• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.57-63
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• 2007

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154[kV] dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in 154[kV] power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method(FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Journal of KIISE:Software and Applications
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• v.31 no.11
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• pp.1496-1504
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• 2004

In this paper, we propose an algorithm for initializing a target vehicle detection, tracking the vehicle and estimating the distance from it on the stereo images acquired from a forward-looking stereo camera mounted on a road driving vehicle. The process of vehicle detection extracts road region using lane recognition and searches vehicle feature from road region. The distance of tracking vehicle is estimated by TSS correlogram matching from stereo Images. Through the simulation, this paper shows that the proposed method segments, matches and tracks vehicles robustly from image sequences obtained by moving stereo camera.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.47-52
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• 2010

In this paper, we introduce a new approach for real-time 3D face pose discrimination based on active IR illumination from a monocular view of the camera. Under the IR illumination, the pupils appear bright. We develop algorithms for efficient and robust detection and tracking pupils in real time. Based on the geometric distortions of pupils under different face orientations, an eigen eye feature space is built based on training data that captures the relationship between 3D face orientation and the geometric features of the pupils. The 3D face pose for an input query image is subsequently classified using the eigen eye feature space. From the experiment, we obtained the range of results of discrimination from the subjects which close to the camera are from 94,67%, minimum from 100%, maximum.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.483-489
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• 2015

In this paper, we propose monocular visual simultaneous localization and mapping (SLAM) in the large-scale environment. The proposed method continuously computes the current 6-DoF camera pose and 3D landmarks position from video input. The proposed method successfully builds consistent maps from challenging outdoor sequences using a monocular camera as the only sensor. By using a binary descriptor and metric-topological mapping, the system demonstrates real-time performance on a large-scale outdoor dataset without utilizing GPUs or reducing input image size. The effectiveness of the proposed method is demonstrated on various challenging video sequences.

• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.7-13
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• 2012

This paper describes the diagnosis techniques using UV images taken in the field under energized condition of power equipments in order to figure out and analyze the abnormal states on the terminals of power equipments. To classify the features of the terminals, the counted No. of the corona generated at the terminals is defined. According to the result detected, the No. of corona detected on the power equipments installed inside a building is less than that installed outside a building, and it strongly depends on the environment and installed condition. Thus, the environmental condition needs enhanced, and stable operation by the periodic inspection under energized condition of the power equipments is required. Especially, the event counting technique using UV camera is useful for the power equipments apart more than 20 m to apply, and there can be an error due to the features of the sensing techniques when the distance between the user and the objects is close less than 15 m. Therefore, the experimental result shows that event counting technique is employed in the case of the distance more than 15 m. The electrical safety can be ensured by using the UV detection technique and the criteria.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.4
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• pp.289-295
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• 2015

This paper describes a ground monocular vision-based measurement algorithm measuring relative range and position of aircraft using the information of wingspan and optical parameters for the camera. A technique obtaining an aircraft image is also described in this paper. This technique can be used as external measurement for autonomous landing instead of ILS. To verify the performance of these algorithms, flight experiment is performed using light sport aircraft with GPS and monocular camera. Finally we obtained the reasonable RMSE of 1.85m is obtained.

• Journal of Korea Multimedia Society
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• v.20 no.12
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• pp.1865-1873
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• 2017

The feature-based visual SLAM requires 3D positions for the extracted feature points to perform 3D-2D motion estimation. LiDAR can provide reliable and accurate 3D position information with low computational burden, while stereo camera has the problem of the impossibility of stereo matching in simple texture image region, the inaccuracy in depth value due to error contained in intrinsic and extrinsic camera parameter, and the limited number of depth value restricted by permissible stereo disparity. However, the sparsity of LiDAR data may increase the inaccuracy of motion estimation and can even lead to the result of motion estimation failure. Therefore, in this paper, we propose three interpolation methods which can be applied to interpolate sparse LiDAR data. Simulation results obtained by applying these three methods to a visual odometry algorithm demonstrates that the selective bilinear interpolation shows better performance in the view point of computation speed and accuracy.

• Journal of Astronomy and Space Sciences
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• v.11 no.2
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• pp.320-326
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• 1994

The KITSAT-1 (Auguse, 1992) and the KITSAT-2(September, 1993) were successfully launched and operated by the SatRec(Satellite Research Center). Both carry the CCD cameras to monitor the image of the earth. We used the camera bench type automatic equipment in the KSRI(Korea Standards Research Institute) to measure the MTF(Modulation Transfer Function) value of the lens attached to the CCD camera. We measured the tangential MTF and the sagital MTF by varing the f-number and the field angle. According to the result, the light from a point source is focused within one pixel of the CCD chip when the f-number is smaller than 4.0, and the MTF value becomes smaller as the field angle increases.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.448-451
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• 2004

MSC (Multi-Spectral Camera) system is an electro-optical camera system which is being developed to be installed on KOMPSAT-2 satellite. High resolution image data from MSC system will be transmitted to the ground-station through x-band antenna called APS (Antenna Pointing System). APS is a directional antenna which will point to the receiving antenna at ground station while the satellite is passing over it. The APS needs to be controlled accurately to provide the reliable communication with big RF link margin. The APS is controlled by ATS (Antenna Tracking Software) which is included in the MSC software. ATS uses the closed loop control algorithm which will use TPF (Tracking Parameter File) as an input for antenna position, and will use two resolve readings from APS as a feedback. ATS has been developed and verified using APS QM (Qualification Model) and all the control parameters for ATS have been tested and verified. Various kinds of maximum, nominal and realistic dynamics for the APS movement have been simulated and verified. In this paper, closed loop servo control algorithm and obtained APS position error from the verification test with APS QM will be presented in detail

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.601-603
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• 2004

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT -2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of $20\%$ over the mission lifetime of 3 years with the functions of programmable gain! offset and onboard image data compression/storage. MSC instrument has one(1) channel for panchromatic Imaging and four(4) channel for multi-spectral Imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the configuration, the interface of MSC hardware and the MSC operation concept are described. And the method of the MSC calibration are described and the design of MSC calibration operation to measure the change of MSC after Launch & Early Operation(LEOP) and normal mission operations are discussed and analyzed.