• 한국정보교육학회:학술대회논문집
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• 2007.01a
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• pp.141-148
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• 2007

ICT는 21세기 지식기반사회에서 교육효과를 증대시킬 수 있는 강력한 도구라는 여러 가지 이유로 ICT 활용교육이 중시되어 왔었고, 학교 현장에서는 ICT를 활용한 교수 학습이 활발하게 도입되었다. 그 중 Excel은 뛰어난 수식 계산과 논리 판단 기능을 갖추고 있어서 간단한 계산에서부터 함수를 이용한 복잡한 수식 작성과 문자의 연산, 데이터의 비교 분석과 그래프를 통한 통계처리까지 거의 모든 종류의 계산을 할 수 있다는 점에서 수학과에서 그 가능성이 제시되어 왔다. 그러나 기존의 연구는 대부분 중 고등학교 수학과에 한정되어 있어 초등학교에서 활용하기에는 무리가 있었다. 이에 본 연구에서는 초등학교 수학과에서의 Excel 활용 수업을 적용하기에 적합한 학습 주제를 선택하여 학생들이 계산하는데 걸리는 시간보다는 문제해결을 위한 사고에 중점을 둔 문제해결 수업모형을 개발하여 적용해 보기로 하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.2
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• pp.123-129
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• 2008

In this paper, we propose the algorithm and circuit implementation to improve the performance of Multiplication using Addition based on H421 code. We expect that our method will be an essential element to make a embedded prototype in Ubiquitous environment.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.207-207
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• 2020

하천으로 유입된 오염물질의 거동을 정확하게 예측하는 것은 하천 시스템의 수질 유지관리에 매우 중요하다. 본 연구에서는 1차 감쇠율(decay rate)을 가진 비보존성 오염물의 비정상 이송해석 방정식의 해를 위해 유한체적기법이 개발되어졌다. 하천 흐름 해석을 위해 자연형 단면에서의 마름-젖음 해석이 가능한 기법이 도입되었다. 이 기법은 2차-정도의 정확성와 Courant 수가 1 까지 안정함을 보장한다. 도입된 기법은 Godnov 형의 유한체적기법을 이용하여 St. Venant 방정식들을 해석하였고 질량 및 운동량 플럭스는 Roe 형의 Riemann Solver 를 사용하여 연산하였다. 오염물의 이송 해석은 추가적인 이송-확산 방정식을 도입을 통해 기존의 St. Venant 방정식과 함께 풀려질 수 있다. 추가된 방정식과 St. Venant 식은 3×3 eigenstructure를 구성하였고 이는 2차원 흐름해석 기법과 유사하게 해석될 수 있었다. 본 연구 모형의 검증을 위해 오염물의 계속적 주입을 가정한 가상 및 실제 하천에 적용되었다. 연구된 기법은 모든 적용에서 합리적 정확도를 가지고 오염물질의 연속적인 특성을 잘 모의하고 있었다.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.1-9
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• 2008

Recently, various researches have been studied on the predict method of land change according to its development. The Cellular Automata(CA) is one of the most popular methods in the urban growth modeling. The basis principle of CA is to repeat operations, which convert the current cell into new cell state by the transaction rule. It will minimize the loss of data by using Fuzzy-AHP and it can lead the flexible urban growth modeling. However, AHP would have a disadvantage to repeat the procedure of the collecting intentions until it derives the weight. Also, it is necessary for the simulation of CA to repeat the operations and the test of data accuracy should be accompanied. The purpose of this study is to predict the Busan city growth model and analyze it according to the automated test method by applying CA as well as Fuzzy-AHP. This study shall improve the difficulties caused by complexity and repetitiveness in the urban grow modeling. The practical modeling could be derived from the verification, and the derived modules could be applied to the similar case studies.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.12
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• pp.56-65
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• 2001

This paper proposes an algorithm for the capacitance extraction of general 3-dimensional conductors in an ideal uniform dielectric that uses a high-order quadrature approximation method combined with the typical first-order collocation method to enhance the accuracy and adopts an efficient matrix-vector product algorithm for the model-order reduction to achieve efficiency. The proposed method enhances the accuracy using the quadrature method for interconnects containing corners and vias that concentrate the charge density. It also achieves the efficiency by reducing the model order using the fact that large parts of system matrices are of numerically low rank. This technique combines an SVD-based algorithm for the compression of rank-deficient matrices and Gram-Schmidt algorithm of a Krylov-subspace iterative technique for the rapid multiplication of matrices. It is shown through the performance evaluation procedure that the combination of these two techniques leads to a more efficient algorithm than Gaussian elimination or other standard iterative schemes within a given error tolerance.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.1
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• pp.155-163
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• 2010

