• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.99-102
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• 2003

This study discusses the determination of removal time of forms with early strength development in high strength concrete. According to the results, as W/B increases by 10％, the setting time is shortened by about 2 hours. The time when compressive strength of 8 MPa is gained is about 20 hours. Bond strength between form and concrete is highest around final setting time, but decreases drastically after that. Amount of concrete sticking on the form is large before setting, but after that, it is little. The rebound value of P type schmidt hammer is measured faster by 2-3 hours than compressive strength. It is also confirmed that the removal of forms is possible when the rebound value of P type schmidt hammer is more than 34

• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.19-24
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• 2007

Covariance components and genetic parameters of weekly live body weight from hatching to six weeks of age and age of sexual maturation were estimated in a laying type Japanese quail line. The univariate and bivariate animal model analysis included hatching group and sex as fixed effects. Each trait was analysed with animal as random effect to fit the additive direct effect. Additional random effects incorporated in the models were changed according to the trait examined. The best model for a trait was chosen based on a likelihood ratio test, comparing the models with and without maternal additive genetic and maternal permanent environmental effects. Heritability estimates of live-weight at hatch and one to six weeks of age with their standard errors were 0.22${\pm}$0.088, 0.39${\pm}$0.099, 0.31${\pm}$0.086, 0.38${\pm}$0.056, 0.46${\pm}$0.055, 0.50${\pm}$0.059, and 0.56${\pm}$0.062, respectively. Direct heritability value of age of sexual maturation was moderate (0.24${\pm}$0.055). The variances due to permanent environmental effect of dam after one week of age and maternal genetic effect after two weeks of age were not important sources of variation. The correlations between direct and maternal genetic effects were negative and ranged from high to moderate values (-0.21 to -0.83). Among the weekly live weights, genetic correlations were generally high between not only successive but also early and late weightings. It suggests that selection for final weight may be based on early weight records. Genetic correlations between age of sexual maturation and live weights were low, favourable but had high standard errors. These results indicate that selection for high weight will potentially result in lower age of sexual maturation only with accurate determination of breeding values.

• Yonsei Medical Journal
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• 제59권9호
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• pp.1115-1122
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• 2018

Purpose: To investigate biomechanical properties of the cornea using a dynamic Scheimpflug analyzer according to age. Materials and Methods: In this prospective, cross-sectional, observational study, participants underwent ophthalmic investigations including corneal biomechanical properties, keratometric values, intraocular pressure (IOP), and manifest refraction spherical equivalent (MRSE). We determined the relationship of biomechanical parameters and ocular/systemic variables (participant's age, MRSE, IOP, and mean keratometric values) by piecewise regression analysis, association of biomechanical parameters with variables by Spearman's correlation and stepwise multiple regression analyses, and reference intervals (RI) by the bootstrap method. Results: This study included 217 eyes of 118 participants (20-81 years of age). Piecewise regression analysis between Corvis-central corneal thickness (CCT) and participant's age revealed that the optimal cut-off value of age was 45 years. No clear breakpoints were detected between the corneal biomechanical parameters and MRSE, IOP, and mean keratometric values. Corneal velocity, deformation amplitude, radius, maximal concave power, Corvis-CCT, and Corvis-IOP exhibited correlations with IOP, regardless of age (all ages, 20-44 years, and over 44 years). With smaller deformation amplitude and corneal velocity as well as increased CorvisIOP and Corvis-CCT, IOP became significantly increased. We provided the results of determination of confidence interval from RI data using bootstrap method in three separate age groups (all ages, 20-44 years, and over 44 years). Conclusion: We demonstrated multiple corneal biomechanical parameters according to age, and reported that the corneal biomechanical parameters are influenced by IOP.

