• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.585-608
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• 2009

The aim of this study was to research the characteristics of science teachers' thinking related to dissolution and diffusion. For this study, five science teachers who majored in chemistry or chemistry education were selected and interviewed. These teachers have been teaching on average for 2$\sim$6 years. From the study, it was discovered that the science teachers didn't recognize the necessity of sorting out diffusion from dissolution. The teachers divided in various mixing phenomena with diverse criteria. The science teachers had difficulty in sorting out diffusion from dissolution based on solubility and Gibbs' energy. The teachers didn't see the linkage between the contents that were divided into chapters, and didn't find omitted contents themselves in the chapters that introduced applicable principles. During the interviews, the teachers felt the need to understand the principles for understanding phenomena. But they did not have the ability to teach these principles after learning about the principles themselves. Therefore, it is necessary to develop teacher education programs, as well as a science curriculum, that helps in linking the knowledge between natural phenomena and principles.

• Tunnel and Underground Space
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• v.15 no.3 s.56
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• pp.195-212
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• 2005

Surface subsidence which occurs with several reasons, such as collapse of gangway, discharge of groundwater, compaction of weak rock mass, and tunnel excavation in shallow depth, gives rise to a serious problem in national infra-structures. In this study, therefore, the mechanism of subsidence has been examined numerically to overcome the passive approach on subsidence occurrence area. With many kinds of numerical studies, the major geotechnical parameters have been selected and the weighted values have been defined for each parameters. Also the authors developed the numerical program which can estimate the possibility of subsidence occurrence, and proposed the decision method for objective and quantitative guideline. It is anticipated that this research will be helpful to establish the hazard map on subsidence region.

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.4
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• pp.405-425
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• 2018

Increasing the problem solving power in school mathematics is the most important task of mathematics education. It is the ultimate goal of mathematics education to help students develop their thinking and creativity and help solve problems that arise in the real world. In this study, we investigated the contents of problem solving according to mathematics curriculum goals from the first curriculum to current curriculum in Korea. This study analyzed the problem-solving contents of the mathematics textbooks reflecting the achievement criteria of the revised curriculum in 2015. As a result, it was the first curriculum to use the terminology of problem solving in the mathematics goal of Korea's curriculum. Interest in problem solving was most actively pursued in the 6th and 7th curriculum and the 2006 revision curriculum. After that, it was neglected to be reflected in textbooks since the 2009 revision curriculum, We have identified the problems of this problem-solving instruction and suggested improvement direction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.771-779
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• 2009

Digital topographical maps used for GIS DB are mainly produced by the traditional way of analogue aerial photogrammetry. Therefore, analogue photos are only available for digital mapping after preprocessing such as film developing, printing and scanning. However, digital aerial camera is able to get digital image directly without preprocessing and thus the performance and efficiency of photogrammetry are extremely increased. This study aims to investigate geometric stability of digital aerial frame camera DMC (Digital Modular Camera). In order to verify the geometric stability of digital aerial camera DMC, some different block conditions with and without cross strips, GPS/INS data and variation of GCPs are introduced in the block adjustment. The accuracy results of every block condition were compared each other by computation of residuals of exterior orientation (EO) parameters. Results of study shows that the geometric stability of the block adjustment with cross strips is increased about 30% against without cross strips. The accuracy of EO parameters of block adjustment with cross strips is also increased about 2cm for X-coordinate, 3cm for Y-coordinate, 3cm for Z-coordinate, and 6" for omega, 4" for phi and 3" for kappa.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.4
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• pp.413-420
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• 2011

This study is to extract landmark buildings for pedestrian navigation from the existing spatial data sets automatically. At first, we defined candidates for landmark based on sight of pedestrian, then extracted final landmark by evaluating attributes of each candidate. The attribute is evaluated with relative or absolute criteria depending on the nature of each attribute. Landmarks extracted through the proposed method are compared to existing landmarks for vehicle and assessment of the validity and the applicability is performed. As a result, extracted Landmarks are expected to help guiding pedestrian effectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.101-109
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• 2011

This paper describes the attempts to improve the performance of an image matching method for multiple image. Typically, matching between two images is performed by using correlation between a reference and corresponding images. The proposed multiple image matching algorithm performs matching in an object space, chooses the image closest to the true vertical image as a reference image, calculates the correlation based on the chosen reference image. The algorithm also detects occluded regions automatically and keep them from matching. We could find that it is possible to create high quality DEM by this method, regardless of the location of image. From the performance improvement experiments through the occlusion detection, we could confirm the possibility of a more accurate representation of 3D information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.29-39
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• 1997

The need of transformation parameters from local geodetic datums to a geocentric coordinate system is becoming more common, with the increasing application of satellite positioning techniques to LIS/GIS survey with cadastral management. In this paper, the national transformation parameters between the Korean geodetic coordinates which is based on the Bessel 1841 ellipsoid and the WGS84 ellipsoid are determined by the least square methods with weighted parameter constraints. Three-dimensional geocentric coordinates are based on GPS observation at 31 stations in the geodetic network, the datum parameters are computed within a standard deviation of less than 1 meter. In South Korea, the national transformation parameters with Bessel geoid-heights are useful for GPS baseline processing and for middle-scale map/database transformation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.4
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• pp.38-38
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• 2001

