• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.404-408
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• 2003

The characterization for several multi-layer embedded inductors with different structures was investigated. The optimized equivalent circuit models for several test structures were obtained from HSPICE. Building blocks are modeled using Partial element equivalent circuit method. The mean and the standard deviation of model parameters were extracted and predictive modeling was performed on different test structure. From this study, the characteristic of multi-layer inductors can be predicted.

• Radiation Oncology Journal
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• 제25권4호
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• pp.249-260
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• 2007

목적: 국내에서 시행되고 있는 세기변조 방사선 치료(IMRT)의 품질 향상을 위하여, 우편으로 시행하는 원격 품질보증 시스템을 개발하고, 이 시스템의 정확성 확인에 이어서, 국내 의료기관에서 타당성을 검증한다. 대상 및 방법: 원격 품질 보증 시스템은 두경부 팬톰과 IMRT의 치료계획 지침을 포함하는 사용자 설명서로 구성되어 있다. 두경부 용 팬톰은 내부에 CT영상에서 분별이 가능한 모사 치료표적(target)과 3개의 위험장기(좌, 우 이하선, 척추)를 포함하고 있으며, 각 모사 장기의 중심에서 열형광 소자(TLD)를 삽입하여 흡수 선량을 측정하도록 구성되어있다. 또한 2차원상의 선량분포를 확인 가능하도록 Gafchromic@EBT 필름을 2개의 평면에 삽입하도록 고안하였다. 고안된 팬톰과 사용자 설명서를 국내의 4개 기관에 보내어, 팬톰에 대한 IMRT치료계획을 수행하고 치료를 시행하였다. 치료계획 시 예측된 치료표적과 위험장기 내의 각 TLD에서 예측되는 절대 선량과 TLD의 측정값을 비교하였고, 횡단면에서 면의 중심을 지나는 2개의 직교하는 수평선과 수직선상에서 예측되는 상대적인 선량분포 값과 실제 측정값을 비교하였다. 결 과: 치료 표적에서의 선량측정 값은 모두 치료계획시의 예측값과 3% 오차 안에서 일치하였으나(평균오차, 1.5%), 좌우 이하선에 해당하는 위험장기에서는 최소 3.3%최대 19.8%의 차이를 보였다. 척추에 해당하는 위험장기에서의 오차의 범위는 $0.7{\sim}1.4%$였다. 2차원 선량분포는 3개 기관에 대한 자료를 분석하였는데, 직선상에서 예측 값과 5%이상의 차이를 보이는 비율이 수평선에서는 $7{\sim}27%$, 수직선상에서는 $7{\sim}14%$였다. 결 론: 본 연구에서 개발한 IMRT치료의 원격 품질보증 시스템과 사용자 설명서는 국내 시행이 가능한 상태로 판단된다. 그러나, 시행 시에 치료표적에서의 오차는 크지 않을 것으로 예상이 되지만, 위험장기에서의 오차는 클 것으로 예상되며, 이에 대한 방안이 마련돼야 할 것이며, 또한 임상의 중요성과 연관해 의미 있는 2차원 선량분포의 기준 마련이 요구된다.

• 청정기술
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• 제26권4호
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• pp.279-285
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• 2020

Laboratories and industrial processes typically involve the use of flammable substances. An important property used to estimate fire and explosion risk for a flammable liquid is the flash point. In this study, flash point data at 101.3 kPa were determined using a SETA closed cup flash point tester on the following solvent mixtures: {2,2,4-trimethylpentane + methylcyclohexane}, {2,2,4-trimethylpentane + ethylbenzene}, and {2,2,4-trimethylpentane + p-xylene}. The purpose of this work is to obtain flash point data for binary mixtures of 2,2,4-trimethylpentane with three hydrocarbons (methylcyclohexane, ethylbenzene, and p-xylene), which are representative compounds of the main aromatic hydrocarbon fractions of petroleum. The measured flash points are compared with the predicted values calculated using the GE models' activity coefficient patterns: the Wilson, the Non-Random Two-Liquid (NRTL), and the UNIversal QUAsiChemical (UNIQUAC) models. The non-ideality of the mixture is also considered. The average absolute deviation between the predicted and measured lower flash point s is less than 1.99 K, except when Raoult's law is calculated. In addition, the minimum flash point behavior is not observed in any of the three binary systems. This work's predicted results can be applied to design safe petrochemical processes, such as identifying safe storage conditions for non-ideal solutions containing volatile components.

• 한국농림기상학회지
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• 제19권3호
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• pp.93-101
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• 2017

2011-2015년까지 경남 하동군 악양 집수역의 해발고도 8~1,073m 범위에 설치된 10개 무인기상관측기에서 0600, 1500 기온 관측값을 수집하여 월별 표준편차를 계산하고, 소기후모형으로부터 예측된 기온의 표준편차 결과를 함께 비교하여 미관측 지점의 추정기술에 실효성이 있는지 평가하였다. 소기후모형에 따른 예측값은 월별 0600, 1500 기온의 표준편차를 각각 88%, 86% 정도 설명할 수 있었지만, 전반적으로 과소추정하는 경향이었다. 겨울철과 여름철에 나타나는 낮은 고도 대비 해발고도가 높아질수록 변이가 작아지거나 커지는 방향성에 있어서 관측값과는 반대양상으로 나타나 당초 기대와는 다른 결과를 보였다. 또 다른방법으로 월별 기온 표준편차와 지형간의 관계를 정량화하여 임의지역의 지형특성과 종관규모 수준의 기온자료 만으로 표준편차 분포를 예측할 수 있을지 회귀분석을 수행하였다. 회귀모형은 해발고도편차에 따라 보정된 월별 기온 외에, 경사도와 경사향 등 기본적인 지형인자와 온난대효과와 냉기집적효과, 개방도 등의 기온과 관련된 변수들을 고려하여 월별로 표준편차를 가장 잘 설명할 수 있는 변수를 1~3개까지 선발하여 만들어졌으며, 월별 결정계수는 0.46부터 0.98 범위로 나타났다. 회귀모델을 이용해 기온이 관측되지 않는 임의지역의 표준편차를 지형변수의 최소-최대값 유효범위 내에서 월별로 예측한다면 70% 수준의 추정능력으로 공간변이 분포도를 나타낼 수 있을 것으로 예상된다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.611-617
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• 2009

This study was aimed at a genetic evaluation of Iranian Holstein cattle for milk and fat yields and calculating daughter yield deviation (DYD) of bulls. The data file that was used in this research included 367,943 first three lactation records of 186,064 Holstein cows which calved between 1983 and 2006 in 11,806 herd-year-season groups. The model included herd-year-season of calving and age at calving as fixed effects and animal and permanent environment as random effects. Mean breeding values of cows for each year were regressed on birth year to estimate genetic trends. Genetic trends in milk and fat yields were greater for cows born after 1997 (59.38 kg/yr and 1.11 kg/yr for milk yield and fat yield, respectively). Animal evaluations were partitioned into contribution from parent average, yield deviation (YD) and progeny. DYD of bulls was calculated as described by VanRaden and Wiggans (1991). DYD provides an indication of the performance of the daughters of a bull without consideration of his parents or sons. Variance of bull DYD was greater than variance of their predicted transmitting ability (PTA). Correlation of bull DYD and PTA was dependent on the number of daughters and when this increased, the correlation of DYD and PTA was increased. Also as lactation number of daughters increased, the correlation of bull DYD and PTA was increased.

• Genomics & Informatics
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• 제13권1호
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• pp.15-24
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• 2015

Fatty acid synthase (FASN, EC 2.3.1.85), is a multi-enzyme dimer complex that plays a critical role in lipogenesis. This lipogenic enzyme has gained importance beyond its physiological role due to its implications in several clinical conditions-cancers, obesity, and diabetes. This has made FASN an attractive pharmacological target. Here, we have attempted to predict the theoretical models for the human enoyl reductase (ER) and ${\beta}$-ketoacyl reductase (KR) domains based on the porcine FASN crystal structure, which was the structurally closest template available at the time of this study. Comparative modeling methods were used for studying the structure-function relationships. Different validation studies revealed the predicted structures to be highly plausible. The respective substrates of ER and KR domains-namely, trans-butenoyl and ${\beta}$-ketobutyryl-were computationally docked into active sites using Glide in order to understand the probable binding mode. The molecular dynamics simulations of the apo and holo states of ER and KR showed stable backbone root mean square deviation trajectories with minimal deviation. Ramachandran plot analysis showed 96.0% of residues in the most favorable region for ER and 90.3% for the KR domain, respectively. Thus, the predicted models yielded significant insights into the substrate binding modes of the ER and KR catalytic domains and will aid in identifying novel chemical inhibitors of human FASN that target these domains.

• Childhood Kidney Diseases
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• 제19권2호
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• pp.125-130
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• 2015

Introduction: This study investigated whether renal and bladder ultrasonography (RBUS) findings performed in children with the first incidence of febrile urinary tract infection (UTI) can predict UTI recurrence, high-grade vesicoureteral reflux (high-grade VUR), or acquired renal scarring (aRS). Methods: In all, 917 children who were admitted to our hospital from January 2001 to October 2010, owing to the first incidence of febrile UTI were enrolled in this study. All children underwent RBUS during admission. The mean follow-up was 7.9 months (standard deviation $[SD]{\pm}13.3$). UTI recurrence rates were calculated according to various clinical parameters. By using bivariate and multiple logistic regression analyses, we determined whether age, sex, abnormal RBUS findings, abnormal dimercaptosuccinic acid renal scan findings, or RBUS findings parameters were predictive of UTI recurrence, high-grade VUR, or aRS. Results: On RBUS, hydronephrosis and congenital anomaly of the kidney and urinary tract significantly predicted UTI recurrence. A small kidney, hydroureter, hydronephrosis, cortical thinning, and increased parenchymal echogenicity significantly predicted high-grade VUR. However, their odds ratios (OR) are low compared to normal RBUS findings (recurrent UTI: OR 0.432 and 0.354 vs. 0.934, respectively, high-grade VUR: .019, 0.329, 0.126, 0.058, and 0.188 vs. 2.082, respectively). No RBUS findings significantly predicted aRS. Recurrent UTI, high-grade VUR, and abnormal RBUS findings significantly predicted aRS (OR of 4.80, 4.61, and 2.58, respectively). Conclusion: RBUS is necessary to exclude severe congenital renal scarring, obstructive uropathy, and renal abscess at the first incidence of febrile UTI and is helpful in determining the need for subsequent clinical imaging.

