• Title/Summary/Keyword: fidelity

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Multi-fidelity uncertainty quantification of high Reynolds number turbulent flow around a rectangular 5:1 Cylinder

  • Sakuma, Mayu;Pepper, Nick;Warnakulasuriya, Suneth;Montomoli, Francesco;Wuch-ner, Roland;Bletzinger, Kai-Uwe
    • Wind and Structures
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    • v.34 no.1
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    • pp.127-136
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    • 2022
  • In this work a multi-fidelity non-intrusive polynomial chaos (MF-NIPC) has been applied to a structural wind engineering problem in architectural design for the first time. In architectural design it is important to design structures that are safe in a range of wind directions and speeds. For this reason, the computational models used to design buildings and bridges must account for the uncertainties associated with the interaction between the structure and wind. In order to use the numerical simulations for the design, the numerical models must be validated by experi-mental data, and uncertainties contained in the experiments should also be taken into account. Uncertainty Quantifi-cation has been increasingly used for CFD simulations to consider such uncertainties. Typically, CFD simulations are computationally expensive, motivating the increased interest in multi-fidelity methods due to their ability to lev-erage limited data sets of high-fidelity data with evaluations of more computationally inexpensive models. Previous-ly, the multi-fidelity framework has been applied to CFD simulations for the purposes of optimization, rather than for the statistical assessment of candidate design. In this paper MF-NIPC method is applied to flow around a rectan-gular 5:1 cylinder, which has been thoroughly investigated for architectural design. The purpose of UQ is validation of numerical simulation results with experimental data, therefore the radius of curvature of the rectangular cylinder corners and the angle of attack are considered to be random variables, which are known to contain uncertainties when wind tunnel tests are carried out. Computational Fluid Dynamics (CFD) simulations are solved by a solver that employs the Finite Element Method (FEM) for two turbulence modeling approaches of the incompressible Navier-Stokes equations: Unsteady Reynolds Averaged Navier Stokes (URANS) and the Large Eddy simulation (LES). The results of the uncertainty analysis with CFD are compared to experimental data in terms of time-averaged pressure coefficients and bulk parameters. In addition, the accuracy and efficiency of the multi-fidelity framework is demonstrated through a comparison with the results of the high-fidelity model.

The Effect of High-Fidelity Simulation Practice Related with Classical Education of Medical Surgical Nursing (성인간호학 이론수업과 연계한 High-Fidelity 시뮬레이션 교육의 효과)

  • Chyn, Yeol-eo;Kim, Kyoung-Mi;Hwang, Hye-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8176-8186
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    • 2015
  • This research was conducted for the purpose of developing a high-fidelity simulation education program, applying it to clinical field and analyzing this program's effect on nursing college students in order to solve problems being caused from the gap between the adult nursing theoretical class and practical education. As the analysis method, this study developed a scenario including an algorithm for caring hyperkalemia patients, the evaluation check list, and debriefing according to the adult nursing theoretical class's learning goal and measured the high-fidelity simulation program's effect in using the non-equivalent control group pre-test and post-test design. As the results from the analysis, there secured the simulation education program's general properties and dependent variable's homogeneity in the experimental group and the control group. The nursing simulation practice program for hyperkalemia patients showed slight effect on the experimental group compared to the control group in fields such as nursing practice ability, problem solving ability, critical thinking skills, self-confidence of nursing, and knowledge. (t=-83.313, p<.001, t=-3.169, p=.003, t=-2.473, p=.017, t=-4.036, p<.001, t=-5.044, p<.001). High-Fidelity simulation programs in conjunction with an adult nursing theory classes of nursing students nursing practice ability, problem solving ability, critical thinking skills, self-confidence of nursing, and knowledge. This simulation program may be an effective educational method for nursing practice and also support improved quality of nursing education.

Analysis of IR-UWB Tapered Slot Antenna Radiation Pattern using the Group delay and Fidelity (군 지연 및 충실도를 이용한 IR-UWB용 테이퍼 슬롯 안테나 방사패턴 분석)

  • Kim, Keun-Yong;Ko, Yong-Mok;Park, Kyoung-Jin;Kang, Een-Kyun;Lee, Dae-Woo;Park, Jong-Hyun;Ra, Keuk-Whan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.308-315
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    • 2013
  • In this paper, Tapered slot antenna of IR-UWB was Designed and fabricated using HFSS and we suggest the beam width of the broadband antenna using group-delay and fidelity. For this purpose, acquired data from the Network Analyzer was analyzed in the time domain by using the chirp-Z transform and Simulation was conducted and confirmed with the CST microwave studio. Analysis of the antenna radiation pattern is the antenna separation at intervals of 0.5 metres and then transmit antenna is fixed and the receiving antenna 360 degree intervals of 10 degree each, The results of the analysis are as follows, and analyzer of the fidelity of the antenna's performance. An analysis of more than 90 percent of the cases is less than ${\pm}40$ degrees in good fidelity, more than 90% less than ${\pm}40$ degrees and lowe fidelity. In conclusion, Analysis of Beam width of wideband antenna with more precise is possible through using these radiation pattern using fidelity.

A study on the UWB Antenna Design Techniques for Improving Pulse Fidelity (펄스 충실도 개선을 위한 UWB 안테나 설계기법 연구)

  • Kim, Jung-Min;Kang, Eun-Kyun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.299-307
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    • 2013
  • In this paper, design of UWB Antenna which propagate impulse by pulse fidelity and distortion equation was induced and applied. UWB Antenna which has directional characteristic in UWB band should have low radiation loss and impulse radiation distortion. As a result, the paper designed wide band impedance transformer and microstrip slotline transit region structured antenna feeder line. By using the fabricated UWB antenna, the radiation pattern was measured in the radio anechoic chamber. Pulse fidelity of impulse radiation show good results more than 93% within ${\pm}30^{\circ}$ beam width.

