• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.108-115
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• 2015

Multilateration systems are used to provide the position of aircraft in flight or on airport runways. In the multilateration systems, the interrogator is an important transmitter that used to interrogate the airplanes with appropriately scenario in surveillance airspace. Whisper-Shout interrogation sequence, which is one of the key functions of the interrogator, can control airport traffic density when intruder airplanes are coming into the surveillance airspace. Therefore collision chance between airplanes could be reduced and also get highly accurate location of incoming airplane in multilateration systems. In this paper, we developed the interrogator that allows it to transmit Mode A/C and Mode S interrogations which is similar to existing secondary surveillance radar. With appropriately controlled Whisper-Shout sequence in the interrogator, the multilateration systems can avoid synchronous garbling and FRUIT phenomenons caused by receiving multiple responses from a number of airplanes.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.88-96
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• 2009

In this Study, FR-ECC(Fire Resistance Engineered Cementitious Composites) in which at same time it can improve the endurance and fire-resistance efficiency of a Structure was developed, and the experimental study such as thermal characteristic, Fire-resistance efficiency, and etc was performed for using FR-ECC as the repair materials for building and civil Structure. Moreover, it was evaluated about the field applicability of FR-ECC. As a result, FR-ECC is superior to the existence fire resistance repair mortar in strength and durability property. Also, FR-ECC was exposed to have the characteristic of being excellent than existence fire resistance mortar in the field applicability.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.60-60
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• 2019

지속가능한 개발이 주목받고 남북 평화의 시대를 맞이하여 임업분야와 농업 축산분야가 결합된 혼농임업(Agroforestry)이 주목받고 있다. 혼농임업(Agroforestry)은 식량, 과실, 풀사료, 땔감, 목재 등을 생산하고 토양보전을 실천하여 지속농업을 가능케 하는 복합영농의 한 형태이며, 북한 산지의 경우 황폐화된 산지가 많아 경제성과 산림녹화를 동시에 해결할 수 있어 많은 관심을 받고 있다. 본 연구는 강원도 하늘목장을 시범목장으로 선정하여 조사를 실시하였고, 연구조사지의 총 면적은 2.4ha로 백두대간과 오대산국립공원이 인접한 지역으로 다양한 식물상을 파악할 수 있는 지역이다. 그러므로 외래종침입에 따른 생태적 교란을 방지하기 위하여 완충지대를 설정하고 식물상 조사를 실시하였다. 그리고 조사지내의 대표 수종으로 선정된 모수만 남기고 벌채를 실시하여 변화양상을 모니터링 하였다. 2014년~2017년 총 3개년 계절별 조사를 통해 임간초지의 식물상 정보를 파악하였고 임간초지의 관속식물상을 조사한 결과 92과 250속 323종 4아종 43변종 6품종으로 총 376분류군이 조사되었다. 자원식물의 유용도 분석한 결과 식용자원(E)이 160분류군으로 가장 많은 비율을 차지하고 있었으며, 약용(M) 141분류군, 관상용(O) 45분류군으로 나타났으며, 용도미상(U) 식물도 73분류군이 분포하고 있는 것으로 나타났다. 또한 연구 대상지역의 특성을 고려하여 조성된 초지 내에서 조사료로 사용할 수 있는 식물 종을 파악하였다. 나아가 미비한 임간초지 식생의 DB를 구축하고, 지속가능한 녹색성장을 모색하여야 할 것이다.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.195-209
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• 2012

