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Ethernet is one of the most widely-deployed and utilized local-loop networking technology across the world, and IEEE 802.3az working group has confirmed EEE(Energy Efficient Ethernet) standard proposal based on LPI (Low Power Idle) mode. This paper suggests Synchronizing Adaptive LPI Control Mechanism in a bid to improve the energy efficiency between interfacing terminals on Ethernet network and the Ethernet switches. This mechanism determines ON and OFF durations of consecutive cycles based on the measured incoming traffic quantities from the terminals. It keeps transferring cycle information which is the most proximate to the traffic bursting cycles while resting in idle is left to LPI mode by conveying the corresponding information to the switch. This paper conducts the performance evaluations with simulations on Poisson distribution traffic and burst traffic. The result has shown that the suggested mechanism in this paper improves the overall performance by reducing the energy consumption rate compared to the existing mechanism, keeping the average packet delay to the similar state as before.

In this work, a defected microstrip structure (DMS), methods to calculate the new characteristic impedance of DMS line, and, as an application example, a design of microwave wilkinson power dividers using DMS pattern are described. DMS patterns are inserted for the desirable effects of periodic structure such as size-reduction and increased line width for high characteristic impedance. In order to calculate the proper characteristic impedance of DMS microstrip line, the quarter-wavelength transformer model method and an analytic calculation method are adopted. As an example, the DMS microstrip line with 70.7 characteristic impedance is designed, calculated and inserted into the wilkinson power divider. The size of designed power divider with DMS patterns is only 82% of a reference power divider composed of normal microstrip lines, while the circuit performances are very well preserved even after the size-reduction.

Aimed at the deficiency of existing modeling method of traffic guidance system based on Multi-Agent, the advantage of Unified Modeling Language (UML) and Hierarchical Colored Petri Nets (HCPN) is combined to model the system. The modeling method using UML and HCPN is first put forward, and more UML diagrams are constructed so as to model the framework of traffic guidance systems. Moreover, the mapping rules from UML model to HCPN is set up, the formal model of traffic guidance system is gotten, and design error may be found by formal verification and validation of HCPN model. So UML model can be improved and correct UML model can be gotten.

In this paper, we show the design and contents on the developments of the apparatus for manufacturing the cargo box gate panel. This automation apparatus was developed to substitute for human labor. This is driven on the rail. After detecting the location of hinge and adjusting the drilling location by manual, the automation apparatus carries out drilling automatically. Multi axis drilling unit is used to get 3 holes with 1 operation at once. At recent manufacturing sites, the introduction of automation equipment is broadly being attempted for saving labor costs, alleviating work intensity, and improving productivity in various areas. As for the manufacturing factory for cargo box of large-sized trucks, the entire process depends on labor at this high-intensity manufacturing site. Especially, the gate fixing on both sides of the cargo box takes about 7 people who execute drilling and assembly. The purpose of this study is to design and produce such series of tasks which can be completed by two laborers. In this report, the apparatus and system design, control method to develop auto-drilling machine is introduced.

A mobile ad-hoc network (MANET) is a group of wireless mobile nodes that dynamically form a network without any pre-established infrastructure or centralized administration. Because of the limited communication range between mobile nodes in ad hoc networks, several network hops may be needed to deliver a packet from one node to another one in the wireless networks. To do this communication, a routing protocol is used to determine routes between these nodes. Unfortunately, the mobility of the nodes can cause the network to change rapidly resulting in an unpredictability of the routes between any two nodes. This is the central dilemma in mobile ad-hoc network routing because the links are not reliable and can fail anytime. In this article we explore the key design tradeoffs that need to be considered when designing mobile devices to operate in ad-hoc mode. In particular, we explore the performance impact several of routing protocols based on the mobility rate and number of active sources.

This paper presents a novel sensorless control method of permanent magnet synchronous motors at standstill and low speed based on a low-frequency current signal injection. The approach superimposes a persistent LF current signal into the estimated d-axis to get the rotor position error angle-related signal by detecting the corresponding voltage response and current response. Then the rotor position and motor speed are obtained. Theoretical analysis and simulation results demonstrate that the approach can achieve sensorless control of permanent magnet synchronous motors at zero and low speed, ensure good dynamic and static performances, and achieve effective control when applied to servo system. Finally, a test prototype system which used a digital signal processor and space vector pulse width modulation technology has been developed. Experimental results show that the system has better static, the effectiveness and dynamic performance of the adaptive test signals in a sensorless controlled surface-mounted permanent magnet synchronous machines.

