Showing papers in "Optics and Lasers in Engineering in 1995"

TL;DR: In this article, the Fourier transform was used to estimate the in-plane components of strain on a propellant simulant containing burn holes, up to strains of approximately one-third.

TL;DR: A new strategy for processing phasestepped data from birefringent materials is proposed and involves demodulation of intensity signals and the classification of periods of data using fuzzy sets.

TL;DR: Digital image correlation is used to find the disparities between corresponding points in a pair of images, for each of these models, with subpixel accuracy, in a parallel optical-axis model and a converging optical- axis model.

TL;DR: It is demonstrated that interference phase can be obtained from a fringe pattern using the spatial domain method known as spatial synchronous detection (direct interferometry) but without the usual fringe carrier introduced into the interferometer.

TL;DR: In this article, the Fourier transform fringe analysis is applied to surface shape measurement, and a frequency shift is employed to eliminate the occurrence of any wraps in the resulting phase distribution.

TL;DR: A new method of fringe-pattern analysis by spatial phase stepping (SPS) is presented, which combines the computational simplicity of phase stepping with the single image analysis capability of the Fourier transform method.

TL;DR: In this article, a laser-based system for remotely measuring the surface temperature of parts coated with thermographic phosphor (Y 2 O 3 :Eu) is described, and the results of a proof-of-principle test conducted on a stationary coupon coated with Y 2O 3 : Eu immersed in an atmospheric-combustor, chamber are described.

TL;DR: In this paper, the effect of cyclic deformation on the corrosion behavior of polarised metallic electrodes in aqueous solution was investigated using real-time holographic interferometry.

TL;DR: In this paper, a summary of laser mode splitting and its applications is presented, where several applications of the laser mode split to laser physics and metrology are described, including study of mode competition, abnormal dispersion, and measuring angles.

TL;DR: This paper describes the development of an integrated fuzzy-rule-based automatic visual inspection system that combines fuzzy logic analysis and computer vision systems to provide a practical approach to general purpose visual inspection applications.

TL;DR: In this paper, the birefringence of a linearly polarised shear wave propagating along the thickness direction of the component is used to determine the directions of the two other principal axes.

TL;DR: An extension to the basic PLL scheme to demodulate noisy fringe patterns is presented and the bandwidth of the iterative PLL system is gradually decreased to improve the signal-to-noise ratio of the detected phase as well as to resolve noise-generated phase inconsistencies.

TL;DR: In order to optimise prosthetic life, it is necessary to improve the design of components and implantation techniques, which is clearly also beneficial to both patients and hospitals.

TL;DR: Several approaches to the problem of determining the reference phase shifts in a perturbing environment are critically evaluated using computer simulations and a practical example confirms the predictions of the numerical simulations and demonstrates the feasibility of using reference phase shift estimates to improve data reduction procedures.

TL;DR: In this article, a study on evaluating an epoxy-based coating was conducted, which aimed to determine the performance of the coating on a low carbon steel as a result of chemical contaminations.

TL;DR: In this article, a video-based laser speckle technique has been developed for noncontact analysis of fatigue in situ and at speeds approaching video frame rates, which is a method of full field inspection which both locates fatigue damage sites and measures damage severity.

TL;DR: The application of a CCD camera operating in the time delay and integration (TDI) mode, for imaging and contouring the complete periphery of curved objects, is described in this paper, based on projection moire principles.

TL;DR: In this paper, a moire interferometer was designed and constructed based on a general system design using a reflective crossed-line diffraction grating to produce the four beams of light necessary for interferometry.

TL;DR: In this article, the WF is incorporated into a synthetic discriminant function (SDF) for robust optical pattern recognition and classification, which achieves a 100% success rate in discriminating one class of images from another.

TL;DR: In this paper, a configuration of long-range optical triangulation with a collimated beam is presented, and the influence of spot size on the image spread is discussed, which is the main factor causing inaccuracy in the collimated beacons triangulations.

TL;DR: An algorithm to determine voltages to be applied to both x and y scanner controllers for directing the laser beam is presented and has proven to be numerically and experimentally straightforward and easy to implement.

TL;DR: In this article, an experimental method is described which can measure the directions and magnitudes of residual stresses in metal, using large shearing speckle interferometry combined with the hole drilling method to measure the surface deformation around the hole.

TL;DR: Neural networks are applied to two simple fringe analysis problems, to find the radius of a one-dimensional curved surface from its simulated fringe projection intensity distribution and to identify four lensshaped objects of different radii of curvature from real fringe patterns obtained under different illumination conditions.

TL;DR: In this article, a polarimetric fiber-optic sensor embedded in a plexiglass model received the acoustic signals generated by an ultrasonic transducer and showed promising results in determining acoustical properties of polymeric materials and locating internal defects.

TL;DR: In this paper, a new birefringent phase shift method applied in isodyne fringe pattern distinction is developed and the phase map obtained by the new method corresponds to the isodynes surface in whole fields.

TL;DR: An in-plane deformation inspection system which has been built up for an automatic acquisition of interferograms at different stages of a test is described and qualified and quantitative results are obtained.

TL;DR: In this article, a new mathematical method of describing and analysis of polarised light, based on double-complex numbers, is presented, and transformation formulas derived in the paper describe the changes of polarisation or unpolarisation state of a beam transmitted through various types of linear birefringence polarisers and retarders.

TL;DR: Experimental results of the optical conversion of speckle images into transformed images with additive, signal-independent noise statistics using the real-time photochromic properties of bacteriorhodopsin are presented.

TL;DR: In this paper, component level inspection was carried out on the integrated circuit, diode, resistor and capacitor, and the implementation of transputers for real-time image processing was successfully achieved.