• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.301-308
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• 2018

Objectives. The age-based Cole formula has been employed for the estimation of endotracheal tube (ETT) size due to its ease of use, but may not appropriately consider growth rates among children. Child growth is assessed by calculating the body surface area (BSA). The association between the outer diameter of an appropriate uncuffed-endotracheal-tube (ETT-OD) and the BSA values of patients at 24-96 months of age was our primary outcome. Methods. Cole formula, BSA, age, height, weight and ultrasound measurement of subglottic-transverse-diameter were evaluated for correlations with correct uncuffed ETT-OD. The Cole formula, BSA, and ultrasound measurements were analyzed for estimation rates in all patients and age subgroups. The maximum allowed error for the estimation of ETT-OD was ${\leq}0.3mm$. Patients' tracheas were intubated with tubes chosen by Cole formula and correct ETT-OD values were determined using leak test. ETT exchange rates were recorded. Results. One-hundred twenty-seven patients were analyzed for the determination of estimation rates. Thirteen patients aged ${\geq}72months$ were intubated with cuffed ETT-OD of 8.4 mm and were accepted to need uncuffed ETT-OD >8.4 mm in order to be included in estimation rates, but excluded from correlations for size analysis. One-hundred fourteen patients were analyzed for correlations between correct ETT-OD (determined by the leak test) and outcome parameters. Cole formula, ultrasonography, and BSA had similar correct estimation rates. All three parameters had higher underestimation rates as age increased. Conclusion. The Cole formula, BSA, and ultrasonography had similar estimation rates in patients aged ${\geq}24$ to ${\leq}96months$. BSA had a correct estimation rate of 40.2% and may not be reliable in clinical practice to predict uncuffed-ETT-size.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.4
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• pp.11-18
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• 2018

The beauty is like the bubble of beer, and behavior scholars have been regarded as worthless to study. As a result, the aesthetic in construction projects has resulted in underestimation or neglect. The fundamental cause of this result is that it is not easy to estimate the value of the aesthetic. The hedonic calculus by Bentham has a possibility to valuating the intangible or invisible goods. In this context, this study proposes a method to valuate architectural aesthetic based on the hedonic calculus by Bentham. As a precondition for suggesting the valuation method, this study defined the architectural aesthetic as the value of attraction that affects the value of the built environment. As the concept of beauty that conforms to the architectural aesthetic, it has established the concept of beauty as 'the phenomenon of combining the foreground and background of Hartmann'. In addition, the scope of the value measurement is defined as 'built environment' so as to include not only the building but also the surrounding environment. We have reinterpreted the seven dimension of the hedonic calculus proposed by Bentham and systematized the method of valuation of the architectural esthetic based on the seven dimension. The result of this study is meaningful in that it presents a new perspective and approach to architectural aesthetic. And it will be used as grounds for valuation and analytical approach to architectural aesthetic and will be used as a basis for expanding the field of study from aesthetic to value.

• Atmosphere
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• v.32 no.4
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• pp.277-295
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• 2022

The global weather prediction model, Korean Integrated Model (KIM), has been in operation since April 2020 by the Korea Meteorological Administration. This study assessed the performance of heat waves (HWs) in Korea in 2020. Case experiments during 2018-2020 were conducted to support the reliability of assessment, and the factors which affect predictability of the HWs were analyzed. Simulated expansion and retreat of the Tibetan High and North Pacific High during the 2020 HW had a good agreement with the analysis. However, the model showed significant cold biases in the maximum surface temperature. It was found that the temperature bias was highly related to underestimation of downward shortwave radiation at surface, which was linked to cloudiness. KIM tended to overestimate nighttime clouds that delayed the dissipation of cloud in the morning, which affected the shortage of downward solar radiation. The vertical profiles of temperature and moisture showed that cold bias and trapped moisture in the lower atmosphere produce favorable conditions for cloud formation over the Yellow Sea, which affected overestimation of cloud in downwind land. Sensitivity test was performed to reduce model bias, which was done by modulating moisture mixing parameter in the boundary layer scheme. Results indicated that the daytime temperature errors were reduced by increase in surface solar irradiance with enhanced cloud dissipation. This study suggested that not only the synoptic features but also the accuracy of low-level temperature and moisture condition played an important role in predicting the maximum temperature during the HWs in medium-range forecasts.

