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A hyper-redundant manipulator is made by mounting the serial and/or parallel mechanisms on top of each other as modules. In discrete actuation, the actuation amounts are a limited number of certain values. It is not feasible to solve the kinematic analysis problems of discretely actuated hyper-redundant manipulators (DAHMs) by using the common methods, which are used for continuous actuated manipulators. In this paper, a new method is proposed to solve the trajectory tracking problem in a static prescribed obstacle field. To date, this problem has not been considered in the literature. The removing first collision (RFC) method, which is originally proposed for solving the inverse kinematic problems in the obstacle fields was modified and used to solve the motion planning problem. For verification, the numerical results of the proposed method were compared with the results of the genetic algorithm (GA) method. Furthermore, a novel DAHM designed and implemented by the authors is introduced. [ABSTRACT FROM AUTHOR]

The recent growth of industrial computed tomography (CT) scanning systems facilitates volumetric data acquisition for complete industrial components in a non-destructive manner. A potential application of this technology is reverse engineering. However, reconstructing a computer-aided design (CAD) model using industrial CT-scanned data involves many problems. In this paper, we present a semi-automatic method for reconstructing a CAD model from industrial CT-scanned data for reverse engineering. First, the methods to generate a point cloud and feature points from industrial CT-scanned data are presented. Then, two integrated solutions, namely surface feature-based strategy and geometric primitive feature-based strategy, are introduced to reconstruct the surfaces. Finally, modelling operations such as surface trimming and surface deformation are performed to generate the final model. A variety of industrial components were tested to demonstrate the applicability of our method. We also conducted an experiment to validate the accuracy of our method. [ABSTRACT FROM PUBLISHER]

A study of the accelerated light fading behavior of face-mounted color photographic materials has shown that alterations on the surface of the materials influence their fading characteristics. With the help of spectral density measurements it became apparent that the application of materials such as silicone rubber adhesive film and acrylic sheeting, but also laminating films, onto the surface of the prints accelerated the degradation of the colorants, especially the yellow dye, in chromogenic materials. In the case of silver dye bleach materials, however the opposite effect was observed. The influence of the material combination on the stability of face mounted color photographic prints was demonstrated to vary considerably. In order to better assess the inherent damage potential of the materials themselves, these were examined by means of instrumental analysis and measurements of pollutant gasses. Besides off-gassing compounds such as acetic acid and changes in pH caused by aging of the adhesive,face-mounting with a rigid plastic sheet (acrylic glazing) also affected the respective fading behavior of the various materials that were tested. [ABSTRACT FROM AUTHOR]

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Colour image watermarking is usually achieved by modifying the image luminance or by processing each colour channel separately. This paper presents a watermarking approach by hiding logo duplicates in DWT domains of the achromatic component of the colour image, and then a proposed technique of saturation adjustment is used to distribute the marks into each colour channel. To improve the detection robustness, an adaptive weighting scheme is also proposed to combine the extracted watermark duplicates in the extraction stage. Experimental results demonstrate that the proposed methods successfully make the watermark perceptually invisible and robust to image processing operations such as low-pass filtering, JPEG, JPEG 2000, scaling and cropping. [ABSTRACT FROM AUTHOR]

Mounting substrates for contemporary oversized photographs, including wood boards, foam boards, plastic boards, aluminum, aluminum composite materials and honeycomb panels, are described. Manufacturing processes, physical characteristics and aging properties are discussed. A comparative table shows the characteristics of some of the materials described. [ABSTRACT FROM AUTHOR]

The article focuses on the aspect accuracy of the polar alignment of the equatorial mount and its application to prevent trailing of stars in astrophotography. Topics discussed include the several factors affecting the tracking of an equatorial mount such as alignment, calibration, and flexure, the proper adjustment of the mount, and the aspect on how the polar alignment error (PAE) displayed on the handset.