordinating crawl gait for quadruped robot and has a good control stability.

The electricity power supply company has entered the era of market economy as the deepening of reform, and the pressure to run the company well is increasing gradually. However, some questions, such as malicious default, electricity bills evasion, electricity cheat, and so on, still have not been solved. How to effectively avoid the arrearage risk and improve the economic benefit is key for the enterprises. This paper mainly studied the power users credit rating evaluation based on big data. This system proposed a new algorithm model which combined traditional k-Nearest Neighbor (KNN) and Simulated annealing (SA) and used the big data software framework and data processing technology to rapid construct the users portrait as well as evaluate the users rating and credit rating division, evaluation, and so on. Finally, the results were presented and then laid a good foundation for the researches in future.

The high-speed train is typically powered by the catenary wire suspended from poles or towers along the rail. An important issue of the high-speed train's power supply is how to set the precise contact force between the pantograph and catenary wires in real time. It is not a trivial task to investigate the pantograph-catenary contact force regulation in engineering practice since the model of a pantograph cylinder is nonlinear and time-varying with dead zone and time delays. In this paper, we propose an adaptive extremum seeking based contact force control strategy for pantograph-catenary systems. The contact force can be regulated in real time without any knowledge of the pantograph cylinder model. Both simulation and experiment results are provided to illustrate the effectiveness of the design.

Ultracapacitors have been supplied as main power in urban rail vehicle due to their characteristic of high efficiency. Given the model complexity and hard constraints of the ultracapacitors, the charging current control of ultracapacitors under this condition is challenging as fast charging is required. In this paper, an on-line fast model predictive control is proposed to address the problem based on extended interior-point method. By utilizing fixed barrier parameter and warm start mechanisms, the on-line fast MPC substantially simplifies the solving process and regulates the charging current of ultracapacitors rapidly and precisely. Meanwhile, a Kalman filter is integrated to estimate the system states and to adapt the load uncertainty. Experiment results are presented to demonstrate the effectiveness of the proposed control method.

In this paper, a novel three-phase 12/10 switched reluctance motor(SRM) is investigated. For the conventional 12/10 SRM, the motor has six phases. However, by means of shifting stator pole, the motor has some advantageous characteristic with three phases and short flux path. This is good for increasing the output torque and reduction in cost. Therefore, firstly, the basic structure and principle are introduced. Furthermore, the characteristic analysis such as inductance and torque are implemented through finite element method. In the meanwhile, in order to verify the performance, one prototype motor is designed in comparison with conventional 12/10 SRM. The results show that the proposed motor offers better performances.

In this paper, the core loss characteristic of a novel bearingless switched reluctance motor is investigated. Firstly, the basic structure and principle of the proposed motor is presented. Furthermore, a core loss model is introduced in which flux density waveforms in the different parts of the motor are predicted by means of finite element analysis. The effect of control system on the core loss is also considered. Thirdly, the improved stein Metz equation is used for core loss calculation. Finally, the influences of the main parameters of the motor iron loss were analyzed.

In order to solve the coupling problem between torque and suspending force control in the conventional bearingless switched reluctance motor, a novel permanent magnet biased bearingless switched reluctance motor structure is proposed in this paper. Its configuration and working principle are introduced. In order to explain advantages of proposed structure, conventional structures are also compared. Further, basic design method for proposed structure and mathematic model for suspending force are described. Finite element method (FEM) is employed to get characteristic profiles. Based on the analysis, a prototype motor is designed and manufactured. Finally, validity of proposed structure is verified by the experimental results.

The extraction of vegetation cover information has significance for watershed resource and environmental quality assessment, management and development, and sustainable development. This paper extracts the vegetation fraction using the 2009 TM image data of the Yiluo River Basin, based on the dimidiate pixel model. Vegetation fraction is divided into five categories from low to high in order to study the spatial variation of vegetation cover situation. The results show that the basin's vegetation cover is good overall, with an average 60%. High value region of vegetation cover is located in Luanchuan, and near Bear Ear Mountain, and the southern of Luonan County. The low value region is located in Song County and the River part of Luoning County. The area of vegetation's fraction is greater than 80%, and accounts for 57% of the entire study area, mainly concentrated in the Luhun reservoir to Luoning County. Less than 20% accounts for less than 5%, and mainly along both sides of the rivers, Luonan County and Luoyang City. The results will provide the basis for regional development and controlling.

Entrepreneurship education is a necessary requirement and an important training target for college students. In China, college entrepreneurship education just starts, so there are still lots of parts needed to be improved. What the main problem exists is that college entrepreneurship education lacks a set of training mode. This paper gives the concept of college entrepreneurship education and its training target. Besides, it establishes a “four-in-one” training mode of college entrepreneurship education. This research provides a scientific reference for the establishment and improvement of college entrepreneurship education, which is important in the process of it.

Graphene is ideally suited to electrochemistry by virtue of its high surface area and impressive electronic properties. Nitrogen incorporation can be used to tailor the properties of graphene. Here we present a simple solvothermal technique to produce a nitrogen-containing foam-like macroporous graphene powder doped with up to 15 wt% nitrogen. This is applied as an effective non-precious, metal-free electrochemical catalyst for oxygen reduction in acid media.