• Journal of Oral Medicine and Pain
• /
• v.40 no.4
• /
• pp.146-154
• /
• 2015

Purpose: The purpose of present study was to develop a method for assessing the chronological age of Korean adults based on the relationship between age and size of pulp cavity using dental radiographs of mandibular first molars. Methods: A total of 325 dental radiographs of Korean adults with known age and gender were selected for the study (199 males and 126 females) which were taken in the period between January 2009 and June 2014 at the Pusan National University Dental Hospital. The measurements were carried out on both orthopantomographs (OPGs) and intraoral periapical radiographs of mandibular first molar and the following ratios were calculated: pulp chamber floor height ratio (F/L), pulp chamber ceiling height ratio (R/L), and pulp chamber depth ratio (D/L). Results: The ratios of measurements on intraoral periapical images of mandible first molar generally produce more reliable data than the measurements on OPGs. The pulp chamber floor height ratio and pulp chamber thickness ratio showed significant correlation with age, whereas the pulp chamber ceiling height ratios showed weak correlation with age. It was found that the best correlations between the ratios and age were found for pulp chamber thickness ratios (r=-0.731 to -0.751). The multiple regression models were derived using 3 ratios that were significantly correlated with age. The determination coefficients ($R^2$) of the models ranged from 0.556 to 0.596. Conclusions: Our results indicate that the pulp chamber thickness and pulp chamber floor height in mandibular first molar are an age-dependent variable in adults which can be used to estimate age with reasonable accuracy. The higher image quality of dental radiographs will probably narrow the age estimation error and improve dental age estimation.

• Korean Journal of Social Welfare
• /
• v.50
• /
• pp.235-263
• /
• 2002

The present study is designed to explore restructuring direction of the old-age income maintenance system and development direction of the Seniority Pension Scheme(SPS) in Korea. While the SPS is trifling scheme with tiny benefit amount and small budget, the SPS has important role that function as only public income maintenance scheme for both the low income class and the excluded from public pension and public assistance at present stage because of immature National Pension. This study starts with the research question why serious mis-matching problem between needs and resources in old-age income maintenance system occur. Thus this study explores fundamental change direction of the old-age income maintenance system which is coincide with further situation change(demography, labour market, family structure). Also this study explores desirable SPS's development direction as taking into account relation with other public old-age income maintenance system. This paper suggests basic direction of old-age income maintenance system as follows: principle of universal and individual security; principle of sustainability; principle of equity. Under general principle, this paper also proposes largely two development scenario of the SPS. The one is to maintain present transitional and provisional scheme with trying scheme's substantiality. The other is to change into permanent old-age income maintenance scheme for the excluded public pension and public assistance. At this point it is the public pension's role that the SPS's development direction is determined. If the public pension keep one pension per one earner as present system, non-contribution pension as present SPS should maintain continuously. However, if the public pension reorganize into basic pension of one pension per one person and earning-related pension, the SPS should be managed temporarily until mature of public pension. Therefore whether the public pension play basic security role for all elderly or not will determine the SPS development direction.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.24 no.1
• /
• pp.161-169
• /
• 1994

Hemangioma is a common tumor characterized by the proliferation of blood vessels. Some authorities believe that this lesion is not a true neoplasm, but rather a developmental anomaly or harmatoma. This lesion may be present at any age, but most cases are present at birth or arise at an early age, and the central hemangioma of the jaw is uncommon. The usual radiographic appearance of a hemangioma may have one or more of the following characteristics: a soap-bubble or honey-comb effect with multiloculated cyst like lesions having a fine fibrillar framework visible within them. The roots of teeth mayor may not show resorption. The authors have experienced a case of hemangioma, that occured in anterior mouth floor and Mn.symphysis area cured by means of surgical excision without dysfunction and facial disfigurement.

• The korean journal of orthodontics
• /
• v.9 no.1
• /
• pp.117-123
• /
• 1979

The aspects examined in the present study concerning the location and position of the lower third molar and the interrelationships of this molar, the gonial angle, and the second lower molar in subjects aged 8-24 are based on measurements made from 472 orthopantomograms. The following conclusion were drawn on the basis of the present study. 1. The gonial angle decreased with age, but slight enlarging occurred in the age group 20-21. 2. The angulation of the third molar in relation to the second molar did not correlate with the size of the gonial angle but decreased with developmental stage. 3. The mesial angle between the longitudinal axis of the second molar and the mandibular base line correlated significantly with the gonial angle. The above angle were smaller in Class II, Divison 2 and larger in Class III than in Class I and Class II, Division 1. 4. The rate of presence of lower third molar was 74.4%.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 2007.11a
• /
• pp.532-541
• /
• 2007

