ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677547

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper, a new result on the robust stability region construction in the parameter space of linear uncertain systems is presented. Based on the concept of coordinate transformations in the parameter space and a simple optimization technique, the new stability analysis result is then extended for constructing a union of hyperellipsoids with larger and larger volumes to approximate the whole robust stability region in the parameter space. The computational process involves only simple algebraic operations of matrices, singular value decompositions, and solutions of Lyapunov equation. Thus, the method can be easily programmed using existing software packages. This approach is applicable to linear systems described by state‐space models and high‐order differential equations. Some numerical examples are included to illustrate the method.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677548

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper, an algorithm is developed to estimate the frequencies of the sinusoids corrupted by white noise. First, the input data is analyzed by a large order autoregressive (AR) spectral estimator, and then we root the prediction error filter (PEF) to get a set of zeros. Using a zero‐clustering algorithm, we partition the zeros into clusters. From these zero clusters, we construct filters to enhance the sinusoids. Then, using frequency estimators, we estimate the frequencies of the sinusoids from the filtered data. The results presented in this paper demonstrate that the proposed algorithm provides a better resolution ability and estimate accuracy than that of the conventional AR spectral estimator, especially for close sinusoids at lowSNR.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677549

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Flux estimation is essential in most advanced control schemes of induction machines like indirect field‐orientation control and feedback linearizing approach. In this paper, optimal control theory and Lyapunov stability analysis are applied to design the full‐order flux observer of induction machines. The observer refers only to measurable quantities which are composed of terminal voltages, currents and rotor speed. The time‐invariant and time‐varying portions of the error dynamics of the observer are minimized separately. The degree of relative stability of the observer can be prescribed at the beginning of the design and is independent of speed variations. In the presence of uncertainty in rotor resistance, a sufficient condition for the design with bounded estimation errors is derived and the resultant residual can be formulated explicitly. Results from computer simulations show that the method exhibits excellent convergent characteristics and robustness to rotor resistance uncertainty.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677550

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper describes a novel neural network, called MATNET, to perform the medial axis transformation which is often used to extract a stick‐figure‐like representation from a binary object for pattern analysis or recognition. The MATNET is derived from the structure of the retina, which consists of five neural layers, namely, receptors, horizontal cells, bipolar cells, ganglion cells, and response. In principle, the horizontal cell is implemented for distance computation; the bipolar cell (B‐net) and the ganglion cell (G‐net) are implemented for calculation of local minimum and local maximum, respectively. The B‐net and G‐net are concerned with the maximal neural network (Maxnet). The properties of Maxnet are also discussed. Experimental results show that the MATNET performs reasonably.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677551

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper presents a method of speaker identification over telephone system based on channel‐effect cancellation. A set of inverse channel spectra is chosen as the basis for generating a channel‐effect‐cancellation filter. The speaker identification scheme is based on vector quantization where the codebooks of each speaker are trained without channel effect. When the speech signal of a speaker goes through the telephone system, a proper channel‐effect‐cancellation filter is generated to minimize the channel effect on the speech signal. The experiments show that the channel effect is mostly contributed by telephone handsets rather than by the transmission lines. By using the proposed method, an identification rate of 93.8% can be achieved for 100 speaker tests.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677552

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper, pi‐coefficients are used to represent the linear time‐invariant error subsystem and to analyze the nonlinear time‐varying update rule of the error model for a model‐reference adaptive system (MRAS). Several factors affecting the system stabilities — unmodeled dynamics, sampling intervals, input frequency, andσ‐modification — are analyzed by the quantitativer‐pcurves. By this analysis, the gradient update rule is quantitatively shown a feature lacking robustness in an MRAS, but it can be improved by utilizingσ‐modification. All these factors can easily be determined by the pi‐coefficients to obtain the best robust characteristics.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677553

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper describes a windowed register file management technique for Prolog that we call “SORWT'’ (Splittable Overlapped Register Window Technique). This scheme is implemented in our Prolog system. Two pointers, the CWP (Current Window Pointer) and TWP (Top Window Pointer), are used with the register file so that the environment, choice point and arguments can be stored in register windows. This greatly reduces the number of memory accesses and procedure call/return overhead. This paper describes in detail how Warren instructions can be implemented in a windowed register file system. A mapping function between register windows and memory window areas and register file overflow/underflow handling algorithms are also presented. In addition, to cope with argument overflow problems in a window, the concept of extended windows is proposed.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677554

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A conceptual design, performance analysis, system optimization and simulation of an OTEC (Ocean Thermal Energy Conversion) power plant was carried out in the present study. The OTEC plant acts as the bottom cycle of the Third Nuclear Power Plant, utilizing the warm water discharged from the nuclear plant as the heat source and the cold deep seawater pumped from the nearby sea bottom as the heat sink. The nominal net power output from the OTEC plant is estimated to be 8.74 MWe. A plant simulation was further carried out to study the OTEC plant performance due to seasonal variation of the warm water temperature, which shows that the OTEC plant is able to deliver an electricity of 5.18×107kWH per year. The net power output in the winter season will be reduced to about one eighth of that in the summer season. The final discharged warm water temperature was shown to be below 29°C all year around, so that the current thermal pollution problem of the nuclear power plant can be eliminated. Additionally there is the side benefit of 8.74 MWe net power generation from ocean energy resource. This OTEC plant will become economically feasible if the installation cost is considered as a thermal pollution control investment.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677555

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An automatic storage system comprised of two storage carousel conveyors and a retrieval apparatus integrated by computers has been considered in this paper. The order picking problem for such a two‐carousel‐single‐server system is presented here. The retrieval time is analyzed by a two‐stage solution procedure for the scheduling sequence of retrieving items from the system in order to satisfy an order requirement. The analytical results can be directly applied for the scheduling of the carousel storage system.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677556

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor