Earticle

Accuracy of designing and producing a micro-force measuring device is 0.1μN, through the device, the maximum supporting force of living water striders sample and their legs were measured. The results showed that the maximum supporting force of living water striders is 23.6 times its weight, the maximum supporting force of living water striders greater than the sum of six legs, the reason that living water strider’s chest and abdomen touched water surface on process of measuring; Established supporting force model of water strider leg, analyzed the factors associated with supporting force, the key parameters are the water strider leg length and depth of water dimple; Compared the water strider leg’s the maximum supporting force of the measurement value and the calculated value according to theoretical model, verified the correctness of the supporting force model.

RFID (Radio-Frequency Identification) tags have been widely used because of convenience. These conveniences which RFID has made the RFID tag become a tool to certify him or herself. The RFID tags, which have the function to easily prove ownership, are mainly used to prove one’s financial assets such as credit card or bus card passes. However, due to its ease of use to prove one’s assets, RFID tag has lots of vulnerabilities. Nowadays the vulnerability of rechargeable RFID cards has become an issue. This paper researches about the vulnerabilities of existing RFID tags and suggests countermeasures.

Multisensor distributed information fusion white noise wiener deconvolution estimator is presented in this paper. The algorithm is using the modern time series analysis method and white noise estimator under the linear minimum variance optimal fusion criterion. Gevers-Wouters (G-W) algorithm are also used in this paper. This paper presents information fusion algorithm including scalar weighted and covariance intersection fusion. The algorithm analyzes the relationship between the accuracy and the computation of the two fusion algorithm. The formula of optimal weighting coefficients is given. Compared with the single sensor case, the accuracy of the fused filter is greatly improved. It can be applied to signal processing in oil seismic exploration, communication and other fields. A simulation example for information fusion Bernoulli-Gaussian white noise deconvolution filter shows its correctness and effectiveness.

Based on large-scale wind power base of our country, the modeling and solving for multi-objective reactive power optimization of large-scale wind power integration are studied. To make sure of the hierarchical and regional balance of reactive power under normal circumstances and to have the power of supporting the safety of the grid in case of emergency, a solving thinking presents that capacitor switching and transformer tap adjusting and other discrete equipments are first, and the action sequence of generator and dynamic reactive power devices and other continuous equipments setting follows, which is presented that optimization problem is decomposed into continuous variable optimization and discrete variable optimization. The genetic algorithm is presented for finding global optimal solution. The coding of control variables and strategies for the cross and mutation operation are mainly studied, and determine each objective weight of multi-objective optimization. Case studies show that the proposed thinking is reasonable.

As GPS technology has been developed with other mobile communications, GPS function is essentially loaded on mobile devices including smartphone and tablet PC. Thus, users can exchange information based on the current location of the GPS through the application service such as path-finding and current velocity. However, since it is difficult to identify accurate means of transportation of a user, there is limitation on providing high-quality service and information. For instance, it causes unnecessary data consumption that providing unnecessary traffic information to a user walking or riding city rails.

In this paper, we present a novel method in fault diagnosis of rolling bearing based on time-frequency feature parameters and wavelet neural network. First, the time feature parameters are extracted from the vibration signal. Then the empirical mode decomposition (EMD) is used to decompose the signals of rolling bearings into a number of intrinsic mode functions (IMFs), and then the IMF energy-torques could be calculated through the vibration signal. Finally, those time-frequency feature parameters are taken as fault samples to train wavelet neural network (WNN)．The analysis results from the experimental show that the time- frequency feature parameters and WNN is effective in rolling bearing fault diagnosis. This paper provides the theoretical foundation for fault diagnosis in rotary machines.

According to the statistics of the national police agency, children are accounted for the high percentage of the reports about damage from the crime of kidnapping. Child protection means all types of services and programs that society or adults can do for children in order to promote their healthy growth and development process. The balance and harmony in surveillance and privacy protection is one of today's sensitive issues. Current CCTV is permitted on the premise of the clear notification, when used in the legal purposes of policing, security, transportation, and etc. In this paper, for the prevention of child-related crime, wide-area surveillance cameras and PTZ cameras with high magnification were used in schools, apartments, and playgrounds. The system tracking and monitoring abnormal face using the AdaBoost algorithm was proposed. In the method for detecting abnormal face by the use of methods to move the center of the whole image, 95.5% of the abnormal facial recognition rate and the average speed of 17 frames of abnormal facial recognition were obtained. It is considered that this system will help prevent crime through the detection and tracking the faces of intelligent offenders who are emerging as a serious social problem.

