• Economic and Environmental Geology
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• v.43 no.6
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• pp.615-623
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• 2010

Seismic refraction survey is a geophysical method that delineates subsurface velocity structure using direct wave and critically refracted wave. The generalized reciprocal method(GRM) is an inversion technique which uses travel-time data from several forward and reverse shots and which can provide the geometry of irregular inclined refractors and structures underlain by hidden layer such as low velocity zone and thin layer. In this study, a simple Excel-GRM routine was tested for fast mapping of the interface between weathering layer and bedrock during the survey, with employing a pair of forward and reverse shots. This routine was proved to control the maximum dip of approximately $30^{\circ}C$ and maximum velocity contrast of 0.6, based on the panel tests in terms of dipping angle and velocity contrast for the two-layer inclined models. In contrast with conventional operation of five to seven shots with sufficient offset distance and indoor data analysis thereafter, this routine was performed in the field shortly after data acquisition. Depth to the bedrock provided by Excel-GRM, during the field survey for Cheongju granite area, correlates well with the elevation of the surface of soft rock from the drill core and SPS logging data. This cost-effective routine developed for quickly delineating the bedrock surface in the field survey will be readily applicable to mapping of weathering zone in narrow zone with small variation of elevation of bedrock.

• Proceedings of the Korea Association of Information Systems Conference
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• 2000.05a
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• pp.195-199
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• 2000

본 논문에서는 인터넷 상의 영상에 기반한 교통 감시 시스템을 구현한다. 영상 기반의 교통 감시 시스템은 루프 감지기 등의 센서를 이용한 방법에 비해 비용과 설치, 유지, 보수면에서의 장점으로 인하여 많이 연구되고 있다. 제안한 시스템은 인터넷상에서 FPA(Field Processing Agent)와 TSM(Traffic Surveillance Manager)으로 구성되며, FPA는 TSM에게 도로 영상과 차량의 속도, 도로 점유율과 같은 교통 정보를 제공한다. 차량의 평균 속도와 도로 점유율은, 도로색 영상과 연속된 입력 영상간의 샘플링 지점의 색상 차이변화를 이용하여 추출한다. 제안한 방법은 근사적인 교통정보를 추출해 주며, 입력 영상 전체에 대한 처리 과정 없이 제한된 영역만을 처리하기 때문에, 실시간 감시 시스템을 구축하는데 용이하다.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1511-1514
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• 2003

본 논문에서는 지능형 방송에서 내용 기반 검색 서비스에 관해 연구하였다. 이를 통해 MPEG-7 오디오/비주얼 서술자들을 이용하여 TVAF 메타데이타와 메타데이타 전송 서비스 스키마를 확장하였다. 그리고 MPEG-7 오디오 서술자를 이용한 내용 기반 검색 시 나리에 제안된 스키마를 적용하여 효용성을 증명하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.211-211
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• 2004

최근 인터넷 비즈니스의 증가로 고객 수요를 정확하게 예측하여 적절한 상품을 추천하는 추천 시스템의 개발 및 사용이 활발해지고 있다. 현재의 추천 시스템은 주로 내용 기반 추천(Content based Filtering)과 협력적 추천(Collaborative Filtering)을 사용하고 있으나 이러한 추천 시스템으로는 추천의 이유나 배경의 설명이 곤란하며, 시시각각 변하는 사용자의 의도를 파악하고 적절하게 응답하기에는 부족한 면이 있다.(중략)

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.616-619
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• 2004

최근 대용량 데이터의 저장과 검색을 요구하는 파일시스템이 필요하게 됨에 따라, 별도의 서버를 두지 않고 분산된 클라이언트가 메타데이터를 직접 관리하면서 모든 저장 장치들에 접근할 수 있는 SAN 기반 리눅스 클러스터 파일시스템의 연구가 활발하게 진행 중에 있다. 이러한 대규모 파일 시스템을 위해서는 동적 해싱을 이용한 디렉토리 관리가 요구되므로, 본 논문에서는 그 중 확장 해싱 디렉토리 구조와 선형 해싱 디렉토리 구조를 설계 및 구현하고, 구현된 시스템을 이용하여 성능평가를 통해 두 디렉토리 구조의 성능을 분석한다. 비교 분석 결과, 파일의 삽입 성능에서는 선형 해싱 기반의 디렉토리가 우수하였으나, 공간 활용면에서는 확장 해싱 기반의 디렉토리가 우수한 성능을 보였다.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.1-14
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• 2010

