• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1034-1037
• /
• 2003

Recently in the field of precision positioning device, the contact-free actuators are gaining focuses with their outstanding performances by eliminating mechanical frictions. Th is paper is about the driving algorithm for contact-free linear actuator. The proposed driving algorithm has similar structure of drives of switched reluctance motor and reduces the normal forces and force ripple. The simulation and experiment are executed to verify the proposed method.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10c
• /
• pp.375-377
• /
• 1998

실생활에서 사용되는 은행전표에는 많은 숫자 항목이 포함되어 있다. 이 항목들에 나타나는 숫자들은 단순히 숫자들의 배열이 아니라 콤마나 하이픈 등이 포함되어 있으며 많은 경우 숫자들끼리 서로 접촉되어 있다. 본 논문에서는 이런 시중 은행에서 사용되는 전표의 필기 숫자 항목을 처리하기 위한 시스템을 제안하고 이 효용성을 확인하기 위한 실험결과를 보였다. 실험은 크게 숫자분할 알고리즘에 대한 실험과 전체 시스템 성능에 대한 실험으로 나뉜다. 접촉된 두 숫자의 분할 알고리즘 성능 결과는 78.1%의 분할 성공률을 보였고 은행전표의 필기숫자 항목에 적용 결과는 53.5%였다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.9
• /
• pp.983-989
• /
• 2011

A numerical algorithm for predicting fretting wear was developed using the boundary element method (BEM). A contact analysis was performed numerically using the relation between the elastic displacement and uniformly distributed loading of a rectangular patch on a semi-infinite solid. Geometrical updating based on nodal wear depths was performed. The wear depths were computed using the Archard's equation for sliding wear. In order to investigate the efficiency of BEM for predicting fretting wear, a problem involving a two-dimensional cylinder on a flat contact was analyzed, comparing it with the simulation model proposed by McColl et al. that was based on the finite element method. The developed method was then applied to the analysis of a spherical contact and it was shown that the developed simulation technique could efficiently predict fretting wear. Moreover, the effect of a step cycle on the solution obtained by the developed method was investigated.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.12
• /
• pp.148-158
• /
• 2003

In this paper, efficient and accurate contact search algorithm is proposed for the contact problems by the finite element method. A slave node and a maser contact segment is defined using the side of a finite element on the contact surface. The specific goal is to develop techniques of reducing the nonsmoothness of the contact interactions arising from the finite element discretization of the contact surface. Contact detection is accomplished by monitoring the territory of the slave nodes throughout the calculation for possible penetration of a master surface. To establish the validity of the proposed algorithm, some different process and geometries examples were simulated. Efforts are focused on the error rate that is based on the penetrated area through the simulations fur large deformation with contact surface between deformable bodies. A proposed algorithm offers improvements in contact detection from the simulation results.

• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1987-1989
• /
• 2003

3차원 형상을 측정하는 측정법으로는 접촉식과 비접촉식이 있는데 최근에는 물체의 표면을 손상 시키지 않으면서 물체의 변형 상태 등을 정밀하게 측정할 수 있는 비접촉식 측정법이 주로 사용되어 지면서 변형, 진동, 결함 등의 다양한 측정 분야에 찰용되고 있다. 이는 광학 간섭의 하나인 Twyman-Green 간섭계를 이용하여 간섭 무의 패턴을 PZT Controller로 위상 이동하여 CCD 카메라로 물체의 영상을 얻어 위상 지도를 추출, 이미지를 분석하여 3차원 물체를 해석하고자 한다. 하지만 이미지 측정시 미세 진동 및 조명 등에 의한 노이즈가 발생하게 되어 물체의 정확한 정보를 얻기가 어려워 노이즈 제거를 위한 이미지 처리 알고리즘 개발과 Unwrapping 처리, 위상이동 알고리즘 개발 등을 통하여 좀더 정확한 정보를 얻고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.2
• /
• pp.199-204
• /
• 2017

In this study, we present a home appliance load identification algorithm. The algorithm utilizes complex sensory data in order to improve the existing NIALM using total power usage information. We define the influence graph between the appliance status and the measured sensor data. The device identification prediction result is calculated as the weighted sum of the predicted value of the sensor data processing algorithm and the predicted value based on the total power usage. We evaluate proposed algorithm to compare appliance identification accuracy with the existing NIALM algorithm.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.12 no.3
• /
• pp.363-370
• /
• 1999

This study presented an modeling method for the connections in mixed structure with reinforced concrete columns and steel beam using finite element method. The contacting surfaces between concrete and steel are modeled using master-slave contact algorithm and the incompatible mode elements were used in the steel tube subjected to bending. The characteristics of mixed structure was that diaphragm was used for transferring force from beam to column. The three dimensional nonlinear analysis was performed and the analytical results compared with experimental results in order to prove modeling method.

• Proceedings of the KAIS Fall Conference
• /
• 2011.05b
• /
• pp.583-585
• /
• 2011

이 논문에서는 비접촉 방식의 심박 및 호흡 검출이 가능한 FFT를 이용하는 새로운 검출 방식의 알고리즘을 제안한다. 기존 FFT 방식은 주파수 도메인에서 필터링을 수행한 후 IFFT 후 특징점 추출 알고리즘을 수행하여 심박 및 호흡을 추출한다. 이 논문에서는 제안된 FFT 방식을 사용하여 기존의 FFT 방식과 달리 FFT를 한 후 주파수 영역에서 바로 심박수 및 호흡수를 추출할 수 있음을 제안한다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.6
• /
• pp.659-665
• /
• 2010

This paper proposes a control algorithm for quadruped robots moving on irregularly sloped uneven surfaces. Since the body balance of a quadruped robot is controlled by the forces acting on its feet during touchdown, the ground reaction force (GRF) is controlled for stable running. The desired GRF for each foot is generated on the basis of the desired galloping pattern; this GRF is then compared with the actual contact force. The difference between the two forces is used to modify the foot trajectory. The desired force is realized by considering a combination of the rate change of the angular and linear momenta at flight. Then, the amplitude of the GRF to be applied at each foot in order to achieve the desired linear and angular momenta is determined by fuzzy logic. Dynamic simulations of galloping motion were performed using RecurDyn; these simulations show that the proposed control method can be used to achieve stable galloping for a quadruped robot on irregularly sloped uneven surfaces.

• Smart Media Journal
• /
• v.3 no.2
• /
• pp.14-19
• /
• 2014

This paper presents a novel approach to recognize human gestures using k-NN and DTW based on Con tactless Electronic Potential Sensor(CEPS) in the smart devices such as smart TV and smart-phone in the proposed method, we used a Kalman filter to remove noise on gesture signal from CEPS and a PCA algorithm is utilized for reducing the dimensionality of gesture signal without data losses. And then in order to categorize gesture signals, k-NN classifier with DTW distance measure is considered. In the experimental result, we evaluate recognition performance with CEPS gesutres signal form the above two types of smart devices, and we can successfully identify five different gestures with more than 90% of recognition accuracy.