• Geophysics and Geophysical Exploration
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• v.23 no.2
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• pp.89-96
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• 2020

This tutorial summarizes the coordinate transforms for formulating geophysical problems. To ensure mathematical consistency, this discussion begins with the right-hand rule. Further, the concepts of active and passive transforms are introduced. By extending these concepts, the coordinate transform and its inverse between two coordinates are related to the matrix transpose. The yaw-pitch-roll rotation and the azimuth-deviation-tool face rotation transforms are described as the most frequently used schemes, and the relation between the Rodrigues' rotation formula and these two transforms are mathematically explained. The "Gimbal Lock" problem inherent in yaw-pitch-roll rotation is schematically presented and mathematically derived. As a useful tool overcome this problem, the principle and usage of the quaternion is also described.

• Membrane Journal
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• v.32 no.3
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• pp.198-208
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• 2022

Membrane can selectively separate various substances such as organic substances, liquids, solutes, vapors, gases, ions or electrons according to the separation technology and various uses. Membranes are largely divided into symmetric membranes and asymmetric membranes, and classified into porous and nonporous structure depending on the presence or absence of pores. Also, the interface of the membrane may be molecularly uniform, or chemically or physically non-uniform. Preparation techniques include melt extrusion, stretching, template leaching, track-etching, solution casting, phase inversion, and solution coating method. The prepared membrane can be applied to various applications such as microfiltration, ultrafiltration, nanofiltration, reverse osmosis, gas separation and energy fields. This review provides a tutorial on how to prepare membranes according to the classification and types.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.556-561
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• 2022

Computational material science as an application of Density Functional Theory (DFT) to the discipline of material science has emerged and applied to the research and development of energy materials and electronic materials such as semiconductor. However, there are a few difficulties, such as generating input files for various types of materials in both the same calculating condition and appropriate parameters, which is essential in comparing results of DFT calculation in the right way. In this tutorial status report, we will introduce how to create crystal structures and to prepare input files automatically for the Vienna Ab initio Simulation Package (VASP) and Gaussian, the most popular DFT calculation programs. We anticipate this tutorial makes DFT calculation easier for the ones who are not experts on DFT programs.

• Journal of Fashion Business
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• v.27 no.4
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• pp.88-100
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• 2023

This study analyzed the compositional characteristics of fashion videos and the characteristics of fashion design spreading as trends through Subversive Basics. Literature research and case studies were conducted concurrently. Based on the literature review, an analysis method was designed, focusing on the concept of online video content, Subversive Basics, and the video content type. For the case analysis, videos were collected and classified using Subversive Basics as the keyword. The content was observed, and design features were analyzed. Based on the results, the collected videos were classified into tutorial, curation, and creative content types according to their compositional characteristics. Tutorial content emphasizes practical actions that demonstrate how to make or modify clothing, thereby promoting user-generated content for dissemination. Curation contents provide users with style ideas and information about clothing and purchases to encourage clothing purchases and influence purchase decisions that lead to dissemination through clothing consumption and wear. Creative content showcases the process of modifying and creating clothes to enhance understanding and value of creative design. The characteristics of fashion design utilized in these contents include bold designs with high visual effects as the first category, designs that can be easily and quickly modified due to intentional incompleteness as the second category, and prominently featured body-positive, individualistic designs as the third category. The results of this study can be associated with balanced development between basic design elements and personalized unique designs, catering to consumer needs.

• Korean Journal of Radiology
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• v.25 no.4
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• pp.331-342
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• 2024

The Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) is an instructional initiative of the ASCI School designed to enhance educational standards. In 2021, the ASCI-PT was convened with the goal of formulating a consensus statement on the assessment of coronary stenosis and coronary plaque using coronary CT angiography (CCTA). Nineteen experts from four countries conducted thorough reviews of current guidelines and deliberated on eight key issues to refine the process and improve the clarity of reporting CCTA findings. The experts engaged in both online and on-site sessions to establish a unified agreement. This document presents a summary of the ASCI-PT 2021 deliberations and offers a comprehensive consensus statement on the evaluation of coronary stenosis and coronary plaque in CCTA.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.68-68
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• 2012