• Progress in Medical Physics
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• v.31 no.4
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• pp.135-144
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• 2020

Purpose: Gafchromic films for proton dosimetry are dependent on linear energy transfers (LETs), resulting in dose underestimation for high LETs. Despite efforts to resolve this problem for single-energy beams, there remains a need to do so for multi-energy beams. Here, a bimolecular reaction model was applied to correct the under-response of spread-out Bragg peaks (SOBPs). Methods: For depth-dose measurements, a Gafchromic EBT3 film was positioned in water perpendicular to the ground. The gantry was rotated at 15° to avoid disturbances in the beam path. A set of films was exposed to a uniformly scanned 112-MeV pristine proton beam with six different dose intensities, ranging from 0.373 to 4.865 Gy, at a 2-cm depth. Another set of films was irradiated with SOBPs with maximum energies of 110, 150, and 190 MeV having modulation widths of 5.39, 4.27, and 5.34 cm, respectively. The correction function was obtained using 150.8-MeV SOBP data. The LET of the SOBP was then analytically calculated. Finally, the model was validated for a uniform cubic dose distribution and compared with multilayered ionization chamber data. Results: The dose error in the plateau region was within 4% when normalized with the maximum dose. The discrepancy of the range was <1 mm for all measured energies. The highest errors occurred at 70 MeV owing to the steep gradient with the narrowest Bragg peak. Conclusions: With bimolecular model-based correction, an EBT3 film can be used to accurately verify the depth dose of scanned proton beams and could potentially be used to evaluate the depth-dose distribution for patient plans.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.655-661
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• 2021

Positron emission tomography (PET) images is affected by acquisition time, short acquisition times results in low gamma counts leading to degradation of image quality by statistical noise. Noise2Void(N2V) is self supervised denoising model that is convolutional neural network (CNN) based deep learning. The purpose of this study is to evaluate denoising performance of N2V for PET image with a short acquisition time. The phantom was scanned as a list mode for 10 min using Biograph mCT40 of PET/CT (Siemens Healthcare, Erlangen, Germany). We compared PET images using NEMA image-quality phantom for standard acquisition time (10 min), short acquisition time (2min) and simulated PET image (S2 min). To evaluate performance of N2V, the peak signal to noise ratio (PSNR), normalized root mean square error (NRMSE), structural similarity index (SSIM) and radio-activity recovery coefficient (RC) were used. The PSNR, NRMSE and SSIM for 2 min and S2 min PET images compared to 10min PET image were 30.983, 33.936, 9.954, 7.609 and 0.916, 0.934 respectively. The RC for spheres with S2 min PET image also met European Association of Nuclear Medicine Research Ltd. (EARL) FDG PET accreditation program. We confirmed generated S2 min PET image from N2V deep learning showed improvement results compared to 2 min PET image and The PET images on visual analysis were also comparable between 10 min and S2 min PET images. In conclusion, noisy PET image by means of short acquisition time using N2V denoising network model can be improved image quality without underestimation of radioactivity.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.110-116
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• 2022

Human failure event (HFE) dependency analysis is a part of human reliability analysis (HRA). For efficient HFE dependency analysis, a maximum number of minimal cut sets (MCSs) that have HFE combinations are generated from the fault trees for the probabilistic safety assessment (PSA) of nuclear power plants (NPPs). After collecting potential HFE combinations, dependency levels of subsequent HFEs on the preceding HFEs in each MCS are analyzed and assigned as conditional probabilities. Then, HFE recovery is performed to reflect these conditional probabilities in MCSs by modifying MCSs. Inappropriate HFE dependency analysis and HFE recovery might lead to an inaccurate core damage frequency (CDF). Using the above process, HFE recovery is performed on MCSs that are generated with a non-zero truncation limit, where many MCSs that have HFE combinations are truncated. As a result, the resultant CDF might be underestimated. In this paper, a new method is suggested to incorporate HFE recovery into the MCS generation stage. Compared to the current approach with a separate HFE recovery after MCS generation, this new method can (1) reduce the total time and burden for MCS generation and HFE recovery, (2) prevent the truncation of MCSs that have dependent HFEs, and (3) avoid CDF underestimation. This new method is a simple but very effective means of performing MCS generation and HFE recovery simultaneously and improving CDF accuracy. The effectiveness and strength of the new method are clearly demonstrated and discussed with fault trees and HFE combinations that have joint probabilities.

