• Journal of the Korean GEO-environmental Society
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• v.23 no.9
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• pp.5-16
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• 2022

In recent years due to the development of urban and underground space, the number of ground disasters is increasing, and it is also leading to social problems. To solve the problem, a grouting method is generally used. However, the grouting method has material (grout) limitations in permeability, gelation properties and tensile resistance. Therefore, research on grout materials mixed with fibers is actively carried out to improve the problems. However, in the actual ground injection process, many difficulties have been faced causing the blockage of the inlet port and the injection tube. In this study, 'CNT-mixed grout material' was developed using CNT powder that can reinforce the tensile strength of soils. The uniaxial compressive and tensile strength tests were performed to obtain the optimal content and mechanical properties of the CNT Powder-mixed grout. It was found that the optimal CNT powder content is 0.5% that gives the average maximum strength. A one-dimensional injection test and the bulb formation test were carried out, and it was identified that the injection rate and bulb form could be controlled by pressure and mixing ratio. Field application of the CNT-Mixed grout is simulated using numerical analysis of slopes, foundations, and tunnels reinforced in several types. The positive effect of reducing plastic ranges and settlements was confirmed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.1
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• pp.89-97
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• 2013

Recently, economic and social damages are globally increased due to the heavy snowfall caused by global warming. To reduce the damages of sudden regional heavy snow in roads, suitable countermeasures should be established based on the accurate detection of snowfall intensity for each roadway segment. In this paper, we deal with snowfall intensity detecting algorithm in the road area from CCD Imagery. First, we determine the MLZ (MotionLess Zone), which does not contain lane markings and moving cars, in the image space. Next, snow streaks trespassing the MLZ are extracted with Canny operator and proposed algorithm. Also, the concept of SII (Snow Intensity Index), which is the number of snow streaks during one minute in the MLZ, is defined. Finally, the effectiveness of proposed algorithm is proved by visually comparing the imagery and SII value obtained during 69 minutes. In consequence, we figured out that the integration of SII is significantly related to an actual amount of snowfall.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.4
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• pp.99-108
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• 2003

In early year 2003, the previous Urban Planning Law and National Land Use Management Law were abolished and integrated into the Law regarding National Land Planning and Land Use Management. Accordingly, previous Urban Planning Information System is reformed into National Land Use Information System. This paper intends to develop indexes supporting decision-making process and to construct theme map using digital map that can be utilized for the National Land Use Information System. As a base for the index development, necessary database(DB) was established by utilizing the socio-economic information of towns and villages in Busan and a layer of public facilities. Based on the DB, multivariate analyses were performed to examine and analyze the spatial structure of Busan. It was then expressed and constructed as a theme map. The facility theme map was also constructed based on a layer of public facilities and the shortest distance between towns and villages.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.1293-1314
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• 2015

As ICT is becoming a major social infrastructure, the need to strengthen cyber capabilities are emerging. In the major advanced countries including the United States, has a continuing interest in strengthening cyber capabilities and has studied in enhancements of cyber capabilities. The cyber capability assessment is necessary in order to determine the current level of the country, establish policy directions and legislations. The selection of criteria has very important meaning to suggest future policy direction as well as an objective assessment of cybersecurity capabilities. But there are variable criteria for national cyber capabilities assessment such as strategy, legislation, technology, society and culture, and human resources. In this paper we perform the analysis of criteria for the other country's cybersecurity assessments including the U.S. and Europe. And we proposed the criteria for the national cybersecurity assessment reflecting the our country's characteristics.

• Journal of the Korean Geographical Society
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• v.32 no.4
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• pp.479-490
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• 1997

This study attempted to grasp the etimological meaning of the ancient place name Dumo, and to identify when the ancient place names in Dumo system started to be used by Korean people. The results of analysis of generic toponym and specific toponym of the ancient place names in Dumo system are as follow: Firstly, Chumong, the name of the founder of the Koguryo Dynasty, and his two sons Biryu,the founder of the kingdom Biryu-Paekche, and Oncho, the founder of the kingdom Paekche, are presumed to originate from place name, not from person's name. Particularly, the name of Chumong is considered to be a person's name which comes from Dumo system. Oncho, who claimed to be a son of Chumong, a person of north-Puyo, transterred the capital of his kingdom to the present site of Dumo in Chunggung-dong, Hanam city in present, which is thought to be an early capital of Paekche or a part of it. Secondly, the word of Dumo means a warm space which is surrounded by mountains, protected from wind, endowed with river which provided with water. This kind of spatial cognition gradually evolved as the prototypical locational artifice which was diffused to Manchuria and Japan, and is believed to be introduced to the Korean Peninsula.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1156-1160
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• 2006