Due to the line impedance impact on islanded low-voltage microgrids, traditional droop control cannot guarantee the proper power sharing between distributed generation (DG) units. In the meanwhile, droop control would cause voltage and frequency deviation, which will influence the power quality of customers. This paper proposed an enhanced droop control scheme with autonomous frequency restoration control. Reactive power sharing problem is solved by adding a redesigned virtual impedance and voltage compensation loop, which ensures PCC voltage in nominal range. To the problem of frequency deviation, autonomous frequency restoration loop is added. Small signal model of frequency control is established to analyze the stability. In circumstance of frequent load switching, the frequency can properly restore to nominal value, with smooth and stable transient process. The simulation results demonstrate the effectiveness of the proposed control strategy.

Acoustic Emission (AE) technique can successfully applied for condition monitoring of low speed rotating components such as rolling bearing and gearbox of Wind Turbines. This technique is able to detect very small energy released rates from incipient defect in a very early stage. Wide range of signal processing methods can be apply for diagnosing faults and fatigues in AE spectrums and the changes in wave forms are very significant to recognize the failures. Condition monitoring and Fault identification (CMFI) of wind turbine health using automated failure detection algorithms can improve turbine reliability. AE testing is based condition monitoring system uses data already collected at the wind turbine controller. It is an effective way to monitor wind turbines for early warning of failures and performance issues. CMFI methods are classified into model-based and signal-based methods. They can be implemented with or without the use of artificial intelligence. The object of this thesis is to design a model-based CMFI scheme for WTs, which can be used under normal operation conditions.

Under the situation that existing information protection systems adopt an approach that tackles malicious codes based on already known signatures or analyzed behavior/feature, they are limited in detecting and identifying the unknown and the deformation of the malicious code. The present study, as a means of overcoming such a shortcoming, proposes a way of endpoint application control capable of more securely protecting endpoint devices (PCs) from intrusion of malicious codes and attacks through exploitation of an application or operating system vulnerability, by implementing a hybrid of technology such as whitelist-based application execution control via authentication of integrity, media access control, prevention of modification of important files, and control over IP/port attempting for process access or reverse link.

A new axial vacuum dynamic sealing technology for rough surface, sliding dynamic sealing, is proposed, for the realization of well as the affecting factors. The conclusions that if the conditions are suitable, it is easy to realize the seal’s rolling and sliding movement, and axial vacuum dynamic seal on cpartial vacuum chamber in hot-rolled pipe with continuous and efficient plasma descaling process. Based on simplified sealing model, the paper studies preliminarily this sealing mechanism, discusses the conditions of the seal implementation at the entrance and exit of the partial vacuum chamber, asertain rough surface can be achieved.

In this paper, we designed a serial programming interface (SPI) suitable for embedded systems, especially for Bluetooth baseband. Proposed architecture is compatible for the APB bus in AMBA bus architecture. The 8-bit design of the SPI module is in charge of transferring the data and the instructions between the external devices and the coprocessors. We adopted the cyclic redundancy check method for the error correction. Also, we provided the interface for multimedia cards. The designed SPI module was automatically synthesized, placed, and routed. Implementation was performed through the Altera FPGA and well operated at 25MHz clock frequency.

Switched reluctance motor is a new type of AC speed-adjustable system with high application value; it has lots of advantages such as simple structure, consistence and durability, low cost, wide speed range and prominent fault-tolerant ability. However, it also has obvious defects such as torque ripple and vibrating noise. By researching the related references at home and abroad, the mechanism, advantages and disadvantages of those control strategies are introduced and analyzed detailed in this article, moreover, the future trend of development in the research direction is also prospected.

In this paper, a modified form of the most efficient resonant LLC series parallel converter configuration (SPRC) is proposed. The proposed system comprises of an additional LC circuit synchronized along with the existing resonant tank of LLC configuration (LLC-LC configuration). With the development of power electronics devices, resonant converters have been proved to be more efficient than conventional converters as they employ soft switching technique. Among the three basic configurations of resonant converter, Series Resonant Converter (SRC), Parallel Resonant Converter (PRC) and Series Parallel Resonant Converter, the LLC configuration under SPRC is proved to be most efficient providing narrow switching frequency range for wide range of load variation, improved efficiency and providing ZVS capability even at no load. The modified LLC configuration i.e., LLC-LC configuration offers better efficiency as well as better output voltage and gain. The efficiency tends to increase with increase in input voltage and hence these are suitable for high input voltage operation. In this paper, LLC topology of SPRC and a modified LLC topology (LLC-LC) of SPRC for the closed loop control of a BLDC motor are simulated and their performances are compared and analyzed.

