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    An approach to geometrical modelling of slope curves and discontinuities
    (ELSEVIER SCIENCE BV, 2008) Turanboy, Alparslan; Goekay, M. Kemal; Uelker, Erkan
    Conventional geometrical methods for mining applications such as geologic mapping, cross-sections, logging, stereo-nets, contours and others are so sophisticated that often additional explanations are needed. After studying conventional geometrical methods, we decided to analyze both general slope curves and discontinuities of open pit mines used in excavations in rock mass to achieve meaningful 3D results by using linear mathematical transformation and isometric perspective methods. In addition, a new reorganization of discontinuities as a construction method has been developed according to their spatial orientations. In the developed method, slope curves and discontinuities were geometrically analyzed in a rectangular prism. An example of a detailed structural study of the Dogankuzu South Block Bauxite Open Pit Mine in Seydisehir, Turkey is given. Results indicate that there is a high similarity in both slope curves and discontinuity traces on free surfaces. The main aim of this study is to present a fast and practical visualization of these structures using directly conventional surveying instruments such as theodolite and compass-clinometer or periodic product maps. Present limitations of the method and further studies are also stipulated. (C) 2008 Elsevier B.V. All rights reserved.
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    An artificial immune system approach to CNC tool path generation
    (SPRINGER, 2009) Uelker, Erkan; Turanalp, Mehmet Emin; Halkaci, H. Selcuk
    Reduced machining time and increased accuracy for a sculptured surface are both very important when producing complicated parts, so, the step-size and tool-path interval are essential components in high-speed and high-resolution machining. If they are too small, the machining time will increase, whereas if they are too large, rough surfaces will result. In particular, the machining time, which is a key factor in high-speed machining, is affected by the tool-path interval more than the step size. The present paper introduces a 'system software' developed to reduce machining time and increased accuracy for a sculptured surface with Non-Uniform Rational B-Spline (NURBS) patches. The system is mainly based on a new and a powerful artificial intelligence (AI) tool, called artificial immune systems (AIS). It is implemented using C programming language on a PC. It can be used as stand alone system or as the integrated module of a CNC machine tool. With the use of AIS, the impact and power of AI techniques have been reflected on the performance of the tool path optimization system. The methodology of the developed tool path optimization system is illustrated with practical examples in this paper.
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    Automatic knot adjustment using an artificial immune system for B-spline curve approximation
    (ELSEVIER SCIENCE INC, 2009) Uelker, Erkan; Arslan, Ahmet
    Reverse engineering transforms real parts into engineering concepts or models. First, sampled points are mapped from the object's surface by using tools such as laser scanners or cameras. Then, the sampled points are fitted to a free-form surface or a standard shape by using one of the geometric modeling techniques. The curves on the surface have to be modeled before surface modeling. In order to obtain a good B-spline curve model from large data, the knots are usually respected as variables. A curve is then modeled as a continuous, nonlinear and multivariate optimization problem with many local optima. For this reason it is very difficult to reach a global optimum. In this paper, we convert the original problem into a discrete combinatorial optimization problem like in Yoshimoto et al. [F. Yoshimoto, M. Moriyama. T. Harada, Automatic knot placement by a genetic algorithm for data fitting with a spline, in: Proceedings of the International Conference on Shape Modeling and Applications, IEEE Computer Society Press, 1999, pp. 162-169] and Sarfraz et al. [M. Sarfraz, S.A. Raza, Capturing outline of fonts using genetic algorithm and splines, in: Fifth International Conference on Information Visualisation (IV'01), 2001, pp. 738-743]. Then, we suggest a new method that solves the converted problem by artificial immune systems. We think the candidates of the locations of knots as antibodies. We define the affinity measure benefit from Akaike's Information Criterion (AIC). The proposed method determines the appropriate location of knots automatically and simultaneously. Furthermore, we do not need any subjective parameter or good population of initial location of knots for a good iterative search. Some examples are also given to demonstrate the efficiency and effectiveness of our method. (c) 2008 Elsevier Inc. All rights reserved.