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3D electromagnetic design and electrical characteristics analysis of a 10-MW-class high-temperature superconducting synchronous generator for wind power

  • Kim, J.H.;Park, S.I.;Le, T.D.;Kim, H.M.
    • Progress in Superconductivity and Cryogenics
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    • v.16 no.2
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    • pp.47-53
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    • 2014
  • In this paper, the general electromagnetic design process of a 10-MW-class high-temperature superconducting (HTS) synchronous generator that is intended to be utilized for large scale offshore wind generator is discussed. This paper presents three-dimensional (3D) electromagnetic design proposal and electrical characteristic analysis results of a 10-MW-class HTS synchronous generator for wind power. For more detailed design by reducing the errors of a two-dimensional (2D) design owing to leakage flux in air-gap, we redesign and analyze the 2D conceptual electromagnetic design model of the HTS synchronous generator using 3D finite element analysis (FEA) software. Then electrical characteristics which include the no-load and full-load voltage of generator, harmonic contents of these two load conditions, voltage regulation and losses of generator are analyzed by commercial 3D FEA software.

A Study on the Instructional Design of Flipped Learning for 'Creative Problem Solving Methodology' Course ('창의적문제해결방법론' 교과목의 플립러닝 수업 설계에 관한 연구)

  • Han, Jiyoung
    • Journal of Engineering Education Research
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    • v.22 no.1
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    • pp.22-28
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    • 2019
  • The purpose of this study is to develop instructional design model of flipped learning suitable for engineering education field and to draw out effects and improvements by applying it to actual lessons for engineering college students. Literature review and case studies were conducted to achieve the purpose of the study. For a case study, flipped learning was applied to 'creative problem solving methodology' which is a liberal arts course of engineering college at D university in Gyeonggi-do. As a result of the literature review, the PARTNER model was applied and weekly instructional guide was presented by each stage. In addition, the results of analysis on the reflection journal showed that the students were more able to achieve the deepening learning stage through active participation in class than the existing class, and found that they had a more challenging plan after the class.

Series Solution of High Order Abel, Bernoulli, Chini and Riccati Equations

  • Henk, Koppelaar;Peyman, Nasehpour
    • Kyungpook Mathematical Journal
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    • v.62 no.4
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    • pp.729-736
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    • 2022
  • To help solving intractable nonlinear evolution equations (NLEEs) of waves in the field of fluid dynamics we develop an algorithm to find new high order solutions of the class of Abel, Bernoulli, Chini and Riccati equations of the form y' = ayn + by + c, n > 1, with constant coefficients a, b, c. The role of this class of equations in NLEEs is explained in the introduction below. The basic algorithm to compute the coefficients of the power series solutions of the class, emerged long ago and is further developed in this paper. Practical application for hitherto unknown solutions is exemplified.

Synthesis and 3D-QSARs Analyses of Herbicidal O,O-Dialkyl-1-phenoxyacetoxy-1-methylphosphonate Analogues as a New Class of Potent Inhibitors of Pyruvate Dehydrogenase

  • Soung, Min-Gyu;Hwang, Tae-Yeon;Sung, Nack-Do
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1361-1367
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    • 2010
  • A series of O,O-dialkyl-1-phenoxyacetoxy-1-methylphosphonate analogues (1~22) as a new class of potent inhibitors of pyruvate dehydrogenase were synthesized and 3D-QSARs (three dimensional qantitative structure-activity relationships) models on the pre-emergency herbicidal activity against the seed of cucumber (Cucumus Sativa L.) were derived and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indeces analysis (CoMSIA) methods. The statistical values of CoMSIA models were better predictability and fitness than those of CoMFA models. The inhibitory activities according to the optimized CoMSIA model I were dependent on the electrostatic field (41.4%), the H-bond acceptor field (26.0%), the hydrophobic field (20.8%) and the steric field (11.7%). And also, it was found that the optimized CoMSIA model I with the sensitivity to the perturbation ($d_q{^{2'}}/dr^2{_{yy'}}$ = 0.830) and the prediction ($q^2$ = 0.503) produced by a progressive scrambling analyses were not dependent on chance correlation. From the results of graphical analyses on the contour maps with the optimized CoMSIA model I, it is expected that the structural distinctions and descriptors that subscribe to herbicidal activities will be able to apply new an herbicide design.

Design of Field Coil for High Temperature Superconducting motor considering Operating Current (운전전류를 고려한 고온초전도 모터용 계자코일의 설계)

  • 조영식;서무교;백승규;김석환;손명환;권영길;홍정표
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.315-317
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    • 2002
  • The value of I$_{c}$(critical current) in HTS (High Temperature Superconducting) tape has a great influence on B(equation omitted) (magnetic field amplitude applied perpendicular to the tape surface). Therefore, I$_{c}$ of HTS magnet is determined by not only operating temperature but also the B(equation omitted). In shape design of field coil for the HTS motor, a method to reduce the B(equation omitted) and to determine operating current should be considered in order to optimal design. On the basis of the magnetic field analysis, this paper deals with various field coil shape to obtain operating current of HTS motor by using analytical method. And also this paper discusses the operating current of 100hp class HTS motor by using I$_{c}$-B(equation omitted) curve.curve.

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Characteristic of Magnetic Field Distribution of 100hp Class High Temperature Superconducting motor (100hp급 고온초전도 모터의 자장분포특성)

  • 이정종;조영식;주진홍;홍정표;권영길
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.312-314
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    • 2002
  • Magnetic circuit design of HTS (High Temperature Superconducting) motor is important to achieve the power at a given load condition, and it is essential to the thermal design for HTS motor rotors. To determine the result of thermal design, the magnetic field distribution has to be known exactly. On the basis of the 2 dimensional magnetic field analysis, the magnetic field distributions due to several cases are calculated by using Biot-Savart equation and magnetic image method. And the I$_{c}$ of HTS field coil was calculated by using I$_{c}$-B(equation omitted) curve and 3D FEA(Finite Element Analysis).is).

