• 제목/요약/키워드: Field-scale model

검색결과 961건 처리시간 0.03초

이공계열 대학원생 핵심역량 진단도구 개발 및 타당화 연구: A연구중심대학 사례 (Development and Validation of Core Competency Scale For Graduate Students in the Field of Science and Engineering)

  • 배상훈;조은원;한송이;정유지;김경언
    • 공학교육연구
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    • 제27권2호
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    • pp.35-50
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    • 2024
  • The purpose of this study is to identify the core competencies of graduate students at A research university in the context of graduate education in science and engineering, and to develop and validate a diagnostic tool to measure them. To achieve the research objectives, first, 6 factors and 18 sub-competencies of core competencies were derived based on a review of domestic and foreign studies, cases of excellent research-centered overseas universities, and interviews with members of A University. Second, a theoretical model was constructed by deriving behavioral indicators based on the core competencies and sub-competencies, and a preliminary survey was conducted on 188 graduate students of University A to verify the statistical validity of the theoretical model. Results of exploratory and confirmatory factor analysis, the core competencies of graduate students at A research university consisted of 6 factors, 16 sub-competencies, and 77 items. Specifically, it included "Independent research capability(13 items)", "Social Entrepreneurship(10 items)", "Academic agility(15 items)", "Ingenious Challenges(15 items)", "Collegial Collaboration(9 items)", and "Mueunjae leadership(15 items)". This study contributes to the development of theories related to core competencies of graduate students in science and engineering, and has practical significance as a basis for a data-driven competency-based graduate education system.

Flux pinning and critical current density in $TiO_2$-doped $MgB_2$ superconductor

  • 강지훈;박정수;박진우;이영백
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.172-172
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    • 2010
  • $MgB_2$ doped with $TiO_2$ was prepared by the in-situ solid state reaction to study the effects of $TiO_2$ dopant on the flux pinning behavior of $MgB_2$ superconductor. From the field-cooled and the zero-field-cooled temperature dependences of magnetization, the realms of vortex-glass and vortex-liquid states of $TiO_2$-doped $MgB_2$ were determined in the H-T diagram (the temperature dependence of upper critical magnetic field and irreversibility line). The critical current density was estimated from the width of hysteresis loops in the framework of Beam's model at different temperatures. The results indicate that nano-scale $TiO_2$ inclusions play a role of the effective pinning centers and lead to the enhanced upper critical field and critical current density. It is suggested that the grain-boundary pinning mechanism is realized in $TiO_2$-doped $MgB_2$ superconductor.

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TiO2 Nano-doping Effect on Flux Pinning and Critical Current Density in an MgB2 Superconductor

  • Kang, J.H.;Park, J.S.;Lee, Y.P.;Prokhorov, V.G.
    • Journal of Magnetics
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    • 제16권1호
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    • pp.15-18
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    • 2011
  • We have studied the $TiO_2$ doping effects on the flux pinning behavior of an $MgB_2$ superconductor synthesized by the in-situ solid-state reaction. From the field-cooled and zero-field-cooled temperature dependences of magnetization, the reversible-irreversible transition of $TiO_2$-doped $MgB_2$ was determined in the H-T diagram (the temperature dependence of upper critical magnetic field and irreversibility line). For comparison, the similar measurements are also obtained from SiC-doped $MgB_2$. The critical current density was estimated from the width of hysteresis loops in the framework of Bean's model at different temperatures. The obtained results manifest that nano-scale $TiO_2$ inclusions served as effective pinning centers and lead to the enhanced upper critical field and critical current density. It was concluded that the grain boundary pinning mechanism was realized in a $TiO_2$-doped $MgB_2$ superconductor.

Field measurement and numerical simulation of snow deposition on an embankment in snowdrift

  • Ma, Wenyong;Li, Feiqiang;Sun, Yuanchun;Li, Jianglong;Zhou, Xuanyi
    • Wind and Structures
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    • 제32권5호
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    • pp.453-469
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    • 2021
  • Snow accumulation on the road frequently induces a big traffic problem in the cold snowy region. Accurate prediction on snow distribution is fundamental for solving drifting snow disasters on roads. The present study adopts the transient method to simulate the wind-induced snow distribution on embankment based on the mixture multiphase model and dynamic mesh technique. The simulation and field measurement are compared to confirm the applicability of the simulation. Furthermore, the process of snow accumulation is revealed. The effects of friction velocity and snow concentration on snow accumulation are analyzed to clarify its mechanism. The results show that the simulation agrees well with the field measurement in trends. Moreover, the snow accumulation on the embankment can be approximately divided into three stages with time, the snow firstly deposited on the windward side, then, accumulation occurs on the leeward side which induced by the wake vortex, finally, the snow distribution reaches an equilibrium state with the slope of approximately 7°. The friction velocity and duration have a significant influence on the snow accumulation, and the vortex scale directly affected the snow deposition range on the embankment leeward side.

