• Title/Summary/Keyword: Be age-dating

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Method of Recurrence Interval Estimation for Fault Activity from Age Dating Data (연대측정자료를 이용한 단층활동주기 산정 방법)

  • 최원학
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.74-80
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    • 2001
  • The estimation of recurrence interval for fault activity and earthquake is an important input parameter for seismic hazard assessment. In this study, the methods of recurrences interval estimation were reviewed and tentative calculation was performed for age dating data which have uncertainty. Age dating data come from previous studies of Ulsan fault system which is a well developed lineament in the southeastern part of korean Peninsula. Age dating for fault gouges, parent rocks, Quaternary sediments and veins were carried out by several researchers through various methods. Recurrence interval for fault activity was estimated on the basis of the age dating data of minor fault gouge and sediments during past 3Ma. The estimated recurrence interval was about 430-500 ka. Exact estimation of recurrence interval for fault activity need to compile more geological data and fault characteristics such as fault length, amount of displacement, slip rate and accurate fault movement age. In the future, the methods and results of fault recurrence interval estimation should be considered for establishing the criteria for domestic active fault definition.

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The Effect of Horizontal Branch Stars on the Age-Dating of Simple Stellar Populations

  • Chung, Chul;Lee, Young-Wook;Yoon, Suk-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.81.2-81.2
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    • 2010
  • Based on Yonsei Evolutionary Population Synthesis (YEPS), we have investigated the effect of horizontal branch stars (HBs) on the age-dating of simple stellar populations (SSPs). A detailed comparison of YEPS SSP with H_beta of M31 globular clusters (GCs) reveals (1) that the age dating without HB prescription gives ~5 Gyr younger ages for metal-poor M31 GCs, and (2) the age dating with HB prescription does not need any age gap between metal-poor and metal-rich GCs. This result is parallel to the well-known discrepancy in ages derived from integrated Balmer strengths and isochrone fittings of Milky Way GCs (MWGCs). Without a synthetic blue HB model, we cannot explain strong Balmer indices of metal-poor and old MWGCs. Our results suggest that the SSP model with well calibrated HBs should be used for the age-dating of SSPs to avoid a serious underestimation of ages due to the strong Balmer indices.

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Widowed elderly's dating experience and related variables: focusing on gender difference (홀로된 노인의 이성교제경험과 관련변인 - 성별 차이를 중심으로)

  • Yi, Yeong Sug
    • Korean Journal of Human Ecology
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    • v.22 no.4
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    • pp.609-618
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    • 2013
  • The purpose of this study is to explore gender differences in elderly's dating experience and related variables. 427 elderly of age 65 or older participated. The results are as follows. 1. 80% of widowed elderly had no dating experience, and far more elderly men than women had dating experience. 2. Attitudes towards dating, of both elderly themselves and their children, had influence on the elderly's dating experience, regardless of gender. This indicates that the elderly's own acceptance and their children's positive attitude are important to the elderly's dating experience. 3. Gender differences were found in influences of living arrangement (whether they lived with their children or not), economical reasons, and personality factors. These variables proved significant only for the elderly men. More elderly men who did not live with their children than the elderly men who did had experienced dating, and economical reasons along with personality factors proved to be obstructive for elderly men's dating life.

Cosmogenic 10Be Depth Profile Dating of Strath Terrace Abandonment using Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 하안단구 10Be 수직단면 연대측정)