본 연구는 빈도별 수문조건하의 2차원 수리해석모형(FLUMEN) 결과를 제공받아 빈도별 침수범람 등을 분석하고, 이로부터 도출되는 침수면적, 최대침수심, 최대유속 등의 특성정보를 이용하여 침수심보다 상대적으로 홍수 위험에 대한 척도를 나타내어 줄 수 있는 홍수 강도(Flood Intensity) 개념을 도입하여 대상유역에 적합한 홍수 위험지표(Flood Hazard Value) 및 홍수 위험도(Flood Risk Map)를 작성하고자 하였다. 본 연구의 대상지역은 안성천 중류부의 평택시 6개동을 포함하는 약 $12.6km^2$의 대상지역으로 2차원 수리해석모형(FLUMEN)의 분석한 시간별 침수심(Flow Depth), 최대침수심과 최대 유속 등의 결과를 ASCII파일의 XYZ값 형태로 제공받아 ArcGis 등을 이용하여 Point Coverage를 만들고, 이로부터 TIN (Triangulated Irregular Network)작업을 수행한 후 대상지역의 최대 침수심도 및 최대 유속분포도 등을 작성하였다. 그리고, 침수예상도 등으로부터 얻어진 침수면적, 최대 침수심, 최대유속 등을 분석하여 침수심과 유속의 함수로 홍수강도를 정의하고 홍수강도와 홍수발생확률의 곱으로 위험지표를 산정하였고, 산정된 홍수 위험지표를 적용하여 홍수 위험도를 작성하였다. 본 연구로부터 도출되는 홍수 위험지표 및 홍수 위험도는 홍수범람에 의한 인명피해 및 재산손실과 이에 대한 복구 및 구호활동에 소요되는 노력 등의 여러 가지 사회..경제적 역기능을 방지하고자 홍수에 의한 침수특성을 이해하고 홍수에 대비한 적절한 홍수방어대책 수립시의 지원 정보로 제공되어 활용될 수 있다.

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.17-21
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• 2015

Recently, As people's interest in the health of teeth is increased in the medical field changed into aging society, the number of times for the radiological diagnosis is increased. It can be said that the radiation exposure dose of Korean population is increased. It is also growing concern about radiation exposure. Therefore, the basic data for the dental panoramic X-ray system, its investigation and measuring the radiation dose is needed. In this study, we used ALOKA PDM-117 dosimeter and estimated a two-dimensional dose distribution of the dental panoramic X-ray system (VATEC Pax-400). Dose evaluation about the distribution is confirmed from the point of radiation exposure of a patient. Dose distribution of the dental panoramic X-ray system irradiated chin and the facial region to high dose as well as the parts of teeth. It was founded that the eye lens which are sensitive to radiation are exposed to unnecessary radiation, considering the effect of scattered radiation. The results of this study will be used more accurate dose assessment in a variety of object size and location of measuring dose.

• Journal of Korea Multimedia Society
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• v.5 no.6
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• pp.674-682
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• 2002

Nowadays economic and commercial businesses have been increased because of the Internet. As a result of this, electronic commerce is becoming one of the most Interesting topic of discussion. Electronic commerce is equal to a real market, only the place of business is the imaginary space supported by the Internet. There are a few conditions to consider, making electronic commerce work safely. The electronic commerce should be connected by a substantial system and an on-line Protocol. There are some conditions needed for information security, authentication, and payment by electronic currency etc. Although there are many kinds of existing systems, which create services successfully, further research for security is required. Therefore, this paper suggests an authenticated Agent management, which offers more convenience and security than before. Also, this paper shows many authenticated methods for a management system. An Agent that is one of interesting things to study can handle information problems and works related to electronic commerce.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.513-528
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• 2014

The landscape of Christian higher education is changing. Students once spent most of their time in a traditional classroom with a professor, but now they take online and hybrid courses (face to face and online). Some students complete their entire degree in a fully online program. Nearly every type of college in the United States offers online courses. Online learning has clearly moved from a fad to a fixture, and nowhere is that more apparent than at one of the largest universities in the country. As the demand for online course and programs increase, teachers and administrators in Christian universities and colleges face new challenges. Even though some teachers and administrators still believe online education is inferior to traditional face-to-face learning, we found no statistically significant differences in standard measures of learning outcomes between students in the traditional classes and students in the hybrid-online format classes. In this situation, since online education will develop continuously, Christian universities should utilize it variously through complete understanding and research about it predicting the future of online education style.

• The Journal of the Korea Contents Association
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• v.4 no.1
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• pp.90-99
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• 2004

With the spread of internet, the digitalization and the knowledge informatization are in progress rapidly. Specially, numerous users make the various works and use the services on the web. For the most part, these works make use of the XML The XML shines the reusing of the documents because it is separated from contents and sues. Also, it can re-define the logic structure of the document for requirement of the developer. However, the XML document’s size is much larger than common text document because it handles the document type and adds numerous tags for representing structure of the document. To utilize the limited storage devices of Palmtop, PDA and so u, it is necessary to compress and handle the documents efficiently. Recently, the compression techniques for efficiently handling and compressing the XML documents are under way to solve this problem. But most of the existing researches don't support the query processing for the compressed XML documents. In this paper, we design and implement the XML compression algorithm that compresses the XML document and Processes the query of compressed XML document faster and more efficiently than previous techniques.