This paper deals with the classification and distribution of geomorphic surfaces and analysis on effects of geomorphic processes on the landforms in the inaccessable DMZ (Demilitarized Zone) to Wonsan Bay of East Sea coast of Chugaryeong Rift Valley, Central Korea. DEM (Digital Elevation Model) and Landsat images are used for the above anlaysis. The geomorphic surfaces are classified by TPI (Topographical Position Index) for the analysis of the convexity and concavity calculated using topographical elements such as elevation, steepness, and relief. In the Chugayreong Valley, 10 geomorphic surfaces are classified as steep valley, shallow valley, upland drainage, U-shaped valley, plain, open slope, upper slope, local ridge, midslope ridge, and high ridge. Zonal Statistics presents average characteristics of geomorphological processes of surfaces by the relationships between bedrock and relief, surface and relief, and between surface and NDVI. So, these analysis can help to understand geomorphological process such as dissection of lava plateau and watershed divide evolution.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.599-616
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• 2020

Sea-surface temperature (SST) is one of the most important oceanic variables for understanding air-sea interactions, heat flux variations, and oceanic circulation in the global ocean. Extremely low SSTs from 0℃ down to -2℃ should be more important than other normal temperatures because of their notable roles in inducing and regulating global climate and environmental changes. To understand the temporal and spatial variability of such extremely low SSTs in the global ocean, the long-term SST climatology was calculated using the daily SST database of satellites observed for the period from 1982 to 2018. In addition, the locations of regions with extremely low surface temperatures of less than 0℃ and monthly variations of isothermal lines of 0℃ were investigated using World Ocean Atlas (WOA) climatology based on in-situ oceanic measurements. As a result, extremely low temperatures occupied considerable areas in polar regions such as the Arctic Ocean and Antarctic Ocean, and marginal seas at high latitudes. Six earth science textbooks were analyzed to investigate how these extremely low temperatures were visualized. In most textbooks, illustrations of SSTs began not from extremely low temperatures below 0℃ but from a relatively high temperature of 0℃ or higher, which prevented students from understanding of concepts and roles of the low SSTs. As data visualization is one of the key elements of data literacy, illustrations of the textbooks should be improved to ensure that SST data are adequately visualized in the textbooks. This study emphasized that oceanic literacy and data literacy could be cultivated and strengthened simultaneously through visualizations of oceanic big data by using satellite SST data and oceanic in-situ measurements.

• Korea Information Processing Society Review
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• v.23 no.4
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• pp.36-42
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• 2016

• KOREAN POULTRY JOURNAL
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• v.19 no.10 s.216
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• pp.56-59
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• 1987

배합사료 가격 등락의 움직임이 심심치않게 거론되고 축협은 사료가격을 인하했다. 앞으로의 축산$\cdot$ 사료산업은 공히 막연한 수요기대 속에서의 공급기반 확대노력은 지양되어야 할 것이며, 산업의 질적$\cdot$내적인 면에서의 국제경쟁력 강화를 위한 정책적인 배려가 있어야 할 것이다.

• Journal of Korean Elementary Science Education
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• v.40 no.4
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• pp.460-479
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• 2021

The crisis of the COVID-19 pandemic has caused significant changes in education systems worldwide, including in Korea. Due to COVID-19's social distancing policies, the education system was suddenly switched to distance learning, resulting in many problems in primary schools without preparation. The purpose of this study was to investigate a teacher's awareness of science education techniques, responses to issues in science classes, including inquiry activities, advantages and disadvantages, and roles after experiencing distance learning. Survey and focus interviews were conducted for primary school teachers who had previously participated in distance learning, such as online content classes and real-time interactive classes. The study findings showed three conclusions: 1) Primary school teachers conducted one-way and interactive lectures in online classes. It is vital to improve a teacher's digital literacy to improve other teaching methods such as investigation and discussion in online classes. 2) Primary school teachers acknowledged the challenges of field feedback, inquiry item preparations, and safety in inquiry activities of science classes, by providing individual experimental packages and videos and using online discussion and feedback among teacher - student and student - student interactions. 3) Primary school teachers recognized that various types of classes using IT devices and individualized learning were possible as advantages of distance learning. As for disadvantages, it was acknowledged that inquiry activities, cooperative learning, immediate feedback, and interaction among students were challenging. Furthermore, learning gaps were wider in distance learning.