• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.769-774
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• 2019

The development of information technology in a software-centered society as of today is a very important, and the training of software utilizing robots has become popular in recent years. This study proposes efficient SW convergence education by providing curriculum and contents for science + SW convergence education in conjunction with instruction block coding program. It also complements the limitations of existing unstructured chemistry experiment teaching aid, We have developed a 'chemical experiment paradigm' that integrates software education that can be linked with other classes.

• Journal of Drive and Control
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• v.18 no.3
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• pp.8-15
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• 2021

A rear axle steering (RAS) system is attached to the rear of medium and large commercial vehicles that transport large cargo. The existing RAS systems are driven by electro-hydraulic actuator (EHA), and most commercialized EHAs consist of electric motors, hydraulic pumps, relief valves, prefill valves and cylinders. The prefill valve required for such EHAs is a type of check valve with extremely low cracking pressure that should not allow RAS to have noise or vibration, and the prefill valve prevents system negative pressure as well as unstable operation. Most papers on this topic rely on experiments to predict valve performance, and theoretically detailed modeling of valves or pipelines is performed, but it is very rare to evaluate hydraulic vibration characteristics by analysing everything from hydraulic pumps to valves comprehensively. In this study, we proposed an experimental circuit that can predict the performance of the prefill valve. The study also analysed the pressure-flow pulsation that is transmitted to the valve through the pipeline, and how the transmitted pressure-flow pulsation affects the valve vibration.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.1
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• pp.103-109
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• 2021

Fine chips generated by machining have an impact on machine failure and quality of machined products, it is necessary to remove the chips, so the microchip collection and removal device by rotating conveyor belt with neodymium permanent magnets was developed. In this research, to solve the problem for reducing the existing microchips in the tank, a micro-chip removal device by rotating conveyor belt with neodymium permanent magnets developed. In the development of micro-chip removal device, 3D CATIA modeling was used, and the flow analysis and the electromagnetic force analysis were performed with COMSOL Multiphysics program. To evaluate the performance of the prototypes produced, design of experiments (DOE) is used to obtain the effect of neodymium conveyor movement speed on chip removal for the ANOVA analysis of recovered powders. An experiment was conducted to investigate the effect of the conveyor feed rate on the chip removal performance in detail. As a result of the experiment, it was confirmed that the slower the feeding speed of the fine chip removing device, the more efficient the chip removal.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.363-366
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• 2013

오늘날 도난방지, 화재, 범죄예방 등의 안전한 생활을 위한 감시 시스템의 중요성이 강조되고 있다. 이에 영상보안 시장 규모가 급속히 증가하고 있으며 관련 기술도 인공지능을 겸비한 형태로 발전하고 있다. 우리나라도 영상보안 시스템의 수요가 2002년부터 기업과 정부를 중심으로 증가하고 있으며 급속한 성장을 거듭하는 추세는 2012년 이후에도 지속될 전망이다. 특히, 최근에는 적은 대수의 카메라로 보다 넓은 지역을 관찰하고 특정 부분을 확대 관찰할 수 있는 PTZ 카메라의 활용이 증가하고 있다. PTZ 카메라는 카메라에 구동 장치를 추가하여 좌우(Pan), 상하(Tilt)로 카메라의 시점을 이동시킬 수 있으며 특정 부분을 확대하여 관찰할 수 있는 줌(Zoom) 기능을 가진 카메라를 말한다. 이와 같은 장점으로 지능형 PTZ 카메라는 점차 대중화 되고 있다. 하지만, 현재 시중에 판매되는 많은 종류의 PTZ 카메라를 이용한 영상보안 감시는 실제로 사용자들이 동작하고 사용하는데 있어서 많은 문제점을 가지고 있다. 이에 본 논문에서는 카메라 별로 제공하는 상이하고 왜곡된 좌표 값에서 새롭게 가공한 직관적 절대좌표 값을 추출하여 정확한 목표지점으로의 위치이동과 간편한 카메라 조작을 위한 시스템을 설계하였다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.4
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• pp.145-153
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• 2021

Automated Guided Vehicle (AGV) is commonly used in manufacturing plant, warehouse, distribution center, and terminal. AGV is self-driven vehicle used to transport material between workstations in the shop floor without the help of an operator, and AGV includes a material transfer system located on the top and driving system at the bottom to move the vehicle as desired. For navigation, AGV mostly uses lane paths, signal paths or signal beacons. Various predominant sensors are also used in the AGV. However, in the conventional AGV, there is a problem of not turning or damaging nearby objects or AGV in a narrow space. In this paper, a new driving system is proposed to move the vehicle in a narrow space. In the proposed driving system, two sets of the combined steering-drive unit are adopted to solve the above problem. A prototype of AGV with the new driving system is developed for the comparative analysis with the conventional AGV. In addition, the experimental result shows the improved performance of the new driving system in the maximum speed, braking distance and positioning precision tests.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.565-570
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• 2021

