• Title/Summary/Keyword: 절대연령

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SHRIMP Zircon U-Pb Geochronology, Geochemistry and Sr-Nd Isotopic Study of the Cheongju granitoid rocks (청주 화강암의 SHRIMP 저어콘 U-Pb 연대, 지구화학 및 Sr-Nd 동위원소 연구)

  • Cheong, Won-Seok;Kim, Yoon-Sup;Na, Ki-Chang
    • The Journal of the Petrological Society of Korea
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    • v.20 no.4
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    • pp.191-206
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    • 2011
  • The emplacement ages, whole-rock geochemistry and Sr-Nd isotopic compositions of granitoid rocks from Cheongju area, South Korea, were investigated for delineating their petrogenetic link to the Jurassic Daebo granitoid rocks. Zircon crystals were collected from the diorite, biotite granite and acidic dyke samples in a single outcrop. Cross-cutting relationships show that the emplacement of diorite was postdated by the intrusion of biotite granite. Both rocks have been subsequently intruded by acidic dyke. The U-Pb isotopic compositions of zircon from the diorite, biotite granite, and acidic dyke were measured using a SHRIMP-II ion microprobe, yielding the crystallization ages of $174{\pm}2Ma$, $170{\pm}2Ma$, and $170{\pm}5Ma$, respectively, with 95% confidence limits ($t{\sigma}$). The emplacement ages are consistent with those determined from the above relative ages. The major and trace element patterns of the rocks are consistent with those of the Jurassic Daebo granitoid rocks, possibly suggesting a subduction-related I-type granite. The geochemical signature is, however, betrayed by the Sr and Nd isotopic compositions of these rocks. The isotopic signatures suggest that the rocks were produced either by the partial melting of lower-crust or by the mantle-derived magma contaminated by the basement rocks during its ascent and/or emplacement. In addition, the inherited ages of zircons of the rocks (ca. 2.1, 1.8, 0.8 and 0.4 Ga) suggest a possible assimilation with crustal rocks from the Gyeonggi massif and Ogcheon metamorphic belt.

SEMI-LONGITUDINAL STUDY OF GROWTH AND DEVELOPMENT OF CRANIO-FACIAL SOFT TISSUE OF CHILDREN AGED FROM 3 TO 11 (3-11세 아동의 두개 및 연조직의 성장변화에 관한 준종단적 연구)

  • Park, Young-chel;Choy, Kwang-chul;Han, Hee-kyung
    • The korean journal of orthodontics
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    • v.27 no.6 s.65
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    • pp.891-904
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    • 1997
  • Today's orthodontic treatment goals lie in functional esthetics, and the importance of the latter is increasing gradually in trend. Considering such, study on growth and development of soft as well as hard tissues becomes inevitable. Early studies emphasize mainly on skeletal analysis using cephalometric data. However, more recent studies report that maxillofacial soft tissue, which plays a critical role in determining facial esthetics, is influenced by underlying hard tissue, and yet close relationship between them was not noticed. Cephalometric x-rays were taken of 137 Korean boys and 106 girls with no systemic disease, fair developmental status and normal occlusion for two consecutive years; afterwards, soft tissue analysis, which was divided into four parts, facial form lip position & posture, nose, and thickness, was done to correlate them with general growth.

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Relationship of Low Blood Cadmium and Zinc to Blood Pressure (저농도 혈중 카드뮴과 아연이 혈압에 미치는 영향)