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on-board the NASA's Terra spacecraft provides along-track digital stereo image data at 15m resolution with a base-height ratio 0.6. Automated stereocorrelation procedure was implemented using the ENVI 4.1 software to derive DEMs with $15m{\times}15m$ in 43km long and 50km wide area using the ASTER stereo images. The accuracy of DEMs was analyzed in comparison with those which were obtained from digital topographic maps of 1:25,000 scale. Results indicate that RMSE in elevation between ${\pm}7$ and ${\pm}20m$ could be achieved. Excluding cloud, water and building areas as the factors which make RMSE value exceeding 10m, the accuracy of DEMs showed RMSE of ${\pm}5.789m$. Therefore for the purpose of elevating accuracy of topographic information, we intended to detect the cloud areas and shadow areas by a landcover classification method, remove those areas on the ASTER DEM and then replace with those areas detached from the cartographic DEM by band math.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.425-435
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• 2014

The research for extracting man-made features such as building and road from the aerial photograph or satellite imagery has been performed actively. As lately the resolution of digital aerial photographs was improved, unwanted features(noise) would be often detected. An edge detection algorithm is developed to make up for such a noise problem, make boundaries of wanted objects clear and extract only needed features. The algorithm developed in this research performs separating RGB channels, differencing between channels, transforming in to binary images, excluding noises and restoring shapes, and edge extraction in order. The images to be used for edge detection are prepared through bundle adjustment, DTM extraction, orthorectification and mosaicking. The roof edges of small building on preprocessed digital aerial orthophotos were extracted using the algorithm developed in this study. The validity of the algorithms was proved by comparing edge results of small building extracted in this study with those of conventional methods.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.27-32
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• 2005

DEM is needed for urban modeling, forecasting of floods and the analysis of slope and aspect. It has been generated using digital maps, aerial photos or satellite imageries. Recently, however, many studies on DEM generation from LiDAR data has been conducted because of its efficiency and accuracy. Filtering is said to be the process of making DEM by eliminating non-ground points from LiDAR data. In most researches, some input parameters such as the size of filter are required. The purpose of this investigation is to automatically obtain DEM by eliminating objects of various sizes without the knowledge of the objects' sizes. The experimental results show that most of objects on steep terrain are eliminated by the proposed method.

• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.75-80
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• 2009

Despite its flexibility to complex geometry, three-dimensional (3D) electromagnetic(EM) modeling schemes using finite element method (FEM) have been faced to practical limitation due to the resulting large system of equations to be solved. An efficient 3D FEM modeling scheme has been developed, which can adopt either direct or iterative solver depending on the problems. The direct solver PARDISO can reduce the computing time remarkably by incorporating parallel computing on multi-core processor systems, which is appropriate for single frequency multi-source configurations. When limited memory, the iterative solver BiCGSTAB(1) can provide fast and stable convergence. Efficient 3D simulations can be performed by choosing an optimum solver depending on the computing environment and the problems to be solved. This modeling includes various types of controlled-sources and can be exploited as an efficient engine for 3D inversion.

• Journal of the Korean School Mathematics Society
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• v.25 no.4
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• pp.307-332
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• 2022

This action research was carried out to help students learn fractions computation by making and using semi-concrete fraction manipulatives that can be used continuously in math classes. For this purpose, the researcher and students made semi-concrete fraction manipulatives and learned how to use these through reviewing the previously learned fraction contents over 4 class sessions. Afterward, through the 14 classes (7 classes for learning to reduce fractions and to a common denominator, 7 classes for adding and subtracting fractions with different denominators) in which the principle inquiry learning model was applied, students actively engaged in learning activities with fraction manipulatives and explored the principles underneath the manipulations of fraction manipulatives. Students could represent various fractions using fraction manipulatives and solve fraction computation problems using them. The achievement evaluation after class found that the students could connect the semi-concrete fraction manipulatives with fraction representation and symbolic formulas. Moreover, the students showed interest and confidence in mathematics through the classes using fraction manipulatives.