• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.794-806
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• 2017

It is essential to protect the national space assets and space environment safely as a space development country from the continuously increasing space debris. And Active Debris Removal(ADR) is the most active way to solve this problem. In this paper, we studied the Artificial Neural Network(ANN) for a stable recognition model of vision-based space debris tracking system. We obtained the simulated image of the space environment by the KARICAT which is the ground-based space debris clearing satellite testbed developed by the Korea Aerospace Research Institute, and created the vector which encodes structure and color-based features of each object after image segmentation by depth discontinuity. The Feature Vector consists of 3D surface area, principle vector of point cloud, 2D shape and color information. We designed artificial neural network model based on the separated Feature Vector. In order to improve the performance of the artificial neural network, the model is divided according to the categories of the input feature vectors, and the ensemble technique is applied to each model. As a result, we confirmed the performance improvement of recognition model by ensemble technique.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1744-1752
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• 2013

We investigated the protective effect of UVB inducing photodamage from mulberry extract (ME) and Lithospermum erythrorhizon extract (LE). The contents of total anthocyanin and shikonin as a color compound of ME and LE were 4.92 mg/g and 9.58 mg/g, respectively. The electron donating ability and superoxide radical scavenging activity of ME were 84.32% and 76.34%, respectively. The oxygen radical absorbance capacity of the ME ($545.37{\mu}moles$ TE/g) was higher than LE ($427.18{\mu}moles$ TE/g). MMP-1 production in the HS68 cells were exposed to UVB suppressed by treatment with $200{\mu}g/mL$ of ME (68.6%) and LE (32.7%). ME and LE were applied to a skin aging mouse model, which was induced by the irradiation of UVB to the backs of hairless mice. The value of skin erythema index, wrinkle depth and thickness, epidermis thickness, and collagenous fiber damage in the experiment groups (MEL: ME 3%, MEM: ME 5%, MEH: ME 7%, LEL: LE 3%, LEM: LE 5%, LEH: LE 7%) were remarkably reduced than in the control group (only UVB exposure group), while water capacity increased. The level of total wrinkles depth in the skin was decreased to be 30% of the control group by MEH and LEM. These results suggest that ME and LE are useful cosmetic materials for skin protection against UVB-inducing.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.133-140
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• 2008

The growth of root and shoot normally decline dramatically in mid-summer of Korea, moreover the cool-season turfgrassgrass eventually wither to death over $30^{\circ}C$. The increase of air temperature also drives the heat of soil, that makes stress on root system. The heat stress affects physiological mechanisms of hormonal unbalance that stimulates shoot growth, photosynthesis, and transpiration. To solve those problems, many studies have been carried out to control soil moisture and OM content to decrease soil temperature for dissolving the growth retardant by heat stress. This study initiated to analyze the change of soil temperature with soil moisture, and the effect of soil depth and moisture content on heat transmit and thermal changes on turfgrass growth(productivity, green color, and damage by dryness and high temperature). Kentucky bluegrass plots prepared with 25%, 33%, 40% soil moisture treatments. Soil temperature was measured every five min. with four thermo-sensors at 12 and 2 cm soil depth. The most acceptable growth showed at 33% soil moisture, but the worst result showed at 40%. The soil moisture seriously affected on the growth of Kentucky bluegrass, however the quality of turfgrass may acceptable if we can control soil moisture down to 33% when the flooding season of monsoon.

• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.19-33
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• 2003

The objective of this study was to evaluate the effects of crumb rubber recycled from used tires as a soil incorporation and topdressing materials on a trafficked Korean lawngrass‘Zenith’(Zoysia japonica). In Exp 1, incorporation treatments included three particle sizes (PS: coarse =4∼6.35 mm, medium =2∼4 mm, and One : less than 2 mm in diameter) and two incorporation rate (IR: 10 and 20%). Wear treatments were applied 30 passes per day by compactor weights being 60 kg with soccer shoes. Topdressing treatments included three PS and two topdressing depth (TD: 5 and 10 mm). Wear treatments were the same as described in Exp 1. In Exp 1, the treatment with medium PS+IR 20 resulted in the tendency to have high total clipping yield. There was no significant difference in clipping yield, turfgrass visual color, coverage, and root length among the treatments. Compared to control, tissue Zn levels increased about 6.5-fold by the treatments. The treatment with fine PS +IR 20 caused a less peak deceleration than coarse PS +IR 10. Total porosity, air-filled porosity, and capillary porosity increased with fine PS +IR 20. In Exp 2, compared to controls, however, there was a difference in turfgrass visual color after the termination of traffic treatment. There was no difference in root length. The treatment with fine PS + TD 10 resulted in the highest total clipping yield. As a result of soil physical analysis, soil penetration resistance was reduced by the treatments. The treatment with coarse PS resulted in a less peak deceleration than fine PS. In conclusion, turfgrass growth was increased by crumb rubber incorporation which enhanced soil physical properties. The crumb rubber topdressing was able to cushion the crown tissue area while still providing a smooth and uniform surface, improve overall turfgrass quality, and reduce compaction.

• Journal of Broadcast Engineering
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• v.23 no.2
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• pp.246-252
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• 2018

Hand gestures are attracting attention as a NUI (Natural User Interface) of wearable devices such as smart glasses. Recently, to support efficient media consumption in IoT (Internet of Things) and wearable environments, the standardization of IoMT (Internet of Media Things) is in the progress in MPEG. In IoMT, it is assumed that hand gesture detection and recognition are performed on a separate device, and thus provides an interoperable interface between these modules. Meanwhile, deep learning based hand gesture recognition techniques have been recently actively studied to improve the recognition performance. In this paper, we propose a method of hand gesture recognition based on CNN (Convolutional Neural Network) for various applications such as media consumption in wearable devices which is one of the use cases of IoMT. The proposed method detects hand contour from stereo images acquisitioned by smart glasses using depth information and color information, constructs data sets to learn CNN, and then recognizes gestures from input hand contour images. Experimental results show that the proposed method achieves the average 95% hand gesture recognition rate.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.102-109
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• 1986

To know the ecological pattern of bulrush (Scirpus juncoides) seeds in dormancy-breaking responses as affected by different ripening processes, storage conditions, germination conditions, and some of known chemicals concerned, the study was conducted. Among other conditions detected, the burial in 2 cm depth paddy soil, $5^{\circ}C$ storage temperature, pre-maturing process (Green color), high concentration of chemicals used, and flooding paddy surfaces were the most efficient conditions for bulrush seeds to break dormancy and germinate, respectively.

• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.311-321
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• 2007

The diffuse attenuation coefficient for down-welling irradiance $K_d({\lambda})$, which is the propagation of down-welling irradiance at wavelength ${\lambda}$ from surface to a depth (z) in the ocean, and underwater visibility are important optical parameters for ocean studies. There have been several studies on $K_d({\lambda})$ and underwater visibility around the world, but only a few studies have focused on these properties in the Korean sea. Therefore, in the present study, we studied $K_d({\lambda})$ and underwater visibility around the coastal area of the Yellow Sea, and developed $K_d({\lambda})$ and underwater visibility algorithms for ocean color satellite sensor. For this research we conducted a field campaign around the Yellow Sea from $19{\sim}22$ September, 2006 and there we obtained a set of ocean optical and environmental data. From these datasets the $K_d({\lambda})$ and underwater visibility algorithms were empirically derived and compared with the existing NASA SeaWiFS $K_d({\lambda})$ algorithm and NRL (Naval Research Laboratory) underwater visibility algorithm. Such comparisons over a turbid area showed small difference in the $K_d({\lambda})$ algorithm and constants of our result for underwater visibility algorithm showed slightly higher values.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.63-73
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• 1995

