• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.35-38
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• 2009

The paper presents an effective method to detect fire in video surveillance and monitoring system. The main contribution of this work is that we successfully use the Hidden Markov Models in the process of detecting the fire with a few preprocessing steps. First, the moving pixels detected from image difference, the color values obtained from the fire flames, and their pixels clustering are applied to obtain the image regions labeled as fire candidates; secondly, utilizing massive training data, including fire videos and non-fire videos, creates the Hidden Markov Models of fire and non-fire, which are used to make the final decision that whether the frame of the real-time video has fire or not in both temporal and spatial analysis. Experimental results demonstrate that it is not only robust but also has a very low false alarm rate, furthermore, on the ground that the HMM training which takes up the most time of our whole procedure is off-line calculated, the real-time detection and alarm can be well implemented when compared with the other existing methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.815-817
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• 2022

This paper is about the development of an automatic stair climbing trolley for carrying loads without manpower. The design of tri-wheeled structure and center of mass enable the trolley to move on flat ground and also to ascend stairs by self-balancing. The overall design enables the trolley to avoid collision to walls when the trolley rotates on domestic landings. When the camera recognizes the stair, the sensor measures distance from the trolley to the stair. Then the trolley can move to align itself in the middle of the stair and it starts climbing. It can ascend to a specific floor based on the floor number entered by the user. As a result, the automatic stair climbing trolley is expected to help humans by protecting from accidents of dropping loads and saving their power. It is also expected to use for various purposes such as delivering packages, moving and carrying heavy loads in buildings without elevator.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.4
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• pp.145-151
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• 2006

The water line moving on the intertidal flat during a flood indicates depth contours between low and high water lines. The water lines extracted from the consecutive images are rectified to get the ground coordinates of each depth contour and integrated to provide three dimensional information of Intertidal flat topography. The tidal flat outside Saemankeum-1 sea dike shows the most obvious changes of tidal flat topography after the construction of sea dikes. This tidal flat topography was observed using digital camera images, and the calculated depths were very similar to in-situ measurement data. Topography changes obtained from two different period data were also examined.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.677-692
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• 2009

In recent years, lots of studies on the planetary rover systems have been performed around space advanced agencies such as NASA, ESA, JAXA, etc. Among the various technologies for the planetary rover system, the mobility system, navigation algorithm, and scientific payload have been focused particularly. In this paper, the conceptual design for a ground-based model of planetary rover's mobility system to evaluate mobility and moving stability on ground is presented. The status of overseas research and development of the planetary rover systems is also addressed in terms of technical issues. And then, the requirements of the planetary rover's mobility system are derived by means of considering mobility and stability. The designed rover's mobility system has an active suspension with 6 legs that controls 6 joints on the each leg in order to achieve high stability and mobility. This kind of mobility system has already applied to the ATHELE of NASA for various purposes such as transportation and habitation for human lunar exploration activities in the near future (i.e., Constellation program). However, the proposed system has been designed by focusing on the small-sized unmanned explorations, which may be applied for the future Korea Lunar exploration missions. Therefore, we expect that this study will be an useful reference and experience in order to develop the planetary exploration rover system in Korea.

• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.27-34
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• 2017

This study was carried out to estimate structural stabilities in respect of ground footings of plastic greenhouses on reclaimed lands. A 6m-wide multi-span plastic greenhouse with steel spiral piles as well as two 8.2m-wide single-span greenhouses with steel spiral piles and continuous pipe foundation respectively were built up on a reclaimed land with a SPT N-Value of 2 and measured how much the greenhouses were lifted up and subsided. In addition, the uplift capacity of three kinds of spiral piles(${\phi}50$, ${\phi}75$ and ${\phi}100$) was determined on a nearby reclaimed land. The results showed that the greenhouses with spiral piles had a slight vertical displacement like moving up and down but the scales of the rising up and sinking were negligible when compared to that of the greenhouses. The vertical displacement of the multi-span greenhouse ranged from +9.0mm(uplift) to -11.5mm(subsidence). As for the single-span greenhouses with spiral piles and continuous pipe foundation, the measurements showed that it varied from +1.3mm to -7.7mm and from +0.9mm to -11.2mm, respectively. The allowable uplift capacity of spiral piles could all be determined under criteria of ultimate load and accordingly had a value of 0.40kN, 1.0kN and 2.5kN, respectively. It was not entirely certain enough to make a final judgement on structural stabilities in respect of ground footings, it appeared likely however that the greenhouses with steel spiral piles was tentatively observed without any problems on reclaimed lands within the period.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.91-97
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• 2007

