• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.165-168
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• 2016

카메라 캘리브레이션은 실제 세상인 3차원의 좌표와 카메라가 만든 영상의 2차원 좌표 사이에서 수학적 관계를 알기 위해서 필요하다. 보통 체커보드의 교점을 이용하여 2차원의 좌표를 정확하게 찾는데 사용하며, 이는 카메라 캘리브레이션 계산으로 응용된다. 따라서 체커보드의 교점을 정확하게 찾아야만 카메라 캘리브레이션이 정상적인 성능을 낼 수 있다. 현존하는 체커보드 검출 방법은 입력 인수를 많이 필요로 하거나 정확도가 낮아 체커보드의 교점을 정확히 입력하지 못하면 좋지 않은 결과가 나타난다. 따라서 체커보드를 자동으로 검출하여 카메라 캘리브레이션 하는 방법은 아직 신뢰도가 낮은 편이다. 본 논문에서는 보다 안정적인 카메라 캘리브레이션을 위해서 체커 보드의 검출 성능을 높이고자 한다. 주위 픽셀들간의 미분 값을 기준삼아 검출된 교점들을 이용하여 체크 모양의 직선을 추측한다. 이 직선을 이용하면 장애물이 있거나 노이즈가 있어서 검출하기 어려운 교점들이 있는 경우에도 교점 보간 (point interpolation) 방법을 사용하여 나머지 교점들을 찾을 수 있다. 보간 과정을 통해서 검출에 방해가 되는 요소들이 있는 상황에서 체커 보드 교점 검출의 성능을 높이도록 하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.2
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• pp.43-50
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• 2018

The camera is a key element in image-based three-dimensional positioning, and camera calibration, which properly determines the internal characteristics of such a camera, is a necessary process that must be preceded in order to determine the three-dimensional coordinates of the object. In this study, a new methodology was proposed to determine interior orientation parameters of a camera semi-automatically without being influenced by size and shape of checkerboard for camera calibration. The proposed method consists of exterior orientation parameters estimation using quaternion, recognition of calibration target, and interior orientation parameter determination through bundle block adjustment. After determining the interior orientation parameters using the chessboard calibration target, the three-dimensional position of the small 3D model was determined. In addition, the horizontal and vertical position errors were about ${\pm}0.006m$ and ${\pm}0.007m$, respectively, through the accuracy evaluation using the checkpoints.

• Annual Conference of KIPS
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• 2006.05a
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• pp.1377-1380
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• 2006

사회가 풍요롭고 생활수준이 높아짐에 따라 사람들은 자신의 건강상태에 신경을 많이 쓰고 있다. 또한 유비쿼터스 시대가 시작되면서 언제 어디서든 간단하고 편하게 건강 상태를 체크할 수 있는 시스템이 필요하게 되었다. 이 시스템은 일상생활에서 시간과 장소의 제약 없이 개인이 자신의 심박변이도 상태를 체크 할 수 있다. 보통 큰 병원에서나 사용 해야만 했던 부담감 대신 항상 스스로 자신의 건강상태를 확인하여 그 결과에 따라 맞게 대처 할 수 있다. 브레드 보드와 마이컴을 이용하여 SPO2 센서를 통해 들어온 신호를 PDA로 전송하고, 측정된 HRV(Heart Rate Variability : 심박변이도) 신호를 임베디드 시스템을 이용하여 PDA의 화면에 그래프로 나타내는 GUI 환경의 시스템이다.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.1
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• pp.25-30
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• 2017

Currently, most of the grain sorter uses CCD optic camera to find defective products. The aim of this paper is to use the CCD camera, and aim for improving the sorting power of the grain separator by using NIR(Near Infrared Radiation) sensor based on moisture content measurement algorithm. We intend to develop a system to develop an NFC imaging system in real time by developing an NIR imaging system and developing the grain sorter system that is considered to be defective in real time by checking the internal moisture content of the raw material in the real time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.477-479
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• 2017

