• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.237-242
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• 1996

A theoretical formulation for the analysis of free vibration of clamped-free cylindrical shells with plates attached at arbitrary axial positions was derived and it was programed to get the numerical results which yield natural frequencies and mode shape of the combined system of plate and shells. The frequencies and mode shapes from theoretical calculation were compared with those of commercial finite element code, ANSYS as well as modal test in order to validate the formulation. The effects of the thickness and location of the plate were evaluated.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.35.5-35
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• 2001

The purpose of the study is to develop a synthetic method for generating arbitrary number of not the same but similar texture images. The method includes processes to extract basic shape elements from texture images originating in actual objects, to select them to reappear the image features and to arrange them in a image plane. The authors have already proposed the shape-pass type filter bank assuming that the sensual impression mainly depends on minute shapes existing in the texture images. By use of nine basic shape elements, namely black/white-roof, black/white-line, black/white-snake, black/white-pepper, and cliff, natural texture images originating in actual objects have been characterized by feature vectors in a nine dimensional space. To generate arbitrary number of similar texture images, minute shape pieces ...

• Journal of KIISE:Software and Applications
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• v.35 no.9
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• pp.572-587
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• 2008

The Self-organizing Feature Map(SOFM) that is one of unsupervised neural networks is a very powerful tool for data clustering and visualization in high-dimensional data sets. Although the SOFM has been applied in many engineering problems, it needs to cluster similar weights into one class on the trained SOFM as a post-processing, which is manually performed in many cases. The traditional clustering algorithms, such as t-means, on the trained SOFM however do not yield satisfactory results, especially when clusters have arbitrary shapes. This paper proposes automatic clustering on trained SOFM, which can deal with arbitrary cluster shapes and be globally optimized by graph cuts. When using the graph cuts, the graph must have two additional vertices, called terminals, and weights between the terminals and vertices of the graph are generally set based on data manually obtained by users. The Proposed method automatically sets the weights based on mode-seeking on a distance matrix. Experimental results demonstrated the effectiveness of the proposed method in texture segmentation. In the experimental results, the proposed method improved precision rates compared with previous traditional clustering algorithm, as the method can deal with arbitrary cluster shapes based on the graph-theoretic clustering.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.943-949
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• 2005

For the psychophysical experiment of tactile perception of shapes, experimental system consists of vibrator, tactile stimulation array, measurement and control system is designed and prepared. The psychophysical experiment for the tactile perception of shape is carried out by the estimation of the subject group. Through the experiment the threshold of tactile perception to multi-stimuli with some line shape is obtained. Also the appropriate tactile stimulus intensity and frequency of the tactile stimulation array to recognize arbitrary shapes effectively are derived and discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.672-675
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• 1997

This paper presents the identification of rotor dynamic parameters. The solution of the system equation can be obtained using least square method. The sensitivity analysis is performed to extract optimized solution, which is considered to be insensitive to inherent measurement errors. The cosine and sine term of orbit shapes can be obtained by experiment the orbit analysis at a different speed after doing orbit analysis at an arbitrary selected speed. This values measured time domain used to search the stiffness and damping coefficients of rotor bearing.

• Journal of Ship and Ocean Technology
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• v.10 no.1
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• pp.27-37
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• 2006

Current loads acting on offshore vessels are important for predicting the hydrodynamic and structural responses of the vessels. It is also true for analyzing the behavior of moored systems under the action of ocean current. Unfortunately there are few standardized current load coefficients for offshore vessels and it is extremely difficult to be applied to arbitrary hull shapes, if any. Therefore current load coefficients for three hull shapes are calculated in this study using a CFD code, which is well known in the shipbuilding industry. In order to validate the present approach, a typical VLCC is taken as numerical example and resulting current coefficients are compared with experiment together with the OCIMF data. The comparison shows a good agreement in the qualitative sense. Two additional models considered herein are a shuttle tanker and a FPSO under deepwater condition $(WD/T{\geq}6)$. The present numerical approach may be utilized for practical design of offshore vessels.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.207-212
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• 1999

A computational method based on the three-dimensional finite element method is developed for the deformation analysis of roll forming process. the method approximates the process as a kinematically steady state deformation of strip. For industrial usefulness of the simulation method several rolls with arbitrary shapes in one stand can be considered. The shapes and the thickness distributions of strip after roll forming were examined by comparing computation results with experiments It is concluded that the tool is useful enough to predict the process. The overall simulation method was integrated into a sorftware package to help the industrial roll-design.

• Journal of KSNVE
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• v.7 no.2
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• pp.331-345
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• 1997

A theoretical formulation for the analysis of free vibration of clamped-free cylindrical shells with plates attached at arbitrary axial position(s) was completed and it was programed to get the numerical results which yield natural frequencies and mode shape of the combined system of the plate and the shells. The frequencies and mode shapes from theoretical calculation were compared with those of commercial finite element code, ANSYS. In order to validate the theory, modal test was also performed by impact test and FFT analysis. The results shows good agreement with those of ANSYS and test results in frequencies and mode shapes. The method developed herein is likely to be used for the analysis of the free vibration of the clamped-free circular cylindrical shells with any kinds of lids such as hollow circular plates, conical shells, spherical shells, or semi-spherical shells.

• Journal of applied mathematics & informatics
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• v.8 no.3
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• pp.899-907
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• 2001

Complex variable methods are used to solve the first and the second fundamental problems for infinite plate with two holes having arbitrary shapes which are conformally mapped on the domain outside of the unit circle by means of rational mapping function. Some applications are investigated and some special cases are derived.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.658-663
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• 2013

A new formulation of the MNDIF method is introduced to extract highly accurate eigenvalues of concave acoustic cavities with arbitrary shapes. It is said that the MNDIF method cannot yield accurate eigenvalues for concave cavities. To overcome this weak point, a new approach of dividing a concave cavity into two convex domains is proposed. The validity of the proposed method is shown through a case study.