• Advances in nano research
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• 제12권2호
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• pp.197-212
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• 2022

The purpose of this study is to develop an automatic software system for bone age evaluation and to evaluate its accuracy in testing and feasibility in clinical practice. 20394 left-hand radiographs of healthy children (2-18 years old) were collected from China Skeletal Development Survey data of 1998 and China Skeletal Development Survey data of 2005. Three experienced radiologists and China-05 standard maker jointly evaluate the stages of bone development and the reference bone age was determined by consensus. 1020 from 20394 radiographs were picked randomly as test set and the remaining 19374 radiographs as training set and validation set. Accuracy of the automatic software system for bone age assessment is evaluated in test set and two clinical test sets. Compared with the reference standard, the automatic software system based on RUS-CHN for bone age assessment has a 0.04 years old mean difference, ±0.40 years old in 95% confidence interval by single reading, a 85.6% percentage agreement of ratings, a 93.7% bone age accuracy rate, 0.17 years old of MAD, 0.29 years old of RMS; Compared with the reference standard, the automatic software system based on TW3-C RUS has a 0.04 years old mean difference, a ±0.38 years old in 95% confidence interval by single reading, a 90.9% percentage agreement of ratings, a 93.2% bone age accuracy rate, a 0.16 years of MAD, and a 0.28 years of RMS. Automatic software system, AI-China-05 showed reliably accuracy in bone age estimation and steady determination in different clinical test sets.

• 재활복지
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• 제17권4호
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• pp.221-244
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• 2013

본 연구는 중증장애인을 대상으로 자립생활의 구성요인 중 자기결정권과 역량강화가 공동체 관계 및 생산성에 어떻게 영향을 미치는지 탐색적으로 검증하였다. 이를 위해 2012년 5월부터 7월까지 약2개월에 걸쳐 장애인자립생활센터 및 인권센터 이용 장애인을 대상으로 자료를 수집하였다. 연구결과 첫째, 장애인의 자기결정권 수준은 연령, 학력, 배우자 유무, 수급 여부, 월소득 유무, 거주형태, 장애 발생시기, 장애등급 등의 변인에 따라 유의미한 차이가 나타났고, 역량강화 수준에서는 학력과 장애등급 등의 변인에 따라 유의미한 차이를 보이는 것으로 나타났다. 둘째, 장애인의 공동체관계 형성 수준은 연령, 학력, 배우자 유무, 거주형태, 장애 발생시기, 장애등급 등의 변인에 따라 유의미한 차이를 보이는 것으로 나타났고, 생산성 수준에서는 학력, 배우자 유무, 수급 여부, 월소득 유무, 중복장애 여부, 장애등급 등의 변인에 따라 유의미한 차이를 보이는 것으로 나타났다. 셋째, 장애인의 자기결정권과 역량강화가 공동체관계에 미치는 영향을 살펴본 결과, 자기결정권, 역량강화 변인 모두 장애인들의 공동체관계에 유의미한 정(+)적 영향을 미치는 것으로 나타났다. 넷째, 장애인의 자기결정권과 역량강화가 생산성에 미치는 영향을 살펴본 결과 역량강화 변인만이 장애인들의 생산성에 유의미한 정(+)적 영향을 미치는 것으로 나타났다. 따라서 향후 장애인의 공동체관계 및 생산성을 높여 자립생활을 영위해나가기 위해서는 자기결정권과 역량강화가 중요한 변수임을 확인할 수 있었다. 이를 위해서는 사회복지실천 및 재활과정에서 자기결정권 및 역량강화의 중요성을 인식하고, 이와 관련된 다양한 프로그램을 개발하고 활성화 시켜나가야 할 것이다.

• Ocean and Polar Research
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• 제39권4호
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• pp.279-292
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• 2017

We determined the maturity and growth of the Marbled sole, Pseudopleuronectes yokohamae based on monthly sampling in the West Sea of Korea from February 2009 to December 2010. Determination of sex of P. yokohamae was by gonadal inspection, and age and growth were determined by analyzing the otolith. The biological minimum size of P. yokohamae female was 24.5 cm. The seasonal changes in the ratio of a translucent zone to an opaque zone revealed that the end of the translucent zone of the otolith were annuli formed in May once a year. We compared 8 type growth equations with several length-at-age data. By using the length-at-monthly age data of these, the calculated von Bertalanffy growth equations were $L_t=41.7(1-e^{-0.47(t+0.24)})$ for females and $L_t=32.7(1-e^{-0.75(t+0.01)})$ for males. We estimated that 24.5 cm was the total length of 2 year old P. yokohamae spawns in the cold water season from January to April, and grows to 8 years old for females and 6 years old for males in the West Sea of Korea.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.53-56
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• 2008