근래 탄소 단원자 두께의 2차원 결정재료인 그래핀은 연구자들에게 연구대상물질로 가장 각광 받고 있지만 그 합성법 및 이에 따른 분석법은 매우 제한되어 있다. 특히 분석의 핵심인 결정구조 및 원자구조 등을 탐구하기 위해서는 투과전자현미경(TEM)의 이용이 필수적이다. 최근 수차보정 기법을 이용한 투과전자현미경의 비약적인 발전으로 인해 탄소와 같이 가벼운 원소의 단원자까지 이미징해 낼 수 있는 수준에 이르고 있지만 정확한 그래핀 분석을 위해서는 전자현미경의 기본적인 이해와 분석사례 중심으로 깊이 있게 분석법을 살펴보는 것이 유용하다. 본 Tutorial에서는 전자현미경의 기본적인 이론과 최첨단 투과전자현미경의 소개, 그리고 이 투과전자현미경을 이용한 그래핀의 분석 방법과 그 사례들, 제한점등에 대해 알아본다. 그래핀의 층수분석을 위한 전자회절법, 그래핀의 결정입계 분석을 위한 전자회절, 암영상법 및 원자분해능 이미징, STEM영상 기법, 그래핀을 나노재료 분석에 지지막으로 이용하는 방법, bilayer 그래핀 등에 대해 살펴본다. 그리고 저전압에서 작동하는 저손상 단원자 분해능의 성능과 미래의 응용 가능성, 발전방향등을 전망해 본다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.67-67
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• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, exhibits fascinating electrical properties, such as a linear energy dispersion relation and high mobility in addition to a wide-range optical absorption and high thermal conductivity. Graphene's outstanding tensile strength allows graphene-based electronic and photonic devices to be flexible, bendable, or even stretchable. Recently many groups have reported high performance electronic and optoelectronic devices based on graphene materials, i.e. field-effect transistors, gas sensors, nonvolatile memory devices, and plasmonic waveguides, in which versatile properties of graphene materials have been incorporated into a flexible electronic or optoelectronic platform. However, there are several fundamental or technological hurdles to be overcome in real applications of graphene in electronics and optoelectronics. In this tutorial we will present a short introduction to the basic material properties and recent progresses in applications of graphene to electronics and optoelectronics and discuss future outlook of graphene-based devices.

• 한국정보교육학회:학술대회논문집
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• 2007.08a
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• pp.261-266
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• 2007

21세기는 정보통신매체가 주도하는 정보화 사회, 멀티미디어 시대로 우리나라에서는 지식정보사회에 필요한 인력 양성을 위해서 교육 개혁을 지속적으로 추진하고 있다. 이의 일환으로 학교에 교육용 소프트웨어를 보급하여 실제 교수 학습에서 활용하고 있는데, 그 형태가 선진 주요국에서 나타나지 않고 국내에서만 나타나는 독특한 형태이다. 이에, 본 연구에서는 국내에서 활용되고 있는 교육용 소프트웨어의 유형을 분석하고, 국내외 교육용 소프트웨어의 활용 수준을 조사한 후 실제 교수 학습에 교육용 소프트웨어를 투입하여 튜토리얼형 교육용 소프트웨어의 효과에 대해서 알아보고, 국내의 교육용 소프트웨어의 활용 방향과 향후 교육용 소프트웨어의 개발 방향을 제시하고자 한다.

• Journal of Korea Technology Innovation Society
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• v.6 no.1
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• pp.74-91
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• 2003

Science and Technology University(STU) will be established by twenty-two government institutes next year. STU has latent problems with geographical limitations caused by organizing the faculties and facilities of the government research institutes, which are located all over the country. This study tries to examine the Educational Administration(Opreation) Model of STU and analyse expected problems and further, proposes the introduction of cyber education system which will maximize efficiency of educational operation of the system and enhance learning. It also discusses the practical problems in the implementation of cyber education system.

• Journal of applied mathematics & informatics
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• v.35 no.5_6
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• pp.623-649
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• 2017

Retrial queues have been widely used to model the many practical situations arising from telephone systems, telecommunication networks and call centers. An approximation method for a simple Markovian retrial queue by reducing the two dimensional problem to one dimensional problem was presented by Fredericks and Reisner in 1979. The method seems to be a promising approach to approximate the retrial queues with complex structure, but the method has not been attracted a lot of attention for about thirty years. In this paper, we exposit the method in detail and show the usefulness of the method by presenting the recent results for approximating the retrial queues with complex structure such as multi-server retrial queues with phase type distribution of retrial time, impatient customers with general persistent function and/or multiclass customers, etc.