• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2002년도 학술.기술논문발표회
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• pp.11-15
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• 2002

This study is intended to analyze the relationship between the rebound value of P type schmidt hammer and the compressive strength for a quality control of concrete. According to the results, the compressive strength of standard curing specimen increases in proportion to age, but that of air curing specimen hardly increases after 28 days. The rebound value of P type schmidt hammer, however, increases due to carbonation of concrete in air curing specimen. The correlativity between the rebound value and the compressive strength is very favorable in the case of standard curing specimen, but drops remarkably in the case of air curing specimen. Thus, as application of age coefficient is required for exact estimation of the compressive strength, the age coefficient is derived from this study. The age coefficient of P type schmidt hammer is higher at the age of 3 and 7days, and drops significantly, compared with the age of 28days. And it is lower before 28days than that of N type schmidt hammer suggested in Japan, and shows the similar tendency after 28days.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.75-78
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• 2005

This raper investigates the effect of curing temperature on strength development of concrete incorporating cement kiln dust(CKD) and blast furnace slag (BS) quantitatively. Estimation of compressive strength of concrete was conducted using equivalent age equation and rate constant model. An increasing curing temperature results in an increase in strength at early age, but with the elapse of age, strength development at high curing temperature decreases compared with that at low curing temperature. Especially, the use of 35 has a remarkable strength development at early age and even at later age, high strength is maintained due to accelerated pozzolanic activity resulting from high temperature. Whereas, at low curing temperature, the use of BS leads to a decrease in compressive strength. Accordingly, much attention should be paid to prevent strength loss at low temperature. Based on the strength development estimation using equivalent age equation, good agreements between measured strength and calculated strength are obtained.

• The Journal of Pediatrics of Korean Medicine
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• 제37권2호
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• pp.1-11
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• 2023

Objectives We aimed to compare the bone age (BA) estimation by a deep learning-based program and by a specialist in pediatrics of Korean medicine using the Tanner-Whitehouse 3 (TW3) technique for the cases of children who visited a Korean medicine hospital for growth, and to report the effect of Korean medicine treatment. Methods For three children who visited the Korean medicine hospital for growth, BA estimation by the deep learning program and by the specialist in pediatrics of Korean medicine using the TW3 technique was compared, and the time required for estimation was investigated. The change of height, BA, and predicted adult height (PAH) using deep learning program after Korean medicine treatment was observed. Results BA estimation of the left hand bone X-ray by the specialist using the TW3 technique showed a difference of -0.03 to +0.15 years from the estimation by the deep learning program. The mean estimation time was 5 minutes and 49 seconds per one for the specialist and 48 seconds for the deep learning program. During the treatment period, the height percentile and PAH estimated by deep learning program were increased after Korean medicine treatment compared to baseline while acceleration of BA was suppressed compared to chronological age. Conclusions BA estimation using the deep learning program and the TW3 technique showed a difference of less than 0.15 years, and in three cases of patients with growth as the chief complaint, Korean medicine treatment increased height percentile and PAH without accelerating BA maturation.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.94-97
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• 2006

Timber stand age information of timber in industrialized plantation forest is generally collected by field surveying which is labor-intensive, time-consuming, and very costly. It is also inconsistent in analyses perspective. As an alternative, The objective of this research is to present a practical solution for estimating timber age of loblolly pine plantation using Landsat thematic mapper (TM) images, shuttle radar topography mission (SRTM), and national elevation dataset (NED). A multivariate regression model was developed based upon satellite image-based information (i.e.normalized difference vegetation index (NDVI), tasseled cap (TC) transformation, and derived tree heights). A residual studentized technique was applied to remove potential outliers. After that, a refined age estimation model with a correlation coefficient R-square of 84.6% was obtained. Finally, the feasibility test of estimated model was performed by comparing estimated and measured stand ages of timber plantations using test datasets of plantation stands (2,032 stands). The result shows that the proposed method of this study can estimate loblolly pine stand age within an error of $2{\sim}3$ years in an effective and consistent way in terms of time and cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1721-1737
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• 2020

Human apparent age estimation has become a popular research topic and attracted great attention in recent years due to its wide applications, such as personal security and law enforcement. To achieve the goal of age estimation, a large number of methods have been pro-posed, where the models derived through the cumulative attribute coding achieve promised performance by preserving the neighbor-similarity of ages. However, these methods afore-mentioned ignore the geometric structure of extracted facial features. Indeed, the geometric structure of data greatly affects the accuracy of prediction. To this end, we propose an age estimation algorithm through joint feature selection and manifold learning paradigms, so-called Feature-selected and Geometry-preserved Least Square Regression (FGLSR). Based on this, our proposed method, compared with the others, not only preserves the geometry structures within facial representations, but also selects the discriminative features. Moreover, a deep learning extension based FGLSR is proposed later, namely Feature selected and Geometry preserved Neural Network (FGNN). Finally, related experiments are conducted on Morph2 and FG-Net datasets for FGLSR and on Morph2 datasets for FGNN. Experimental results testify our method achieve the best performances.