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Transonic Magnetohydrodynamic Turbulence

  • LEE HYESOOK;RYU DONGSU;KIM JONGSOO;JONES T. W.
    • Journal of The Korean Astronomical Society
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    • v.34 no.4
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    • pp.321-323
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    • 2001
  • Compressible, magnetohydrodynamic (MHD) turbulence in two dimension is studied through high-resolution, numerical simulations with the isothermal equation of state. First, hydrodynamic turbulence with Mach number $(M)_{rms}\;\~$1 is generated by enforcing a random force. Next, initial, uniform magnetic field of various strengths with Alfvenic Mach number Ma $\gg$ 1 is added. Then, the simulations are followed until MHD turbulence is fully developed. Such turbulence is expected to exist in a variety of astrophysical environments including clusters of galaxies. Although no dissipation is included explicitly in our simulations, truncation errors produce dissipation which induces numerical resistivity. It mimics a hyper-resistivity in our second-order accurate code. After saturation, the resulting flows are categorized as SF (strong field), WF (weak field), and VWF (very weak field) classes respectively, depending on the average magnetic field strength described with Alfvenic Mach number, $(Ma)_{rms}{\ge}1$, $(Ma)_{rms}{\~}1$, and $(Ma)_{rms}{\gg}1$. The characteristics of each class are discussed.

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APPLICATIONS OF TWO-STATE M-INTEGRAL FOR ANALYSIS OF ADHESIVE LAP JOINTS (접착 LAP JOINT 해석을 위한 두 상태 M-적분의 응용)

  • 임세영;이용우
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.04a
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    • pp.35-42
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    • 1997
  • The two-state or mutual M-integral which is derived from tile M-integral and is applicable for two elastic states, is applied for computing all intensity of a singular near-tip field around the vertex of a class of wedge, encountered in adhesive lap joints under mechanical loading. Numerically we verify that a simple auxiliary field associated with every eigenfunction for the composite wedge under consideration exists in the form of the conjugate solution in the sense of tile M-integral. The auxiliary field is then employed for superposition with the elastic field under consideration, and the associated two-state M-integral is computed via the domain integral technique. This enables us to extract the intensity for a singular field information for a singular elastic boundary layer is extracted form the domain integral representation without resort to singular finite element for the wedge vertex.

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A Study on Intertextuality with Other Domains in the 21C Contemporary Fashion - Focused on Animation, Music, Performing Arts and Technology - (21세기 현대 패션에 나타난 타영역과의 상호텍스트성에 관한 연구 - 애니메이션, 음악, 무대예술, 테크놀로지를 중심으로 -)

  • 김혜정
    • Journal of the Korean Society of Costume
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    • v.54 no.2
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    • pp.105-119
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    • 2004
  • Cultural hybridization and global cross-fertilization, begun since the 1990s, mean the hybrid mixture of the low-class popular arts and the high-class fine arts and have found expression in intertextuality by means of the thinking system of de-constructuralist post-modernism. This study was intended to investigate the artistic intertextuality between fashion and art frontiere, especially between such fields as 'animation', 'music', and 'performing arts' and 'fashion', which shows the greatest characteristic of the phenomenon that the non-mainstream culture flows into the mainstream culture. It also aimed to investigate the intertextuality between 'technology' and 'fashion' as the delivery room of the youth culture and copycat culture due to the benefit of technologies since the 20th-century digital revolution. Animation as the neo-pop art with the popular code coming to the forefront in the 21th century integrated high-class fashion and low-class fashion into one through the combination of fashion and humor, and the musical element referring to the social difference of the cultural field and the social strata is becoming the 21th-century fashion icon through its fusion with the pictorial tendency along with the leisure-time life of the non-mainstream strata. In terms of intertextuality in performing arts, fashion style performs an important role in the presentation of performing arts and since the de-construction of the fin-de-ciecle form and its fusion with media have taken place, fashion works become and element of the origin that has an influence on a series of film, dance, dramatic elements and the like. The paradigm of technology made it socially and culturally possible to achieve the architecture of clothing system necessary for fashionable technical clothing by allowing the possibility of imitation, the function of technology to form popular culture. The intertextual tendency in the 21th-century fashion began from the de-constructive phenomenon of existing norms and now takes the multicultural character of surpassing a certain domain or concept. And it positions itself as the total art of spearheading the low-class culture and the non-mainstream culture as the hybrid domain of mainstream and non-mainstream cultures or high-class and low-class cultures.

Comparative Study on Structural Behaviors of Skull in Occlusions for Class I and Full-CUSP Class II (정상 I급 교합과 Full-CUSP II급 교합의 두개골 구조거동 비교 해석연구)

  • Lee, Yeo-Kyeong;Park, Jae-Yong;Kim, Hee-Sun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.4
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    • pp.309-315
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    • 2016
  • Recently, finite element analysis technique has been widely used for structural and mechanical understandings of human body in the dentistry field. This research proposed an effective finite element modeling method based on CT images, and parametric studies were performed for the occlusal simulation. The analyses were performed considering linear material behaviors and nonlinear geometrical effect, and validated with the experimental results. In addition, the skull models with two different molar relations such as Class I and full-CUSP Class II were generated and the analyses were performed using the proposed analytical method. As results, the relationships between the mandibular movement and occlusal force of both two models showed similar tendency in human occlusal force. However, stress was evenly distributed from teeth to facial bone in the skull model with Class I, while stress concentration was appeared in the model with full-CUSP Class II due to the changes of occlusal surfaces of the model.