1) 버섯종균 생산 시스템 개선 버섯의 품질과 수량을 좌우하는 주요 요인은 종균의 활력이다. 그러나 말라위에서는 종균의 활력이 낮아 조그마한 350cc 음료수 병에 배양 완성하는데 20일이 소요되는 등 노동력의 비효율성을 개선하였다. 따라서 350cc 병을 3500cc 비닐봉지로 개선하여 입봉하는데 소요되는 시간을 10배 이상으로 단축 개선하였다. 또한 곡립종균을 액체종균으로 대처한 결과 균사생장 속도가 빨랐으며 작업속도가 빨라졌다. 곡립 수수를 밀로 대체하여 종균제조 노동력을 효율적으로 전환하였다. 2) 버섯재배사 환경관리 개선 버섯재배의 4대 환경조건은 온도, 습도, 환기, 광이다. 그러나 말라위의 버섯재배사는 4대 환경조건 조절을 자연상태에 의존하고 있다. 그럼에도 불구하고 비닐로 커버된 상태에서 문을 닫아두어 과습이 되고 환기가 되지않았다. 이를 개선하기 위하여 직경 5cm 환기공을 버섯재배사 당 4개씩 만들도록 지도하였다. 3) 버섯배지 개선 말라위에서는 옥수수 대를 잘라 버섯배지로 주로 이용하고 있다. 이를 개선하여 말라위 북부지역(다광)에 대규모 사탕수수 공장을 방문하여 사탕수수 박을 이용하여 버섯재배 기술을 교육하였다. 이를 이용함으로서 버섯 균사생장속도를 빠르게 하고 균사량의 축적을 높이도록 하여 고품질 다수확하는데 교육을 하고 컨설팅을 실시하여 개선하였다. 4) 버섯 배지 야외발효 후 지면재배 시도로 시간 단축과 비용절감 말라위 버섯배지 혼합제조법은 옥수수대 한가지로서 영양원이 없다. 이를 개선하여 배지를 수분을 흡수시킨 후 야외 퇴적하므로서 배지의 물리성을 개선하고 야외발효 과정 중 양분이 합성되어 양질의 배지를 만드는 방법이다. 야외발효한 배지를 봉지에 담아 균상에 입상하는 불편함과 나무로 만들어진 균상대의 과습으로 인한 곰팡이 발생과 개미 침입으로 썩는 것 등을 방지하기 위하여 지면재배 방법으로 개선하였다. 이 지면재배는 균상 만드는 나무재료와 인건비 절감. 병해충 발생 방제 뿐만아니라 고품질 다수확할 수 있는 방법으로 개선 교육과 시범 시연을 실시하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.405-411
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• 2008

The Nakdong River Estuary Barrage (NREB) was constructed in 1987 to prevent saltwater intrusion and to provide the sustainable water supply in the upstream channel. Sediment dredging has been conducted to eliminate deposited sediments in the approached upstream channel of the NREB. Fluvial changes and sedimentation problems have been continued due to urbanization and development in the watershed as well as construction of the NREB. However, the sufficient field monitoring and researches for sedimentation characteristics and bed changes have not been performed after construction of the NREB. Therefore, bed elevation changes and seasonal sediment concentration distribution were analyzed using the quasi-steady state model with historical field data in this study. The water surface elevation changes with and without sediment dredging operation were calculated using the developed quasi-steady state model and finally the sediment dredging effects were evaluated.

• Journal of Practical Engineering Education
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• v.16 no.3_spc
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• pp.327-332
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• 2024

The spread of smart phones provides users with a variety of services, making their lives more convenient. In particular, financial transactions can be easily made online after user authentication using a smart phone. Users easily access the service by authenticating using a PIN, but this makes them vulnerable to social engineering attacks such as spying or recording. We aim to increase security against social engineering attacks by applying the authentication method including imaginary numbers when entering a password at the door lock to smart phones. Door locks perform PIN authentication within the terminal, but in smart phones, PIN authentication is handled by the server, so there is a problem in transmitting PIN information safely. Through the proposed technique, multiple PINs containing imaginary numbers are generated and transmitted as processed values such as hash values, thereby ensuring the stability of transmission and enabling safe user authentication through a technique that allows the PIN to be entered without exposure.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.97-104
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• 2006

Though stringent guidelines are in place to protect the harbor environment, pollution from ships, from the ports terminals. Discharge from the ballast tanks of ships, though illegal, does occur. Such vessels, arriving from distant ports of call, can introduce exotic species of plants and animals, causing disruption of the local food web. Discharges rich in nitrogen can generate the rapid growth of plankton, eventually leading to a condition known as red tide that is lethal to some coastal organisms. In addition to the harbor's negative effects on marine organisms, the diesel engines of the ships and the trucks that haul cargo to and from the ports release large volumes of diesel exhaust into the atmosphere. IMO(International Maritime Organization) is strongly proceeding with adoption of a new maritime environment convention and coming into effect for regulation enhancement about the pollutants which are happened in a ship recently. Study about the conventions that our country currently comes into effect, and there is during forwarding and correspondence must be performed effectively. In this paper, International convention on the control of harmful Anti-Fouling system on ship, Ballast water management, Prevention of air pollution from ships, treat a main pending problem in ocean related environmental regulation convention.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.657-667
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• 2015

