• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.18-30
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• 2009

Recently, although the requirement of quality of VOD content has been transferred upto the class of HD, conventional management systems characterized by OS dependency are truly limited in quality of video image, stability, and compatibility of network environments. In addition most of the content management systems realize very limited capabilities for the real affairs of content management and distribution services in such an OS dependent environment. In this paper, we propose a new scheme of HD-Class VOD Content Management System to solve these problems. We design and implement the proposed system based on open sources by using H.264 video compression method. The proposed system offers high quality content management method based on opened systems and independent on-line distribution method so that it can be realized as an integrated management scheme for VOD contents. Moreover, our system solves the problems of occasional cutting-down video, small screen, and poor image quality that exist in the conventional wmv-type CMS. According to the result of performance evaluation, our system maintains sufficient performance and tolerence for the case of large scale HD content operations or fabrications. We expect that the proposed integrated DB scheme will especially be effective when the content management applications are changed from Internet Web environments to mobile terminal environments.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.302-311
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• 2023

This study was conducted to evaluate the applicability of castor oil (CSO) as a natural wood preservative. CSO was treated into wood blocks prepared with domestic and imported wood species using a vacuum-pressure method, and then treatability, leachability and decay resistance of the CSO-treated wood blocks were examined. Although CSO was penetrated effectively into wood blocks of all wood species, the CSO-treatability was the highest in Western hemlock, followed by Japanese larch (LA), soft maple and Mongolian oak due to the difference of its anatomical structure. Except for LA, the more retained, the more leached during a saline water-immersing process for 48h. The use of ethanol added to reduce the viscosity of CSO affected negatively the treatability and leachability of wood blocks. Decay resistance, which was evaluated by the weight loss of wood blocks exposed against Fomitopsis palustris (FOP) and Trametes versicolor, of the CSO-treated/leached wood blocks was superior to that of control. Especially, most of wood blocks treated with preserving solution composed of only CSO (CSO-2) did not decayed and showed a very low weight loss against FOP. The decay resistance results from CSO retained in wood blocks after leaching. The retention of CSO could identify using the observation of X-ray microscope. Length of wood strips, which were treated with CSO-2 and then immersed in saline water for 2 weeks, hardly changed in all cutting directions. In addition, weight gain and length-swelling rate of the wood strips were extremely low compared to those of control. These results indicate that moisture resistance of the wood strips was improved by the CSO treatment. It is concluded that the treatment of CSO using a vacuum-pressure method provides the decay resistance and dimensional stability of wood, and thus CSO can be used as a natural wood preservative on various indoor and outdoor circumstances.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.3-17
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• 1998

The purposes of this study is to investigate the possibility of planting trees at space land in the riverside. The space land is for the green space. Calculating the plantable space in the representation section and the flood flowing stability of the existing banks based on the hydrological and meteorological data of the Kap-Chon riverbasin located in Tae-jon, the following results are drawn. (1) The flood discharges in each flow section are $698.7m^3/s$ in section 1, $654.6m^3/s$ in section 2, and $1353.3m^3/s$ in section 3 during 100 years recurrence interval. Because the designed-flood discharges in those sections are $1719.9m^3/s$, $2119.7m^3/s$, and $1512.8m^3/s$ respectively, safety for flood flowing is sufficient in existing banks. (2) The possible clearance for planting trees is 1.80m in section 1, 3.90m in section 2, and 0.01m in section 3. Planting clearance is enough in section 1 and 2. However, planting should be planned after estimating a rise-height due to the bridge piers, because many piers under riverine-highway are now on the construction in section 2. The section 3 does not have sufficient clearance for planting trees, but the planting is possible after getting enough flow area with slope by cutting the terrace land on the river artificially heightened. (3) In case of planting a tree 70cm diameter in $1m^2$ in section 1, the water level increases by 0.60m. Planting a tree in a $48m^2$ area increases the water level by 0.90m. Considering that plantable clearance is 1.8m in section 1, it is sufficient to flow safely. But if the trees are planted so compactly from the upper stream, expected heavy resistance is expected due to caught materials on the trees. So, trees have to be planted widely in upper streams but compactedly in lower streams. (4) The river width without changing, Kap-Chon's flow channel can be snaked in accordance with the nature law the wide terrace land in the riverside. Decreased flow area due to planting trees will be compensated by the inclination of terrace land. And, it is theoretically proved that the flood discharge is safe even though the terrace land on the river is parked similar to the nature. Planting trees in the terrace land of the Kap-chon river to the extent that flood flowing is not adversely affected, we can get the enjoyable park to citizens not spending expensive cost. It also contributes to the recovery of ecosystem, which gives the natural beauty of river and shade to citizens and becomes good natural-educational places for children.