  • Lee, Duk-Hee;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.25 no.2 s.38
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    • pp.148-156
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    • 1992
  • A case-control study was conducted to investigate the relationship between blood cadmium, blood zinc and cadmium/zinc ratio and hypertension. Eighty-three hypertensive and seventy-seven normotensive study subjects matched for age and sex were selected from the workers who had no history of job-related cadmium exposure, in Ulsan city and it's vincinity, Korea. The blood cadmium in hypertensive group was $2.90{\eta}g/mL$, which was significantly higher than that of control group, $1.99{\eta}g/mL$(P<0.01). After stratifing for smoking and age variables, the relationship was still remained. The blood cadmium/zinc ratio in hypertensive group was 2.46, which was significantly higher than that of control group, 1.65(P<0.01), After stratifing for smoking and age variables, the relationship was still remained. There was no significant differance in blood zinc between hypertensive and control group. On multiple logistic regression analysis, the blood cadmium/zinc ratio is highly significant than blood cadmium. In conclusion, there is the possible relationship between blood cadmium level which has been known to be within normal limits and hypertension. But, futrher cohort studies to define the effect of cadmium on human hypertension are required.

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The Estimated Dietary Fiber Intake of Korean by Age and Sex (한국인의 연령과 성별에 따른 식이섬유 섭취 상태)

  • Lee, Hye-Jung;Kim, Young-Ah;Lee, Hye-Sung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.9
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    • pp.1207-1214
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    • 2006
  • The purposes of this study were to determine the estimated dietary fiber (DF) intakes per capita/day of Korean as of 2001 by age groups and sex, and to analyze the major food sources of DF using the data on per capita consumption of each food reported in the 2001 Reports of Korean National Nutrition Survey and the newly-established DF database. The mean daily intakes of DF of Korean increased with increasing age until 49 years and thereafter decreased with aging. The intakes of DF/1,000 kcal increased with increasing age until 64 years and thereafter decreased with aging. On the average, the Korean people under age of 49 did not meet adequate intake (AI) of DF (12 g/1,000 kcal) in Dietary Reference Intakes (DRI) for the Koreans. The male people less satisfied the AI than the female did. The major food groups contributed to DF intakes of Korean adults were high in the order of vegetables, cereals, fruits, seasonings, legumes and seaweeds. Regardless of age and sex, vegetables, cereals and fruits were three major sources of DF for Koreans who obtained approximately 75% of DF from those sources. It has been shown that rice was the first single food source of DF intake for the age groups less than 12 years, however Kimchi was the first major source for all the age groups over 12 years. The infant and elderly groups obtained more DF from 10 major single food sources than the other age groups did. The results of the study revealed that the present levels of DF intakes of Korean in all age groups except the elderly group are insufficient to meet the AI for DF. Therefore the beneficial effects of DF on health and the increased consumption of DF from the variety of food sources should be emphasized through the continuous nutritional education.

Sea Level Fluctuation in the Yellow Sea Basin (황해 분지의 해수면 변동)

  • PARK, YONG AHN;KHIM, BOO KEUN;ZHAO, SONGLING
    • 한국해양학회지
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    • v.29 no.1
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    • pp.42-49
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    • 1994
  • A series of radiocarbon dating from intertidal, subtidal, and inner continental shelf deposits investigated along the west coast of Korea as well as from its offshore sea floor (namely, the eastern Yellow Sea Basin) how (1) the Holocene sea level rise, i.e., the ecstatic sea-level history during the oxygen isotope stage 1, and (2) pre-Holocene sea-level fluctuations during the oxygen isotope stages 2 and 3. Marine geophysical investigations in the Yellow Sea reported a possible development of desert and loses deposits due to dieselization under the cold and dry climate during the Last Glacial Maximum. The Kanweoldo deposit overlain unconformably by the Holocene intertidal deposits, which is mainly exposed along the tidal channels and intertidal flats in the Cheonsu Bay, the west coast of Korea, shows the characteristic cryogenic structure (cryoturbation). Such cryoturbation structure of the Kanweoldo deposit appears to indicate the cold and dry climate under the ecstatic sea-level paleoshoreline standing before and after of the pre-Holocene interstitial period (about 30000 y BP is suggested and its shoreline curve is constructed.