Dynamic vibration response of functionally graded porous nanoplates in thermal and magnetic fields under moving load

  • Ismail Esen;Mashhour A. Alazwari;Khalid H. Almitani;Mohamed A Eltaher;A. Abdelrahman
    • Advances in nano research
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    • 제14권5호
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    • pp.475-493
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    • 2023
  • In the context of nonclassical nonlocal strain gradient elasticity, this article studies the free and forced responses of functionally graded material (FGM) porous nanoplates exposed to thermal and magnetic fields under a moving load. The developed mathematical model includes shear deformation, size-scale, miscorstructure influences in the framework of higher order shear deformation theory (HSDT) and nonlocal strain gradient theory (NSGT), respectively. To explore the porosity effect, the study considers four different porosity models across the thickness: uniform, symmetrical, asymmetric bottom, and asymmetric top distributions. The system of quations of motion of the FGM porous nanoplate, including the effects of thermal load, Lorentz force, due to the magnetic field and moving load, are derived using the Hamilton's principle, and then solved analytically by employing the Navier method. For the free and forced responses of the nanoplate, the effects of nonlocal elasticity, strain gradient elasticity, temperature rise, magnetic field intensity, porosity volume fraction, and porosity distribution are analyzed. It is found that the forced vibrations of FGM porous nanoplates under thermal and live loads can be damped by applying a directed magnetic field.

거대언어모델(LLM)이 인식하는 공연예술의 차별 양상 분석: ChatGPT를 중심으로 (Analysis of Discriminatory Patterns in Performing Arts Recognized by Large Language Models (LLMs): Focused on ChatGPT)

  • 최지애
    • 지능정보연구
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    • 제29권3호
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    • pp.401-418
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    • 2023
  • 최근 ChatGPT 등의 등장으로 거대언어모델(이하 LLM: Large Language Model)에 대한 사회경제적 관심이 고조되고 있다. 생성형AI의 일종인 거대언어모델은 대본 창착이 가능한 수준까지 이르고 있다. 이러한 측면에서 일반인과 전문가들이 광범위하게 활용할 거대언어모델에서 공연예술 전반 혹은 특정 공연예술물이나 단체의 차별 이슈(성차별, 인종차별, 종교차별, 연령차별 등)를 어떻게 묘사하는지에 관심을 가지고 해결해 나가야 할 것이다. 그러나 아직 거대언어모델에서 공연예술의 차별 이슈에 대한 본격적인 조사와 논의는 이루어지지 않고 있다. 따라서 본 연구의 목적은 거대언어모델로부터의 공연예술 분야 차별이슈 인식 양상을 텍스트 분석하고 이로부터 공연예술분야가 대응할 시사점과 거대언어모델 개발 시사점을 도출하는 것이다. 먼저 거대언어모델에게 차별에 대한 감수성을 측정하기 위해 9가지 차별 이슈에 대한 BBQ(Bias Benchmark for QA) 질문 및 측정법을 사용했으며, 대표적인 거대언어모델로부터 도출된 답변에 대해서 공연예술 전문가에 의해 거대언어모델이 잘못 인지한 부분이 있는지의 검증을 거친 후에 내용분석법을 통해 공연예술분야의 차별적 관점의 윤리성에 대한 거대언어모델의 인식을 분석하였다. 분석 결과로 공연예술 분야에게 주는 시사점과 거대언어모델 개발 시 주의할 점 등을 도출하고 토의하였다.

자기 검색척도(Self-Monitoring Scale)의 타당성 검정에 관한 연구 (The Study of the Validity Test on the Self-monitoring Scale)

