• Journal of KIISE:Information Networking
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• v.34 no.3
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• pp.203-217
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• 2007

In this paper, a performance evaluation model of Networks with the multiple-buffered crossbar switches is proposed and examined. Buffered switch technique is well known to solve the data collision problem of the switch networks. The characteristic of a network with crossbar switches is determined by both the connection pattern of the switches and the limitation of data flow in a each switch. In this thesis, the evaluation models of three different networks : Multistage interconnection network, Fat-tree network, and other ordinary communication network are developed. The proposed evaluation model is developed by investigating the transfer patterns of data packets in a switch with output-buffers. Two important parameters of the network performance, throughput and delay, are evaluated. The proposed model takes simple and primitive switch networks, i.e., no flow control and drop packet, to demonstrate analysis procedures clearly. It, however, can not only be applied to any other complicate modern switch networks that have intelligent flow control but also estimate the performance of any size networks with multiple-buffered switches. To validate the proposed analysis model, the simulation is carried out on the various sizes of networks that uses the multiple buffered crossbar switches. It is shown that both the analysis and the simulation results match closely. It is also observed that the increasing rate of Normalized Throughput is reduced and the Network Delay is getting bigger as the buffer size increased.

• The Journal of Korean Association of Computer Education
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• v.23 no.4
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• pp.1-11
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• 2020

The purpose of this study is to propose the direction of AI education in K-12 education through investigating and analyzing aspects of the purpose, content, and methods of AI education as the curriculum and teacher training factors. We collected and analyzed 9 papers as the primary literature and 11 domestic and foreign policy reports as the secondary literature. The collected literatures were analyzed by applying a descriptive reviews, and the implications were derived by analyzing the curriculum components and TPACK elements for multi-dimensional analysis. As a result of this study, AI education targets were divided into three steps: AI users, utilizer, and developers. In K-12 education, the user and utilizer stages are appropriate, and artificial intelligence literacy must be included for user education. Based on the current computing thinking ability and coding ability for utilizer education, the implication was derived that it is necessary to target the ability to create creative output by applying the functions of artificial intelligence. In addition to the pedagogical knowledge and the ability to use the platform, The teacher training is necessary because teachers need content knowledge such as problem-solving, reasoning, learning, perception, and some applied mathematics, cognitive / psychological / ethical of AI.

• Korean Journal of Childcare and Education
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• v.10 no.5
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• pp.229-248
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• 2014

The purpose of this study is to draw guidelines on how to select traditional games that would efficiently help and develop multiple intelligences in children. Guidelines standard of section inquiries were prepared through a Delphi survey targeting twenty experts in early childhood education and traditional games. As a result, linguistic intelligence questions regarding writing, listening, speaking and vocabulary acquisition were selected. logical-mathematical intelligence questions regarding strategy, counting, patterns, hypothesis, verification, and comparing, contrasting, calculating ability were selected. Spatial intelligence questions regarding drawing, coloring, representation activities, operating and creating were selected, physical performance intelligence questions regarding global muscles, eye-hand coordination, flexibility, accommodation force, balance, agility and muscular strength were selected. Musical intelligence included questions about singing, and playing musical instruments. Interpersonal intelligence included perspective-taking, role-sharing, cooperation and discussion. For intrapersonal intelligence questions regarding personal significance-ties, planning-decision making, emotional expression and problem solving were selected. Finally, in relation to naturalist intelligence, questions regarding living organisms, inanimate objects and seasons were selected. In addition, traditional games were analyzed based on the finalized guidelines, and the results showed that each of the traditional games would not only work with one intelligence at a time but with other different intelligence as well. In the light of that, the study confirmed the validity of the guidelines on how to select traditional games that would develop multiple intelligences in children.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.173-180
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• 2014

Compressive sensing is a new signal acquisition paradigm that enables sparse/compressible signal to be sampled under the Nyquist-rate. To fully benefit from its much simplified acquisition process, huge efforts have been made on improving the performance of compressive sensing recovery. However, concerning color images, compressive sensing recovery lacks in addressing image characteristics like energy distribution or human visual system. In order to overcome the problem, this paper proposes a new group-sparsity hard thresholding process by preserving some RGB-grouped coefficients important in both terms of energy and perceptual sensitivity. Moreover, a smoothed group-sparsity iterative hard thresholding algorithm for compressive sensing of color images is proposed by incorporating a frame-based filter with group-sparsity hard thresholding process. In this way, our proposed method not only pursues sparsity of image in transform domain but also pursues smoothness of image in spatial domain. Experimental results show average PSNR gains up to 2.7dB over the state-of-the-art group-sparsity smoothed recovery method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.251-260
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• 2003

A three dimensional (3-D) method of analysis is presented for determining the free vibration frequencies and mode shapes of deep, tapered rods and beams with circular cross section. Unlike conventional rod and beam theories, which are mathematically one-dimensional (1-D), the present method is based upon the 3-D dynamic equations of elasticity. Displacement components u/sup r/, u/sub θ/ and u/sub z/, in the radial, circumferential, and axial directions, respectively, are taken to be sinusoidal in time, periodic in , and algebraic polynomials in the r and z directions. Potential (strain) and kinetic energies of the rods and beams are formulated, the Ritz method is used to solve the eigenvalue problem, thus yielding upper bound values of the frequencies by minimizing the frequencies. As the degree of the polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies of the rods and beams. Novel numerical results are tabulated for nine different tapered rods and beams with linear, quadratic, and cubic variations of radial thickness in the axial direction using the 3D theory. Comparisons are also made with results for linearly tapered beams from 1-D classical Euler-Bernoulli beam theory.