• Wind and Structures
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• v.34 no.5
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• pp.421-435
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• 2022

To investigate the non-Gaussian properties of fluctuating wind pressures and the error margin of extreme wind loads on a long-span curved roof with matching and mismatching ratios of turbulence integral scales to depth (L_u^x/D), a series of synchronized pressure tests on the rigid model of the complex curved roof were conducted. The regions of Gaussian distribution and non-Gaussian distribution were identified by two criteria, which were based on the cumulative probabilities of higher-order statistical moments (skewness and kurtosis coefficients, S_k and K_u) and spatial correlation of fluctuating wind pressures, respectively. Then the characteristics of fluctuating wind-loads in the non-Gaussian region were analyzed in detail in order to understand the effects of turbulence integral-scale. Results showed that the fluctuating pressures with obvious negative-skewness appear in the area near the leading edge, which is categorized as the non-Gaussian region by both two identification criteria. Comparing with those in the wind field with matching L_u^x/D, the range of non-Gaussian region almost unchanged with a smaller L_u^x/D, while the non-Gaussian features become more evident, leading to higher values of S_k, Ku and peak factor. On contrary, the values of fluctuating pressures become lower in the wind field with a smaller L_u^x/D, eventually resulting in underestimation of extreme wind loads. Hence, the matching relationship of turbulence integral scale to depth should be carefully considered as estimating the extreme wind loads of long-span roof by wind tunnel tests.

• The Journal of Engineering Geology
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• v.32 no.2
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• pp.241-255
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• 2022

In this study, sieve analysis testing was performed on weathered granite soil from Yecheon (eastern South Korea) before and after water washing in accordance with the sieve analysis regulations of KS F 2302. The changes in particle separation and particle size distribution after washing with water were analyzed. Image analysis using an optical microscope revealed that soil particles were separated into smaller particles by water washing. The change in the particle size distribution curve was assessed using five index values. The increase in the fine particle fraction (<0.075 mm) was 13.67%, the increase in the 0.075-0.25 mm fraction was 19.44%, and the mean particle diameter (D₅₀) decreased by 0.663 mm. In addition, the maximum passage width (B_M) of the particle size distribution curve increased by 21.08% for the #30 sieve, and the moving area (A) of the particle size distribution curve was 69.28%·mm. These results suggest that washing with water is an effective way to prevent underestimation of the fine particle content in soil.

• Animal Bioscience
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• v.35 no.6
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• pp.804-813
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• 2022

Objective: A formula is needed that is practical for current livestock breeding methods and that predicts the approximate rate of inbreeding (ΔF) in populations where selection is performed according to four-path programs (sires to breed sons, sires to breed daughters, dams to breed sons, and dams to breed daughters). The formula widely used to predict inbreeding neglects selection, we need to develop a new formula that can be applied with or without selection. Methods: The core of the prediction is to incorporate the long-tern genetic influence of the selected parents in four-selection paths executed as sires to breed sons, sires to breed daughters, dams to breed sons, and dams to breed daughters. The rate of inbreeding was computed as the magnitude that is proportional to the sum of squared long-term genetic contributions of the parents of four-selection paths to the selected offspring. Results: We developed a formula to predict the rate of inbreeding in populations undergoing four-path selection on genomically enhanced breeding values and with discrete generations. The new formula can be applied with or without selection. Neglecting the effects of selection led to underestimation of the rate of inbreeding by 40% to 45%. Conclusion: The formula we developed here would be highly useful as a practical method for predicting the approximate rate of inbreeding (ΔF) in populations where selection is performed according to four-path programs.

• Nutrition Research and Practice
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• v.16 no.5
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• pp.565-576
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• 2022

BACKGROUND/OBJECTIVES: Various accelerometer equations are used to predict energy expenditure (EE). On the other hand, the development of these equations and their validation studies have been conducted primarily without including older adults. This study assessed the accuracy of 8 ActiGraph accelerometer equations to predict the energy cost of walking in older adults. SUBJECTS/METHODS: Thirty-one participants with a mean age of 74.3 ± 3.3 yrs were enrolled in this study (20 men and 11 women). The participants completed 8 walking activities, including 5 treadmill and 3 self-paced walking activities. The EE was measured using a portable indirect calorimeter, with each participant simultaneously wearing the ActiGraph accelerometer. Eight ActiGraph equations were assessed for accuracy by comparing the predicted EE with indirect calorimetry results. RESULTS: All equations resulted in an overall underestimation of the EE across the activities (bias -1 to -1.8 kcal·min^-1 and -0.7 to -1.8 metabolic equivalents [METs]), as well as during treadmill-based (bias -1.5 to -2.9 kcal·min^-1 and -0.9 to -2.1 METs) and self-paced (bias -1.2 to -1.7 kcal·min-1 and -0.2 to -1.3 METs) walking. In addition, there were higher rates of activity intensity misclassifications, particularly among vigorous physical activities. CONCLUSIONS: The ActiGraph equations underestimated the EE for walking activities in older adults. In addition, these equations inaccurately classified the activities based on their intensities. The present study suggests a need to develop ActiGraph equations specific to older adults.