• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.489-499
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• 1999

This research investigated the applicapability of an improved algorithm to calculate the topographic index, ln($\alpha$/tan B), for the topography of Korea employing channel initiation threshold area(CIT) and an exponent for the gradient(H). hanjaechun subwatershed in Cheongdochun and Dongok subwatershed in Wichun test watershed were selected as study areas. The digital elevation models(DEM) of study areas have been made with the resolution from 10m to 100m. Application of CIT to the traditional algorithm provide reasonable computation method in considering channel pixel impact. Introduction of the gradient exponent(H) made it possible to obtain better flow convergence effect in concave topography comparing with the traditional multiple flow direction algorithm. The improved algorithm shows the capability to relax the overestimation problem of rising limb of hydrograph through reducing overestimated high value of topographic index.

• Geophysics and Geophysical Exploration
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• v.2 no.1
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• pp.43-53
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• 1999

Numerical modeling and inversion for electromagnetic exploration methods are essential to understand behaviour of electromagnetic fields in complex subsurface. In this study, a finite element method was adopted as a numerical scheme for the 2.5-dimensional forward problem. And a finite element equation considering linear conductivity variation was proposed, when 2.5-dimensional differential equation to couple eletric and magnetic field was implemented. Model parameters were investigated for near-field with large source effects and far-field with responses dominantly by homogeneous half-space. Numerical responses by this study were compared with analytic solutions in homogeneous half-space. Blocky inversion model was modified to be applied to the forward calculation in this study and it was also adopted in the inversion algorithm. Resolution for isolated bodies were investigated to confirm possibility and limitation of inversion for electromagnetic exploration data.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.41-46
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• 2014

As the radioactive-related incidents have been occurred frequently such as Fukushima nuclear exposure incident, it is always considered radioactivity normal levels in radiation exposure as a most risk components at several government agencies. In this paper, the data were analyzed by information in the data beyond range of the attributes. The clustering analysis method is used by EM and SimpleKMeans algorithm. The experimental results about US Radioactive associated data is depending on the method of data analysis. It can be seen that the method of the algorithm is different depending on local value of the normal range. The governments need to pay attention to increase the investigation frequency.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.387-396
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• 2008

An integration between construction CAD data and GIS data needs geo-referencing processes of construction CAD data whose coordinate systems are their own native or even unknown. Generally, these processes are based on manually detected conjugate-vertices. In this study, we proposed an semi-automated conjugate -vertices detection method for building features between construction CAD data and a digital map using a vertex attributed string matching algorithm. A geo-referencing function for construction CAD data based on the similarity transform could be derived with those conjugate-vertices. Using our proposed method, we overlaid geo-referenced CAD data to a digital map of the College of Engineering, Seoul National University and evaluated our method.

• Journal of KIISE:Databases
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• v.28 no.4
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• pp.545-557
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• 2001

In this paper we propose a hierarchical classification algorithm based on rough membership function which can reason a new object approximately. We use the fuzzy reasoning method that substitutes fuzzy membership value for linguistic uncertainty and reason approximately based on the composition of membership values of conditional sttributes Here we use the rough membership function instead of the fuzzy membership function It can reduce the process that the fuzzy algorithm using fuzzy membership function produces fuzzy rules In addition, we transform the information system to the understandable minimal decision information system In order to do we, study the discretization of continuous valued attributes and propose the discretization algorithm based on the rough membership function and the entropy of the information theory The test shows a good partition that produce the smaller decision system We experimented the IRIS data etc. using our proposed algorithm The experimental results with IRIS data shows 96%~98% rate of classification.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.301-306
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• 2021

In the field of year-based interpretation of important data, memory laws can be used as a way to enhance educational effectiveness. Studies related to how to remember numbers are conducted in the form of increasing memory rates by presenting information in the form of conventional simple images. We attempt to supplement the method proposed in the paper of numerical algorithm for modifying errors based on mnemonic system in mobile environments. We want to complement the error correction numerical algorithm proposed in previous work. The study was a way to compensate the errors that occur when users enter numerical information in the apps they use. In this work, we want to increase the memory rate based on two-dimensional information by imposing the concept of angles, rather than simply showing data to help recall memories from mistakes. To this end, we propose a problem-solving process using developed app, and implement and evaluate the short distance valid algorithms.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.2
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• pp.305-312
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• 2023

In introducing memory methods in various educational fields, programs in a mobile environment can be used for the purpose of increasing accessibility and enhancing the effectiveness of education. It is much easier to remember words with meaning than to remember numerical information such as years. From the standpoint of increasing the educational effect, the part that needs to be supplemented with the help of the application can be said to be numerical information. Most studies related to conventional numerical memory have focused on the form that helps memory by imaging numbers. In the paper on memory-based meta-record algorithms in the mobile environment, the application developed in the previous study attempts to supplement this by discovering and simply modifying the user's mistakes in the entered numerical information. In this study, we aim to increase the memory rate by constructing metadata based on personalized log information and correcting mistakes. To do this, applications suitable for the mobile environment are developed, a structure of meta-record data is proposed, and meta-record application algorithms are implemented and evaluated.

• Journal of Internet Computing and Services
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• v.25 no.2
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• pp.93-99
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• 2024

In this paper, we derive the Partial Differential Bond Price Equation (PDBPE) by using Ito's Lemma to determine the pricing of bond on term-structure of interest rate (TSIR) model with jump. From PDBPE, the Maclaurin series (MS) and the moment-generating function (MGF) for the exponential function are used to obtain a numerical solution (NS) of the bond prices. And an algorithm for determining bond prices using Monte Carlo Simulation (MCS) techniques is proposed, and the pricing of bond is determined through the simulation process. Comparing the results of the implementation of the above two pricing methods, the relative error (RE) is obtained, which means the ratio of NS and MCS. From the results, we can confirm that the RE is less than around 2.2%, which means that the pricing of bond can be predicted very accurately using the proposed algorithms as well as numerical analysis. Moreover, it was confirmed that the bond price obtained using the MS has a relatively smaller error than the pricing of bond obtained by using the MGF.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.495-508
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• 1994

A backcalculation procedure to determine the layer moduli of flexible pavement structure is developed using matrix solution technique. Forward calculation computer program adopted in this backcalculation procedure is SINELA which is one of layered elastic computer programs. Data base system is used as a tool for setting initial seed moduli and depth to virtual bedrock in backcalculation procedure. The validity and applicability of the proposed backcalculation procedure are verified through various numerical model tests. From the results of comparison analysis with FPEDD1, it is found that the proposed procedure gives more efficient and accurate results.

• Proceedings of the Korea Water Resources Association Conference
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• 2001.05a
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• pp.230-235
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• 2001