• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.1
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• pp.69-76
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• 2005

The purpose of this study was to establish the accuracy of the industrial photogrammetry system constructed with INCA2 metric camera and V-STARS system on steel box girder measurement under industrial measurement condition. The objective of the measurement was to determine the distances of plane to plane or plane to libs, precise positions of the bolt holes and angles of the plane to plane on the steel box girder using coded targets, tape targets, edge targets and target adapters. The measurement undertaken has shown that industrial photogrammetry method were a very accurate and more importantly were produced quickly to measure the steel box girder.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.43-49
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• 2020

Along side with the rapid growth of local governments' advertising bills, there are few studies focused on the effectiveness of these ads. Especially one of the media being used by the local governments is the Korea Express Train (KTX), where they advertise in the train coaches' KTX video monitor. Unfortunately the ads in KTX are exposed without audio mostly. The current study, therefore, probed on the effectiveness of these ads. This study utilized transportation theory and content analysis methodology to give insight to its discourse. We established two analysis units (camera and subtitles), and then analyzed 107 local government ads. From the camera analysis, it is observed that local governments' festival and tour promotion ads more often employ dynamic angles such as drone shot and long shot. Also, from subtitles usage analysis, it is observed that many of the ads make use of large size titles and subtitles which could prevent viewers seeing visual shots. In the special case audio-less KTX ads, this study recommends emphasis on subtitles which will enhance the ad effectiveness of the ad messages.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.5
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• pp.467-473
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• 2007

In this paper, we present a position-based robot hand tracking scheme where a pan-tilt camera is controlled such that a robot hand is always shown in the center of an image frame. We calculate the rotation angles of a pan-tilt camera by transforming the coordinate systems. In order to identify the model parameters, we applied two optimization techniques: a nonlinear least square optimizer and a particle swarm optimizer. From the simulation results, it is shown that the considered parameter identification problem is characterized by a highly multimodal landscape; thus, a global optimization technique such as a particle swarm optimization could be a promising tool to identify the model parameters of a robot hand tracking system, whereas the nonlinear least square optimizer often failed to find an optimal solution even when the initial candidate solutions were selected close to the true optimum.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.51.2-51.2
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• 2016

Hayabusa, the Japanese asteroid sample returning mission, acquired more than 1400 scientific images of its target asteroid (25143) Itokawa using the Asteroid Multi-band Imaging Camera (AMICA). It took images at a wide coverage of the phase angle a (Sun-Itokawa-Hayabusa) from $a{\sim}0^{\circ}$ to ${\sim}35^{\circ}$, providing a unique opportunity for studying the opposition effect (a sharp surge in brightness of asteroidal surface). Here we present a study of the opposition effect on Itokawa using the AMICA multi-band data. We found that (1) the opposition strength near the opposition is independent of the incident/emission angles of the light, also (2) it weakly depends on the wavelength showing the strongest surge around 0.7 um, and (3) the reflectance increases linearly at a>$1.5^{\circ}$ while nonlinearly at a<$1.5^{\circ}$ as approaching the opposition point. In particular, we noticed that the increasing rate has a correlation with the reflectance in the nonlinear domain whereas no detectable correlation with the reflectance in the linear domain. From these results, we conjecture that the coherent backscattering opposition effect is a dominant mechanism for the nonlinear opposition surge at a<$1.5^{\circ}$ while shadow hiding opposition effect is responsible for the linear opposition surge at a>$1.5^{\circ}$.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.1
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• pp.27-35
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• 2013

This paper proposes a face tracking algorithm for a viewpoint adaptive multi-view synthesis system. The original scene captured by a depth camera contains a texture image and 8 bit gray-scale depth map. From this original image, multi-view images that correspond to the viewer's position can be synthesized using geometrical transformations, such as rotation and translation. The proposed face tracking technique gives a motion parallax cue by different viewpoints and view angles. In the proposed algorithm, the viewer's dominant face, which is established initially from a camera, can be tracked using the statistical characteristics of face colors and deformable templates. As a result, a motion parallax cue can be provided by detecting the viewer's dominant face area and tracking it, even under a heterogeneous background, and synthesized sequences can be displayed successfully.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.2
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• pp.227-233
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• 2015

