• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.25-32
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• 2013

This study examined the status of the vegetation around Gangcheonsan provincial park located in Sunchang-gun in Jeollabuk-do and Damyang-gun in Jeollanam-do from June 4 to October 12, 2011. Gangcheonsan vegetation was arranged 9 plant communities in accordance with data of 28 releves. Major forest vegetation included Quercus variabilis communityand Quercus variabilis-Quercus serrata community, Pinus densiflora community, and Pinus densiflora-Quercus variabilis community (evergreen coniferous forest in all), and Phyllostachys nigra var. henonis community (plantation). Wetland vegetation included Salix gracilistyla community (riverbank forests), Phragmites japonica community, and Polygonia thunbergii community. Gangcheonsan Provincial Park has beautiful scenery that is in harmony with fantastically-shaped rocks, waterfalls, and valleys and conserves a specific plant community habitat distributed through the forest wetlands including its valleys. It is necessary to conduct long-term monitoring with its focus on Pinus densiflora community, Lycoris koreana community, and Lycoris squamigera community in the provincial park to grasp the characteristics of ecological inhabit changes in major communities and provide active methods for conservation, restoration, and publicity.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.1
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• pp.71-80
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• 2014

Full-mouth reconstruction of a patient using dental implants is a challenge if there is vertical and horizontal bone resorption. Therefore, it is should be cautious in making the fixed prostheses that restore the function and the esthetics of the gingiva and teeth. In full mouth rehabilitation, CAD/CAM system makes it possible to fabricate restorations with high precision, regardless of span of the restoration. Recently, Palladium-silver (Pd-Ag) alloy which is highly biocompatible and millingable has been developed to compensate for the shortcomings of the titanium or zirconia. This clinical report presents the reconstruction of a maxillary arch with a cement retained implant supported fixed prosthesis using a Pd-Ag alloy generated by CAD/CAM system on eleven osseointegrated implants. The occluding surfaces were made of Pd-Ag alloy, to decrease the risk of chipping or fracture. The prostheses were esthetically pleasing, and no clinical complications have been reported after two years.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2303-2315
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• 2008

Finally, Musan-Bongdong section in Kyeong-Ui corridor opened on 11. DEC.2007, which is a historical event, because this connection means the restoration of 56 yrs' disconnection since 1951 and also starting point launching to connect china, Mongolia, Russia for continental railway logistic infrastructure. This is also one of master plans about the northern line in TAR, carried out by UNESCAP, so this study will touch up each country's railway status and the next tasks related with trans-continental railway such as North Korea, Russia, China. Also, this study reveal a mid-long term development strategy to improve the North Korea railroad for a continent rail link and international railroad transportation between China and Russia, and also checks the way of confrontation to the domestic infrastructure for the activation of the continent railway and the north and south, investigates concretely how to establish TAR northern part routes as soon as possible.

• Journal of Species Research
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• v.2 no.2
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• pp.203-222
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• 2013

The district of Ganghwa-gun in the western coast (Seohae) of the Korea is consisted of several islands, Ganghwa-do, Seokmo-do, Gyodong-do, Jumun-do, Boreum-do, Seogeom-do and Donggeom-do. Since several islands of them were connected to mainland of Korea by bridges, the islands attract a lot of tourists from Seoul, Incheon and Gyeonggi-do areas. Construction of new roads, pensions, resort areas and restaurants provided economical benefits to local residents while natural vegetation of these islands has deteriorated continuously. Before biodiversity of vascular plants in these regions is damaged seriously by human impacts, it is needed to conserve original vegetation of the islands for restoration and monitoring in the future. Therefore, the primary purpose of the study is to clarify the flora of Donggeom-do, belonging to Ganghwa-gun. From the 15 times of field trips to the island, we have collected a number of vascular plants, 512 taxa in total, including 110 families, 329 genera, 449 species, six subspecies, 52 varieties, four forms and one hybrid. Of 512 taxa investigated, we have identified 12 taxa to be endemic to Korea. Six taxa were endangered or rare species which were designated by the Ministry of Environment and Korea Forest Service, respectively. 25 taxa were recognized as floristic regional indicator species designated specially by the Ministry of Environment. Seven species have shown their northern or southern distributional limit ranges, and 29 taxa were recognized as halophytes. The naturalized plants were identified as 55 taxa, and their naturalization ratio was 10.7%.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.1
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• pp.155-165
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• 2018

As medical healthcare industry is growing up rapidly these days, providing various new healthcare service is considered carefully. Health information is considered to be more important than financial information; therefore, protecting health information becomes a very significant task. Ransomware is now targeting industry groups that have high information value. Especially, ransomware has grown in various ways since entering maturity in 2017. Healthcare industry is highly vulnerable to ransomeware since most healthcare organizations are configured in closed network with lack of malware protection. Only meeting the security criteria is not the solution. In the case of a successful attack, restoration process must be prepared to minimize damages as soon as possible. Ransomware is growing rapidly and becoming more complex that protection must be improved much faster. Based on ISO 27799 and 27002 standard, we extract and present security measures against advanced ransomware to maintain and manage healthcare system more effectively.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.13-24
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• 2014