Nucleotide Insertion Fidelity of Human Hepatitis B Viral Polymerase

  • Kim, Youn-Hee;Hong, Young-Bin;Suh, Se-Won;Jung, Gu-Hung
    • BMB Reports
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    • v.33 no.2
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    • pp.126-132
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    • 2000
  • The hepadnaviruses replicate their nucleic acid through a reverse transcription step. The MBP-fused HBV polymerase was expressed in E. coli and purified by using amylase affinity column chromatography. The purified protein represented DNA-dependent DNA polymerase activity. In this report, the MBP-HBV polymerase was shown to lack 3'$\rightarrow$5' exonuclease activity, like other retroviral RTs. The ratio of the insertion efficiency for the wrong versus right vase pairs indicates the misinsertion frequency (f). The nucleotide insertion fidelity (1/f), observed with the MBP-HBV polymerase and HIV-1 RT, was between 60 and 54,000, and between 50 and 73,000, respectively, showing that they are in close range. A relatively efficient nucleotide incorporation by the MBP-HBV polymerase was observed with a specificity of three groups: (1) A : T, T : A>C : G, G : C (matched pairs), (2) A : C, C : A>G: T, T : G (purine-pyrimidine and pyrimidine-purine mispairs), and (3) C : C, A : A, G : G, T : T>T : C, C : T>A : G, G : A (purine-purine or pyrimidine-pyrimidine mispairs), and their order is (1)>(2)>(3). The data from the nucleotide insertion fidelity by the MBP-HBV polymerase suggest that the HBV polymerase may be as error-prone as HIV-1 RT.

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Experiences among Undergraduate Nursing Students on High-fidelity Simulation Education: A Focus Group Study (일 대학 간호대학생의 시뮬레이션 교육 경험 분석)

  • Lee, Ju-Hee;Kim, So-Sun;Yeo, Ki-Sun;Cho, Su-Jin;Kim, Hyun-Lye
    • The Journal of Korean Academic Society of Nursing Education
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    • v.15 no.2
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    • pp.183-193
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    • 2009
  • Purpose: The purpose of this study was to explore experiences among undergraduate nursing students in a high-fidelity simulation education course for a semester. Method: The participants in this study were 10 nursing students in the senior classes and volunteers. Data collection was conducted using a focus group interview for 100 minutes, which was recorded on video tape. Transcribed data was analyzed through qualitative content analysis. Result: The results of this study were deduced as 4 codes and 22 themes. Study participants reported experiences due to the simulation method itself, interaction among peer group and personal experiences during high-fidelity simulation education. Additionally, experiences related to clinical application were examined. The participants indicated positive outcomes such as developing clinical judgment skills and confidence. Conclusion: Overall, the results of this study supported the usability and effectiveness of a high-fidelity simulation education method in undergraduate nursing curriculum. Further studies are needed to provide more reliable and valid educational information.

Effects of High-fidelity Simulator and Standardized Patient on Nursing Care for Children with Fever in Nursing Students (고충실도(High-fidelity) 시뮬레이터와 표준화 환자 (Standardized Patient)를 활용한 발열환아 간호 교육의 효과)

  • Ha, Young-Ok
    • Korean Parent-Child Health Journal
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    • v.20 no.1
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    • pp.10-17
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    • 2017
  • Purpose: This study was conducted to investigate the effects of simulation-based education using high-fidelity simulator and standardized patient in nursing care for children with fever on nursing students. Methods: A total of 166 senior nursing students who completed pediatric nursing practicum courses participated in this study. The single group study design with pretest and posttest was used. The simulation education was provided for 200mins including orientation, simulation preparation, simulation practicum, and debriefing. Pre and post surveys were performed using questionnaires on clinical performance competency, communication skills, critical thinking disposition and self-confidence. Results: The mean scores of clinical performance competency (t=-2.56, p<.05), communication skills (t=-6.39, p<.001), critical thinking disposition (t=-3.43, p<.001), and self-confidence (t=-3.72, p<.001) in posttest were significantly higher than those in pretest. Also, clinical performance competency in nursing care for children with fever has significant relationships with communication skills, critical thinking disposition and self-confidence. Conclusion: The results indicate that simulation-based education using high-fidelity simulator and standardized patient is an effective strategy for improving clinical performance competency, communication skills, critical thinking disposition and self-confidence in nursing students. Further study is needed to verify the effects.

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Constrained adversarial loss for generative adversarial network-based faithful image restoration

  • Kim, Dong-Wook;Chung, Jae-Ryun;Kim, Jongho;Lee, Dae Yeol;Jeong, Se Yoon;Jung, Seung-Won
    • ETRI Journal
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    • v.41 no.4
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    • pp.415-425
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    • 2019
  • Generative adversarial networks (GAN) have been successfully used in many image restoration tasks, including image denoising, super-resolution, and compression artifact reduction. By fully exploiting its characteristics, state-of-the-art image restoration techniques can be used to generate images with photorealistic details. However, there are many applications that require faithful rather than visually appealing image reconstruction, such as medical imaging, surveillance, and video coding. We found that previous GAN-training methods that used a loss function in the form of a weighted sum of fidelity and adversarial loss fails to reduce fidelity loss. This results in non-negligible degradation of the objective image quality, including peak signal-to-noise ratio. Our approach is to alternate between fidelity and adversarial loss in a way that the minimization of adversarial loss does not deteriorate the fidelity. Experimental results on compression-artifact reduction and super-resolution tasks show that the proposed method can perform faithful and photorealistic image restoration.