The estimation of soil parameters of multilayer structure leads to useful information for designing a safe grounding system. This paper presents a nonlinear regression based estimation scheme to extract soil parameters from the kernel function of apparent earth resistivity. The kernel function of apparent earth resistivity can be obtained from the measured apparent earth resistivity data. The performance of the proposed method has been verified by carrying out a numerical example.

A generic simulator and data-driven generic simulation are widely used to reduce modeling efforts. The concept of a generic simulator includes the extracting and storage of the common parts of a domain. The common parts in semiconductor manufacturing simulation can be the scheduling logic and the operation rules of automated material handling systems, such as auto-guided vehicles or overhead hoist transfers. The execution of a simulation instance with pre-programmed common parts is triggered by providing the required data. Simulation analysts do not need to create separate simulation models unless special logic or operation rules not included in the common parts are considered. Emerging requirements for a generic simulator can be summarized as follows. For the best decisions, it is necessary to study every aspect of alternatives thoroughly. However, the volume of data increases significantly as the number of alternatives and variables associated with the data increases. Because previously introduced generic simulators have difficulties in handling large volumes of data, simulation analyses are often limited and not satisfactory. In addition, the statistical functions of commercial simulation packages used in semiconductor line modeling leave something to be desired. That is, they are not easy to use and not particularly powerful. This paper demonstrates an improved generic simulation framework with enhanced features. It is capable of handling large volumes of data, utilizing abundant statistical functions, and reducing the data preparation time. With the proposed framework, simulation analysts can reduce the simulation modeling time while exploring many alternatives with a powerful statistical analyzer and a rapid visualization tool. These features are expected to contribute to more efficient decision making. This research is a case study of a leading electronics company in South Korea.

Generally, a wind turbine may have inferior reactive power dynamic performance where constant power control is adopted by a wind farm equipped with doubly fed induction generators (DFIGs). As a result, power system disturbance may incur grid faults where the wind farm cannot provide enough reactive power to the grid. This paper proposes a novel reactive power control strategy with centralized management for a wind farm. The real-time signal representing the voltage at a specified remote location -- a point of common coupling (PCC), is taken into account as an increment of the given value of the reactive power before being transmitted into each wind turbine by the distributed communication networks. In order to implement real-time regulation with reactive power output to the entire wind farm, this signal is meanwhile fed into the control loop in the rotor-side converter. Considering the issue of widely geographical distribution for each individual wind turbine, this paper studies the impact of communication delay on the system performance. As simulation results showing, in both of the cases of grid faults and wind speed fluctuation, the system with this control strategy can provide reactive power complement and keep the bus voltage stable. By using frequency domain analysis, this research also explores that different delay time may result in control failure due to multi-frequency harmonic incurred in the cases of long-term delay.

In this paper, a LED smart lighting control system is developed for applying to poultry farms. There are disadvantages of the conventional system adjusting incandescent bulbs of illumination, of which energy efficiency is very low. In order to solve this drawback, a smart control system is applied to poultry farms. The proposed smart control system has several advantages as follows. First, the energy efficiency can be increased in comparison to the existing system. Secondly, the illumination control range can be increased. The maximum illumination is improved by 10 times more than that of the existing system and the calorific value inside the poultry house can be reduced. Furthermore, using the developed smart control system a farmer can control remotely his poultry farms through real-time monitoring with a personal computer and smart phone.

An environmental monitoring application is designed to monitor and track various kinds of environmental phenomena such as water pollution and global warming. By collecting detected sensor data from the sensors installed at a target place, a monitoring system analyzes and predicts an environmental change. For smoothly answering a user query, a data abstraction model is designed to rapidly process an amount of sensor data by employing data filtering, data aggregation, and data summarization. In order to dynamically represent the different layer of sensor data in a region, we design FLSA (Flexible Layered Sensor Data Abstraction), which supports a flexible layer of SGSA (Slope Grid for Sensor Data Abstraction). When the sensor data is transmitted to a server, FLSA make some clusters to shows several layer of sensor data depending on sensor data gradient. Each cell of FLSA has a set of SGSA to represent each sensor data layer in the cell. This layered SGSA of FLSA is useful to represent a distributed sensor data in a cell. When an abstraction model is used to environmental monitoring, there is a trade-off between faster data processing and data representation. FLSA focuses on data representation to show detailed condition of a target place.