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Quantitative Electroencephalographic Findings in Obsessive-Compulsive Disorder (강박 장애의 정량화 뇌파 소견)

  • Youn, Tak;Kwon, Jun Soo;Cho, Maeng-Je;Kim, Yong Sik;Rhi, Bou-Yong
    • Korean Journal of Biological Psychiatry
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    • v.3 no.2
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    • pp.216-221
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    • 1996
  • The quantitative EEGs of obsessive-compulsive disorder patients were analyzed using spectral analysis and compared to age and sex-matched controls. The subjects were 19 patients(men=15, women=4) suffering from obsessive-compulsive disorder(DSM-III-R). Absolute power, relative power and interhemispheric asymmetry of EEG were used to compare obsessive-compulsive disorder patients with controls. In order to fit the EEG data to a normal distribution, a log transformation of power values of every bandwidth in each deviation was calculated prior statistical analysis. The Wilcoxon rank test was performed to compare obsessive-compulsive group to the control group. In obsessive-compulsive disorder, abnormalities of quantitative EEGs are prominent in fronto-central. These results ore compatible with other brain imaging studies of obsessive-compulsive disorder and suggested that fronto-central area plays an important role in the pathophysiology of obsessive-compulsive disorder.

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A Study on Poverty Characteristics of Rural Elderly Households (농촌노인가구의 빈곤특성에 대한 비교연구 - 빈곤율과 빈곤감을 중심으로 -)

  • Kim, Young-Joo
    • Korean Journal of Social Welfare
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    • v.60 no.4
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    • pp.31-53
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    • 2008
  • This study intends to verify the poverty characteristics of the rural elderly households so as to provide more specific data for the intervention of social welfare in the improvement of quality of life of the rural elderly. According to my study of the absolute poverty ratio, the poverty gap, the relative poverty ratio, the subjective poverty ratio, the subjective economic level and the life satisfaction level of the rural elderly households in comparison with those of the other groups, the conclusion is as follows: First, the total living cost of the rural elderly households is rather low with the food cost taking about 30% of the total living cost. Second, in terms of the poverty ratio based on socio-demographic characteristics, higher poverty ratio show among women, older people and households of fewer members. Third, 82.2% of the rural elderly households living with an income below the minimum living cost is found around the poverty line. Fourth, the rural elderly households show a comparatively higher poverty ratio than the other groups in the absolute and relative poverty, but lower economic strain than other groups in the subjective poverty ratio and life satisfaction level. In short, the rural elderly households' poverty level is generally high and therefore need ways of active economic supports, while a political approach to the subjective needs of the regional and intergenerational groups is also required.

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A Study on the Characteristics of Poverty of North Korean Settlers: A Comparison with the South Korean Poor (장기 정착 새터민의 빈곤특성 연구: 남한 빈곤층과의 비교 고찰)

  • Kim, Yeun-Hee;Cho, Young-A;Yoo, Si-Eun
    • Korean Journal of Social Welfare
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    • v.61 no.1
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    • pp.195-218
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    • 2009
  • The purpose of this study was to analyze the phenomenon of poverty among North Korean settlers in Korea in terms of its magnitude, the severity, and its determinants by comparing it with the South Korean poor. The data used for this analysis were the second Korean Social Welfare panel data for the South Koreans and the third longitudinal study on North Korean settlers in the South. The average household income of the North Korean settlers reached about 70% of the South Korean counterparts. The percentage of the North Korean households that earn 200% of the poverty line was about the same as the South Koreans, which indicates the improvement of the economic status of the long-term settlers in the South. However, the North Korean settlers below 100% of the poverty line were twice as much , and those under 50% of the poverty line were 8 times more than their South Korean counterparts. Despite the improved economic status of the long-term North Korean settlers in the South, those who still live below the poverty line tend to remain in poverty, which is chronic and severe. The determinants of the North Korean settlers' poverty were identified as age, number of household members in employment, alcohol problem and health satisfaction level. Policy implications were discussed in conclusion.