• Phonetics and Speech Sciences
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• 제11권4호
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• pp.9-18
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• 2019

This study aimed to investigate the correlation between speaker's chronological age (CA) and perceived age (PA) and to specify the effect of pitch and speech rate as acoustic cue on judging age, using perceptual testing and acoustic analysis. Three tasks were conducted to identify the degree of listener's accuracy about age estimation. Three perception tasks were conducted to measure the accuracy of 80 Korean listeners when presented with different types of speech. In all the tasks, participants listened to speech samples and gave their estimate of the speaker's age in figures. It was found that Korean listeners are able to gauge the age of a speaker fairly precisely. CA and mean PA were positively correlated in all three tasks. It is clear that the amount and type of information included in the voice samples affected the accuracy of a listener's judgement. Moreover, the result revealed that listeners make use of acoustic information such as pitch and speech rate to estimate speaker's age.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.236-239
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• 2004

The ternary blended cement(TBC) which the ability of resistance for seawater, the effect of decreation of hydration heat of concrete and long-age strength are known to be superior to other types was used to derive the estimation function of 91-age strength, 28-age strength with 28-age strength, 7-age strength respectively by analyzing the characteristics of statistics of compressive strength. The sample specimens was made after testing the variations of slump, air-contents during 30 minutes for consideration of transportation period. The functions might be expected to be useful for construction smoothness and reasonable quality control of concrete with TBC.

• Journal of the Korean housing association
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• 제19권2호
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• pp.31-42
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• 2008

Research outcome shows the following: 1. Estimation by the year 2015 on the number of the aged people and on the number of the household of living alone and living with spouse only, per age-cohort by 5 years, per basic self-govern-ins local groups and the city of Daegu. The result is supposed to serve as meaningful basic material in building up future policies in many areas for the aged people living in their homes. 2. Estimation varies according to the areas and the age-cohorts. In urban areas, increase of the numbers of the households of the aged people living alone and living with spouse only is estimated in every age-cohort. In rural areas, variance between two age-groups, old-old and young-old, is observed. Both of the numbers of the households for the aged living alone and the aged living with spouse only have increased continuously by the year 2005. But the hither-to increase tendency is estimated to reverse itself to a decrease starting from the younger within the young-old age group, and the ratio of the old-old age-group in rural population will sharply increase starting from the year 2005. Such increase in the number of the aged people in need of the housing and the social support requires the increasing policy consideration for the issue of housing for the aged living in their homes. In spite of the decreasing tendency in the number of the aged people living alone and living with spouse only in rural areas, still there will continue to be more number of such households than in urban area for the time being. The government of Gyeongsangbuk-Do should pay more consideration to the old-old aged living alone and living with spouse only in rural areas, while being prepared for the sharply increasing households for the aged living alone and living with spouse only in urban areas.

• Journal of Oral Medicine and Pain
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• 제39권2호
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• pp.69-77
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• 2014

Purpose: It aims to verify the applicability of existing age estimation methods derived from data of foreign population groups to Korean population groups. Moreover it is to suggest a new way applicable to practical age estimation on the basis of newly calculated regression formulae from data of Korean population groups and develop a subsidiarily applicable method to the existing method. Methods: Ratio of pulp cavity to dental crown was calculated by measuring the height and width of dental crowns and pulp cavities at the cervical line from 4,034 first and second upper molars, first and second upper premolars, first and second lower molars and first and second lower premolars on both left and right sides of 400 patients who had been treated in Dental Hospital of Yonsei University College of Dentistry, and regression equations were derived from the values of the ratio. Results: The equation with correlation coefficients the highest among females was as follows: age=$107.96-75.684{\times}{\sharp}17$ TCHI-$53.741{\times}{\sharp}26$ TCVI-$40.664{\times}{\sharp}45$ TCVI-$56.307{\times}{\sharp}46$ TCVI. Randomized anohter Korean female subjects (n=20) are applicated to the new equation. Mean of error of estimate is 10.322 years, standard deviation is 12.852 years. Minimum of error of estimate is 1.018 years, maximum is 21.365 years Conclusions: The error range of age estimation was found to be slightly wider when the existing regression formulae of Drusini were applied to Korean population groups. Also age estimation in females using the ratio of pulp cavity to dental crown measured with the length and width of dental crowns and pulp cavities from maxillomandibular molars was observed to have the highest reliability in the research. However, we consider that advanced equations of regression are needed to apply to both molars and premolars of males and females in the future.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.3893-3898
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• 2012

In previous studies we predicted future trends in cancer incidence for each prefecture in order to plan cancer control. Those predictions, however, did not take into account the characteristics of each prefecture. We therefore used the results of age-period-cohort analysis of incidence and mortality data of Osaka, and estimated the incidence and mortality of cancers at all sites and selected sites. The results reflect the characteristics of Osaka, which has and is expected to have large number of patients with liver cancer. We believe our results to be useful for planning and evaluating cancer control activities in Osaka. It would be worthwhile to base the estimation of cancer incidence and mortality in each prefecture on each population-based cancer registry.