Under frequency load shedding is widely used under emergency situations in the power system. It significantly ensures frequency stability of power system by dropping excessive loads at certain places. In order to improve the traditional UFLS schemes, the rate of frequency change is taken into consideration when calculating the quantity of active power imbalance in the power system. The measure factors of frequency change rate are analyzed and a new function is created to calculate the active power imbalance based on frequency and voltage. Moreover, a new method which utilizes frequency and voltage sensitivity to determine the location and corresponding quantity of load shedding is proposed. Voltage stability should be maintained at the time of recovering system frequency stability. The simulation results based on IEEE39 buses system show that the new self-adaptive scheme of load shedding is more reasonable and superior.

Server-less RFID systems are used more and more widespread recently, which allow RFID readers authenticating a specific tag without the help of on-line backend servers, it brings higher design requirements for RFID security protocols. In this paper, a mutual RFID authentication protocol and its corresponding serach ptotocol for server-less systems are proposed. The security properties of these protocols are analyzed as well by comparing with the related protocols.

In this paper, a sliding mode-PID control approach is proposed for free-floating space manipulator. Free-floating space manipulator has nonlinear dynamics and interactions between the manipulator and the spacecraft. In this paper, dynamic of space manipulator system is presented by dynamically equivalent manipulator (DEM) model. DEM is a fixed-base manipulator and its dynamics behavior under any control law is identical to dynamics behavior of space manipulator. Using sliding mode-PID control, sliding mode controller and PID controller properties are applied to the control system. In this case, high control gain leads to reduction of reaching time but increment of oscillation. Therefore fuzzy logic can be used as an intelligent approach in order to tune PID-like sliding surface gains. Simulation shows satisfactory results in tracking and error cancellation.

According to the Pseudo-random numbers for the end-hopping technique, an end-hopping communication model combined with Stream Cipher is established, then the key problems of the model are discussed. The model shows the communication based on the clocked nonlinear sequence use random hopping port, which could prevent hackers from seizing the hopping rules of port, and it is an effective way to secure the information. The work analyzes the security of the model , verifies the feasibility of the communications technology in theory, and the performance of the program is simulated.

The objective of this paper is to optimize the parameters of non-coherent detectors such as coherent and non-coherent integration number for various non-coherent detectors such as square law detector, linear detector and logarithmic detector in weibull clutter environment for Ultra Wide Band Short Range Radar in Automotive applications. The detection performance of the detectors is analyzed for fixed false alarm probability of 0.001 and simulation has been done in order to verify it.

Clustering is an efficient method adopted in various routing algorithms for wireless sensor networks. However, most clustering algorithms are not suitable for heterogeneous networks. In this paper, we propose a Density-based Energy-efficient Clustering Heterogeneous Algorithm (DECHA). In DECHA, we define the density of a node and together with its energy condition to adjust the probability for the candidate cluster head selection dynamically. Candidate cluster heads further evaluate the energy level of its neighbors and adjust to find more proper cluster heads. Moreover, we design an intra-cluster algorithm as well as a multi-hop inter-cluster routing algorithm. Simulation results show that cluster heads are properly deployed in a heterogeneous wireless sensor network. Compared with some popular algorithms, in our DECHA, the stability period and network lifetime and prolonged and total energy consumption is prominently reduced.

Dempster-Shafer Evidence Theory can infer the context only with some native sensed signals but its number of assumptions is limited, compared to the number of evidence. In this research, we proposed a method that can increase the number of sensors collecting symptoms for more dynamic contextual inference yet with reduced calculation load increase. This is possible by clustering sensors with relevance to a situation and fusing data hierarchically.

