• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.764-781
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• 2013

In this paper, we propose a highly precise vehicle detection method with low false alarm using billboard sweep stereo matching and multi-stage hypothesis generation. First, we capture stereo images from cameras established in front of the vehicle and obtain the disparity map in which the regions of ground plane or background are removed using billboard sweep stereo matching algorithm. And then, we perform the vehicle detection and tracking on the labeled disparity map. The vehicle detection and tracking consists of three steps. In the learning step, the SVM(support vector machine) classifier is obtained using the features extracted from the gabor filter. The second step is the vehicle detection which performs the sobel edge detection in the image of the left camera and extracts candidates of the vehicle using edge image and billboard sweep stereo disparity map. The final step is the vehicle tracking using template matching in the next frame. Removal process of the tracking regions improves the system performance in the candidate region of the vehicle on the succeeding frames.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.613-623
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• 2000

Digital TV tuner for 8-VSB modulation was developed with satisfying the requirements of ATSC. The double frequency conversion and the active tracking filter in the front-end were used to reduce interference of the adjacent channels and multi-channels, which suppress If beat and image band. However, it was impossible to get frequency mapping between tracking filter and first VCO(Voltage Controlled Oscillator) in the double conversion digital TV tuner differing from conventional NTSC tuner. This paper, therefore, suggests the available structure and a new method for automatic frequency selection by obtaining the mapping of frequency characteristic over tracking voltage and the combined hardware which compose of Micro-controller, EEPROM, D/A(Digital-to-Analog Converter), OP amp and switch driver to solve above problems.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.6
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• pp.35-41
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• 2007

We proposed an eye gaze tracking system under natural head movements. The system consists of one CCD(charge-coupled device) camera and two front-surface mirrors. The mirrors rotate to follow head movements in order to keep the eye within the view of the camera. However, the mirror controller cannot guarantee the fast head movements, because the frame rate is generally 30Hz. To overcome this problem, we applied Kalman filter to estimate next eye position from the current eye image. In the results, our system allowed the subjects head to move 60cm horizontally and 40cm vertically, with the head movement speed about 55cm/sec and 45cm/sec, respectively. And spatial gate resolutions were about 4.5 degree and 5.0 degree, respectively, and the gaze estimation accuracy was 92% under natural head movements.

• Korean journal of communication and information
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• v.64
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• pp.5-30
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• 2013

This paper conceptualizes the two-faced platform based on interface studies and two-sided market theory to critically analyze today's information technology culture such as the Internet. With this conceptual framework, the Internet can be investigated to have two faces, in which the square of user's openness, sharing, and participation is unfold on the front face, whereas the market of tracking, surveillance, and control of user's activities is formed on the other face. The two faces contradictorily coexist, resulting in technological and cultural dynamics on the Internet. Therefore, the Internet today as a two-faced platform can be described as a square-market interface. By analyzing on transformation of the web architecture, shift of informational commodity from content to data, and web bugs' user tracking across two faces, it examines how the world wide web itself can function as a two-faced platform. Lastly, implications and further works are suggested to improve the two-faced platform as a conceptual framework and to deeply analyze broader information technology culture based on it.

• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.121-128
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• 2004

As the first step of the real time monitoring system of the solar radio disturbance, we constructed the control system of the solar radio telescope. An 1.8m antenna built by Korean Astronomy Observatory has been used, and the observed radio flux is transformed to the digital signal by the powermeter. We have also developed a computer program CBNUART in order to control the telescope system and the powermeter. As the sun rises, the telescope begins to observe the sun, and ends the observation automatically at sunset. The CBNUART enables the telescope automatically to go to the position of the sunrise for the beginning the observation and come back to the setposition after the ending the observation at the sunset. An active tracking routine is adopted in order to improve the tracking accuracy of the control system, and we used an optical telescope equipped in front of the antenna for control test. The tracking test shows that our control system can track with the accuracy of arc seconds, and the 50 minute pointing test shows that the pointing accuracy of right ascension and declination are 1.12 and 0.08 arc minutes respectively.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.1
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• pp.37-45
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• 2008

This paper proposes a half-silvered mirror display system designed to demonstrate useful information about things on display into the air. It helps the spectators gain quick access to information near the area where the things are put on display. This paper deals with three matters: First, tracking based on camera images created in real time enables the provision of information about the things that are both still and moving. Second, as information is output based on the real-time coordinates of things on display, the parallel processing-based tracking algorithm is used to ensure smooth transfer. Third, a half-mirror is placed in front of the display area to establish an augmented reality system and visual distortion caused by mirror angle is adjusted by the reflection transformation matrix. The objectives of this system are to arouse the spectators' interest in things on display and offer easy and quick access to information about them.

• Interaction and multiscale mechanics
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• v.1 no.2
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• pp.191-209
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• 2008

In this paper, we model grain boundary evolution based on a multiple level set method. Grain boundary migration under a curvature-induced driving force is considered and the level set method is employed to deal with the resulting topological changes of grain structures. The complexity of using a level set method for modeling grain structure evolution is due to its N-phase nature and the associated geometry compatibility constraint. We employ a multiple level set method with a predictor-multicorrectors approach to reduce the gaps in the triple junctions down to the grid resolution level. A ghost cell approach for imposing periodic boundary conditions is introduced without solving a constrained problem with a Lagrange multiplier method or a penalty method. Numerical results for both uniform and random grain structures evolution are presented and the results are compared with the solutions based on a front tracking approach (Chen and Kotta et al. 2004b).

• ETRI Journal
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• v.37 no.1
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• pp.138-146
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• 2015

This paper presents a new non-constraining online optical handwritten signature reconstruction system that, in the main, makes use of a transparent glass pad placed in front of a color camera. The reconstruction approach allows efficient exploitation of hand activity during a signing process; thus, the system as a whole can be seen as a viable alternative to other similar acquisition tools. This proposed system allows people with physical or emotional problems to carry out their own signatures without having to use a pen or sophisticated acquisition system. Moreover, the developed reconstruction signature algorithms have low computational complexity and are therefore well suited for a hardware implementation on a dedicated smart system.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.355-362
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• 2009

Most material of engineering interest undergoes solidification process from liquid to solid state. Identifying the underlying mechanism during solidification process is essential to determine the microstructure of material which governs the physical properties of final product. In this paper, we expand our previous two-dimensional numerical technique to three-dimensional simulation for computing dendritic solidification process with fluid convection. We used Level Contour Reconstruction Method to track the moving liquid-solid interface and Sharp Interface Technique to correctly implement phase changing boundary condition. Three-dimensional results showed clear difference compared to two-dimensional simulation on tip growth rate and velocity.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.23-28
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• 2011

Electromagnetometers (EMA) have been widely used in articulatory studies as their temporal resolution can capture most speech activities and the fleshpoint information allows one to readily quantify and analyze tongue shape. However, the drawback is that the data lacks details of activity in the pharyngeal region. Several studies have attempted to estimate the unknown pharyngeal shape of the tongue, but few studies are based on unimodal data containing both front and back regions of the tongue at the same time. We use Stone's ball bearing method to obtain fleshpoint data as well as tongue shape. We further introduce a novel way of connecting balls and attaching them onto the tongue to ensure accurate tracking. An Artificial Neural Network is applied to build a map between observable flesh-points, unknown tongue shape, and pharyngeal region and is optimized to efficiently address nonlinearity.