  • Kim, Dong-Eun;Seong, Yeong Bae;Kim, Jong-Geun
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.4
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    • pp.21-31
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    • 2019
  • Timing of terrace formation is a key information for understanding the evolution of fluvial systems. In particular, dating strath terrace (i.e. timing of terrace abandonment) is more difficult than depositional terrace that is conventionally constrained by radiocarbon, OSL and other dating methods targeting samples within terrace deposit. Surface exposure dating utilizing cosmogenic 10Be provides more reliability because it can be applied directly to the surface of a fluvial terrace. Thus, this method has been increasingly used for alluvial deposits. As well as other geomorphic surfaces over the last decades. Some inherent conditions, however, such as post-depositional 10Be concentration (i.e. inheritance), surface erosion rate, and density change challenge the application of cosmogenic 10Be to depositional terrace surface against simple bedrock surface. Here we present the first application of 10Be depth profile dating to a thin-gravel covered strath terrace in Korea. Monte Carlo simulation (MCS) helped us in better constraining the timing of abandonment of the strath terrace, since which its surface stochastically denuded with time, causing unexpected change of 10Be production with depth. The age of the strath terrace estimated by MCS was 109 ka, ~4% older than the one (104 ka) calculated by simple depth profile dating, which yielded the best-fit surface erosion rate of 2.1 mm/ka. Our study demonstrates that the application of 10Be depth profile dating of strath terrace using MCS is more robust and reliable because it considers post-depositional change of initial conditions such as erosion rate.

Optically stimulated luminescence dating of heated materials from the early Bronze age in central Korea (한국 중부지역 청동기시대 전기 유적의 광 여기 루미네선스를 이용한 연대측정)

  • Kim, Myung-Ji;Hong, Duk-Geun
    • Journal of Conservation Science
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    • v.16 s.16
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    • pp.5-14
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    • 2004
  • Luminescence dating is based upon the premise that several commonly occurring minerals (e.g. quartz and feldspar) can be used as natural dosimeters, recording the amount of radiation to which they have been exposed. We report results of optical dating on quartz samples separated from archaeological remains (burnt soils and potteries), which were excavated at Myungam-Ri, Asan, and Chungnam province and at Sayang-Ri, Chinchun, Chungbuk province, considered as the cultural site of the early Bronze Age. The resultant dates were in good agreement with the ages derived by archaeological assessment. It is concluded that the optical dating introduced in here should contribute significantly to future archaeological dating work.

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Radiocarbon Dating Practices by Benzene Liquid Scintillation Method (벤젠-액체 섬광계수법에 의한 $^{14}C$ 연대측정)

  • Lee, Yeon-Gyu;Choi, Jeong-Min;Kim, Chang-Gyu
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.3
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    • pp.180-187
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    • 1999
  • Radiocarbon dating method using benzene liquid scintillation was performed on the oyster shell fragments which producted from the shell mounts at Hadong Mogdori in Kyeongsangnamdo. This paper described to the age dating method and compared to the result. The carbon in sample is synthesized to a benzene through the sample preparation, $SrCO_3$, $SrC_2$, $C_2H_2$ and $C_6H_6$ synthesizing process. Age dating is calculated by Wallac 1415 Liquid Scintillation Counter. The result of age dating is estimated to be $4905{\pm}112$ yr BP in Yosu Univ. which is a good agreement with the result in Shimane Univ. ($4912{\pm}123$ yr BP). Radiocarbon dating method using benzene liquid scintillation is a simple and economical in operation and establishment, it has a potential instrumentation in the university and research institute.

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The Meaning of Dating and Marriage among Well-Educated Korean Couples at the Optimal Marriageable Age (고학력 결혼적령기 커플들의 연애와 결혼에 대한 의미 및 젠더 정체성)