Cyanobacteria frequently dominate the freshwater phytoplankton community in eutrophic waters. Cyanotoxins can be classified according to toxicity as neurotoxin (Anatoxin-a, Anatoxin-a(s), Saxitoxins) or hepatotoxin (microcystins, nodularin, cylindrospermopsin). Microcystins are present within cyanobacterial cells generally, and they are extracted by the damage of cell membrane. It has been reported that cyanotoxins caused adverse effects and they are acculmulated in aquatic oganisms of lake, river and ocean. In natural, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, in process of water treatment, the use of copper sulfate to remove algal cells caused extraction of a mess of microcystins. Microcysitns are removed by physical, chemical and biological methods according to reports. The reduction of nutrients (N and P) inflow is basic method of prevention of cyanobacteria bloom formation. However, it is less effective than investigation because nutrients already present in the eutrophic lake. In natural lake, cyanobacteria bloom are not formed because macrophytes invade from coastal lake by eutrophication. Therefore, a coastal lake has to recover to prevent of cyanobacteria bloom formation.

• Korean Security Journal
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• no.42
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• pp.229-249
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• 2015

As the post-cold war era and globalization go on, national security problems which were not traditional national security problems such as terrorism, crime, environmental disasters, economic crises, cyber-terrorism, diseases, and energy problems threat humanity and nations and demands changes. Also, with the change, the concept of "big government" has emerged as the role of nation expanded. The modern society sees every country change from small government to big government in order to realize the establishment of welfare state. A comprehensive interpretation of security is needed in order to comprehensive protection of citizens beyond outside invasion such as crime, new disaster, terrorism. In Korea, incidents such as Cheonan-Ham, Yeonpeyong-Do, foot-and-mouth disease, Ddos terrorism, pirates hostages, mad cow disease, AI are happening and the humanitarian support for North Korea and the summit of South and North Korea are at a standstill. Also, National emergency management system, comprehensive emergency management center, countrol tower, national security system, cooperation with citizens, establishment of legal and institutional system are needed. The importance of this research is on the reestablishment of new national security and emergency management system according to the comparison between the national security and counter-terrorism system of Korea and that of the United States which is a leading country in this field. Also, the establishment of national emergency management act is needed as a statute for effective function as currently various laws and administrative organizations are dispersed.

• Korean Journal of Heritage: History & Science
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• v.48 no.3
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• pp.4-29
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• 2015

To protect cultural heritages from damage and destruction, evaluating the crime prevention environments is considered extremely important. This study analyzed the crime patterns related to cultural heritages, classified the crime environments by their types, and deduced the elements of the CPTED(Crime Prevention Through Environment Design), aiming to present the indices for evaluating the crime prevention environments. The results of this study can be summarized as follows. First, the crimes related to cultural heritages that must be prevented were identified as the night time trespassing and arson. According to the results of the analysis of external environments based on crime actions, the crime prevention environments of cultural heritages were classified into 10 types. Second, the important evaluation principles of the cultural heritage CPTED were the access control, surveillance reinforcement and the surrounding environment. Third, the access control that cover the internal region, boundary, external region and surroundings were classified into 22 indices. The surveillance reinforcement covers natural, organized and mechanical surveillance with 21 indices. Fourth, the applicability of the CPTED evaluation index was presented according to the types of the cultural crime prevention environments. The results confirmed that the maximum 43 indices were applicable to the seowon(lecture hall), hyanggyo(Confucian school), and gwana(district government office), and the minimum 10 indices, to the ramparts. Finally, the 43 indices were applied to Donam Seowon to validate their applicability. The results confirmed that most of the indices were applicable with the partial supplements. The evaluation index presented in this study is likely to contribute to studies in the cultural heritage CPTED field and to the protection of cultural heritages. Furthermore, this study is considered significant because it unleashed continuous concerns on and developments of CPTED. However, as the field survey to validate the applicability of the indices was limited to only one type, it may require further objective verification such as through an expert's examination of the validity and applicability of the evaluation index. In addition, to accommodate the index in related policies and systems, more precise verifications of the indices by type are considered necessary.