With the recent advances in medical technology and health care, the prevention and treatment of diseases has developed. Accordingly aging has rapidly progressed. In this life span and aging society, demand for diagnostic centered medical care is increasing rapidly. In this paper, we propose a wearable patient check system based on FPGA that can be controlled by sensors. In the existing hospital, a doctor or nurse visited the patient every hour to check the condition. However, in this paper, patients, doctors and nurses can check the patient's condition at the desired time using patient check system. In addition, the tilt sensor is used for the patient who is uncomfortable to easily control. The proposed FPGA-based hardware architecture consists of an algorithm for enlarged image processing, a TFT-LCD Controller, a CIS Controller, and a Memory Controller to output the patient's status image. Implemented and validated using the DE2-115 test board with Cyclone IV EP4CE115F29C7 FPGA device and its operating frequency is 50MHz.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.143-154
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• 2002

Recently, new appliances have become built-in ethernet Port but most of the old devices have serial port. So, it complicates and needs long time to maintain at a long distance. It can only controllable and fixable using modem. In this paper, we developed an embedded STEP converter within Linux operating system and other application software so that serial devices(PBX) can control in the ethernet network After completion of development processes, test was conducted. In the remote places, it was connected the STEP converter and controled the serial PBX. Finally, we confirmed that it can apply to other equipments.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.2
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• pp.143-152
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• 2001

Objects : The aim of this study was to determine whether the P3 elicited by the negative emotional stimuli is different to that by positive stimuli. Methods : We measured the event-related potentials, especially P3 elicited by the facial photographs in 12 healthy subjects. Subjects were instructed to feel and respond to the rare target facial photographs imbedded in frequent non-target checkerboards. Results : We found that amplitude of P3 elicited by negative emotional photographs was significantly larger than that by the positive stimuli in healthy subjects. Conclusion : These findings suggest that P3 elicited by facial stimuli may be used as a psychophy-siological variable of the emotional processing.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.8
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• pp.309-314
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• 2014

To generate a complete 3D model from depth images of multiple RGB-D cameras, it is necessary to find 3D transformations between RGB-D cameras. This paper proposes a convenient view calibration technique using a spherical object. Conventional view calibration methods use either planar checkerboards or 3D objects with coded-pattern. In these conventional methods, detection and matching of pattern features and codes takes a significant time. In this paper, we propose a convenient view calibration method using both 3D depth and 2D texture images of a spherical object simultaneously. First, while moving the spherical object freely in the modeling space, depth and texture images of the object are acquired from all RGB-D camera simultaneously. Then, the external parameters of each RGB-D camera is calibrated so that the coordinates of the sphere center coincide in the world coordinate system.

• Smart Media Journal
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• v.4 no.2
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• pp.17-25
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• 2015

In this paper proposes an idea for using NFC(Near Field Communication) on smalt mobile devices, you can easily control the electric wheelchair system. In this system with previous researches controlled a power wheelchair in a mobile device using Bluetooth communication, the board communicates with the integrated control of the wheelchair. With smart mobile devices, the wheelchair control board integrating the signal generated by checking real time so that the user can easily monitor the state of the wheelchair. Users are using smalt mobile devices, the wheelchair can be controlled easily, and the setting at any time according to the state of the individual and can be used. HEX format control is directly in hardware, allowing analysis was read, the user settings are typically used to match cards which support NFC technology such as bus card for registration, storing the selected information and enable read and were applicable. By applying this system, wheelchairs oriented aids disabled and older people able to access to provide with stability.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.186-194
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• 2008

This paper has implemented a ubiquitous healthcare system that can measure and check the electrocardiogram of a human body in anytime and anywhere. The implemented prototype is composed of electrocardiogram measurement terminal, data gathering base node, and medical information server. The implemented node constructs a sensor network using the Zigbee protocol and the TinyOS is installed on each node. The data gathering base node is linux-based node that can transfer sensed medial data through wireless LAN. And, the medical information server stores the processed medical data and can promptly notify the urgent status to the connected medical team. Through experiment, we confirmed the possibility of ubiquitous healthcare system based on sensor network using the Zigbee.