• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.319-326
• /
• 1998

Structural intensity of plates experiencing bending vibration is analytically evaluated using the modal analysis based on the assumed mode method. In the analysis, material internal loss and localized damping are considered. The power obtained by structural intensity integration over the circle containing the excitation source is compared with the power injected into plates to verify the accuracy of the presented method and; to evaluate the convergence of mode superposition. The intensity integration is carried out varying the circle radius and the integral step to investigate their effects in case of the power estimation using structural intensities. In addition, the dominant component among internal forces in the energy transfer by the bending vibration of a stiffened plate is investigated.

• Journal of the Korean Home Economics Association
• /
• v.48 no.4
• /
• pp.71-81
• /
• 2010

For a pattern to be a scientific and reasonable drafting method. it should be based on the human body, have fewer measuring items, be easy to learn, and be able to make good-looking clothing that fits many people. Therefore, the height, foot length and circle radius in the Durumagi drafted in this study examined to improved the drafting method for Korean Durumagi. As a result, a pattern drafting method was developed in which Moo, Gutsup, Ansup and length of clothing were naturally derived according to the size of individuals.

• Proceedings of the KIEE Conference
• /
• 2004.05a
• /
• pp.135-137
• /
• 2004

In this paper, a new method which is based on mathematics is proposed for the obstacle-avoidance and path-planning (OAPP) of robotics in unknown environment. The robot just knows the start point and the goal point. The robot is represented by a circle(not a point) whose radius is one. After being sensed, the obstacles are represented by some mathematic functions and when avoiding the obstacles, the robot path will be generated autonomously. Along this path, the robot can get the goal point at last. The simulation results show that the proposed method works very well.

• Journal of Ocean Engineering and Technology
• /
• v.24 no.6
• /
• pp.61-70
• /
• 2010

This study presents free vibration analyses of perforates steel plates with various cutouts. Four different parameters (shape, size, curvature radius ratio, and rotation of cutouts) were considered to investigate the effects of those parameters on the free vibration characteristics, such as natural frequencies of the perforated steel plates. Three different shapes of cutouts are circle, square, and triangle, and the considered sizes are 5, 10, 15, 20, and 25 mm. For the triangular and square cutouts, the characteristic radii of the inscribed circles of those cutouts were defined. In addition, the curvature radius ratio was defined as the ratio of curvature radius of bluntness and the characteristic radius. Then, total seven different curvature radius ratios (0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1) were considered. To investigate the rotation effect of the cutouts, it was considered four rotations ($0^{\circ}$, $15^{\circ}$, $30^{\circ}$, and $45^{\circ}$) for the square cutouts and three rotations (0, 15, and 30) for the triangular cutouts. All the free vibration analyses were conducted using a general purpose finite element program. From the analyses we found that the most influential parameter for the free vibration response of the perforated plates is the size of cutout. The other factors such as the shape, curvature radius ratio, and rotation are minors; they mainly change the natural frequency as long as the size effect is accompanied.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.12
• /
• pp.174-181
• /
• 1999

This paper describes the effect of the stylus tip size on the shape error in surface topography measurement. To analyze the distortional effect of an actual surface geometry origination from the finite stylus size, the surface is modeled as a sinusoid and the stylus tip as a circle. The magnitude of this distortion is defined as the ration of standard deviation, and this is expressed as an analytic function of the stylus tip radius and the geometrical parameter of a sinusoid. In this paper, the spectrum analysis of the profile is applied to investigate the distortional effect due to the mechanical filtering of the stylus in the frequency domain. and, the cumulative power spectrum is proposed to assess the shape error of measured data according to the various stylus tip sizes. From these results, a new method to select proper stylus tip radius is proposed.

• Journal of the Korean School Mathematics Society
• /
• v.10 no.4
• /
• pp.519-533
• /
• 2007

In this paper we study a equality $\frac{1}{h_a}+\frac{1}{h_b}+\frac{1}{h_c}=\frac{1}{r}$ which contains altitudes and radius of inscribed circle of triangle. We search some paths for proving the equality, and find out 9 proof method of the equality which is related with descriptive geometry, coordinate geometry, and vector geometry.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.99.1-99
• /
• 2002

In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplacian operator with input image which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along t...

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2014.07a
• /
• pp.463-464
• /
• 2014

최근 다양한 모바일 기기를 통한 슈팅 게임이 등장하고 있다. 본 논문에서는 배경을 상하로 움직이고 음악을 포함하여 물방울 객체를 피하는 게임을 개발하고자 한다. 먼저 물체 충돌을 판정하기 위하여 두 객체의 중심점과 반지름을 이용하여 빠르게 충돌을 판정하는 방법을 이용하였으며 물체를 피하면 점수를 제공하고 또한 난이도를 제공함으로써 게임의 흥미를 부과하였다.

• Journal of the Chungcheong Mathematical Society
• /
• v.22 no.4
• /
• pp.739-741
• /
• 2009

Given $\alpha$ > 1, there exist $C(1/\alpha)$-polynomials of the form $z^n-\sum_{k=0}^{n-1}\;a_kz^k$, where $\sum_{k=0}^{n-1}\;a_k=1$, $a_{n-1}>0$ and $a_k{\geq}0$ for each k. In this paper, we obtain lower bounds for $a_{n-1}$.

• Journal of Integrative Natural Science
• /
• v.10 no.1
• /
• pp.40-42
• /
• 2017

In this note, we study a generalization of a certain polynomial $z^n-{\sum\limits_{k=0}^{n-1}}a_kz^k$, where $\sum\limits_{k=0}^{n-1}a_k=1$, $a_k{\geq}0$ for each k, whose all zeros except for z=1 lie on the circle of radius 1/2 with center at the origin.