With the rapid and bursting development of computer and control science, research on iterative learning control system is a hot topic. Random delays of control and measurement signals during transmission over wireless network seriously affect the convergence performance of iterative learning control (ILC) systems. System based on step random delay model, the transfer matrix is derived, which contains random delay impact factor. For different cases of random delay, characteristic value and other elements of the shifting of the lower triangular matrix are analyzed respectively determine the rate of convergence and strong convergence. Analysis shows that the convergence speed is reduced, robust convergence have also been affected. Especially, the impact of control signal delays on robust convergence is greater than that of measurement signal delays. Simulation results are provided to demonstrate correctness of the conclusion. Finally, some potential improvement of proposed method is pointed out.

Over the years, air traffic has continued to increase. The development of modern systems has made it possible to cope with this increase, whilst maintaining the necessary level of safety. The Traffic Alert and Collision Avoidance System (TCAS) has been developped to reduce the risk of mid-air collision and is currently mandated on all large transport aircraft This system is based on interrogations to determine the altitude and relative positions of nearby aircraft. Despite technical advances in ATC systems, there are cases when the separation provision fails due to a human or technical error. Any separation provision failures may result in an increased risk of a midair collision. These systems would generate a high rate of unnecessary alarms especially in dense terminal areas and pilots become stressed and wrong actions can be made. A new design of TCAS is investigated in this paper to compensate for any limitations of ATC performance and decrease the rate of unnecessary alerts. It is based on transmitting altitudes and GPS coordinates between aircraft transponders to determine the accurate positions and directions of movement of nearby aircraft.

Electrochemical machining (ECM) is a method based on electrochemical process for removing metals in mass productions. In this research, cartridge house inner cavity ECM of a gun barrel, with three deep cavity, is analyzed. So that, according to the various set ups, the optimized machining parameters are obtained. The comparison between ECM and conventional methods from this point of view, shows good advantages of this method, so that, the machining efficiency is more than 15 times less and with very high-surface quality. Besides, the dimensional accuracy of the workpiece repeatability process in this machining method is noticeable. Experimental results indicate that Inner cavity of gun barrel chamber with high precision can be easily done by ECM method.

The objective of this work is to propose two new algorithms for collision detection for real-time application. They are applicable to rigid objects enclosed in boxes in order to improve the time of collision detection. The proposed algorithms, called Neuro-SAT and perceptron learning with displacement of the base frame, will be compared with the algorithm Separating Axis Test (SAT) based on the hierarchy of the OBB tree. A grasping operation of an object, with a robotic hand, was executed to test the developed algorithms. The results, of simulation experiments, reveal a great improvement in the time of collision detection.

Multisensor distributed information fusion state estimator is presented in this paper. The algorithm deals with descriptor and non descriptor discrete time time-invariant stochastic linear system which is described by state space model. Under the assumption of the observability of the system, the state of the system is a linear combination of input white noise, observation white noise and observation signal. Further non-recursive state estimators algorithm is presented, which can be computed by the white noise estimators and measurement predictor. In order to improve the accuracy of the state estimator, this paper presents information fusion algorithm including matrix weighted, diagonal matrices weighted, scalar weighted and covariance intersection fusion, in the sense of linear minimum variance. The formula of optimal weighting coefficients is given. The algorithm analyzes the relationship between the accuracy and the computation of the four fusion algorithm. A simulation example for non descriptor system with 3 sensors shows its correctness and effectiveness.

This paper considers the cooperative control of a group of autonomous underactuated vessels (AUV). The control objective for each vessel is to maintain its position in the formation while Formation Reference Point (FRP) tracks a predefined spatial path. In order to achieve this goal, we use vectorial backstepping to solve two subproblems: one is geometric task, anther is dynamic task. The former guarantees that the FRP tracks the spatial path, while the later ensures accurate speed control along the path. A dynamic guidance system with feedback from the state of all AUV ensures that they have the same priority (no leader) when moving along the path. The controller is proposed basically based on Lyapunov direct method and backstepping technique. Simulation results are presented and discussed.

Data Aggregation Scheduling in Ubiquitous sensor networks is a major research interest for many researchers with the objective of reducing energy consumption and maximizing the network lifetime. Also the capacity of a channel for transmitting quantum states called the quantum capacity should be maximized,The sensor nodes should periodically forward data to the base station. Since battery power and bandwidth are the two resources to be effectively utilized the sensor nodes forwards data to the nearest neighbor node which inturn forwards the data to its neighbors and this repeats until all the sensors data aggregates at the base station. In a large network scheduling the sensor nodes for forwarding the data is very much essential and since the topology of the USN changes dynamically , finding such a schedule is also very difficult. In [1] the authors proposed a bosonic network model for communication. In this paper we present a quantum bosonic data aggregation method for constructing the optimal schedule of nodes for data aggregation called QBDAS (Quantum Boson Data aggregation scheduling) protocol. The main idea is to search a optimal schedule through utilizing the observable or measurable physical properties the network topology.