  • 이선아
    • 대한간호학회지
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    • 제28권3호
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    • pp.751-759
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    • 1998
  • The study of the validity test on the self-monitoring scale for nurses In this study, both the literary survey as well as empirical research has been executed to test the validity of the scales that measure the construct of the self-monitoring scale. The self-monitoring scale could not be classified into five factors as Snyder suggested. Many other scholars (Briggs, Cheek and Buss, 1980) suggested 3 different classifications which was accepted by Snyder and Gangestad (1986). John, Cheek and Klohnen(1996) claimed a two-factor classification. As has been discussed, factor analysis is used to prove convergent validity within the factor and discriminant validity between the factors. However, depending on the researchers, many variations in classification of the factors were found and a lack of content and discriminant validity were found in the previous research findings. It is also important to note that Snyder's self-monitoring scale did not factor-load at over. 30 for all 25 items, regardless of how many factors could be classified. According to findings of this study, the self-monitoring scale neither classified as five, three or two factors nor factor loaded as hypothesized. It is also clear that Snyder's self-monitoring scale lacks convergent validity as the sub-factors of the scale failed to prove its uni-dimensionality. The A self-monit oring scale not only fail to overcome the problems of Snyder's self-monitori ng scale but even lost the attractiveness of the self-monitoring scale. In this study it was also found that the A self-monitoring scale was not classified in either in a two or three-factor classification as hypothesized. It is, of course, not desirable to use any scale that lacks convergent and discriminant validity even though it has been widely used and has held a great deal of influence on the field of social psychology. To overcome the shortcomings of Snyder's self-monitoring scale, Lennox and Wolfe(1984) suggested 13 items. This study was dedicated to test the validity and reliability of the scale, in which we found that the data presented in validity as the two factors were class ified and loaded as expected. Reliability was also proven by checking Cronbach's α for each factor and for the total items. In addition, a confirmatory factor analysis was executed for the 13 items using LISREL 8.12 program to confirm convergent validity in a two-factor classification. The model was fitting and sound : however, the self-monitoring scale was unfitted and not validated. Thus, it is recommended to use not the original nor the abbreviated self-monitoring scale but the 13 items in future studies. It should also be noted that items 7 and 13 should be removed to obtain better uni-dimensionality for the 13 items. These items loaded at over. 30, too high for the two factors in the test results of Factor analysis. In addition, it is necessary to double-check the cause of two-hold loading at over .30 for the two factors. It could be a problem caused by data or by the scale itself. Therefore, additional studies should follow to better clarify this matter.

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탄성파 속도를 이용한 철도 토공노반의 다짐도 평가 (Evaluation of Degree of Compaction of Railroad Trackbed Fills Using Elastic Wave Velocities)

  • 김학성;정영훈;강동엽;이성혁
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1650-1658
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    • 2011
  • The quality control of compaction fills has been commonly performed via the field density measurement and plate load tests. However, the engineer frequently encounters difficulties in actually controling the quality due to the uncertainty in the field density measurement as well as the plate load tests. To overcome these difficulties, Park et al. (2009) proposed an alternative quality control method based on the measurement of the compressive wave velocities. In this study, the compressive wave velocities measured in the full-scale model test site were analyzed. Direct arrive seismic tests were performed after the completion of each trackbed layer. To identify a relationship between elastic wave velocities and degree of compaction, laboratory compaction tests were conducted.

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제상모드에 대한 실차 내부 환기유동의 정량적 가시화 연구 (Quantitative Visualization of Ventilation Flow for Defrost Mode in a Real Passenger Car)

  • 이진평;이상준
    • 한국가시화정보학회지
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    • 제8권2호
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    • pp.40-44
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    • 2010
  • Thermal comfort inside a passenger car has been receiving large attention in automobile industries. Especially, the performance of windshield defroster is important in the design of a car to ensure passenger comport and safety. Thereby, better understanding on the ventilation flow along the vehicle windshield is essential to evaluate the performance of windshield defroster. However, most previous studies dealt with the defrost flow using CFD (computational fluid dynamics) calculations or scale-down model experiments. In this study, a real commercial automobile was used to investigate the flow discharged from the vehicle defroster and the ventilation flow along the windshield using a PIV velocity field measurement technique. The experimental data would be useful to understand the flow characteristics in detail and also can be used to validate numerical predictions.

Defrost nozzle의 영향을 고려한 3차원 승용차 실내 유동 및 온도 해석 (3-D Numerical analysis of flow and temperature field in the cabin of the automobile with defrost nozzle discharged air)

  • 강규태;배인호;황지은;박원규;장기룡
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2001년도 추계 학술대회논문집
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    • pp.31-36
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    • 2001
  • The velocity and temperature profiles in the cabin of the automobile affect greatly to the comfort of the passenger. In this paper, the three dimensional flow and temperature analysis in the cabin of the automobile which is geometrically complicated was performed to investigate and predict the velocity and temperature profile. The three dimensional Navier-Stokes code used in this case was validated by performing of a 1/5 experimental scale model vehicle flow anal)rsis successfully. The temperature field of cavity was analyzed for Energy-equation code validation. The comparison of the results are made with the polished computational data and give a coincided one.

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