DGA (Dissolved Gas Analysis) is the traditional transformer fault diagnosis method, but it mainly depends on the experience of operators. In order to solve the limitations of traditional method, this paper introduces intelligent method for fault diagnosis of transformer. The intelligent method made fusion of various data, including SCADA data, oil dissolved gas sensor data, related electrical test data, operation maintenance records, and so on, employed space-time weighting fusion method based on BP neural network, and put forward the model of transformer fault diagnosis based on multi-source information fusion, which improved the accuracy of the transformer fault diagnosis dramatically.

The commonly used hardware verification languages, such as SystemVerilog have explicit coverage constructs which entitle verification engineers the power to model the function of design into coverage requirement. Verification Engineers usually subtract the functional coverage from their knowledge of the design requirements and map them into coverage points which can be expressed by hardware verification languages. However due to the limitation of syntax of these hardware verification languages, it is very hard in a reasonable way to specify the coverage points for the kind of module whose output is decided by scale-size relationship of its inputs. This paper presents a workaround to analyze the total effective scenarios for this kind of module. The paper also provides a method on how to model these effective scenarios with current syntax of hardware verification language.

Systems have recently performed multiple functions through a combination of several IPs. SystemVerilog has useful components for modeling and verification at System-level. The OOP of SysemVerilog supports only single inheritance in a verification environment based on a layered testbench of SystemVerilog. It is restricted to construct environment verification. SystemC is a language for system level design at multiple abstraction levels and supports multiple inheritance. We adopt SystemC to design components of a verification platform which employ multiple inheritance, and combine it with the SystemVerilog-based verification platform using SystemVerilog DPI and the ModelSim macro in this paper. Employing the multiple inheritance of SystemC makes the design of a verification environment simple and easy through code reusability. Another characteristic of OOP with SystemVerilog and SystemC is that it can create a reconfigurable verification platform.

Particle Swarm Optimization (PSO) algorithm is a new swarmed intelligent optimization technique, which has been widely used to solve various and complex optimization problems, but there are still premature, low precision, slow convergence phenomenon. We proposed an improved PSO based on update strategy of double extreme value by analyzing the updating ways of double extreme. Improved algorithm has good global searching capability through the classical test function, the new algorithm has solutions of high precision, fast convergence, and it is proved that the new algorithm is feasible and effective.

This paper introduces a kind of building steel automatic welding system and it adopts submerged arc welding to complete the welding. There are four processes in the welding, including arc, melting, extrusion and insulation, which are completed by the single chip C8051F021.To ensure the arc and melting processes are accomplished accurately, the voltage and current double closed loop is used to determine whether the arc ignition is success and the melting time are estimated by arc energy accumulation from real-time judgment. Using power devices IGBT, inverse variable technology and programming logic devices (PLD) to constitute a new type of arc welding inverse variable power source. Programming on the PLD with VHDL language and get PWM’s simulation waveform. The results show that the PWM waveform designed by VHDL has high control precision, flexible control, able to adjust the power switch tube dead time, effectively protect switch safety work, and improve the efficiency of welding.

With the wide application of probabilistic systems, the research of counterexample generation for probabilistic system with model checking has attracted wide attention. For counterexample of complex parametric system, proposes a counterexample generation algorithm for multiple until constraint formulae of probabilistic computation tree logic act on continuous time probabilistic model and gives another counterexample computation method based on automaton theory. At last, the example analysis is given. The theoretical analysis and example result show that the feasibility and validity of the method.

This paper presents an adaptive Takgi-Sugeno (T-S) fuzzy terminal sliding-function controller (AFTSFC) approach to synchronize two chaotic systems with parameter mismatch. First, an appropriate terminal sliding function (TSF) is designed and then represented by the T-S fuzzy model. The T-S fuzzy terminal sliding-function (FTSF) is applied to the control law. Different from classical terminal sliding mode control, which uses a discontinuous switching control law, the FTSF control uses a continuous control law and thus avoids the chattering problem. The linear matrix inequality (LMI) problem is solved to obtain the initial feedback control gain, and the adaptive law of the control gain is adapted online to estimate parametric mismatch. Based on the Lyapunov stability theory, the AFTSFC guarantees that the error of synchronization is uniformly ultimately bounded (UUB); i.e., the drive and response chaotic systems can be synchronized with only a small bounded error. The simulation results demonstrate that the proposed method is able to provide a satisfactory synchronization performance.