The pond wetlands in agricultural landscape are important natural resources that carry out the function of bio-diversity conservation. However, recently, those have been gradually embedded as their utility value were disappeared. And, the assessment methods used for pond wetlands are insufficient. Therefore, this study was conducted to examine the conservation value of pond wetlands by using the modified RAM, and present the improvement of assesment methods. The study sites, a total of 32 pond of 4 types by land use, were selected on the basis of Ramsar Convention. Through the analysis of precedent studies, the weighted 8 functions were adjusted. According to the assessment results, pond wetlands made the largest contribution to Fishery and Herpetile Habitat function. In addition, it also made large contribution to Floral Diversity, Wildlife Habitat, and Water Quality Protection function. On the other hand, it made a small contribution to Aesthetics and Recreation, Runoff Attenuation, Shoreline /Stream Bank Protection, and Flood/Storm Water Storage function due to the characteristics of small-scale pond wetlands. In the assessment of 8 functions, house type showed the worst assessment result, and mountain type showed the best assessment result. It is thought that those are due to land use type in terms of vicinity. 10 items among 52 of the modified RAM showed the same assessment results in all land use types. Accordingly, it is required to be deleted and modified the assessment method. On the other hand, it is required to add age, interference, and water use to the assessment method. It is thought that these results can be utilized for the development and modification of assessment methods focused on pond wetlands in rural area.

• Nuclear Engineering and Technology
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• v.39 no.3
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• pp.231-236
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• 2007

Due to the occasional occurrences of stress corrosion cracking(SCC) in steam generator tubing(Alloy 600), degraded tubes are removed from service by plugging or are repaired for re-use. Since electrodeposition inside a tube does not entail parent tube deformation, residual stress in the tube can be minimized. In this work, tube restoration via electrodeposition inside a steam generator tubing was performed after developing the following: an anode probe to be installed inside a tube, a degreasing condition to remove dirt and grease, an activation condition for surface oxide elimination, a tightly adhered strike layer forming condition between the electro forming layer and the Alloy 600 tube, and the condition for an electroforming layer. The reliability of the electrodeposited material, with a variation of material properties, was evaluated as a function of the electrodeposit position in the vertical direction of a tube using the developed anode. It has been noted that the variation of the material properties along the electrodeposit length was acceptable in a process margin. To improve the reliability of a material property, the causes of the variation occurrence were presumed, and an attempt to minimize the variation has been made. A Ni alloy electrodeposition process is suggested as a primary water stress corrosion cracking(PWSCC) mitigation method for various components, including steam generator tubes. The Ni alloy electrodeposit formed inside a tube by using the installed assembly shows proper material properties as well as an excellent SCC resistance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.206-215
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• 2007

Ad-Hoc network technology is a mobile internet technology of the future that will be used widely not only in Mobile Network but also in Wireless Personal Area Network (WPAN) and Ubiquitous Network For this to occur, distributed routing protocol design, loop prevention for link information reduction in overhead for control messages and route restoration algorithm must be improved or complemented. Security techniques that can guarantee safe com-munication between Ad-Hot nodes net also be provided. This study proposes and evaluates a new authentication mechanism for MANET. The mechanism segregates the roles of certification authority to keep with the dynamic mobility of nodes and handle rapid and random topological changes with minimal over-head. That is, this model is characterized by its high expandability that allows the network to perform authentication service without the influence of joining and leaving nodes. The efficiency and security of this concept was evaluated through simulation.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.1-8
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• 2012

Acorn production of some oak species from 2008 to 2010 in Mt. Jiri national park(Pia, Bitjeom, Jangdang, Baemsa, Hansin, and Chilsun) was measured and compared among study area, altitude and aspect because acorns are an important wildlife food resources. Acorns were produced the most in Jangdang and Bitjeom area at year of good fruiting, and those of Bitjeom and Hansin area were produced the most at bad fruiting year. In terms of altitudinal characteristics on acorn production, acorn production in 1000 and 900 m was the most at good fruiting year, and 800 and 900 m at bad fruiting year showed the most production of acorn. Throughout the study period, acorn production on southern slopes was larger than that of northern slopes.

• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.320-328
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• 2017

In order to analyze the influence on derailment safety according to the aging of primary rubber springs widely applied to railway vehicles, characteristic tests were carried out on aged primary rubber spring samples. To analyze the effect of primary rubber spring aging on derailment safety, a vehicle dynamic analysis was carried out. The results of the vertical characteristics test for the rubber spring specimens with 17 years of service life revealed that the displacement restoration function was degraded due to rubber aging and the spring stiffness significantly increased. The results of the running dynamic analysis simulating the twist track running in accordance with the EN14363 standard, compared with the normal vehicle model (Case 1), showed that the derailment coefficient and the wheel unloading of the vehicle model (Case 2) using the aging primary spring characteristic increased, and the derailment safety was degraded. IN particular, it was found that the derailment safety due to the reduction of the wheel load is weak in the transient section where a steep slope change occurs.