Showing papers by "Yung C. Shin published in 1991"

On the natural frequencies of high-speed spindles with angular contact bearings

Abstract: Experimental evidence has shown that the natural frequencies of a high-speed spindle decrease with increasing rotational speeds. While this phenomenon is important to the design and operation of hi...

Design of an optimal damper to minimize the vibration of machine tool structures subject to random excitation

Abstract: The vibration of machine tools during machining adversely affects machining accuracy and tool life, and therefore must be minimized. The cutting forces for stable turning are generally known to be random, and hence excite all the resonance modes. Of all these modes, those that generate relative motions between a cutting tool and a workpiece are of concern. This paper presents a new approach for designing an optimal damper to minimize the relative vibration between the cutting tool and workpiece during stable machining. An approximate normal mode method is employed to calculate the response of a machine tool system with nonproportional damping subject to random excitation. The major advantage of this method is that it reduces the amount of computation greatly for higher-order systems when responses have to be calculated repeatedly in the process of optimization. An optimal design procedure is presented based on a representative lumped parameter model that can be constructed by using existing experimental or analytical techniques. The two-step optimization procedure based on the modified pattern search and univariate search effectively leads the numerical solution to the global minimun irrespectively of initial values even under the existence of many local minima.

Intelligent engineering systems through artificial neural networks : proceedings of the Artificial Neural Networks in Engineering (ANNIE '91) conference, held November 10-13, 1991, in St. Louis, Missouri, U.S.A.

Abstract: This volume contains the edited versions of the technical presentations of the third international gathering of researchers interested in the applications of artificial neural networks, genetic algorithms, and fuzzy logic. The papers in this volume are grouped into five categories: artificial neural network architectures, pattern recognition, neuro-control, neuro-manufacturing, and neuro-engineering systems. Contents include: Theoretical Foundation for CMAC Technique, Embeddable Reconfigurable Neuroprocessors, Heave Compensation Via Neural Networks, Benchmarking Framework for Neuro Algorithms, Handwriting Recognition Using an Art Based Network, Neural Vector Quantization for Image Compression, Training Fuzzy Controller, Genetic Three-Dimensional Packer, and Geophysical Target Identification in Environmental Investigations.