• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.541-547
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• 1999

Corrosion control, in the end-shield cooling system of Wolsung Nuclear Power Plant, is directly related to the control of dissolved oxygen (DO). The current method, being used to deoxygenate the end-shield cooling water, is a chemical treatment by addition of reducing agent, hydrazine, to react with DO. This method has several limitations including high reaction temperature of hydrazine , unwanted explosive hydrogen gas production, and its intrinsic harmful property. A new approach to remove DO using a membrane-based oxygen removal system (MORS) was tried to overcome limitations of the hydrazine treatment. The DO removal efficiency of the MORS was found to be in the range 87% to 98%: The higher vacuum, the lower water flow rate and the higher water temperature tend to increase the DO removal efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.2196-2218
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• 2017

Multicast communication has been widely used in the Internet. However, multicast communication is vulnerable to DoS attack due to static router configuration. In this paper, HMC, a hopping multicast communication method based on SDN, is proposed to tackle this problem. HMC changes the multicast tree periodically and makes it difficult for the attackers to launch an accurate attack. It also decreases the probability of multicast communication being attacked by DoS and in the meanwhile, the QoS constrains are not violated. In this research, the routing problem of HMC is proven to be NP-complete and a heuristic algorithm is proposed to solve it. Experiments show that HMC has the ability to resist DoS attack on multicast route effectively. Theoretically, the multicast compromised probability can drop more than 0.6 when HMC is adopt. In addition, experiments demonstrate that HMC achieves shorter average multicast delay and better robustness compared with traditional method, and more importantly, it better defends DoS attack.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.171-174
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• 2000

The effect of the dissolved oxygen (DO) concentration on the production of manganese peroxidase by Phaenerochaete chrysosporium was studied in the immobilized reactor system. The oxygen levels significantly affected the production of manganese peroxidase (MnP) as well as that of $H_2O_2$. It is known that a high oxygen level is required to produce this enzyme. In this study, however, higher DO concentrations above a critical DO concentration inhibited MnP production. It is thought that a greater $H_2O_2$ production seen with higher DO concentrations caused adverse effects on the MnP production. On the other hand, with lower DO concentrations, $H_2O_2$ did not accumulate enough to stimulate MnP production.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.220-231
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• 2006

The study was conducted to investigate the differences in carbon storage of Quercus mongolica stands with respect to latitude and altitude in Korea. Study sites were located in Mt. Joongwang, Pyeongchang-gun, Gangwon-do (altitudes 1,300 m, 1,000 m, and 800 m), Mt. Taehwa, Gwangju-si, Gyeonggi-do (altitude 350 m), Mt. Wolak, lecheon-si, Chungcheongbuk-do (altitude 300 m), Mt. Baekwoon, Gwangyang-si, Jeollanam-do (altitude 800 m), and Mt. Halla, Jeju-do (altitude 1,000 m). Total carbon storage and annual carbon storage of Q. mongolica stands were 85-210 tonC/ha and 7.2-10.6 tonC/ha, respectively. Lower latitude (NE) stands of Q. mongolica showed more carbon storage and annual carbon storage than higher latitude stands. Carbon storage and annual carbon storage of Q. mongolica stands were increased in low altitude. Carbon storage of Q. mongolica stands was higher in the northern aspect than in the southern aspect. However, there were no significant differences in annual carbon storage between the aspects.

• International Commerce and Information Review
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• v.11 no.1
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• pp.353-378
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• 2009

This paper intends to analyse the export assistance programs for SMEs(Small and Medium-Sized Enterprises) located in Gyeongsangbuk-do Province as well as to suggest export promotion policy for the local government. In order to accomplish these objectives, the present paper makes an extensive survey about export-support programs conducted by Gyeongsangbuk-do Province. The survey was rigorously made to evaluate export-support programs taken by the provincial government of Gyeongsangbuk-do and the regional firms' awareness about them. The paper utilized SPSS for empirical analysis. The frequency analysis was used to know the precision of data and its general features. The Crosstabulation Analysis was also used to evaluate firms' recognition about export-support programs and their practical use, satisfaction and relationships with the characteristics of enterprises. The results show that the local government must effectively systematize export support programs and develop export-support programs customized for the characteristics of enterprises in Gyeongsangbuk-do.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.433-437
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• 1996

We have analyzed the content of the Korean stone star chart. Ch'on-Sang-Yul-Cha-Bun-Ya-Ji-Do(here-after Ch'on-Sang-Do). In the star map we have found 1468 stars, 4 more than the Chinese star catalog Bo-Chun-Ga. The four extra stars form a constellation, Jong Dae Boo. The map projection law used in the star chart is found to be the polar equtorial and equidistance projection. The linear distance of an object on Ch'on-Sang-Do from the center is linearly proportional to the north polar angular distance. We have found from a statistical analysis that most stars with declination lower than 50 are at positions representing the epoch of around the first century. On the other hand, stars near the north pole with declination higher than 50 are at the epoch of about 1300, which is close to the time the chart was engraved. This implies that the original Ko-Gu-Rye Dynasty's star chart has been revised by astronomers of Cho-Sun Dynasty. We have also shown that stars on Ch'on-Sang-Do are engraved in such a way that their area is linearly proportional to the visual magnitude.

• Plant Resources
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• v.5 no.3
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• pp.176-180
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• 2002

This study was conducted to develop the clonal propagation technique through in vitro culture using by leaf sheath explants of Phalaenopsis grown in vitro. The highest frequency of protocorm-like body (PLB) formation was obtained when explants of leaf sheath were cultured on VW medium containing 30g/L sucrose, 500 mg/L activated charcoal, 150 mVL coconut water, 1 mg/L NAA, 1 mg/L 2ip and 2.5 g/L gelrite. The PLB formation rate of VW medium was highest followed by modified Hyponex medium, and lowest in MS medium. Plantlets induced from PLBs transferred to plastic pots including spagnum moss were well developed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.478-479
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• 2006

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.122-125
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• 2008

Sensors used in many USN (Ubiquitous Sensor Network) domain applications generate a large amount of sensor stream data. The volume of sensor stream data is too huge to store the whole data and data speed is too fast to control each of them. In order to provide rapid and reliable context analysis service over sensor stream data, we propose a WHEN-DO context analysis model that supports the functionality of sliding window. This model is designed to be used as follows: If the sensor stream data satisfies condition in 'WHEN' clause, then it will execute actions in 'DO' clause in WHEN-DO context analysis model. The proposed WHEN-DO context analysis model can be applied to many other USN environment applications such as monitoring the status of a building and then taking actions in corresponding context condition.

• Journal of architectural history
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• v.13 no.3
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• pp.21-36
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• 2004

Most of the studies on Confucian Architecture dealt with the administrative system and typification. The study was about the outline buildings of the Architecture. However, specific view of personal architecture is limited. The aim of this study is to clarify the idea of Seonbi, Confucian Scholars in Choson Dynasty, in building the second house, Byul-Seo Architecture. The Byul-Seo was used to Jang-Su(藏修) for training oneself and teaching his students, and You-Sik(遊息) for strolling the surrounding of nature. The Byel-Seo in Bogil-do by Gosan Yoon, Sun-Do is influenced not only by the idea of Confucianism which is 'knowing through by approaching to object(格物致知)', but also by Feng-shui and Taoism. From the idea of Gosan Yoon, Sun-Do in Byul-Seo Architecture, ecology and spirit of the times must applied to our modern architecture.