ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677531

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The use of statistical analysis in line detection is necessary because of the noises induced by signal amplification and the random variations due to the microtexture of the object surface. Hunt et al. [5] have shown that the method derived from statistical signal detection theory has better performance than the Hough transform both in line detection and estimation. In this paper, we first derive two likelihood ratio tests for detecting a line in both gray level and binary images. These tests have some invariance properties. We also present some experimental results of detecting a line in the simulated image and also an edge line in the real image to demonstrate the usefulness of the tests. Then extensions of these tests to detect a parametric curve or a general shape or multiple curves are discussed in detail. Finally, a complete analysis of the Bayesian approach to line detection, particularly in the normal distributed case, is carried out successfully, and practical considerations of the whole theory are discussed with a conclusion that the theory is realistic and can be applied in many practical situations, and in some cases better than the Hough transform.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677532

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The problem of detecting step edge points which fall on curves (called curved edge points) is solved. Based on the moment‐preserving principle, the solution can be used to estimate curved edge locations to subpixel accuracy. The locations are approximated by parabolic equations. Experimental results, which show that the proposed detector is more effective for detecting curved edges and boundary corners than conventional line‐type edge detectors, are included.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677533

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper, we consider the multi‐modal function optimization problem. An automata model with improved learning schemes is proposed to solve the global optimization problem. Theoretically, we prove that the automaton converges to the global optimum with a probability arbitrarily close to 1. The numerical simulation results show that the automata approach is better than both the well‐known gradient approach and the simulated annealing method. The simulation results also show that our automata model converges faster than the other existing models in the literature.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677534

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An experimental analysis of the absorption removal of carbon dioxide with the presence of inert solid particles on the surface of the absorbent liquid is presented. A batch absorber with quiescent absorbent liquid has been applied to study the absorption removal of carbon dioxide by water in the isothermal system. The flour powder is introduced as the inert solid particles in the carbon dioxide absorption system. Tests with the flour powder in water are examined. The mass fluxes of carbon dioxide for the cases with and without the flour powder are then compared to elucidate the effects of inert solid particles on isothermal gas absorption. The results indicate a significant difference between these two cases for the concentrations of the flour powder in the absorbent liquid (WF) being in the range of experimental conditions, namely 0.001 to 0.03 g flour in 10 ml liquid. In general, the inert solid particles of the flour powder as the impurities in water with WF in the range of this study tend to decrease the carbon dioxide absorption rates for the experimental absorption system under investigation. Thus, various concentrations of inert solid particles cause various levels of surface resistance and affect the gas absorption rates. This kind of information is very useful for the gaseous pollutants removal that the impurities of inert solid particles contaminate the isothermal gas absorption system, and for the absorption removal of carbon dioxide associated with the control of the green house effect.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677535

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper, two methods, the Individual Calibration Method (ICM) and the Simultaneous Calibration Method (SCM), are used to calibrate a vision system with two cameras. The first approach calibrates a camera individually. For the second approach, two or more sets of camera intrinsic and extrinsic parameters are determined simultaneously such that the position errors for the 3‐D points are minimized. We show, theoretically and experimentally, the following results: (a) the offsets of the image centers do not affect significantly the position and orientation of a coordinate frame with respect to a stereo vision system with two cameras; (b) the lens distortion will not change dramatically the position and orientation of a coordinate frame with respect to a stereo vision system. We also find that (a) there is a difference in the determination of an object's location for the simultaneous and individual calibration methods; (b) the approach of calibrating two cameras simultaneously has the advantage of better accuracy over the method of individual calibration.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677536

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A new approach to resolve overlapping echoes is proposed. Inverse filtering is performed in a windowed frequency interval to avoid the enhancement of highly distorted signal spectrum. Using the partially inverse filtered signal spectrum as the data base, nonlinear spectral estimation techniques are then applied to resolve the number of overlapping echoes present and to obtain high resolution estimate of the individual echo time delays. Numerical and experimental results verify the effectiveness of the proposed new approach.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677537

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A new method called “Control Plane Rotation Scheme (CPRS)” has been developed here for the analysis of flatness error in terms of the minimum zone definition, which conforms to the ISO/R1101 specification. An application of the phase‐shifting interferometry was performed for on‐line measurement of gage blocks. Experimental results were quite consistent with the specified grade of the inspected gage block with only an uncertainty of up to 0.005μm.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677538

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Either measured displacements or calculated displacements are required in the available implicit algorithms. Two new formulations of the implicit algorithms will be presented herein. Neither measured displacements nor calculated displacements are used in the new algorithms. Hence, propagation errors can be significantly reduced in performing pseudodynamic tests. A series of simulations have been performed to study the error propagation characteristics of the algorithms. For the sake of comparisons, the error propagation characteristics of the implicit algorithm originally proposed by Thewalt and Mahin and that suggested by Shing and Manivanna are also considered in this study.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677539

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The results obtained in many experimental data show that the effect of turbulent diffusion on the performance of an electrostatic precipitator (ESP) is significant. The ways of handling the turbulent diffusion effect in different efficiency models are different. The effects of turbulent diffusion modeling on ESP performance models are investigated by comparing various models which include plug, Deutsch, Cooperman, Leonard‐Mitchner‐Self (L‐M‐S), and 2nd‐order closure models. The results obtained show that the largest difference of the estimation values of collection efficiency between various models in the range 0–10000 cm2/s of diffusivity is about 28%. When the diffusivity is less than 300 cm2/s, thex‐direction diffusion effect makes no obvious contribution to collecting process but they‐direction diffusion effect makes a marked contribution. When the diffusivity is larger than 300 cm2/s, the uncollected particles are mixed well in they‐direction and the influence ofx‐direction diffusion effect on collection efficiency becomes sensitive with the increase in diffusivity. Moreover, it is shown that the collection efficiency decreases when the entrance concentration increases. When the flow velocity is small, the migration velocity increases with increasing flow velocity. This anomalous phenomenon can be explained by the ionic wind effect, and the case studies show that there exists a maximum collection efficiency when the flow velocity is about a half of the ionic wind velocity.

ISSN:0253-3839    

DOI:10.1080/02533839.1993.9677540

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor