• Journal of The Korean Association For Science Education
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• v.27 no.6
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• pp.488-496
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• 2007

The aims of this study are to investigate how Kepler found a scientific problem for the retinal image theory and to investigate how Korean middle-school students respond when the same situation is applied to them. Kepler found the scientific problem in the eye vision through the critical analysis of contemporary theories of vision, based on his relevant knowledge of optics. When the same situation was applied to the Korean middle-school students, only a few students found the same scientific problem as Kepler. From the results, it is suggested that in developing creativity teaching materials, situations like Kepler's problem finding need to be included in programs.

• Journal of the Korean Chemical Society
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• v.52 no.2
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• pp.179-185
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• 2008

purpose of this study is to investigate the relationship between high school students' Problem Finding Ability (PFA) and chemistry problem solving ability. To achieve this purpose, the interrelationship between the results of PFA in ill-structured scientific problem situation and the scores of sham examination in chemistry I of College Scholastic Ability Test (CSAT) was analyzed. The results of this study turned out to be as follows: There was correlation (r=.346) between the score of PFA test and that of sham examination in chemistry I of the CSAT. And a little correlation (r=.390) between PFA and students application ability which is one of the sub factors in sham examination of the CSAT. Especially, in the high achievers group there was high correlation (r=.446) between students fluency which is one of the sub factors in PFA, and application ability. This implies that the application ability of high achievers has something to do with their PFA for a variety of problems. As for the PFA between high achievers and low achievers, there was no significant difference (t=.830, p=.411).

• East Asian mathematical journal
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• v.31 no.4
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• pp.505-525
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• 2015

The purpose of this study is to analyze teaching method of addition and subtraction of whole number in Korea and New Zealand lower grade textbook and to get some suggestive points to develop mathematics curriculum and for a qualitative improvement of textbook. To do this, we will analyze focusing on teaching material, type and method of teaching, cases of real teaching and in the case of New Zealand, we will analyze portfolios together to see what kind of things do they deal with related to addition and subtraction. From these analyzing, the results are as follows: First, the guideline of accomplishment of group of year are stated in 2009 revised curriculum in Korea but it is rough. On the other hand, the level of accomplishment from kindergarten to high school are stated divided by eight kinds of thing in New Zealand curriculum. Second, there were common and different points in the aspect of teaching material. The common points are that both of our Korea and New Zealand are using materials related to real life intimately and the diifferent points are to use technology such as calculator and computer. They are more widely used in New Zealand than our Korea. Third, Korea had used routine method mainly but New Zealand had used method to develop creativity of learner such as to write problem corresponding to expression, posing problem corresponding to information, to complete table and find pattern and to write word problem to explain pattern and so on. Fourth, we could see special calculation strategies in the case of teaching addition and subtraction such as concept of double, compensation, various strategy based on counting of number, addition of the same number, magic square, near-double which are not finding in our mathematics textbook. Fifth, in the New Zealand textbook they had used teaching methods inducing curiosity of learner such as finding message and puzzle problem than solving given problem simply.

• The KIPS Transactions:PartA
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• v.10A no.4
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• pp.369-374
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• 2003

Ant Algorithm is used to find the solution of Combinatorial Optimization Problems. Real ants are capable of finding the shortest path from a food source to their nest without using visual informations. This behavior of real ants has inspired ant algorithm. There are various versions of Ant Algorithm. Ant Colony System (ACS) is introduced lately. ACS is applied to the Traveling Salesman Problem (TSP) for verifying the availability of ACS and evaluating the performance of ACS. ACS find a good solution for TSP When ACS is applied to different Combinatorial Optimization Problems, ACS uses the same parameters and strategies that were used for TSP. In this paper, ACS is applied to the Multicast Routing Problem. This Problem is to find the paths from a source to all destination nodes. This definition differs from that of TSP and differs from finding paths which are the shortest paths from source node to each destination nodes. We introduce parameters and strategies of ACS for Multicasting Routing Problem.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.110-115
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• 2021

With the era of the 4th Industrial Revolution, education on artificial intelligence is one of the important topics. However, since existing education is aimed at knowledge, it is not suitable for developing the active problem-solving ability and AI utilization ability required by artificial intelligence education. To solve this problem, we proposes PBL-based education method in which learners learn in the process of solving the presented problem. The problem presented to the learner is a completed project. This project consists of three types: a classification model, the training data of the classification model, and the block code to be executed according to the classified result. The project works, but each component is designed to perform a low level of operation. In order to solve this problem, the learners can expect to improve their computational thinking skills by finding problems in the project through testing, finding solutions through discussion, and improving to a higher level of operation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.437-447
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• 2003

We propose the methods to design the finite impulse response (FIR) and the infinite impulse response (IIR) lattice filters using Schur algorithm through the spectral factorization of the covariance matrix by circulant matrix factorization (CMF). Circulant matrix factorization is also very powerful tool used fur spectral factorization of the covariance polynomial in matrix domain to obtain the minimum phase polynomial without the polynomial root finding problem. Schur algorithm is the method for a fast Cholesky factorization of Toeplitz matrix, which easily determines the lattice filter parameters. Examples for the case of the FIR Inter and for the case of the IIR filter are included, and performance of our method check by comparing of our method and another methods (polynomial root finding and cepstral deconvolution).

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.1
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• pp.97-105
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• 2009

In this paper, the performance of AP(Alternating Projection) and EM(Expectation Maximization) algorithms is investigated in terms of detection of multiple signals, resolvability of coherent signals and the efficiency of sensor array processing. The basic idea of these algorithms is utilization of relaxation technique of successive 1D maximization to solve a direction finding problem by maximizing the multidimensional likelihood function. It means that the function is maximized over only for a single parameter while the other parameters are fixed at each step of the iteration. According to simulation results, the algorithms showed good performance for both incoherent and coherent multiple signals. Moreover, some advantages are identified for direction finding with very small samples and fast convergence. The performance of AP algorithm is compared with that of EM using multiple criteria such as the number of sensor, SNR, the number of samples, and convergence speed over uniform circular array. It is resulted AP algorithm is superior to EM overally except for one criterion, convergence speed. Especially, for EM algorithm there is no performance difference between incoherent and coherent case. In conclusion, AP and EM are viable and practical alternatives, which can be applied to a direction under due to the resolvability of multi-path signals, reliable performance and no troublesome eigen-decomposition of the sample-covariance matrix.

• Structural Engineering and Mechanics
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• v.54 no.6
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• pp.1045-1059
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• 2015

Form-finding for cable-membrane structures is a delicate operation. During the last decades, the force density method (FDM) was considered to be an efficient method to address the problem. Many researchers were devoted to improving this method and proposed many methods such as natural force density method (NFDM), improved nonlinear force density method (INFDM), et al. In this paper, a modified nonlinear force density method (MNFDM) is proposed. In this method, the stresses of membrane elements were transformed to the force-densities of cable nets by an equivalent relationship, and then they can be used as initial conditions. By comparing with the forming finding results by using the FDM, NFDM, INFDM and MNFDM, it had demonstrated that the MNFDM presented in this paper is the most efficient and precise.

• Journal of Korea Game Society
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• v.4 no.3
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• pp.55-64
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• 2004

A dynamic graph is suitable for representing and managing dynamic changable obstacles or terrain information in 2D/3D games such as RPG and Strategy Simulation Games. We propose a dynamic hierarchical graph model with fixed level to perform a quick A* path finding. We divide a graph into subgraphs by using space classification and space model, and construct a hierarchical graph. And then we perform a quick path fading on the graph by using our dynamic graph operators. With our experiments we show that this graph model has efficient properties for finding path in a dynamic game environment.

• Journal of Korean Association for Spatial Structures
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• v.21 no.4
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• pp.49-56
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• 2021

This study aims to develop a form-finding algorithm for a single-layered pneumatic membrane. The initial shape of this pneumatic membrane, which is an air-supported type pneumatic membrane, is to find a state in which a given initial tension and internal pneumatic pressure are in equilibrium. The algorithm developed to satisfy these conditions is that a nonlinear optimization problem based on the force method considering the deformed shape is formulated, and, it's able to find the shape by iteratively repeating the process of obtaining a solution of the governing equations. An computational technique based on the Gauss-Newton method was used as a method for obtaining solutions of nonlinear equations. In order to verify the validity of the proposed form-finding algorithm, a single-curvature pneumatic membrane example and a double-curvature air pneumatic membrane example were adopted, respectively. In the results of these examples, it was possible to well observe the step-by-step convergence process of the shape of the pneumatic membrane, and it was also possible to confirm the change in shape according to the air pressure. In addition, the calculation results of the shape and internal force after deformation due to initial tension, air pressure, and self-weight were obtained.