The purpose of this study was to investigate the changes of various balls velocity under the different surface conditions after impact. For this study, four different balls were used which are golf ball, tang-tang ball, table tennis ball, and iron ball. And two different types of ground conditions were used which are artificial grass green and glass green. Movements of putter head and ball were recorded with 2 HD video cameras(60 Hz, 1/500s shutter speed). Small size control object($18.5cm{\times}18.5cm{\times}78.5cm$) was used in this study. To transfer the same amount of kinetic energy to the ball, pendulum putting machine was used. Analyzing the process of impact and the ball movement, a putter was digitized the whole movement but the ball was digizited within the 50cm movement. Velocities were calculated by the first central difference method(Hamill & Knutzen, 1995). Putter head velocities were about 112.2cm/s-116.2cm/s at impact. Maximum ball velocities were appeared 0.08s-0.10s after impact no matter what the ground conditions are. Table tennis ball recorded higher ball velocities than the other ball velocities and iron ball recorded the lowest ball velocity in this group. But Table tennis ball was influenced with the frictional force and immediately was decreased at the artificial grass green condition. If an object is received the kinetic energy under the static condition(v=0cm/s), the object recorded the maximum velocity shortly after the impact and then decreased the velocity because of the frictional force. The ball distance from the start position to the peak velocity position is about 6cm-10cm under the 112.2cm/s-116.2cm/s putting velocity with putter. 0.25 seconds later after impact balls were placed 40cm distance from the original position except iron ball. In this study, ball moving distances were too short therefore it was not possible to investigate the reactions after the translational force is disappeared. Rotational force would play a major role at the end of the ball movement. Future study must accept two things. One is long distance movement of ball and the other is balanced ground. Three-piece ball is a good item to investigate the golf ball movement on the different surface conditions.

• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.183-190
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• 2007

The site effects of seismic stations were evaluated by conducting a simultaneous inversion of the stochastic point-source ground-motion model (STGM model; Boore, 2003) parameters based on the accumulated dataset of horizontal shear-wave Fourier spectra. A model parameter $K_0$ and frequency-dependent site amplification function A(f) were used to express the site effects. Once after a H/V ratio of the Fourier spectra was used as an initial estimate of A(f) for the inversion, the final A(f) which is considered to be the result of combined effect of the crustal amplification and loca lsite effects was calculated by averaging the log residuals at the site from the inversion and adding the mean log residual to the H/V ratio. The seismic stations were classified into five classes according to $logA_{1-10}^{max}$(f), the maximum level of the site amplification function in the range of 1 Hz < f < 10 Hz, i.e., A: $logA_{1-10}^{max}$(f) < 0.2, B: 0.2 $\leq$ $logA_{1-10}^{max}$(f) < 0.4, C: 0.4 $\leq$ $logA_{1-10}^{max}$(f) < 0.6, D: 0.6 $\leq$ $logA_{1-10}^{max}$(f) < 0.8, E: 0.8 $\leq$ $logA_{1-10}^{max}$(f). Implication of the classified result was supported by observing a shift of the dominant frequency of average A(f) for each classified stations as the class changes. Change of site classes after moving seismic stations to a better site condition was successfully described by the result of the station classification. In addition, the observed PGA (Peak Ground Acceleration)-values for two recent moderate earthquakes were well classified according to the proposed station classes.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.1-12
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• 2011

There has been the increasing concern with the safety of seven major urban infrastructure such as road, electricity, water supply, sewerage and so on due to urban expansion and new town development. However, high technology development for the common duct which can be an alternative for the safety issue has not been completed due to the law of the national security area. Existing management method of the common duct by people could not respond to the urgent accidents adequately and immediately since it is impossible for us to get access to that in case of fire or gas leak. This study suggests to the method of installing monitoring devices and processing CCTV images with a water supply in a TestLab(a variety of the USN(Ubiquitous Sensor Network) equipment was tested in the TestLab in KICT). The suggested management method of common duct facilities make it possible to do real-time monitoring and prompt access and response to an accident inside the common duct.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.293-302
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• 2014

Radar systems are used in remote sensing mainly as space-borne, airborne and ground-based Synthetic Aperture Radar (SAR), scatterometer and Doppler radar. Those systems are composed of expensive equipments and require expertise and professional skills for operation. Because of the limitation in getting experiences of the radar and SAR systems and its operations in ordinary universities and institutions, it is difficult to learn and exercise essential principles of radar hardware which are essential to understand and develop new application fields. To overcome those difficulties, in this paper, we present the construction and experiment of a low-cost educational radar system based on the blueprints of the MIT Cantenna system. The radar system was operated in three modes. Firstly, the velocity of moving cars was measured in Doppler radar mode. Secondly, the range of two moving targets were measured in radar mode with range resolution. Lastly, 2D images were constructed in GB-SAR mode to enhance the azimuth resolution. Additionally, we simulated the SAR raw data to compare Deramp-FFT and ${\omega}-k$ algorithms and to analyze the effect of antenna positional error for SAR focusing. We expect the system can be further developed into a light-weight SAR system onboard a unmanned aerial vehicle by improving the system with higher sampling frequency, I/Q acquisition, and more stable circuit design.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.3
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• pp.217-222
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• 1996

The moving behaviour of anchovy schools(There were small schools of sardine and round-herring in this anchovy schools} in the bag - net of a large scale set - net was investigated using a scanning sonar, in the Kishihata set - net fishing ground located in Nanao city Ishigawa prefecture, Japan from Dec. 1st to Dec. 4th, 1992. The results obtained are summarized as follows ; 1. Moving behaviour of fish schools between two bag - nets was more in the daytime than in the nighttime. 2. The rate of entering fish schools from the first bag -- net to the second bag - net were 78% when the fish school in the second bag -- net existed. The result suggest that fish school existence in the second bag - net affected the rate of entering fish schools from the first bag - net to the second- bag - net. However, the time of stay of fish school that entered the second bag -- net was very short when the fish school in the second bag - net existed densely. The result suggest that a high fish density in the second bag - net might enlarge the escape rate 3. The majority of fish schools moved to the center and off shore side of the bag - net when fish schools entered the bag - net.