A new and efficient method of designing the transmultiplexer filters is presented. The bilinear equations posed for the FIR filters are solved to achieve perfect reconstruction. For a given combining filter bank a sep...
详细信息
ISBN:
(纸本)1604238216
A new and efficient method of designing the transmultiplexer filters is presented. The bilinear equations posed for the FIR filters are solved to achieve perfect reconstruction. For a given combining filter bank a separation filter bank can be developed by solving a set of algebraic equations. Some examples of a two-channel and four-channel transmultiplexer system are provided to illustrate the method of filter bank designing. Due to the incorporation of integer filters a perfect reconstruction was realized and crosstalk was completely eliminated not only theoretically but also in practice. Such transmultiplexers can be applied to coded signals transmission. It is pointed that the orthogonal filters can be obtained as well.
Damage of bearings is the most common cause of failures of squirrel-cage induction motors. A faulty bearing results in additional motor vibrations. They are reflected in the harmonic content of stator currents. In cer...
详细信息
Damage of bearings is the most common cause of failures of squirrel-cage induction motors. A faulty bearing results in additional motor vibrations. They are reflected in the harmonic content of stator currents. In certain operating conditions the current signal is the sole source of information on the state of the motor. The paper presents a mathematical model of the motor, allowing for rotor eccentricities. Calculated spectra of the stator currents are presented for the cases of operation with rotor vibrations mapping with some approximation the vibrations caused by faulty bearings. The paper presents also results of laboratory simulations for a motor put into vibrations of adjustable frequency. Vibrations of the motor housing simulate the rotor oscillations caused by a damaged bearing. The results of laboratory simulations permitted to define the relations linking vibrations of the air gap with the components in the stator current spectrum.
作者：
H.W. GommaH. YuElectronics
Communication and Computer Engineering Department Helwan University Egypt Faculty of Computing
Engineering and Technology Staffordshire University Stafford UK
Following the appearance of generalized predictive control (GPC) most research attention has been lately directed to guarantee the stability of the closed loop systems. This has been accompanied with relatively less a...
详细信息
Following the appearance of generalized predictive control (GPC) most research attention has been lately directed to guarantee the stability of the closed loop systems. This has been accompanied with relatively less attention to derive new techniques in the spirits of GPC that concerns system performance. This paper presents a new predictive control technique that is able to provide a better performance in terms of system overshoot when compared with the conventional GPC. The idea of the new technique is based on minimizing the rate of change of the predicted output while following the future trajectory. In addition robustness analysis to structured and unstructured uncertainties has been investigated
Power electronic systems are finding applications in increasingly demanding environments. This coupled together with demanding converter specifications requires an integral electrical, thermal and spatial design of th...
详细信息
ISBN:
(纸本)9075815085
Power electronic systems are finding applications in increasingly demanding environments. This coupled together with demanding converter specifications requires an integral electrical, thermal and spatial design of these power electronic systems. This paper investigates and implements an integral design that identifies the interdependencies between the electrical, thermal and spatial designs of a power electronic converter and considers how the interdependencies can be manipulated to meet all the converter specifications simultaneously in a single volume. The integral design procedure is used to design a 2kW power converter for implementation in the automotive environment. The power converter utilizes the automotive liquid coolant system where the coolant has a maximum temperature of 125°C for heat removal. Under these conditions, the design achieves a power density of 120W/in3 (7.3kW/liter). Practical results confirming the design are presented.
This paper presents an analysis of the Slotted DS-CDMA system with modified node components in order to construct a load control structure in which the service rates of each node can be dynamically adapted without usi...
详细信息
A continuous-time analog delay is designed as a requirement for the autocorrelation function in the Quadrature Downconversion Autocorrelation Receiver (QDAR) [1]. An eight-order Padé approximation of its transfer...
详细信息
ISBN:
(纸本)078039397X
A continuous-time analog delay is designed as a requirement for the autocorrelation function in the Quadrature Downconversion Autocorrelation Receiver (QDAR) [1]. An eight-order Padé approximation of its transfer function is selected to implement this delay. Subsequently, the orthonormal form [1] is adopted, which is intrinsically semi-optimized for dynamic range, has low sensitivity to component mismatch, high sparsity and whose coefficients can be physically implemented. Each coefficient in the state-space description of the orthonormal ladder filter is implemented at circuit level using a novel 2-stage gm cell employing negative feedback. Simulation results in IBM's Bi-CMOS 0.12 μm technology show that this delay filter requires a total current of 70 mA at a 1.6 V power supply. The 1-dB compression point of the delay is at 565 mV and the SNR is 47.5 dB. On performing a Monte Carlo simulation it becomes evident that the response of the frequency selective analog delay does not suffer drastically from neither process variations nor component mismatch.
A quantized analog delay is designed as a requirement for the autocorrelation function in the Quadrature Downconversion Autocorrelation Receiver (QDAR) [1]. The quantized analog delay is comprised of a quantizer, mult...
详细信息
ISBN:
(纸本)078039397X
A quantized analog delay is designed as a requirement for the autocorrelation function in the Quadrature Downconversion Autocorrelation Receiver (QDAR) [1]. The quantized analog delay is comprised of a quantizer, multiple binary delay lines and an adder circuit. Being the foremost element, the quantizer consists of a series of comparators, each one comparing the input signal to a unique reference voltage. The comparator outputs connect to binary delay lines, which are a cascade of synchronized D-latches. The outputs available at each line are linked together to reconstruct the incoming signal using an adder circuit. For a delay time of 550 ps, simulation results in IBM's CMOS 0.12 μm technology show that the quantized analog delay requires a total current of 36.7 mA at a 1.6 V power supply. Furthermore, delays in the range of several nanoseconds are feasible at the expense of power. After a Monte Carlo simulation it becomes evident that the response of the quantized analog delay does not suffer drastically from neither process nor component mismatch variations.
Transmultiplexers equipped with integer-to-integer filters can be applied for transmitting coded signals or computer data. The new method of transmultiplexer filter design is presented.
Transmultiplexers equipped with integer-to-integer filters can be applied for transmitting coded signals or computer data. The new method of transmultiplexer filter design is presented.
Ray-space representation is the main technology to realize free viewpoint video system with complicated scenes. Ray-space interpolation is one of key problems to be solved. A new fast ray-space interpolation method th...
详细信息
暂无评论