• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.37 no.3
• /
• pp.114-122
• /
• 2000

This paper proposes a classification method using an amorphous Prototype to minimize classification error caused by such fixed-Prototype-based methods as Fuzzy C-Means, Nearest Neighborring Classification, FMMCNN, and Fuzzy-ART. For this method, a new fuzzy neural network is introduced, in which a convex polytope is generated or adaptively reshaped to classify the given datum into a proper group. Thus, this method contains a function to classify sequential data set. To show the validity of this method, various numerical experiments including comparison results with FMMCNN are presented

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.138-143
• /
• 2008

Recently, a new periodic cellular metal(PCM) named as Wire wove Bulk Kagome(WBK) was introduced. Based on the shape of tetrahedra composing a WBK, WBKs are classified into two types, namely, concave and convex type. They are easily differentiated by changing the assembling sequence. The effect of geometrical parameters such as the wire diameter, strut length and number of layers on the compressive behavior of concave type WBK has already been investigated. In this work, the similar works were performed with the convex type WBKs. It was shown that the compressive strength of the convex type WBK was quite similar to that of the concave type. The compressive strengths of convex type specimens also depend on the slenderness ratio, but a little different from those of concave type specimens in the detailed behavior. And densification occurs earlier than the concave type WBK.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.4
• /
• pp.416-419
• /
• 2000

Let G be an n-vertex convex polygon whose vertices are in general position. We consider an illumination problem of locating two floodlights on the boundary of G, which illuminates G and whose larger angle is as small as possible. We present an O($n^2$) time algorithm under the extended real-RAM model.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.06a
• /
• pp.403-405
• /
• 2006

Boolean 회로는 parallel 알고리즘을 위한 단순하면서도 실제적인 모델이다. Chung & Lee은 Boolean 회로 모델에서 볼록 이분할 그래프를 위한 최대 매칭을 찾는 O($log^2n+logn$ loglogn logb)depth와 $O(bn^3)$ size의 알고리즘을 제시하였다. 본 논문에서는 prefix compulsion 및 ASCEND, odd-even-merge의 방법을 이용하여 이를 개선한 O($log^2n$ logb) depth, O($bn^2$ logn) size의 최대 매칭 알고리즘을 제시한다.

• Korean Journal of Optics and Photonics
• /
• v.4 no.4
• /
• pp.390-396
• /
• 1993

When a one-dimensional telecentric paraxial holographic kinoform is used as a Fourier transform lens, we analyzed three surface-relief structures, i.e., plano-convex, convex-plano and biconvex shapes, employing exact raytracing method based on Snell's law. For the kinoform of E/8 and focal length of 15 mm, the number of zones, the thickness, and the slope of parabolic surfaces are varied by changing the refractive indicies of kinoform material and surrounding medium. It is found that biconvex shape gives the best results in general, although off-axis performance degrades in all cases as the slope of parabolic surfaces increases.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.2
• /
• pp.302-312
• /
• 1992

Three dimensional velocity measurements of a 35.deg. inclined jet issuing into turbulent boundary layer on both concave and convex surfaces have been conducted. To investigate solely the effect of each curvature on the flow field, streamwise pressure variations are minimized by adjusting the shape of the opposite wall in the curved region. From the measured velocity components, streamwise mean vorticities are calculated to determine jet-crossflow interface. The results on convex surface show that the injected jet is separated from the wall and the bound vortex maintains its structure far downstream. On concave surface, the secondary flow in the jet cross-sections are enhanced and in some downstream region from the jet exit, the flow on the concave surface has been developed to Taylor-Gortler vortices

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.6A
• /
• pp.855-861
• /
• 2000

This paper concerns a development of LQ-servo PI controller design on the basis of time-domain approach. The motivation is because the previous design techniques developed on the frequency-domain is not well suited meet the time-domain design specifications. Our development techniques used in this paper is base on the convex optimization methods including Lagrange multiplier, dual concept, semidefinite programming.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.43 no.5
• /
• pp.848-860
• /
• 1994

Generally, to get the minimum distance between two arbitrary shapes that are composed of circular arcs and lines, we must calculate distances for all the possible pairs of the components from two given shapes. In this paper, we propose an efficient method for the minimum distance problem between two shapes by using their structural features after extracting the reduced component lists which are essential to calculate the minimum distance considering the relationship of shape location. Even though the reduced component lists may contain all the components of the shapes in the worst case, in the average we can reduce the required computation much by using the reduced component lists. This method may be efectively applied to calculating the minimum distance between two shapes which are generated by the CAD tool, like in the nesting system.

• Korean Journal of Optics and Photonics
• /
• v.16 no.5
• /
• pp.456-461
• /
• 2005

We numerically investigate the characteristic of single Nd:YAG rod laser with the convex-plane resonator configuration in order to get the best condition for high efficient intra-cavity second harmonic generation(SHG). The beam quality is analyzed with ABCD matrixes including the thermal lensing characteristic of Nd:YAG rod. The analysis is focused on stability, M2, beam waist and mode-volume of laser beam inside the resonator. The best conditions for SHG is obtained when a laser rod is set near the curved laser mirror.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2007.11a
• /
• pp.65-65
• /
• 2007