  • Sin, Hye Lim;Joo, Susanna
    • Journal of Family Relations
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    • v.21 no.1
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    • pp.77-98
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    • 2016
  • Objectives: The aim of this study was to explore perceived meanings of dating and marriage among well-educated Korean couples who were in optimal marriageable ages. Particularly, an emphasis was placed on finding out where the traditional gender norms and post-modern contexts intersect on the couples' course of dating and marriage. Method: We undertook a qualitative analysis of 8 couples (age: 26-34) dating. Participants were limited to university graduates of upper-middle rank universities in Seoul, South Korea. The rationale for choosing such sample was based on the idea that characteristics of class is inherent in the act of dating and marriage, and that such characteristics lead to different contextual experiences in dating and marriage. This study was based on interviews conducted over a three-month time span. The interviews were first transcribed into research text and then subjects and key categories were drawn from the transcripts for analysis. Results: Participants sought meanings of joy, learning, and self-improvement in dating, and they were free from traditional gender norms in their romantic relationships. They viewed marriage as having a permanent companionship with their partner, becoming independent from their parents, and/or a social norm to be followed. Participants reported mixed perceptions about marriage in such fashion that they described their parents' relationship in terms of a gendered leader-supporter relationship, while viewing their own relationship as being genderless partners. In transition to parenthood, however, they regressed to traditional gender norms dichotomized as women being a homemaker and men being a breadwinner. In sum, participants displayed expectations that were inconsistent with regard to dating and marriage over the study period. That is, during the course of dating and early marriage, they did not hold separated gender norms; however, when transitioning from being a newly married couple to giving their first childbirth, expectations shifted to traditional gender norms and values. Conclusion: This suggests that it is not marriage, but the experience of childbirth and motherhood, which strengthen traditional gendered norms, engendering regeneration of the gender norms in families. The results indicate that there is a need to promote co-parenting behavior among the newly-married couples and to educate gender equality about parent roles or for parents in South Korea so that they can overcome traditional gendered norms in family.

Principle and Application of 'Image-mapping' in-situ U-Pb Carbonate Age-dating ('Image-mapping' in-situ U-Pb 탄산염광물 연대측정법의 원리 및 적용)

  • Ha Kim;Seongsik Hong;Chaewon Park;Jihye Oh;Jonguk Kim;Yungoo Song
    • Economic and Environmental Geology
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    • v.56 no.2
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    • pp.115-123
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    • 2023
  • We introduce a new 'image-mapping' in-situ U-Pb dating method using LA-ICP-MS, proposed by Drost et al. (2018), and show the characteristics and usability of this method through several examples of absolute age results determined by first applying it to samples from the Joseon Supergroup of the Early Paleozoic Era in Korea. Unlike the previous in-situ spot analysis, this in-situ U-Pb dating method for carbonate minerals can determine the absolute age with high reliability by applying the 'image-mapping' method of micro-sized domains based on micro-textural observation, as well as determine the absolute age of multiple geological 'events' that occurred after deposition. This was confirmed in the case of determining the syn-depositional age and the multiple post-depositional ages from carbonate minerals of the Makgol and the Daegi Formations. Therefore, if the 'image-mapping' in-situ U-Pb dating method is applied to determine the absolute age of various types of carbonate minerals that exist in various geological environments throughout the geologic era, it will be possible to secure new geological age information.

The Study of Absolute Dating on Jinju Janghungri Kiln site. (진주 장흥리 와요지 유적의 절대편년연구)

  • Yi, Hyeon-Ju;Kim, Dae-Wung;Hong, Jong-Ouk;Shim, Il-Wun
    • 보존과학연구
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    • s.26
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    • pp.189-202
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    • 2005
  • This study carried out to understand thermoluminescence dating of ancient tiles at Jinju Janghungri Kilin site. Also radiocarbon dating by the benzene synthesis method and Liquid scintillation counting method were performed for comparison for the agedetermination of charcoal sample at the obtained same site.1st and 2nd glow curve were obtained according to the typical method thermoluminescence. Plateau tests of revealed the proper temperature range to be $300~440^{\circ}C$ Palaeodose average values were formed to the 2.44Gy.Annual dose of ancient tiles was calculated from soil samples and ancient tiles it self by measuring alpha radiation dose, potassium concentrations and water contents respectively. Annual dose average values were calculated to be 7.012mGy/yr.The radiocarbon age(BP year) was converted to calibrated age(AD/BC year) using high precision curve. Radiocarbon ages were calculated to be AD 15~17 .Comparison of samples with their radiocarbon and thermoluminescence ages for revealed the in range the AD 15~17. This result means that the measured absolute ages are in good agreement with each other within the margin of error.

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