• The Journal of Korean Association of Computer Education
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• v.20 no.2
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• pp.1-11
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• 2017

The demands of computer science education for non-majors in higher education is increasing but relevant evaluation tools for the students' computational artifacts are lack. This research aims to develop a scoring rubric to assess student's computational artifacts in non-major programming course at Computational Thinking point of view. The rubric was developed based on 'CT Practice Design Pattern' as a framework. The rubric consists of 'domain, skills, evaluation, evaluating resources, and scales'. Domains are 'Design of abstract model', 'Design and application of creative artifacts', and 'Analysis of the artifacts'. Experts reviewed the rubric to ensure contents validity. The rubric is resulted in reliable for consistency. This rubric can be revised and applied to application environment accordingly.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1626-1633
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• 2021

In an industrial field, non-destructive testing (NDT) is commonly used to inspect industrial products. Among NDT methods using radiation sources, X-ray laminography has several advantages, such as high depth resolution and low computational costs. Moreover, an X-ray laminography system with stationary source array and compact detector is able to reduce mechanical motion artifacts and improve inspection efficiency. However, this system, called stationary inverse-geometry X-ray laminography (s-IGXL), causes truncation artifacts in reconstructed images due to limited fields-of-view (FOVs). In this study, we proposed a projection data correction (PDC) method to reduce the truncation artifacts arisen in s-IGXL images, and the performance of the proposed method was evaluated with the different number of focal spots in terms of quantitative accuracy. Comparing with conventional techniques, the PDC method showed superior performance in reducing truncation artifacts and improved the quantitative accuracy of s-IGXL images for all the number of focal spots. In conclusion, the PDC method can improve the accuracy of s-IGXL images and allow precise NDT measurements.

• Journal of The Korean Association of Information Education
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• v.18 no.4
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• pp.549-558
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• 2014

This study aims to provide suggestions for software education in an afterschool program, deriving from the analysis of student experiences of working on Scratch team projects. This study reports on the implementation of the 12 week afterschool software education program in an elementary school, where students worked in pairs to learn Scratch programming from ideation to design and presentation. For an in-depth study of student-generated artifacts, we selected three groups' Scratch projects and conducted artifact-based interviews to unpack student experiences working on Scratch projects as a group. Adopting the computational thinking framework as an overarching analytical lens, we focused on examining student experiences from three dimensions of computational thinking (CT), namely, CT concepts, CT practices, and CT perspectives. The present study provides both theoretical and practical implications. Firstly, we demonstrate the feasibility of applying the CT framework for assessing student-generated artifacts in design-oriented software education. We also believe that this study provides important suggestions to future software education programs adopting CT as an overarching design and assessment framework.

• Journal of The Korean Association of Information Education
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• v.16 no.3
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• pp.319-326
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• 2012

In this paper, we studied a design-based learning for Computational Thinking in Computational Literacy. The design-based learning for computational thinking in computational literacy education started from a MIT media laboratory in 2011. We revised the design-based learning and applied it to educational field. We considered educational strategies and derived the implications, after teaching fourth grade gifted students. Moreover we conducted and analyzed a questionnaire survey, observations and interviews. As the result, the design-based learning in computational literacy is effective for creative computational thinking that students create their ideas and make a meaningful artifacts from it. We expect that this study provides the basic data to apply a design-based learning for computational thinking to Computer education.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.63-74
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• 2007

Fast Fourier transform(FFT) is powerful, fast computation framework for convolution in many image restoration application. However, an actually observed image acquired with finite aperture of the acquisition device from the infinite background and it lost data outside the cropped region. Because of these the boundary artifacts are produced. This paper reviewed and summarized the up to date the techniques that have been applied to reduce of the boundary artifacts. Moreover, we propose a new block-based fast image restoration using combined extrapolation and edge-tapering without boundary artifacts with reduced computational loads. We apply edgetapering to the inner blocks because they contain outside information of boundary. And outer blocks use half-convolution extrapolation. For this process it is possible that fast image restoration without boundary artifacts.

• Journal of Practical Engineering Education
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• v.10 no.1
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• pp.49-56
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• 2018

Various types of SW education are being operated by universities for non-major undergraduates. And most of them focus on educating computational thinking. Following this computing education, there is a need for an educational method that implements and evaluates creative computing outcomes for each student. In this paper, we propose a method to realize SW education based on creative computing artifacts. To do this, we propose an educational method for students to implement digital logic circuit devices creatively and design SW algorithms that implement the functions of their devices. The proposed training method teaches a simple LED logic circuit using an Arduino board as an example. Students creatively design and implement two pairs of two input logic circuit devices, and design algorithms that represent patterns of implemented devices in various forms. And they design the functional extension and extended algorithm using the input device. By applying the proposed method, non-major students can gain the concept and necessity of algorithm design through creative computing artifacts.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1860-1868
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• 1998

A simple postprocessing algorithm is proposed to reduce the blocky artifacts of Block Discrete Cosine Transform (BDCT) coded images. Since the block noise is mostly antisymmetric relative to the block boundaries, we model the blocky noise as one-dimensional antisymmertric functions made by superposing DCT basis functions. observing the frequency characteristics of the noies model, we approximate its high frequency components as those of step functions. Then the proposed postprocessing algorithm eliminates the carefully selected high frequency components of step functions in the one-dimensional sN-point DCT domain, when the encoding block size is $N\;{\times}\;N$. It is shown that the proposed algorithm can also be performed in the spatial domain without computational burden of transforms. The experimental results show that the proposed algorithm well reduces the blocky artifacts in both subjective and objectie viewpoints.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.43-50
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• 2007

In recent years the importance of the preservation of cultural artifacts like ancient tombs has been widely accepted domestically and internationally with increasing value of cultural artifacts. However not much technical attention has been paid for the facilities and systems to preserve these artifacts. As a part of the present study, the temperature and relative humidity inside a selected artifact, Shinkwan-ri tomb, have been monitored for a year round to improve the understanding of the indoor thermal environment. In this study, using the Computational Fluid Dynamics calculated the velocity and temperature distribution and offered basic data which are necessary for the best fitted design of tomb air-conditioning device. Through the result of this study, the generation of temperature variation was identified by natural convection. It enables us to get the possibility of humidity variation

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.93-96
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• 2000

In this paper, we present an improved novel interpolator that performs high quality interpolation on both synthetic and real world images. Its structure, which is based on a four directional linear predictor with equiripple windowed samples and phase matching equalizer, provides edge-directional data interpolation so that sharp and artifacts-free images are obtained at a reasonable computational cost.

• Korean Journal of Computational Design and Engineering
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• v.21 no.3
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• pp.306-312
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• 2016

In general, the shape of a 3D printed object is not to be changed after the generation. Most changes, for example, contraction of a molten polymer after cooling is thought to be undesirable. 4D printing however tries to make benefit of a shape change after the part is generated. The shape change is required to be controllable in response to an external stimuli. These artifacts from 4D printing are called kinetic components which are defined as structures formed by combining inert materials and smart materials that change under certain stimuli. We propose a design software that can systematically calculate inert links with smart joints to follow the shape of the target design.