본 논문에서는 웨이브릿 영역에서의 영역 분류와 대역간 예측 및 선택적 벡터 양자화를 이용한 다분광 화상테이타 압축 기법을 제안하였다. 이 방법에서는 각 대역을 웨이브릿 변환 후, 각 대역의 기저밴드의 대역별 특성을 이용하여 영역 분류를 행하였다. 그리고, 다른 대역과 해상도가 동일하고 공간적 분산이 작으며 분광적 상관성이 큰 기준대역 (reference channel)을 결정한 뒤, 이를 영역별 스칼라 및 분류별 가변 벡터 양자화를 행하여 부호화 하였다. 또한 기준대역과의 대역간 상관성이 큰 대역들에 대해서는 영역별 대역간 예측을 행한 후, 활동도가 높은 블록에 대해서만 선택적 벡터 양자화로 부호화를 행하였다. 이때, 활동도가 높은 블록들의 위치정보는 기준대역으로부터 얻어지는 임계치 지도 (threshold map; THMAP)를 이용하였다. 즉, 제안한 방법에서는 각 대역에 대해 웨이브릿 영역에서의 영역 분류 후 영역별 대역간 예측을 행함으로써 다분광 화상데이타에 존재하는 대역간 중복성을 제거하고 선택적 벡터 양자화를 행함으로써 대역내 중복성을 효과적으로 제거하여 압축효율을 향상시킨다. 실제 원격 센싱된 인공위성 화상데이타에 대한 실험을 통하여 제안한 기법의 부호화 효율이 기존의 기법에 비하여 우수함을 확인하였다.

• LOGISTICS
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• v.2 no.4 s.6
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• pp.62-67
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• 2004

지난 5월 1일부로 동유럽 10개국이 유럽연합(EU)에 가입했다. 동유럽 10개국이 EU에 가입했다는 것은 두 가지 측면에서 역사적 장애물을 제거하는 계기가 될 것이다. 하나는 사회주의체제를 벗어나 자본주의 체제로 편입되는 체제전환을 추구해왔으니 구소련이 주도하던 바르샤바동맹국으로서 몸에 베었던 의식과 체제의 잔재를 씻어내기 어려웠으며 이러한 잔재들은 동유럽 국가들의 경제$\cdot$사회 발전을 가로막는 역사적 장애요인으로 작용해 왔다. 따라서 EU가입은 이러한 역사적 장애요인을 극복하는 중요한 계기가 될 것으로 예상된다. 동유럽 10개국은 모든 사회$\cdot$경제 거래를 EU기준에 맞춰야 하며, 도로$\cdot$철도$\cdot$해운$\cdot$항공 등 물류부문에서도 EU의 기준을 충족시켜야 하는 ‘EU 공동체 확적영역’을 수용해야 한다. 따라서 동유럽 물류시장은 EU가입 이후 경제 및 교역발전에 따른 양적 팽창이외에 물류관련 기준과 거래관행이 개선되는 질적 발전도 가능하게 될 것이다. 우선 역내 통관절차가 단순해지는 등 사람, 자본, 화물의 이동이 자유화됨으로써 물동량이 크게 늘어날 것으로 예상되고 또한 동유럽 국가들은 EU로부터 운송 인프라 개발 및 현대화에 필요한 경제적 지원도 받게 된다. 한국해양수산개발원(KMI)은 ‘EU 가입 동유럽 물류시장의 특징과 시사점’이라는 현안분석을 통해 이같이 밝히고 우리나라 물류기업이 동유럽 시장에 진출하는 경우 제조업과 동반진출하고 현지업체와의 제휴관계를 모색하는 것이 바람직하다는 대응방향을 제시했다. 동 현안분석 내용을 요약$\cdot$정리한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.576-576
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• 2016

치수경제성분석, 투자우선순위 및 시설물 규모결정 등의 의사결정과정에서 실무에서는 다차원 홍수피해산정법(MD-FDA)을 현재까지 널리 사용 중이다. 2004년에 개발된 MD-FDA는 대상지역의 자산규모를 행정구역 경계 최소단위인 "읍면동"을 기준으로 계산하여 취합하고, 대상자산이 위치가능한 토지이용정보를 토지피복도로부터 확인하여, 읍면동내 토지이용공간면적을 기준으로 자산정보를 분배(분해)하는 방식으로 이루어진다. 그러나 읍면동 단위의 공간적인 범위는 상당한 면적의 공간적 경계이기 때문에, 이를 평균적인 밀도데이터로 분배 시 공간적인 자산분포에 대해 정밀도를 담보할 수 없다. 이에 본 연구는 행정구역경계인 "읍면동"과 비교할 때 평균적으로 1/30의 면적을 가지는 집계구 단위의 센서스 공간정보자료를 이용하여 방법론을 개선하였고, 이를 MD-FDA 분석체계를 근간으로 센서스자료와 관계된 자료들 간의 연계 및 전체적인 분석과정을 정립하였다. 본 연구에서 제안한 방법을 경기도 동두천시를 대상으로 적용하여 기존 방법에 의한 피해액과 그 차이를 비교하였고, 도로명전자지도의 실제 건물객체 자료(.shp)를 기준으로 오차율을 확인한 결과, 기존 방식에 비해 정밀도가 월등히 향상된 것을 확인할 수 있었다.