Wireless Underground Sensor Networks (WUSN) have the potential to impact a wide variety of novel applications including intelligent irrigation, soil information monitoring, etc, the internet of tings for water-saving agriculture. WUSN consist of wireless devices that operate below the ground surface. These devices are buried completely under dense soil. The main difference between WUSN and the terrestrial wireless sensor network is the communication medium. This work provides an extensive overview of the research and application situations in agricultural internet of things for WUSN. The water-saving agricultural internet of things based on WUSN architecture is developed. Here, the main research for the underground communication channel including methods for predicting signal losses in an underground link. Based on the test model, research tests and results are discussed.

This paper presents the applications of dependency of attributes in information systems for data mining from business datasets. Firstly, we present the theoretical framework for data clustering on small business dataset. It is based on a construction of a hierarchical rough set approximation in an information system for data splitting. The hierarchy is defined by the notion of a nested sequence of indiscernibility relations that can be defined from the dependency of attributes. Secondly, an application of such hierarchy for mining maximal association from a business transactional data is presented. It is shown that the dependency provides clear and provable theoretical approach for data clustering and maximal association rules mining.

Determination of mutual inductance in the WPT system based on the electromagnetic coupling mode is crucial for system design and efficiency optimization. The analytic formulas and experimental methods which only aim at a coupling coil with a certain type of configuration and parameters are not universal approaches. Therefore they can’t serve as a design basis for the system optimization. This paper presents a novel method based on 3D field and circuit coupling analysis to calculate mutual inductance of coupling coils with arbitrary spatial distribution for WPT system. The method can obtain maximum efficiency under the condition that the spatial distribution of coupling coils are irregular and restrained in actual physical systems. The method has made a breakthrough and provided a powerful tool for the design and optimization of electromagnetic coupling power transmission system.

In the paper,We can prepare the PANI in different conditions of acid (HCl, HNO3, H2SO4 and C7H6O6S · 2H2O) by using aniline monomercc chemical oxidative polymerization.With the test of scanning electron microscopy (SEM) ,it shows that the powder of preparation is nanoscale particles, and the size of particle is in the order of tens to hundreds of nanometers. It has good dispersion, but the particle size is nonuniform; With differential thermogravimetric analyzer (DTA) test ,we can obtain the properties of powder in temperature of thermal decomposition and stability. At the room temperature, we test the sensitivity of gas for the ammonia concentration range of 1-7ppm. The result shows that, in different conditions of acids (HCl, HNO3, H2SO4 and C7H6O6S · 2H2O) ,the relationship of sensitivity of gas sensor is linear in response to ammonia gas.With the analysis of the sensitive mechanism for ammonia gas of PANI material,ultimately, we can concluded that, in different conditions of acid, doped PANI materials are suitable to be detected for ammonia in a wide concentration range, the recovery time of response to ammonia gas is shorter and more stabile for the larger organo functional proton acid (C7H6O6S · 2H2O).

IR-UWB has been developed as a standard of indoor ranging technology because it has robust and good transmission characteristics in indoor environments and it can be operated with low power. In this paper, an IR-UWB MAC packet analyzer and a MAC test suite are designed and implemented based on IEEE 802.15.4a, which are useful in developing IR-UWB real time location systems with a resolution of a few ten centimeters. A sniffer device of the packet analyzer monitors IR-UWB wireless networks, captures MAC packet frames, and transmits packet frames to the packet analyzing computer. The packet analyzing program in a computer analyzes received MAC packet frames and displays parsed packet information for developing engineers. The MAC test suite serves as a role of higher layer for testing IR-UWB MAC functions one by one. Developed MAC development tools are used to analyze IEEE 802.15.4a MAC protocol, and it can also be used in other IEEE 802 series MAC protocol by modifying some functions.

In order to gain more information reflecting bridge health status, with fewer sensors, a method based on artificial fish swarm algorithm (AFSA) is proposed to solve optimal sensor placement (OSP) problem. The algorithm takes modal assurance criterion (MAC) matrix obtained from modal analysis of an arch bridge structure as the objective function. Four typical behaviors of artificial fish are applied to search the optimal solution. The results show that AFSA is more effective than the particle swarm optimization (PSO) method, in achieving optimal sensor placement.

Proposes a three-phase four-wire APF with four-leg topology based on one-cycle control. Main circuit adopts three-phase four-leg power topology. The fourth bridge arm connects to the zero line, which can inhibit the system zero sequence current. This topology is suitable for high power balanced and unbalanced load. Applying one-cycle control strategy, compares with the traditional control method of APF, it has advantages, such as fast dynamic response, strong anti-interference ability and so on. Meanwhile, the circuit structure is simple, low cost and easy to implement. Simulation and experimental results show one-cycle control with three-phase four-leg APF can effectively compensate harmonic, zero sequence and reactive current.