• Safety and Health at Work
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• 제5권4호
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• pp.234-237
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• 2014

Background: Inhalation of asbestos fibers can lead to adverse health effects on the lungs. This study describes lung function profiles among individuals with nonmalignant asbestos-related disorders (ARDs). Methods: The study population was from the Workers' Compensation (Dust Diseases) Board of New South Wales, Sydney, Australia. Lung function measurements were conducted in males with asbestosis (n = 26), diffuse pleural thickening (DPT; n = 129), asbestosis and DPT (n = 14), pleural plaques only (n = 160) and also apparently healthy individuals with a history of asbestos exposure (n = 248). Standardized spirometric and single-breath diffusing capacity for carbon monoxide ($DL_{CO}$) measurements were used. Results: Mean age [standard deviation (SD)] was 66.7 (10.3) years for all participants. Current and ex-smokers among all participants comprised about 9.0% and 54.8%, respectively. Median pack-years (SD) of smoking for ex- and current-smokers were 22.7 (19.9). Overall 222 participants (38.6%) and 139 participants (24.2%) had forced expiratory volume in 1 second ($FEV_1$) and forced vital capacity (FVC) measurements < 80% predicted, and 217 participants (37.7%) had $FEV_1/FVC$ results < 70%. A total of 249 individuals (43.8%) had DLCO values < 80% predicted and only 75 (13.2%) had DLCO/VA results < 80% predicted. A total of 147 participants (25.6%) had peak expiratory flow (PEF) measurements < 80% predicted. The presence of ARDs lowered the lung function measurements compared to those of healthy individuals exposed to asbestos. Conclusion: Lung function measurement differs in individuals with different ARDs. Monitoring of lung function among asbestos-exposed populations is a simple means of facilitating earlier interventions.

• 한국음향학회지
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• 제43권2호
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• pp.162-167
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• 2024

풍력발전기에서 방사되는 저주파 소음은 가장 관심이 높은 불만족 사항 중의 하나이다. 이에 본 연구에서는 공학적으로 유용하게 사용할 수 있는 덴마크 모델과 ISO 9613에 기초한 상용 프로그램인 SoundPLAN과 ENPro에 의한 풍력발전기 저주파 소음 예측값들과 측정값을 비교함으로써 모델들에 대한 신뢰성을 살펴보았다. 육상에서 대표적인 3 MW급 풍력발전기를 대상으로 적용한 결과 주파수 12.5 Hz에서 80 Hz 범위에서 측정값과 예측값은 최대 5 dB 이내의 차이를 보였다. 이러한 원인으로는 대상 풍력발전기는 7년 이상 운영되었기 때문에 음향파워레벨의 변화가 생겼기 때문으로 추정할 수 있다. 하지만 저주파 대역에서 가장 정확하다고 할 수 있는 Boundary Element Method (BEM) 예측값과 다른 모델에 의한 예측값 그리고 측정값은 2.5 dB 이내로 잘 일치한 점을 고려할 때 본 연구 대상의 모델들은 3 dB 이내의 편차로 활용될 수 있을 것으로 기대된다.

• Journal of Mechanical Science and Technology
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• 제17권6호
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• pp.935-944
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• 2003

Forced convective boiling heat transfer coefficients were predicted for an annular flow inside a horizontal tube for pure refrigerants and nonazeotropic binary refrigerant mixtures. The heat transfer coefficients were calculated based on the turbulent temperature profile in liquid film and vapor core considering the composition difference in vapor and liquid phases, and the nonlinearity in mixing rules for the calculation of mixture properties. The heat transfer coefficients of pure refrigerants were estimated within a standard deviation of 14% compared with available experimental data. For nonazeotropic binary refrigerant mixtures, prediction of the heat transfer coefficients was made with a standard deviation of 18%. The heat transfer coefficients of refrigerant mixtures were lower than linearly interpolated values calculated from the heat transfer coefficients of pure refrigerants. This degradation was represented by several factors such as the difference between the liquid and the overall compositions, the conductivity ratio and the viscosity ratio of both components in refrigerant mixtures. The temperature change due to the concentration gradient was a major factor for the heat transfer degradation and the mass flux itself at the interface had a minor effect.