• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.04a
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• pp.133-143
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• 1997

In this paper, some of the critical factors in Necking-In process are investigated using a numerical analysis. The optimal processing parameters are established and applied to the actual processes. FEM analysis is carried out based on elastic-plastic work hardening model using ABAQUS/Standard. The results obtained from the commercially available code ABAQUS/Standard are compared with the experimental data and shows a good agreement with experimental data. The purpose of this paper is to search for the relations among the roller angle, feed length, and working force. Stress, strain distribution, displacement and increase in the length of the workpiece are also investigated.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2E
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• pp.38-46
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• 1997

The objective of the paper is to compare the computational complexity of five algorithms for computing time-domain second-order Volterra filter outputs in terms of number of real multiplication and addition operations required for implementation. This study shows that if the filter memory length is greater that or equal to 16, the fast algorithm using the overlap-save method and the frequency-domain symmetry properties of the quadratic coefficients is the most efficient among the algorithms investigated in this paper, When the filter memory length is less than 16, the algorithm using the time-domain symmetry properties is better than any other algorithm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.910-920
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• 1997

In this paper, some of the critical factors in Necking-In process are investigated using a numerical analysis. The optimal processing parameters are established and applied to the actual processes. FEM analysis is carried out based on elastic-plastic work hardening model using ABAQUS / Standard. The results obtained form the commercially available code ABAQUS / standard are compared with the experimental data and shows a good agreement with experimental data. The purpose of this paper is to search for the relations among the roller angel, feed length, and working force. Stress, strain distribution, displacement and increase in the length of the workpiece are also investigated.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.455-464
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• 2005

In this paper, we analyze a queueing system with overload control by arrival rates. This paper is motivated by overload control to prevent congestion in telecommunication networks. The arrivals occur dependent upon queue length. In other words, if the queue length increases, the arrivals may be reduced. By considering the burstiness of traffics in telecommunication networks, we assume the arrival to be a Markov-modulated Poisson process. The analysis by the embedded Markov chain method gives to us the performance measures such as loss and delay. The effect of performance measures on system parameters also is given throughout the numerical examples.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.4
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• pp.307-318
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• 2011

We introduce an algorithm that automatically generates paper templates of a triangulated surface. The surface can be built by cutting, folding, and pasting the paper templates. The algorithm is branched to two strategies : one is to select the longest neghboring edge among many choices, and the other is to select the largest neighboring triangle. Three surfaces, whose triangulation sizes widely range, are successfully built by the algorithm. The two strategies are empirically evaluated in building the surfaces with respect to paper consumption, a measure of cost efficiency, and boundary length, a measure of speed efficiency. Strategy 1 performs in most cases better than the other one with respect to boundary length, but sometimes wins and sometimes loese with respect to paper consumption.

• Kyungpook Mathematical Journal
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• v.45 no.2
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• pp.191-198
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• 2005

In this paper, we introduce a length function for elements of the imprimitive complex reflection group G(m, 1, n) and study its properties. Furthermore, we show that every conjugacy class of G(m, 1, n) can be represented by an admissible diagram. The corresponding results for Weyl groups are well known.

• Honam Mathematical Journal
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• v.34 no.1
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• pp.103-111
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• 2012

Wetzel[5] proved if ${\Gamma}$ is a closed curve of length L in $E^n$, then ${\Gamma}$ lies in some ball of radius [L/4]. In this paper, we generalize Wetzel's result to the non-Euclidean plane with much stronger version. That is to develop a lower bound of length of a triangle inscribed in a circle in non-Euclidean plane in terms of a chord of the circle.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.293-296
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• 2007

This study investigated the out-of-plane elastic buckling load and effective length factor of X-bracing system. The members of X-bracing system which are studied in this paper are rigidly attached to the structure at their end connections, and are pinned or rigidly connected at their point of intersection. The effective length factors are derived for the general case where the tension and compression brace have different material and geometrical properties.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.1
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• pp.87-98
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• 1994

This paper describes a method of constructing VC2 Chord-length spline surface from semi-evenly spaced 3D point array. The suface uses Hermite interpolant as Ferguson surface, and it is an extention of chord-length spline curve to surface The proposed surface may be widely used in interpolating smoothly 3D point data obtaind by measurement or engineering design.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1104-1110
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• 2006

In this paper we present a simple approach to the joint queue length distribution in the nonpreemptive priority M/G/1 queue. Without using the supplementary variable technique, we derive the joint probability generating function of the stationary queue length at arbitrary time.