• Journal of The Korean Association For Science Education
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• v.24 no.3
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• pp.417-428
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• 2004

Conservation reasoning makes operational thought possible as a functional tool and it is the essential concept not only in the area of science and mathematics but also in several aspects of daily life. The abilities to solve mathematical problems and that of scientific reasoning and abstract way of thinking depend on whether thereis conservation reasoning or not and they are critical concepts that enables us to confirm the steps of cognitive development. Therefor in the study, we emphasized the issue that is the ways to speed up the scientific era by analyzing the correlation between the formation of conservation reasoning and neuro-cognitive variables. About 50% of 1-3 grade students did not had conservation reasoning skills. The formation of conservations was not linear. Scientific reasoning ability, planing and inhibiting ability were significantly different in levels of conservation, And, conservation reasonings were significantly correlated with cognitive variables. Scientific reasoning and planning ability significantly explained about 20% of the conservation reasoning ability of 1-3 grades.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.69-78
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• 2017

Shannon of the 5G smartphone and Fourier of the signal processing meet in the sampling theorem (2 times the highest frequency 1). In this paper, the initial Shannon Theorem finds the Shannon capacity at the point-to-point, but the 5G shows on the Relay channel that the technology has evolved into Multi Point MIMO. Fourier transforms are signal processing with fixed parameters. We analyzed the performance by proposing a 2N-1 multivariate Fourier-Jacket transform in the multimedia age. In this study, the authors tackle this signal processing complexity issue by proposing a Jacket-based fast method for reducing the precoding/decoding complexity in terms of time computation. Jacket transforms have shown to find applications in signal processing and coding theory. Jacket transforms are defined to be $n{\times}n$ matrices $A=(a_{jk})$ over a field F with the property $AA^{\dot{+}}=nl_n$, where $A^{\dot{+}}$ is the transpose matrix of the element-wise inverse of A, that is, $A^{\dot{+}}=(a^{-1}_{kj})$, which generalise Hadamard transforms and centre weighted Hadamard transforms. In particular, exploiting the Jacket transform properties, the authors propose a new eigenvalue decomposition (EVD) method with application in precoding and decoding of distributive multi-input multi-output channels in relay-based DF cooperative wireless networks in which the transmission is based on using single-symbol decodable space-time block codes. The authors show that the proposed Jacket-based method of EVD has significant reduction in its computational time as compared to the conventional-based EVD method. Performance in terms of computational time reduction is evaluated quantitatively through mathematical analysis and numerical results.

• Journal of the Korean earth science society
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• v.26 no.1
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• pp.30-40
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• 2005

The purpose of this study is to analyze gifted students' perception of the teaching activities at the gifted science high school (Busan Science Academy), in Busan, Korea, and to investigate the science experiment class practice. In this study, a questionnaire about the curriculum courses, teaching strategies, and evaluation method of the school was administered to 139 gifted students. The verbal interactions during the science experiment class were audio and videotaped, transcribed, and analyzed. The results of this study are as follows: First, according to the gifted students' perception, the credits of specialized courses and advanced elective courses need to be increased and the credits of general courses need to be reduced. Second, teachers at this school mainly use teaching strategies such as lecture, group activities, and discussion; on the other hand, the students prefer diverse teaching strategies such as discussion, lecture, experiment, inquiring activities, and problem solving. Third, students prefer a writing test assessment rather than a written report assessment or portfolio assessment. Fourth, the patterns of verbal interaction were different depending on the level of the teachers' questions and interactions between the students in the experiment class facilitated students' inquiry.

• 대한공업교육학회지
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• v.34 no.1
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• pp.196-209
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• 2009

The purpose of this study was to analyze engineering basic competencies about the time completed a course and educational needs of engineering college graduates. Survey method using questionnaire was the major research method of this study. A survey of 807 engineering college graduates was carried out. Questionnaire were made of the level of engineering basic competencies of engineering college graduates, its priorities of actual vocation and level of engineering basic competencies of major. Major results of the study, some recommendations for future researches were made as follows: The level of engineering basic competencies of engineering college graduates was 3.3 average(5 full marks). Engineering basic competencies that educational needs were high respectively, were an ability to communicate effectively, an ability to design a system, component, or process to meet desired needs, an ability to function on multi-disciplinary teams, an ability to understand global culture and cooperate internationally, an ability to design and conduct experiment as well as to analyze and interpret data, and an ability to engage in life-long learning.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.215-220
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• 2017

This study was conducted to improve the insufficiency of fruit vegetable grafting system developed by National Institute of Agricultural Sciences, Rural Development Administration. When the rotary blade cut the stem of scions and rootstocks, the grafting failure at curved cutting surfaces happened. The cutting depth of a tomato seedling by a rotated cutter was calculated 0.11 mm even when the cutting arm length and the maximum stem diameter were 50 mm and 5 mm, respectively. Mathematical analysis and high-speed photography showed that there was no problem by cutting in straight the stem of scions and rootstocks. The compression test of seedling stems to design the optimal shape of gripper showed that stems were not completely restored when they were compressed above 0.8 mm and 0.6 mm in case of rootstocks and scion, respectively. This study found that the bending angle of stem of tomato seedlings at the grafting period was 10 degree on average. The optimal gripper finger was the edge finger type which could be precisely set center point by adjusting the distance between fingers. In addition, it was found that most of seedling could be grasped without damage when the finger-to-finger distances is set to 2.5 mm for scion and 3.0 mm for rootstocks and finger are coated by 1 mm-thick flexible material.