The authors propose approaches for computerized simulation of meshing of DCAPSBG (double circular-arc profile spiral bevel gear). Algorithms for TCA (Tooth Contact Analysis) computer programs were proposed. This paper presented the key contents and method of TCA computer programming. TCA is an effective tool for meshing analysis of the DCAPSBG, and it is the basis of load tooth contact analysis and finite element analysis. The proposed approach is based on the tooth profile characteristic of the DCAPSBG and developed by Visual Basic and MATLAB mixed programming method. In addition, this paper made TCA analysis and contact area check experiment on gear meshing, and the program had been verified by real examples. This provided an effective approach for the design of DCAPSBG.

Control moment gyroscope (CMG) is widely used as an actuator of spacecraft attitude control Micro-vibrations generated by CMG will influence the performance of high-sensitivity instruments on-board the spacecraft; however, the micro-vibrations characteristics of CMG are not yet clearly understood. This paper concentrates on testing and analyzing the micro-vibrations produced by CMG. Firstly, for the massive weight of CMG, it is impossible to remove the influence of testboard’s inherent characteristic on CMG’s vibration disturbance cannot be isolated with improving testboard stiffness. Hence, a rigid CMG model was developed and used in the control experiment for comparing the modal test results of the CMG model and prototype. Secondly, considering the natural frequency of CMG should be different according to the vitiation of its rigidity and mass distribution, a CMG start up dynamic test was implemented to calculate the working CMG natural frequency. Finally, a disturbing frequency test under multiple CMG gimbal angular speed was designed to calculate the influence from the CMG gimbal angular and its rotation speed and to further provide data for whole satellite CMG vibration disturbance analysis.

The model and control of a human forearm is analyzed. In this work, we study the problem of human hand control carrying a mass. The equation of motion and the natural frequency of the forearm for small angular displacement are derived. We develop new methods that use vector fields in the controller construction for a set of nonlinear dynamical systems. The paper deals with compensate of non-linear system which has a similar idea as the method mentioned in linear system. The nonlinear control design procedure, as in the case of linear systems, involves three steps. The first step is the devise of a state-feedback control law, the second step involves the design of a state estimator, and the third step merges the first two steps to obtain a collective controller–estimator compensator. We have managed to design a control law for the non-linear representation of a system, in such a way that the representation of a closed loop system is affine, controllable, and observable and a closed loop system is asymptotically stable. Throughout any motion, the forearm can be considered a one-link robot manipulator which could be exploited to benefit people with disabilities (missing extremities).

For the shortcoming that the PI controller parameters can’t been dynamic tuning in constant voltage control system of doubly-fed wind turbines, a PI controller parameters dynamic tuning strategy based on the ant colony optimization (ACO) algorithm is presented. This strategy makes the two parameters in PI controller as the ant of the ant colony, the controlled absolute error integral function that between terminal voltage actual value and its reference value for doubly-fed wind turbines is selected as the optimization objective, the PI controller parameters dynamically is adjusted in the control process. When the wind speed changes and the grid voltage drops, the dynamic and non-dynamic parameter tuning methods are compared and analyzed. The simulation results show that the constant voltage control system using the PI controller parameters tuning strategy based on the ant colony optimization algorithm is superior to non-dynamic tuning method on the stability and response time of system.

In the OFDM (Orthogonal Frequency Division Multiplexing) system, the fast synchronization is required which in general could be achieved using the preamble located in the header part of the data packet. The modulated and transmitted signal experiences the frequency selective fading due to the multipath channel. As the recent OFDM systems have been applied to the various application areas, the coverage increases which can be translated into the wide range of the signal power variation observed at the receiver side. To obtain the optimum signal level the gain control block at the receiver front-end should be capable of processing wider range of the signal power than the conventional systems. If the signal power is not controlled properly, the overall system performance is expected to be deteriorated due to the quantization errors generated in the process of the analog to digital signal conversion. Therefore it is required to control the received signal power at the optimum level. In this paper, the gain control block is implemented based on the FPGA (Field Programmable Gate Array) hardware. The implemented block adopts multiple gain steps which are optimized by using the statistical characteristics of the quantized signal at the ADC (Analog to Digital Converter) output. The proposed design is shown to provide the enhanced convergence speed and reduced processing time while the hardware complexity is increased marginally compared with the conventional system.