• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.664-671
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• 2017

Non-point source pollution is the emission source that unspecifically releases pollutants to water system from unspecific places such as cities, agricultural lands, mountains, and construction sites and its discharge path is not easily identified. Also, it is difficult to design and manage the reduction facilities for the emission quantity is primarily affected from weather conditions like rainfall. Since 2006, the significance of non-point source pollution reduction has been grown in Republic of Korea and this reinforces needs for the installation of reduction facilities. However, because the standards for the installation details and reduction efficiency are not clarified by law, people are preferring technologies that do not require particular maintenance and high expenses. The purpose of this study is to examine and maintain the efficiency of non-point source pollutants reduction facility which uses expended polypropylene as a media. The higher the depth of the media, the less range of variations in the reduction efficiency was observed and the final efficiency was also increased. When the media depth was 60 cm, the average reduction efficiency was 94% and 90% where linear velocities were 10 m/hr and 20 m/hr respectively. The results from 180 minutes operation in 10 m/hr and 20 m/hr of linear velocities were slightly different in head loss changes which were caused by media depth variations. The backwash experiments which were conducted in triplicate showed the reduction efficiency decreased as the time went on because of the media clogging. However, it was found that after the backwashing the reduction efficiency was increased as effective as the efficiency of the initial filtration.

• Korean Security Journal
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• no.27
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• pp.129-159
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• 2011

Physical security has always been an extremely important facet within the security arena. A comprehensive security plan consists of three components of physical security, personal security and information security. These elements are interrelated and may exist in varying degrees defending on the type of enterprise or facility being protected. The physical security component of a comprehensive security program is usually composed of policies and procedures, personal, barriers, equipment and records. Human beings kept restless struggle to preserve their and tribal lives. However, humans in prehistoric ages did not learn how to build strong house and how to fortify their residence, so they relied on their protection to the nature and use caves as protection and refuge in cold days. Through the history of man, human has been establishing various protection methods to protect himself and his tribe's life and assets. Physical security methods are set in the base of these security methods. Those caves that primitive men resided was rounded with rock wall except entrance, so safety was guaranteed especially by protection for tribes in all directions. The Great Wall of China that is considered as the longest building in the history was built over one hundred years from about B.C. 400 to prevent the invasion of northern tribes, but this wall enhanced its protection function to small invasions only, and Mongolian army captured the most part of China across this wall by about 1200 A.D. European lords in the Middle Ages built a moat by digging around of castle or reinforced around of the castle by making bascule bridge, and provided these protections to the resident and received agricultural products cultivated. Edwin Holmes of USA in 20 centuries started to provide innovative electric alarm service to the development of the security industry in USA. This is the first of today's electrical security system, and with developments, the security system that combined various electrical security system to the relevant facilities takes charging most parts of today's security market. Like above, humankind established various protection methods to keep life in the beginning and its development continues. Today, modern people installed CCTV to the most facilities all over the country to cope with various social pathological phenomenon and to protect life and assets, so daily life of people are protected and observed. Most of these physical security systems are installed to guarantee our safety but we pay all expenses for these also. Therefore, establishing effective physical security system is very important and urgent problem. On this study, it is suggested methods of establishing effective physical security system by using system integration on the principle of security design about effective security system's effective establishing method of physical security system that is increasing rapidly by needs of modern society.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.4
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• pp.22-32
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• 2013

This study aimed to reveal the establishment process and design concept of KoKwan park built in modern Busan, which is called three major park includes YongDuSan park and TaeJeong Park, by analyzing BusanIlbo published modern period in Busan and 'Busan' published modern Busan prefecture. In KoKwan, there was installed DuMoPo Waegwan. The Japanese residents built the cemetery and memorial stone for Tsunohe Heigo's sudden death in the KoKwan hill, who was an envoy dispatched by Tsusima prefecture, in order to enhance awareness of the old territory DuMoPo Waegwan. In 1916, the Japanese residents repaired ruined the place by rasing funds and donated to Busan prefecture. Busan prefecture went public this place as a park. Meanwhile, In order to commemorate the 50th anniversary of the opening of Busan port, Oike Chusuke's memorial statue was built in private house neiboring KoKwan park. He became the richest person in Busan while engaged in commerce and industry since he come to the Busan the year before the opening of Busan port. He donate garden site includes his statue and 10,000 Won for KoKwan park construction expenses to Busan prefecture Busan prefecture invite Oya Rejo, who was Osaka-Hu's landscape designer, to design the KoKwan park. He visited Busan and survey KoKwan park and other Busan's park and submitted the plan to Busan prefecture. His Plan for KoKwan includes shrine and Oike's statue, arboretum and greenhouses, children's play garden, etc. Oya's design concept of KoKwan park was analyzed as follows: the juxtaposition of the sacred and secular, the succession of present landscape context, the complement of parks content, the tool of nation-state formation. KoKwan park was completed with cost 20,000 won, insufficient budget compared with Oya's estimated amount. However, in this thesis, it was not cleared whether Busan prefecture built the park as it was. In 1945, after the independence, KoKwan Park was destroyed due to build Dong-gu Office, houses. The remained subjects from this study are to clarify the process the destruction of the park.