• Communications of the Korean Mathematical Society
• /
• v.18 no.3
• /
• pp.559-568
• /
• 2003

We introduce the notion of two-scale convergence for partial differential equations with random coefficients that gives a very efficient way of finding homogenized differential equations with random coefficients. For an application, we find the homogenized matrices for linear second order elliptic equations with random coefficients. We suggest a natural way of finding the two-scale limit of second order equations by considering the flux term.

• Journal of the Institute of Convergence Signal Processing
• /
• v.11 no.3
• /
• pp.183-188
• /
• 2010

In this paper we propose a detection method of the medial axis of the continuous stripes on the LoG scale-space. Our method detects the medial axis of continuous stripes iteratively by varying the scale of LoG operator. Small-scale LoG operator detects two +/- pole pairs centered on the edge positions of stripe by the zero-crossing detection. The more increase the scale of LoG scale-space, the more close two poles to the medial axis of stripe. The medial axis of continuous stripe is the position where two poles is overlapped. The proposed method detected robustly the medial axis of continuous stripes stronger than the thinning methods used to binary image.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.2_2
• /
• pp.357-361
• /
• 2024

Halloysite nanotube (HNT) has a nanotube structure with the chemical formula of Al₂Si₂O₅(OH)₄·nH₂O and is a natural sediment of aluminosilicate. HNT has been used as additive to improve the mechanical properties of epoxy composites with exchange of amine group as a terminal functional group using huge amount of organic solvents. In order to save time and simplify complicated procedures, a dry coating machine was designed and used for amine group exchange in previous research. For better applications, it was conducted with different parameters and with scale up settings. Best condition was found to reduce usage of solvent, time and man power.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2000.08a
• /
• pp.337-340
• /
• 2000

조명 및 반사광의 성질에 의해 블러링이 발생하고 이런 영상을 인식하는 경우 정확한 에지 검출이 어렵게 된다. 이를 최적으로 검출하기 위해 일정하게 에지를 검출할 수 있는 가우시안 함수와 2차 미분 함수를 합성한 새로운 하이브리드 함수를 제안하고 실제 영상과 컨볼루션 한 후 함수의 $\sigma$값을 변화시키면서, Canny 알고리즘의 방향성 에지 검출 방법을 적용하여 에지를 검출하였다. 그 결과 Sobel, Robert, Canny 에지 검출방법보다 0.2~14㏈ 정도 안정적으로 에지가 검출되었다.

• Journal of the Korea Convergence Society
• /
• v.7 no.6
• /
• pp.287-295
• /
• 2016

This study was conducted of students in their youth, who were having behavioral and emotional problems, anxiety, depression, and ADHD in their school. The participants took part in equestrian sports programs(equestrian program and apparatus program) twice a week, for 60 minutes each. To make progress in the study, mainly 4 scales are used as the standards of preliminary and post inspections : emotional and behavioral development scale, anxiety scale, depression scale, and ADHD scale. After conducting two-way ANOVA analysis, the conclusion was made as follows. The equestrian sports and horse riding exercise program which were used in this study did had an positive effect on emotional and behavioral scale, depression scale, anxiety scale, and ADHD scale. Moreover, it is determined that the equestrian sports had more positive effects than the equestrian sports which used apparatus. However, to precisely compare and contrast the effects of equestrian sports programs and apparatus programs, the follow-up studies need to limit the control group.

• Journal of the Institute of Convergence Signal Processing
• /
• v.2 no.1
• /
• pp.53-62
• /
• 2001

In this paper, the hybrid function by local scale control is proposed to detect the optimal edges from blurred images. In the case of image capturing, some blurring is occurred by the characteristics of the illumination and the reflected light. During processing the blurred image, it is difficult to detect perfect edges. This algorithm proposed a new hybrid function which is merged Gaussian function and the second derivative of Gaussian function. And it detects the optimal edges applying directional edge detection by Canny algorithm as the scale factor of $\sigma$ in the given local mask has been changed after convolving the hybrid function for input image. In the result, the performance is confirmed that this algorithm is better than Sobel, Robert and Canny edge detector by analyzing the some test images. And the results is obtained 0.2 ㏈ ~ 14 ㏈ of PSNR than those conventional method.

• Journal of the Korea Convergence Society
• /
• v.9 no.7
• /
• pp.337-346
• /
• 2018

The purpose of this study was to identify the characteristics and the attributes related to Internet use in patients with Internet addiction. This study is a descriptive secondary analysis study, at Internet addiction clinics used the data of 63 patients diagnosed with Internet addiction. Data were obtained from Internet addiction clinic Electronic Medical Records(EMR), there was included the Korean Internet addiction scale(K-scale), Beck Anxiety Inventory(BAI), Beck Depression Inventory(BDI), Barratt Impulsivity scale(BIS), Conners ADHD Rating Scale(CAARS), Lubben Social Network Scale(LSNS). K-scale had significantly correlations with Internet use time per day, anxiety, impulsivity, Attention deficit Hyperactivity Disorder(ADHD) symptom. In stepwise multiple regression, factors significantly affecting ADHD symptom (${\beta}=.37$), Internet use time per day(${\beta}=.29$), Impulsivity(${\beta}=.25$), which accounted for 44% of the variance. Results indicate that patients with Internet addiction had psychological difficulties and suggest that children with ADHD needed to intervention for appropriate internet use.

• Journal of the Korean Solar Energy Society
• /
• v.37 no.2
• /
• pp.67-75
• /
• 2017

We have investigated the operating characteristics of $1,600m^2$ large-scale solar thermal system installed in an eco-friendly energy town in Chungbuk Innovation City. The operation criteria of the collecting pump and storage pump were different from the existing standard, and it was confirmed that each pump works well according to the changed criteria. Based on the data of the representative day, the daily collecting heat (efficiency) and the production (storing) heat (efficiency) were estimated. It was confirmed that the daily collecting heat (efficiency) of the flat plate type was higher than that of the evacuated tube type, but the useful heat production was more in evacuated tube type collector.

• Journal of the Korea Convergence Society
• /
• v.4 no.3
• /
• pp.1-5
• /
• 2013

This study deals with simplified load calculation and structural testing for scale down model of small wind turbine blade. First, the blade was designed and produced scale down to 0.2 ratio of initial blade. And moments were acquired by simplified load calculation equations according to IEC 61400-2 standard. Also, structural test using weight was conducted to obtain the maximum moment. Therefore maximum moments were compared at calculation and test.

• Journal of information and communication convergence engineering
• /
• v.2 no.3
• /
• pp.177-181
• /
• 2004

In this paper, we suggest an Iris recognition system with an excellent recognition rate and confidence as an alternative biometric recognition technique that solves the limit in an existing individual discrimination. For its implementation, we extracted coefficients feature values with the wavelet transformation mainly used in the signal processing, and we used neural network to see a recognition rate. However, Scale Conjugate Gradient of nonlinear optimum method mainly used in neural network is not suitable to solve the optimum problem for its slow velocity of convergence. So we intended to enhance the recognition rate by using Levenberg-Marquardt Back-propagation which supplements existing Scale Conjugate Gradient for an implementation of the iris recognition system. We improved convergence velocity, efficiency, and stability by changing properly the size according to both convergence rate of solution and variation rate of variable vector with the implementation of an applied algorithm.