• Journal of Platform Technology
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• 제6권4호
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• pp.3-10
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• 2018

A projection-based active information display system was proposed. The proposed system is based on Intelligent Space and a steerable projector mounted mobile robot which is called Ubiquitous Display (UD). In order to transfer visual information for a human in the Intelligent Space, the UD projects a certain shape of an image with a fixed size. Due to redundancy of degree of freedom (DOF), there are lots of situations to project a same shape and size of the image on a surface. In this paper, we describe a method to determine a goal posture of the UD. Here, the goal posture is the most efficient position and orientation of the UD so as to project visual information and it is determined by the Intelligent Space. To verify the proposed method, simulation and demonstration are carried out.

• 한국표면공학회지
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• 제42권6호
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• pp.301-310
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• 2009

Recently, it has been increasing for the eco-environment plating and surface treatment of eco-environment to decrease hazardous materials. Particular eco-environment can be applied to electronics or automotive parts of industry. In the case of mobile phone, if there were fired, the products bearing dye may be contaminated with the hazardous and wasted. we can obtain the original metal color by electro coloring by metal salt, get rid of hazardous gas, decrease the wasted sludges. Now, the industrial patent number is increasing in Korea, we can accomplish the development of green industry by supporting technical trend of the plating and surface treatment in eco-environment.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1047-1050
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• 2013

Molecular dynamic simulations were performed to examine the wetting behavior of a graphite surface textured with nanoscale pillars. The contact angle of a water droplet on parallelepiped or dome-shaped pillars was investigated by systematically varying the height and width of the pillar and the spacing between pillars. An optimal inter-pillar spacing that gives the highest contact angle was found. The droplet on the dome-covered surface was determined to be more mobile than that on the surface covered with parallelepiped pillars.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.76-77
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• 2013

스마트폰 화면의 대형화와 테블릿 PC 비중 확대와 더불어 모바일용 터치스크린의 평균 면적이 확대됨에 따라 휴대폰 터치 글라스상의 ITO의 단락을 방지하기 위하여 carbon black을 이용한 스퍼터링 공법을 진행하였으며, 최적 증착 조건 도출 및 기존 인쇄 방식과 대등한 투과도 수치를 확보하였다.

• 재활복지공학회논문지
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• 제8권3호
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• pp.187-196
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• 2014

본 논문은 경사로에 위치하는 Mobile Walker의 안전성 확보를 위한 직진성 향상알고리즘을 제안한다. Mobile Walker는 경사면주행 시 로봇의 무게와 경사도에 의한 외력으로 인해 경로 이탈을 하게 된다. 이를 보정하기 위해 본 논문에서는 노면의 기울기에 따른 외력을 추정하고, 이를 모터출력에 가감하는 제어기를 사용하였다. 또한 사용자가 입력하는 목표 회전각속도와 로봇의 회전각속도와의 비교를 통해 각 구동축에 가중치를 인가하는 알고리즘을 사용하였다. 제안한 보정 제어기를 적용한 결과, 경사면 이동 시 이탈거리는 무보정 실험의 경우 발산하지만 경사로 보정 알고리즘을 적용하였을 경우에는 이탈거리가 최대 10cm 이내로 안정적인 주행을 하는 것을 확인할 수 있었으며, 이탈거리 변화율 또한 1m 이후 안정화되어 더 이상의 변화가 발생하지 않는 것을 확인할 수 있었다.

• Journal of Korean Vacuum Science & Technology
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• 제6권2호
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• pp.105-107
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• 2002

a-C:H films were coated on windows of mobile telephone by RF plasma chemical vapor deposition equipment made in our company. Thickness of the coatings is about 0.7 micrometers and they have high hardness, low friction coefficient, good adhesion, high optical transparency and chemical inertness. Knoop hardness of the diamond-like carbon films on glass substrate is 2328 kg/mm$^2$. The adherence between films and substrate is good and shows to be 69 N by scratching test. The optical performance is improved obviously owing to coat the film on it. The index of the coated windows is 2.5, transmission of visible light is larger than 90%, and transmission of ultraviolet light decreases by 30% and the ultraviolet light can be obstructed obviously. The coated glass also has self-clean effect and decontamination ability. The films have hydrophobic character and the soakage angle of water drop is larger than 90 degrees. The windows have fog-proof ability owing to eliminate the capillary phenomena in the inner surface. The physics and chemical properties of the coated windows are steady. Study indicates that the performance of a-C:H coated mobile phone windows are improved notably on wear-resistance, corrosion-proof and optical properties and it is excellent mobile windows protective coatings.