This paper investigates children's comprehension and production of demonstrative pronouns (DPs), 'zhege' (this) and 'nage' (that), in Mandarin Chinese. Subjects are children of ages three, four, five and six. Based on the results of the present experiment, children's developmental stages and the corresponding age grading are provided. Also, the present study incorporates a physical clue into the experiment. The result suggests that in the acquisition of deixis children rely highly on physical context to work out the meaning distinction. In addition, Piaget's egocentrism hypothesis and H. Clark's marking hypothesis are examined in the study. The result seems to support the egocentrism hypothesis. Subjects under the age of six do fail to shift the deictic center when they and the experimenter have a different perspective. As for the marking hypothesis, the study seems to challenge the hypothesis. The result shows that children actually performed better on the marked term 'zhege' than the unmarked member 'nage'.

• Korean Journal of Child Studies
• /
• v.12 no.2
• /
• pp.5-17
• /
• 1991

The purpose of the present study was to investigate developmental trends and relationships between justice and friendship. Four different interviews were administered individually to fifty 4-to 8-year old children. In the Justice domain, the interviews consisted of open-ended questions devised to investigate the children's understanding of justice and a hypothetical story dilemma based on Damon(1977). In the friendship domain, the interviews consisted of open-ended questions based on Bigelow(1975; 1977) and Damon(1977) and a hypothetical story dillema based on Selman(1981). The developmental stage of each concept was determined through content analysis of the responses each child. Statistical analysis of obtained data was by percentage and Goodman-Kruskal's ${\gamma}$. * The results showed that children's conceptions of justice and of friendship developed in an age-related manner during early and middle childhood. While there was a significant correlation between children's conceptions of justice and friendship, this result was due to age-relatedness. The results of the present study support a domain specific approach to social cognition.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.493-496
• /
• 2004

The change of creep deformation mechanism due to the persistent change of stress conditions requires the constitutive relation for the analysis of long tenn behaviors considering age dependent material properties of concrete. In the present research, the process of time dependent behaviors in structure is divided into two stages; the non-mechanical deforming level which causes creep and shrinkage deformations, and the mechanical deforming level which causes mechanical deformations by the restraints of non-mechanical deformations due to internal or external factors. The incremental constitutive relation is derived by expanding the total stress-strain relation on the present time, with respect to the reference time using the Taylor series, and the modulus of elasticity in early ages of concrete was defined thru this process.

• Journal of Korean Physical Therapy Science
• /
• v.1 no.2
• /
• pp.243-249
• /
• 1994

The following analysis is conducted to the 108 employed physical therapist males 46, female 62 in Taegu and Kyung-Pook for the purpose of research on their present status from August in to September 17 in 1994. The percentage of the female polled is 57.4 % and the age of 21 to 30 is 79.7 %. The number of people who have worked over five years in general hospital is 8(7.4 %) and in local clinic 5(4.6 %). This report is researched in to the proportion of the males to females, age, career period, job classification, and salary range.

• Korean Journal of Veterinary Research
• /
• v.28 no.1
• /
• pp.199-202
• /
• 1988

The present study was carried out to investigate the serum enzyme activities of racehorses. The enzymes investigated were aspartate and alanine aminotransferase (GOT, GPT), ${\gamma}$-glutamyl transpeptidase(${\gamma}$-GTP), Lactic dehydrogenase(LDH), creatine phosphokinase(CPK), and alkaline phosphatase(ALP). Animals used were 30 healthy racehorses(♀17, ♂13) average weighing 435kg and were from 2 to 8 years of age. LDH activity was progressively decreased with age and next in the order of GOT and CPK activities. GOT and ${\gamma}$-GPT activities were not changed with age but ALP activity tended to be decreased wish age. Activities of GOT, GPT, ${\gamma}$-GTP and ALP were higher in female than in male. There was no difference in CPK activity by sex, and no difference was found out among breeds.

• Korean Journal of Child Studies
• /
• v.9 no.1
• /
• pp.19-32
• /
• 1988

The purpose of the present study was to investigate the view that animism is a result of immature concepts of life. Two studies were conducted for this purpose Study I examined developmental trends in animistic thinking and Study II examined children's knowledge of living things. The subjects of Study I were 10 males and 10 females at each level, 6, 8, 11 and 14 years of age and university students, for a total of 100 subjects. The subjects of Study II were 9 boys and 9 girls at each age level, 6, 7 and 8 years of age and university students, for a total of 78 subjects. According to the results of study I and study II, animistic thinking decreased up to middle childhood but increased at later childhood and adulthood. The conception of living things was acquired at 7 years of age. All things considered, there was no evidence that animism is a result of immature concepts of life.