• Journal of Advanced Navigation Technology
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• v.6 no.2
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• pp.113-118
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• 2002

In this paper, an internal GPS antenna for mobile phones is designed and fabricated. For the miniaturization of the antenna, high permittivity dielectric substrate((${\varepsilon}_r$=90) and small ground plane ($13mm{\times}13mm$) are used. To increase the receive gain, the antenna is composed with LNA(Low Noise Amplifier). Results of the manufactured antenna($13mm{\times}13mm{\times}8mm$) show that the maximum antenna gain is about 12 dBi, the axial ratio is less than 3 dB, and the current consumption of LNA is less than 4 mA.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.371-376
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• 2006

Digital high resolution cameras are widely available, and are increasingly use in digital close-range photogrammetry. And photogrammetry instruments are developing rapidly and the precision is improving continuously. The building of 3D terrains of high precision are possible and the calculation of the areas or the earthwork volumes have high precision due to the development of the technique of the spatial information system using computer. Using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D modeling of high-accuracy in pixel degree through digital close-range photogrammetry with bundle adjustment for digital elevation model generation.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.223-226
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• 2000

Currently a multichannel system for virtual 3-D sound rendering is under development. Robust sound image formation and smooth real time interactivity are main design Points. The system utilizes VBAP algorithm as virtual sound image positioning. Overall system settings can be easily configured. We developed software, RIMA. as a driving Program of the system. At this stage, it is possible to position virtual sound images at arbitrary positions in three-dimensional space. The characteristics of the system are discussed. The system has been applied to the KAIST Bicycle Simulator to generate the virtual sound field.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.848-851
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• 2002

Recently, there are lots of concerning on the integration of robot and virtual reality with the trends of the research of intelligent robot and mined reality. In this paper, a 3D GUI system is proposed based on Internet for remote controlling and monitoring of agent robot working for itself. The proposed system is consists of a manager ordering a new position and displaying the motion of robot, an agent robot moving to the destination according to the indication, a positioning module detecting the current position of robot, and a geographical information module. A user can order the robot agent move to a new position in a virtual space and watch the real images captured from the real sites of the robot. Then, the agent robot moves to the position automatically with avoiding collision by using range finding and a path detection algorithm. We demonstrate the proposed 3D GUI system is supporting a more convenient remote control means far the robots.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.417-421
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• 2004

최근 들어 사진측량은 광센서 및 컴퓨터기술 발전과 같은 관련분야의 발전과 자료처리과정의 자동화 및 사용자의 편의성에 대한 요구로 수치사진측량(Digital Photogrammetry)이라는 새로운 학문분야로 발전하고 있다. 수치사진측 량은 지형지물 및 자연환경에 대한 기하(geometric), 복사(radiometric) 및 의미적(semantic) 정보를 수치영상으로부터 획득하는 기술로 정의되고 있다. 그 적용분야 역시 크게 증가하여 사회 전반에 응용되고 있으며 앞으로 GPS(Global Positioning System), GIS(Geographic Information System) 및 RS(Remote Sensing)와 연계되어 발전 및 응용의 잠재력이 클 것으로 예상된다. 따라서 본 연구에서는 수치사진측량의 발전과정 및 정확한 지형자료의 해석을 중심으로 수치사진측량에 의한 영상 정보를 보다 쉽고, 정확하게 해석하여 정보 취득 관한 적용 가능성을 제시하고, 도시지역의 지상 D/B자료와 지하시설물 D/B를 하나의 3차원 시각화로 나타냄으로써 도시의 모든 시설물을 통합하여 보다 효과적인 유지ㆍ관리, 재해방지, 합리적 의사결정에 기여하고자 한다.

• Journal of Sensor Science and Technology
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• v.32 no.5
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• pp.300-306
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• 2023

A hull-cleaning robot sticks to the surface of a vessel and moves for efficient cleaning. Precise path planning and tracking using the current position is crucial. Many robots rely on the INS algorithm, but errors accumulate. To fix this, GPS, sonar, and USBL are used, though with limitations. Selecting suitable sensors for the surface operation and accurate positioning algorithm are vital. In this study, we developed a robot position estimation algorithm using the structure of a ship. Problems that arise when expanding the 2D position estimation algorithm used in existing wall structures to 3D were evaluated and methods for solving them were proposed. In addition, we aimed to improve performance by deriving singularities that exist in the robot path and proposing an error correction algorithm based on the singularities.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.2
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• pp.14-20
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• 2006

A controller design procedure for an electro-hydraulic positioning systems has been developed using $H{\infty}$ control. The generalized plant models and weighting function for multiplicative uncertainty modelling error was presented along with $H{\infty}$ controller designs in order to investigate the robust stability and performance. Both disturbance rejection and command tracking performances were improved with the $H{\infty}$ controller, and the better uniformity of time response is achieved across wide range of operating conditions than the PID, LQR and LQG control scheme. The multiplicative uncertainty case was specifically suited for the design of an electro-hydraulic positioning control systems using $H{\infty}$ control.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.6
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• pp.566-573
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• 2004

This paper describes the ubiquitous home network (uHome-net) testbed and LonRF intelligent devices based on LonWorks technology. These devices consist of Neuron Chip, RF transceiver, sensor, and other peripheral components. Using LonRF devices, a home control network can be simplified and most devices can be operated on LonWorks control network. Also, Indoor Positioning System (IPS) that can serve various location based services was implemented in uHome-net. Smart Badge of IPS, that is a special LonRF device, can measure the 3D location of objects in the indoor environment. In the uHome-net testbed, remote control service, cooking help service, wireless remote metering service, baby monitoring service and security ＆ fire prevention service were realized. This research shows the vision of the ubiquitous home network that will be emerged in the near future.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.297-305
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• 2021

Monocular depth estimation helps the robot to understand the surrounding environments in 3D. Especially, deep-learning-based monocular depth estimation has been widely researched, because it may overcome the scale ambiguity problem, which is a main issue in classical methods. Those learning based methods can be mainly divided into three parts: supervised learning, unsupervised learning, and semi-supervised learning. Supervised learning trains the network from dense ground-truth depth information, unsupervised one trains it from images sequences and semi-supervised one trains it from stereo images and sparse ground-truth depth. We describe the basics of each method, and then explain the recent research efforts to enhance the depth estimation performance.

• Journal of the Korean Society for Railway
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• v.10 no.3 s.40
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• pp.343-349
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• 2007

The flow velocity distribution at inlet and exit of a DPF was measured using a Pitot tube and 2-D positioning equipment. An adaptor which was designed for accessing the Pitot tube probe into inlet of the DPF was fabricated with inlet flange of the DPF. The Pitot tube which was mounted in the 2-D positioning machine could access to the inlet of the DPF through the rectangular window of the adaptor. Automation of the velocity measurement at the inlet and exit of the DPF was effectively achieved and measuring time was reduced drastically. The flow velocity distribution at the inlet of the DPF showed parabola shape with maximum velocity near to the center of the DPF, as expected. The velocity distribution at the exit of the DPF showed crown shape, that is, the flow velocity distribution near to the center of the DPF is lower than that at surrounded peripheral region of the DPF.