Agriculture in South Korea is losing productivity due to the lack of manpower as aging population increases. To overcome this, the agricultural robot market is growing rapidly, and research is being conducted on remote control and autonomous driving of agricultural robots. This work designs the appearance and structure of agricultural robots and implements the devices and control systems for driving. By utilizing and optimizing LiDAR sensors, we applied object recognition technology, which is an essential function for autonomous driving. This can reduce labor costs and improve productivity of transportation tasks that require the most labor in agriculture.

• Composites Research
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• v.20 no.1
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• pp.8-14
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• 2007

Nonlinear aeroelastic analyses of composite wing with flap are performed considering free-play and dynamic stiffness of actuator. Doublet-Hybrid method is used for the calculation of subsonic unsteady aerodynamic forces. Free-play is modeled as a bilinear spring and is linearized by using the describing function method. Dynamic stiffness is obtained from governing equation of gear system and the aeroelastic analyses were performed according to ply-angle of laminate and material. The linear and nonlinear flutter analysis results show that the flutter characteristics are significantly dependent on the free-play and dynamic stiffness. from the nonlinear flutter analysis, various types of limit cycle oscillations are observed in a range of air speeds below or above the linear divergent flutter boundary.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.205-207
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• 2021

The way to develop an IoT device is to mount the sensor required by the application on a platform such as Arduino or Raspberry Pi, and write the sensor driver and application. At this time, if the driving driver for the sensor has already been written and the application can access the driver as a standardized API, then Plug&Play of the sensor will be possible. The old way to do this is because the sensor interface is too complicated to use on the current platform. In this paper, when a standardized sensor and driver with a USB terminal are plugged into the Raspberry Pi, we propose a method for automatically installing the driver. Application developers can get sensor values through Linux's file access API without worrying about sensor drivers. The proposed technique is currently being implemented on Raspberry-Pi.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.21-32
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• 2024

Since leather shoes cannot be washed with water, there is a need for a cleaning method that can remove extraneous substance from the inside and outside of shoes and senitize the inside of shoes without using water. For this purpose, this paper develops a shoes cleaning machine control system that automatically controls the entire process of shoes cleaning in a shoes cleaning machine that quickly cleans the inside and outside of shoes using compressed air, sterilization solution. The developed system uses Rasberry Pi, a general purpose single board computer(SBC), to control various actuators of the shoes cleaning machine. The shoes cleaning machine operated by the developed system shows a sterilization efficiency of more than 99% and an odor removal efficiency of more than 86% in a cleaning time of less than 1 minute.

• Journal of Korean Society of Forest Science
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• v.97 no.1
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• pp.61-70
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• 2008

This study was conducted to develop a mobile tower-yarder with tractor for agriculture and forestry that is the efficient yarder in steep terrains, thinning operation and small scale logging operation. It was designed and manufactured that the power source of tower-yarder is equiped three hydraulic pump connected to PTO of tractor, and three hydraulic pump is used to operate the four motor for drum, the cylinder for clutch of interlocker, the cylinder for tower expanding and the out-rigger cylinder. It was to adopt the running skyline system and the inter-lock function, and to equip the double capstan drum, the storage drum and the clutch for interlock in the development of tower-yarder. It was to develop the tower-yarder which the winch torque of double-capstan drum, the traction force of double-capstan drum, the number of rotation of double-capstan drum and the line speed is $191kg{\cdot}m$, 1,910 kgf, 220.5 rpm and 138.5 m/min, respectively. And it was known that the optimum flange diameter of the main and haulback storage drum is about 360 mm and about 460 mm in order to storage the main line length of 250m and the haulback line length of 450 m. The carriage was made to adopt the running skyline system and to equip the lock function in order to the convenience of chocking and the fall down preventing of tree. It was provided to develop the wire remote controller for the inter-lock function, the convenience of control and the efficiency of yarding. In development process, this tower-yarder was attached the 3-point linkage hitch equipment and the tire wheel for the traction and moving of tower-yarder. Also, it was equipped that the out-rigger and the guy line in order to raise the safety and efficiency of yarding of tower-yarder.