• 한국압력기기공학회 논문집
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• 제16권1호
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• pp.84-91
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• 2020

The APR1400 reactor stud holes can be stuck due to high temperatures, high pressure, prolonged engagement, and load changes according to pressure changes in the reactor. Threaded surfaces of a stud hole should be cleaned for the sealing of pressure in reactor vessel by removing any foreign materials which may exist in the stud holes. Human workers can access to the stud hole for the cleaning of stud holes manually, but the radiation exposure of human workers is increased. Robot is an effective way to work in hazardous area. So we introduced robot for the cleaning of stud holes. Localization of mobile robots is generally based on odometry, but with increased mileage, position errors can be accumulated. In order to eliminate cumulative error and to ensure stability of its driving, laser sensors and new control algorithm were utilized. The distance between the robot and the wall was measured by laser sensors, and the control algorithm was implemented so as to travel the desired trajectory by using the measured values from sensors. The performance of driving and hole sensing were verified through field application, and mobile robot was confirmed to be applicable to the APR 1400 NPP.

• 한국기계가공학회지
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• 제15권6호
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• pp.9-15
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• 2016

Due to material-specific vulnerabilities, the surfaces of the liquid crystal glasses used in mobile phones can crack easily, with even the smallest cracks undergoing propagation. To protect the glass surfaces, films are attached to the surfaces during the mobile phone production process. However, after machining the liquid crystal, removal of the film on the liquid crystal surface using chemical and mechanical methods is required. In this research, a peeling apparatus was developed for removing the films attached to liquid crystal surfaces during the production process. Mechanical attachment and design automation through experimentation and finite element modelling were performed to confirm the validity of the design.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.521-525
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• 2011

Lane marking detection is one of important issues in the field of autonomous mobile robot. Especially, in urban environment, like pavement roads of downtown or tour tracks of Science Park, which have continuous patterns on the surface of the road, the lane marking detection becomes more important ability. Although there were many researches about lane detection and lane tracing, many of them used vision sensors mainly to detect lane marking. In this paper, we obtain 2 dimensional library data of 'Intensity' and 'Distance' using one laser rangefinder only. We design a simple classifier and filtering algorithm for the lane detection which uses only one LRF (Laser Range Finder). Allowing extended usage of LRF, this research provides more functionality not only in range finding but also in lane detecting to mobile robots. This work will be technically helpful for robot developers to design more simple and efficient autonomous driving system using LRF.

• 로봇학회논문지
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• 제18권4호
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• pp.427-435
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• 2023

This paper proposes a method of estimating the pose of a mobile robot by using a learning model. When estimating the pose of a mobile robot, wheel encoder and inertial measurement unit (IMU) data are generally utilized. However, depending on the condition of the ground surface, slip occurs due to interaction between the wheel and the floor. In this case, it is hard to predict pose accurately by using only encoder and IMU. Thus, in order to reduce pose error even in such conditions, this paper introduces a pose estimation method based on a learning model using data of the wheel encoder and IMU. As the learning model, long short-term memory (LSTM) network is adopted. The inputs to LSTM are velocity and acceleration data from the wheel encoder and IMU. Outputs from network are corrected linear and angular velocity. Estimated pose is calculated through numerically integrating output velocities. Dataset used as ground truth of learning model is collected in various ground conditions. Experimental results demonstrate that proposed learning model has higher accuracy of pose estimation than extended Kalman filter (EKF) and other learning models using the same data under various ground conditions.