A remote telesounder system was manufactured to investigate the behavior and distribution characteristics of fish and was tested to verify its performance and effects int he set net fishing ground located off the Namhae island, Oct. 26~27, 1994. The activity pattern of fish was observed at the buoy station installed in a set net and it was also analyzed simultaneously at the remote base station on land located at distance of about 1.5km away from the buoy station. Several findings at both the buoy station and the base station were as follows: The images of color display monitor at the base station on land were very well coincident with the records observed at the buoy station. The lower part of slope net and bagnet fluctuated irregularly, and its variations were about 3.6m and 6.0m, respectively. In the daytime, the fish school entered playground, passed slope net with 5~7m depth, moved dispersedly at night and at twilight the entrance was rare. In the bagnet, in the daytime the fish school swam in the layer of 8m in depth, at night the fishes dispersed in the entire layer and at twilight they formed dense school. The fishes caught by the set net were about 500kg with 20 species. Anchovy was the most dominant species. In conclusion, the remote telesounder was a convenient and powerful system for investigating the distribution pattern and the swimming behavior of fish entering in set net.

• Journal of Korea Multimedia Society
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• v.15 no.10
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• pp.1196-1204
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• 2012

In this paper, a series of algorithms are proposed for controlling different kinds of multimedia contents and realizing interact between human and computer by using single input device. Human gesture recognition based on NUI is presented firstly in my paper. Since the image information we get it from camera is not sensitive for further processing, we transform it to YCbCr color space, and then morphological processing algorithm is used to delete unuseful noise. Boundary Energy and depth information is extracted for hand detection. After we receive the image of hand detection, PCA algorithm is used to recognize hand posture, difference image and moment method are used to detect hand centroid and extract trajectory of hand movement. 8 direction codes are defined for quantifying gesture trajectory, so the symbol value will be affirmed. Furthermore, HMM algorithm is used for hand gesture recognition based on the symbol value. According to series of methods we presented, we can control multimedia contents by using human gesture recognition. Through large numbers of experiments, the algorithms we presented have satisfying performance, hand detection rate is up to 94.25%, gesture recognition rate exceed 92.6%, hand posture recognition rate can achieve 85.86%, and face detection rate is up to 89.58%. According to these experiment results, we can control many kinds of multimedia contents on computer effectively, such as video player, MP3, e-book and so on.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.171-177
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• 1982

Optical properties of sea water were studied in the western channel of the Korea Strait, based on the data obtained from fifteen oceanographic stations in July, 1980. Submarine daylight intensity was measured at intervals of 5m depth in the upper 70m layer by using the underwater irradiameter (Kahlsico $\#268_{WA}360$). The mean absorption coefficients of the sea water were shown as $0.098(0.063\sim0.183),\;0.129(0.090\sim0.270), 0.081(0.044\sim0.142),\;and 0.087(0.036\sim0,142)$ for clear, red, green, and blue color respectively. The transparency ranged from 11.5 to 24m(mean 18.3m). The mean water color in this area was $3.5(3\sim4)$ in Forel scales. The relation between absorption coefficient $(\kappa)$ and transparency (D) was $\kappa=1.72/D,\;\kappa=2.33/D,\;\kappa=1.41/D,\;and \kappa=1.44/D$ for clear, red, green, and blue color respectively. The rates of light penetration for clear, red, green, and blue color in four different depths were computed with reference to the surface light intensity respectively. The mean rates of light penetration in proportion to depths were as follows; clear : $57.90\% (5m),\;23.40\%\;(15m),\;6.23\%\;(30m),\;1.00\%\;(50m).$ $red\;:\;48.95\%\;(5m),\;14,81\%\;(15m),\;2.76\%\;(30m),\;0.28\%\;(50m).$ $green:\;63.20\%\;(5m),\;30.47\%\;(15m),\;10.03\%\;(30m),\;2.24\%\;(50m).$ $blue\;:\;62.70\%\;(5m),\;30.00\%\;(15m),\;9.75\%\;(30m),\;1.70\%\;(50m)$