In this study, an indoor test environment was developed for studying the vision stabilizer of an unmanned vehicle, using a virtual environment and a 6-axis motion simulator. The real driving environment was replaced by a virtual environment based on the Aberdeen Proving Ground bump test course for military tank testing. The vehicle motion was reproduced by a 6-axis motion simulator. Virtual reality driving courses were displayed in front of the vision stabilizer, which was located on the top of the motion simulator. The performance of the stabilizer was investigated by checking the image of the camera, and the pitch and roll angles of the stabilizer captured by the IMU sensor of the camera.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.392-395
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• 2006

This paper presents the experimental results at slamming phenomenon. The air pressure cylinder was used to ensure repeatability of the impact. The results showed that the adopted experimental technique was very excellent in terms of repeatability when is compared to that of the free drop tests. The pressure time histories, magnitude of peak pressure and the behavior of jet spray were obtained. The flat specimen was tested for various incident angles. To estimate the incident speed of the specimen high speed camera was used. The high speed camera was also useful tool in understanding the behavior.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.2
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• pp.244-250
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• 2003

In this paper, the relationship between a slave robot and the uncertain remote environment is modeled as the impedance to generate the virtual force to feed back to the operator. For the control of a tele-operated mobile robot equipped with camera, the tele-operated mobile robot take pictures of remote environment and sends the visual information back to the operator over the Internet. Because of the limitation of communication bandwidth and narrow view-angles of camera, it is not possible to watch the environment clearly, especially shadow and curved areas. To overcome this problem, the virtual force is generated according to both the distance between the obstacle and robot and the approaching velocity of the obstacle. This virtual force is transferred back to the master over the Internet and the master(two degrees of freedom joystick), which can generate force, enables a human operator to estimate the position of obstacle in the remote environment. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. This force reflection improves the performance of a tele-operated mobile robot significantly.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.105-108
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• 2002

Highly swept leading edge extension(LEX) applied to delta wings has greatly improved the subsonic maneuverability of contemporary fighters. In this study, systematic approach by PIV experimental method within a circulating water channel was adopted to study the fundamental characteristics of induced vortex generation, development and its breakdown appearing on a delta wing model with or without LEX in terms of four angles of attack$(15^{\circ},\;20^{\circ},\;25^{\circ},\;30^{\circ})$ and six measuring sections$(30\%,\;40\%,\;50\%,\;60\%,\;70\%,\;80\%)$ of chord length. Distributions of time-averaged velocity vectors and vorticities over the delta wing model were compared along the chord length direction. High-speed CCD camera which made it possible to acquire serial images is able to get the detailed information about the flow characteristics occurred on the delta wing. Especially quantitative comparison of the maximum vorticity featuring the induced pressure distribution were also conducted to clarity the significance of the LEX existence.

• Smart Structures and Systems
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• v.24 no.6
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• pp.745-757
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• 2019

Road surface deteriorations such as potholes have caused motorists heavy monetary damages every year. However, effective road condition monitoring has been a continuing challenge to road owners. Depth cameras have a small field of view and can be easily affected by vehicle bouncing. Traditional image processing methods based on algorithms such as segmentation cannot adapt to varying environmental and camera scenarios. In recent years, novel object detection methods based on deep learning algorithms have produced good results in detecting typical objects, such as faces, vehicles, structures and more, even in scenarios with changing object distances, camera angles, lighting conditions, etc. Therefore, in this study, a Deep Learning Pothole Detector (DLPD) based on the deep region-based convolutional neural network is proposed for autonomous detection of potholes from images. About 900 images with potholes and road surface conditions are collected and divided into training and testing data. Parameters of the network in the DLPD are calibrated based on sensitivity tests. Then, the calibrated DLPD is trained by the training data and applied to the 215 testing images to evaluate its performance. It is demonstrated that potholes can be automatically detected with high average precision over 93%. Potholes can be differentiated from manholes by training and applying a manhole-pothole classifier which is constructed using the convolutional neural network layers in DLPD. Repeated detection of the same potholes can be prevented through feature matching of the newly detected pothole with previously detected potholes within a small region.