This paper is to investigate the change of the period of hot weather concrete with elapse of age based on climate data. Climate data for 30 years and 5 years are used respectively. Determination of the period of hot weather concreting on architectural execution in Korea according to the specifications of AIJ, KSCE, and ACI are discussed. According to the research, the period of hot weather concreting with each specification in most regions lasts over 35 days. Compared with the period of cold weather concreting in hillside and inland area, coastal areas have shorter period in the same latitude. The period of hot weather concreting tends to decrease with high latitude. As expected, with the elapse of age, the period of hot weather concrete exhibited to decrease, especially, big city like Seoul, Busan etc had remarkably increased period by as much as a week. This is due to the global warming and industrialization effect with the elapse of age.

• Imaging Science in Dentistry
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• 제44권2호
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• pp.103-113
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• 2014

Purpose: In this study, we aimed to develop dental charts for Turkish children and young adults of both genders within the age group of 4.5-22.5 years according to tooth mineralization and eruption in a format similar to that proposed by AlQahtani et al. Materials and Methods: In total, 753 digital panoramic radiographs from 350 males and 403 females were assessed. The permanent teeth were evaluated according to the classification system described by Demirjian et al. The eruption stage was assessed with Bengston's system, which was modified by AlQahtani et al at four points. Results: Teeth generally developed earlier in females than in males. This was particularly notable in the age group of 5-14 years. However, this difference was usually visible in only one stage, not in all teeth. It has been determined that the mixed dentition period ended with the shedding of the second deciduous molars in both genders. Conclusion: The dental charts presented here included information that could be beneficial to dental clinicians in making appropriate diagnosis and planning orthodontic and surgical procedures. These charts also provided datasets for preliminary dental age estimation in Turkish children and young adults.

• Computers and Concrete
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• 제20권5호
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• pp.529-537
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• 2017

Excessively elevated temperature can lead to cracks in prestressed concrete (PC) continuous bridge with box girder on the pier top at cement hydration age. This paper presents a case study for evaluating the behavior of PC box girder during the early hydration age using a two-stage computational model, in the form of computer program ANSYS, namely, 3-D temperature evaluation and determination of mechanical response in PC box girders. A numerical model considering time-dependent wind speed and ambient temperature in ANSYS for tracing the thermal and mechanical response of box girder is developed. The predicted results were compared to show good agreement with the measured data from the PC box girder of the Zhaoshi Bridge in China. Then, based on the validated numerical model three parameters were incorporated to analyze the evolution of the temperature and stress within box girder caused by cement hydration heat. The results of case study indicate that the wind speed can change the degradation history of temperature and stress and reduce peak value of them. The initial casting temperature of concrete is the most significant parameter which controls cracking of PC box girder on pier top at cement hydration age. Increasing the curing temperature is detrimental to prevent cracking.

• 가정과삶의질연구
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• 제32권2호
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• pp.53-75
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• 2014

The purpose of this study was to develop and validate the "Authentic Parental Competence Scale" for mothers with school-age children. Based on a literature review, the study found that 'authentic parental competence' could be divided into parenting comperence, self-system competence, and social competence. In addition, the scale comprised three factors consisting of 43. The study collected data through behavior event interview(BEI), focus group interview(FGI), and three times Delphi investigation. The scale for mothers of school-age children consisted of a total of 129 items, which included three different dimensions (knowledge, skill, and attitude), and four factors were extracted from factor analysis following a survey of 362 mothers. The factors were labeled as "ability of developmental positive parenting," "ability of playing a role as a citizen and making social contributions," "ability of self-understanding and interpersonal relations," and "ability of self-growth and self-determination." In addition, the results revealed that the "Authentic Parental Competence Scale" showed an appropriate level of construct validity, reliability of the scales, distribution of item response, and item discrimination.