• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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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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• v.19 no.2
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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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• v.39 no.2
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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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• v.13 no.8
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.103-104
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• 2021

This study attempted to confirm the possibility of estimating condensation time and initial compressive strength with five types of estimation needles in the existing Durometer D type. In order to determine the surface finishing operation time and develop a method for estimating the initial age compression strength, an estimation needle capable of complexly measuring the estimation time and the initial age compression strength based on the Durometer D type was derived as 1.5, 2.0mm.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.305-309
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• 2006

SAR (Synthetic Aperture Radar) technology, which is not influenced by cloud cover because of using electromagnetic wave of long wavelength, has an advantage in mapping the earth. NASA, recognizing these strong points of SAR, launched SRTM (Shuttle Radar Topography klission), and acquired the topographic information of the earth. SRTM and NED (National Elevation Data) of USGS were used for the research and vegetation height map was produced through differentiating the two data. Correlation between SRTM-NED and planting year was analyzed to see the relationship. Strong correlation was detected and it shows the feasibility of estimating timber age and eventually creating timber age map from SRTM-NED. Additional analyses were conducted to check if the linearity is influenced by regional characteristics and forest uniformity. As results, the correlation between SRTM-NED and timber age is influenced by roughness of the terrain. Overall, this paper shows that timber age estimation using SRTM and NED can be sufficiently practical.

• Imaging Science in Dentistry
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• v.53 no.2
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• pp.91-99
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• 2023

Purpose: This systematic review aimed to investigate the correlation between chronological age and dental pulp volume in cone-beam computed tomography (CBCT). Materials and Methods: The literature was searched in 4 databases(PubMed, Scopus, Web of Science, and Google Scholar). Within each study, the outcome of interest was the correlation (r) between chronological age and pulp volume. A random-effect meta-analysis was conducted. Subgroup analysis was carried out according to sex and tooth type. Results: Of 5,693 identified studies, 27 fulfilled the inclusion criteria and were selected for meta-analysis. These articles focused on single-rooted teeth (n=21), multi-rooted teeth (n=6), maxillary teeth (n=14), mandibular teeth (n=6), and maxillary and mandibular teeth (n=12). The relationship between chronological age and dental pulp volume was examined in the entire population (r= -0.67), men (r= -0.75), and women (r= -0.77) in single- and multi-rooted teeth. The results of the total population analysis showed a relatively strong negative relationship between age and pulp volume. Conclusion: This study suggested that CBCT is a reliable and repeatable tool for dental age estimation. A strong inverse relationship was observed between pulp chamber volume and age. Further studies on the correlation between chronological age and pulp volume of multi-rooted teeth may be beneficial.

• Journal of Oral Medicine and Pain
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• v.46 no.2
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• pp.21-32
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• 2021

Purpose: The purpose of the present study was to investigate the correlation between age and 34 radiomorphometric parameters on panoramic radiographs, and to provide generalized linear models (GLMs) as a non-invasive, inexpensive, and accurate method to the forensic judgement of living individual's age. Methods: The study included 417 digital panoramic radiographs of Korean individuals (178 males and 239 females, mean age: 32.57±17.81 years). Considering the skeletal differences between the sexes, GLMs were obtained separately according to sex, as well as across the total sample. For statistical analysis and to predict the accuracy of the new GLMs, root mean squared error (RMSE) and adjusted R-squared (R²) were calculated. Results: The adjusted R²-values of the developed GLMs in the total sample, and male and female groups were 0.623, 0.637, and 0.660, respectively (p<0.001), while the allowable RMSE values were 8.80, 8.42, and 8.53 years, respectively. In the GLM of the total sample, the most influential predictor of greater age was decreased pulp area in the #36 first molar (beta=-26.52; p<0.01), followed by the presence of periodontitis (beta=10.24; p<0.01). In males, the most influential factor was the presence of periodontitis (beta=9.20; p<0.05), followed by the number of full veneer crowns (beta=2.19; p<0.001). In females, the most influential predictor was the presence of periodontitis (beta=18.10; p<0.001), followed by the tooth area of the #16 first molar (beta=-11.57; p<0.001). Conclusions: We established acceptable GLM for each sex and found out the predictors necessary to age estimation which can be easily found in panoramic radiographs. Our study provides reference that parameters such as the area of tooth and pulp, the number of teeth treated, and the presence of periodontitis should be considered in estimating age.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.533-540
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• 2014

We propose an age estimation-based smart digital signage for the next-generation airport service. The proposed system can recognize the face of the customer so that it can display the selective information. Using a webcam, the system captures the face of the customer and estimates the age of the customer by calculating the wrinkle density of the face and applying bayesian classifier. The developed age estimation method is tested with a face database for the performance evaluation. We expect the new digital signage may improve the satisfaction of customers of the airport business.

• Journal of Nutrition and Health
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• v.38 no.4
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• pp.320-326
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• 2005

This study was conducted to estimate dietary choline intake of Koreans according to gender, age and region by using the data on per capita food intake in 1998 and 2001 and the data on choline contents of foods customarily eaten by Koreans. Sixty-four and 97 kinds of food items were used for the estimation of choline intake in 1998 and 2001, respectively. And these corresponded to approximately $90\%$ of the total amount of food intake and energy intake. Based on these food items and choline content, per capita choline intake of Koreans was estimated to be 623.0 mg and 602.4 mg in 1998 and 2001 respectively , 687.2 mg and 659.1 mg in 1998 and 2001 for male, 560.2 mg and 551.0 mg in 1998 and 2001 for female. While the number of foods considered in estimation was higher in 2001 than 1998, choline intake was lower in 2001. The estimated per capita choline intake of male population was higher than that of female population by 108-127 mg, possibly due to the difference in total amount of food intake. The age group with the highest choline intake was different between 2 time points. Although adolescents of 13- 19 years showed the highest intake (712.0 mg) in 1998, mid-aged adults of 30-49 years showed the highest choline intake (662.2 mg) followed by adolescents (645.7 mg) in 2001. In regional comparison, choline intake of the rural population (588.7 mg and 588.3 mg in 1998 and 2001 respectively) was lower than that of population in small to medium-size cities (625.1 mg and 603.9 mg) or in metropolitan cities (637.7 mg and 602.8 mg). This result revealed that per capita choline intake of the Korean population falls within the adequate range with some differences by age, sex and residing area.