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Based on text chunking using HMM, transformation-based learning is made use of to improve the precision of chunk tags further. The training data and the test data are from Penn treebank 4.0, and 13 text chunks are used. Rules are learned automatically according to the rule templates. The precision is improved 4.48%. The detailed analysis that affects the text chunking is given. Different threshold,...
In this paper a low cost implementation of hybrid stepper motor controller and driver is presented. The controller incorporates an inexpensive microcontroller to perform chopper control, current feedback, adaptive ripple torque reduction based on the presented algorithm. The design uses current feedback to compensate torque ripples resulting from both motor structure and pulse commands issued from...
A PC-based fleldbus simulation platform has been designed to be used as a test-bed for distributed control systems development. The FBSIMU (Foundation Fieldbus Function Blocks Simulator) tool can be used for tests via real time procedures some fundamental aspects of distributed control network and smart transmitters. The full platform has been written using LabVlEW due to its graphical interface and...
Advances in metal rolling process automation and tightening quality standards result in a growing demand being placed on fault detection and diagnostics of electrical motors. Misalignment of motor or coupled load on motor shaft is one of the common causes, which creates most of the mechanical faults and leads to motor vibration. Although different algorithms are available for motor condition monitoring,...
The design and development of a software programmable data acquisition system is described here. The design based on sigma-delta ADCs and versatile microcontrollers enables the integration of signal conditioning and digitisation functions, high performance with respect to parameters such as accuracy and resolution and full software programmability of key channel specifications such as amplifier gain,...
Reviewing the direct current control of four-switch three-phase brushless DC motor (BLDCM), to reduce the system cost further and theoretically explore the system's operating mechanism in more depth, the paper put forward a single-current-sensor sliding mode driving strategy. The uniform mathematic equations of four-switch three-phase BLDCM were represented and six kinds of operating modes (model~model6)...
This paper deals with the voltage and frequency controller (VFC) for isolated asynchronous generator feeding 3-phase 4-wire loads for constant power applications such as pico hydro uncontrolled turbines. An AC capacitor bank is used to self excite and to meet the reactive power requirement of the asynchronous generator which is also known as self excited induction generator (SEIG). The proposed VFC...
This paper presents a servo system for linear X-Y table, which is driven by two permanent magnetic linear synchronous motors (PMLSMs), based on a TMS320F2812 DSP controller. In this proposed system, the fully digital servo controller for each PMLSM and the trajectory motion controller for X-Y table are all implemented by a DSP chip. That is, the detection of quadrature encoder pulse (QEP), coordinate...
This paper presents the generalized dynamic modeling of self-excited induction generator (SEIG) using state-space approach. The proposed dynamic model consists of induction generator, self-excitation capacitance and load model are expressed in stationary d-q reference frame with the actual saturation curve of the machine. An artificial neural network (ANN)-model is implemented to estimate the machine...
The increase of nonlinear loads connected to the power systems has created the need for a generalized revision of power concepts and quantities applicable under nonsinusoidal conditions. Parallel to this, changes in the existent standards and the new ones have shown the need for new measurement procedures. In this paper a simple algorithm for the IEEE 1459 single and three-phase quantities calculation...
This paper aims on the development of a non-contact method for measurement of straightness of the rods. The straightness of rod is a major concern in many industrial applications, especially, where rods are forcefully inserted in pipes by machines. If the rod is bent it may cause damage to the channel and the rod, which results in additional cost due to damage. This technique is based on transmitting...
Research into the problem of classification of radar returns from the ionosphere has been taken up as a challenging task for the neural networks (NNs). It appears from the literature review that for the Multi layer Perceptron (MLP) NN trained with backpropagation, reported average classification accuracy was about 96% on the test instances. This paper investigates and designs an optimal classifier...
Recent years have brought hope that driving support systems tailored to the characteristics of each driver can be developed. To accomplish this, a driver model must be constructed that considers the driver's psychological function when inferring driver behavior. This paper thus proposes a method to infer driver behavior by capturing time-series steering angle data at the time of lane change. The proposed...
This paper deals with detecting defects in a multistage gearbox. The gearbox is driven by an induction motor and the output shaft of the gearbox is connected to a DC generator and a DC tacho-generator. The ripple current and voltage signals supplied by these generators are analyzed for a defect-free gearbox and a defective gearbox with two teeth missing in a particular gear. Multiresolution Fourier...
Sensor fusion is a widely used strategy where the system-variables are unobservable. In this work a (back-propagation neural network) BPNN based sensor fusion model has been developed for tool-condition-monitoring (TCM) in flexible manufacturing applications (as a case study) and different performance improvement strategies have been incorporated with notes on generalized applicability to other sensor...
This paper demonstrates a robust autopilot design for a surface-to-surface skid-to-turn homing missile. The whole design has been carried out in two stages. Input-output feedback linearization(FBLC) has been proposed based on the highly nonlinear and nominal plant model. This control law, designed based on the nominal plant, does not handle the plant uncertainties associated with aerodynamic coefficients...
The photovoltaic generator exhibits a non-linear I-V characteristic and its maximum power point varies with solar insolation. In this paper, a single-phase single-stage inverter capable of tracking maximum power from the photovoltaic array and injecting a sinusoidal current to the load is presented. Mathematical models are formulated and then a tracking algorithm is evolved. Combined photovoltaic...
This paper presents the lagging and leading power factor operations, with near sinusoidal line currents, of the bidirectional buck-boost type improved power quality (IPQC) ac-dc converter that employs power MOSFET embedded four quadrant switches (4QSWs). The topology of the IPQC itself ensures variable bi-directional dc voltage and reversible current in both buck and boost modes, however, application...
Based on some simple arithmetic calculation, an efficient Lossless Image Compression technique is proposed. The proposed algorithm is implemented using Xilinx FPGA. This technique is designed for high quality still image compression, especially PSNR value above 34. This algorithm is most applicable for those images where lossy compression is avoided such as medical and scientific images. The architecture...
Automatic speaker recognition (ASR) refers to the detection of a person's identity from his/her voice with the help of machines. ASR finds its potential applications in telephone based financial transactions, purchase of credit card, information retrieval for surveillance in defense and intelligence organization and study of different dialects in a particular language. In this paper, we describe the...
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