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Surgical Treatment for Longitudinal Epiphyseal Bracket of the Finger (수지의 종적 Bracket 골단에 대한 수술적 치료)

  • Kim, Sung Soo;Kim, Ki Woong;Kim, Jung Ho;Lee, Chan Soo
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.2
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    • pp.154-161
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    • 2020
  • Purpose: To describe the clinical and radiology results of a surgical treatment for clinodactyly due to a longitudinal epiphyseal bracket. Materials and Methods: This study analyzed the records of 11 patients (27 case) with clinodactyly due to a longitudinal epiphyseal bracket who underwent an osteotomy or physiolysis between March 1999 and April 2017. The preoperative range of motion of the proximal and distal interphalangeal joints, the subjective satisfaction of the patient, and the degree of angulation to the ulnar side were examined. The patients were classified into two groups: osteotomy and physiolysis. The results were reviewed retrospectively and compared according to the surgical method. Results: The mean age of the patients who underwent osteotomy was 10.3 years. The average preoperative angle was 25.7° and the average postoperative angle was 13.5° the mean correction rate was 47.4%. The mean age of the patients who underwent physiolysis was 6.0 years the mean preoperative angle was 24.5° and the postoperative angle was 10.7°. The average correction rate was 59.4%. No significant difference in the correction angles was observed between the group who underwent the correction osteotomy and the group who underwent the osteotomy. In each group, the postoperative correction was statistically significant. The range of motion at the last follow-up was not significantly different from the preoperative range of motion. Conclusion: In patients with clinodactyly due to longitudinal epiphyseal bracket, osteotomy or physiolysis may be performed selectively according to age, bone age, and radiological progression. Both surgical methods showed good clinical results and deformity correction.

짧은 주기의 근접쌍성 BD And의 측광 및 그 분석을 통하여 살펴 본 RS CVn형 쌍성의 성질과 그 천체물리학적 의미

  • Kim, Cheon-Hwi;Song, Mi-Hwa;Yun, Yo-Na;Han, Won-Yong;Choe, Yong-Jun
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.55.1-55.1
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    • 2012
  • 2010년과 2011년의 관측시즌에 총 23일의 BVR 측광 관측을 통하여 처음으로 얻은 2세트의 BVR 광도 곡선을 분석하였다. 새로운 두 세트의 BVR 광도곡선은 제1식과 제2식의 깊이가 거의 비슷하지만, 식바깥 부분에서 관측 시즌에 따라 서로 다른 모양의 잘 발달된 파형 모양을 보인다. 이는 BD And가 흑점이 활동이 매우 심한 짧은 주기의 RS CVn형 식쌍성임을 나타내는 것이다. 우리의 극심시각을 포함한 모든 극심시각을 분석하여 BD And의 공전주기가 규칙적으로 변하는 것을 발견하였다. 이 변화를 보이지 않는 제3천체에 의한 광시간 효과로 가정하여, 궤도이심율이 0.83이며, 9.15년의 주기를 가진 광시간 궤도를 결정하였다. Wilson-Devinney 쌍성 모형을 이용하여 흑점과 제3광도를 고려한 두 세트의 광도곡선 해를 산출하였고, BD And의 절대량을 구하였다. 식바깥의 파형 모양의 변화는 주성의 표면에 매우 큰 두 개의 흑점과 그 위치와 이동으로 잘 설명되며, 전체 광도의 약 15%에 해당되는 제3광도가 검출되었다. 주기연구에서 구한 제3천체의 궤도요소와 제3광도의 결합으로 제3천체의 질량과 궤도경사각을 유추하였다. BD And의 성분별의 평균 나이가 등연령 곡선으로부터 태양과 비슷한 4.6${\times}$109년으로 산출되었다. BD And를 포함하여 현재까지 알려진 짧은 주기의 RS CVn형 쌍성들의 H-R도가 항성진화 경로와 함께 제시되며, 그 천체물리학적 의미를 살펴본다.

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