• The Korean Journal of Applied Statistics
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• v.31 no.4
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• pp.427-446
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• 2018

Korea will have a super-aged society within only 30 years according to the United Nations' definition of an aging society and the statistics on Korea's Population projections (2016), indicates that Korea has the fastest ageing speed in the world. There is a lack of data on long-term time-series data on death as related to pension and welfare policies compared to the rapid rate of aging. This paper estimates life expectancy over 245 years (from 1955 to 2200) through past and future forecasts as well as compares the expected life expectancy of the synthetic cohort and the real cohort. In addition, an international comparisons were made to understand the level of aging in Korea. Estimates of the back-projection period were compared with previous studies and the LC model to improve accuracy and objectivity. In addition, the predictions after 2016 reflected the declined mortality rate effect of Korea using the LC-ER model. The results showed an increase in life expectancy of about 30 years over 60 years (1955-2015) with an expected life expectancy of the real cohort over the second century (1955-2155) higher than the synthetic cohort. The comparative advantage of life expectancy of real cohorts was confirmed to be a common trend among comparative countries. In addition, Japan and Korea have a higher life expectancy and starting from 85 to 90 years old, all comparative countries show that the growth rate for the life expectancy of synthetic and real cohorts is less than previous years.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.2
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• pp.166-181
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• 2020

This paper attempts to compare and analyze the intensity, trend, and regional gap of income inequality, capitalizing upon the Age-Period-Cohort model which considers age, time and cohort effects, with the 1998-2018 Korea Labor Panel (KLIPS) survey data for respondents living in the Capital and Non-Capital Regions. The main analysis results are as follows. First, in the case of both cohort and age effects, those in their 50~60s, including the so-called baby boomers and '386 generation' living in the Capital Region, have relatively lower income inequality effect compared to that of other age groups and cohorts in the Non-Capital Region. Second, the micro-individual characteristics cannot be ignored to account for a regional gap in income inequality, but rather the effects of structural and institutional omitted variables and the social discrimination effects of individual characteristics variables are more significant in explaining it. Overall, intra-and inter-cohort income inequalities appear to overlap.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.456-460
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• 2005

The purpose of this study is to develop a estimation model of migration with only population data using the cohort-survival model which has been used for forecasting future population. The fluctuation of population can be bisected to the natural change which can be occurred by birth and death and the social change which means migration. The factors of the social change are usually very important for establishing rural policies. However, researches using migration data has limitations because the usage of them are restricted. For verifying a estimation model of migration, comparing estimated population in 2000 year and migration quantity between 1996 and 2000 of 25 gu with real values, using population data and death ratio from 1995 to 2000 of the 25 gu in Seoul. Result shows a reliable data that R-square of forecating population model is 0.9755 and migration is 0.9180. So these model are worth to estimate a population and migration quantity to restricted migration data.

• Journal of the Korean Geographical Society
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• v.46 no.2
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• pp.212-232
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• 2011

The main objective of this study is to establish a population projection method based on the biregional cohort-component method and to apply it to population projections for Busan. Some drawbacks of using the net migration cohort-component method in a regional or local level population projection are demonstrated. A biregional cohort-component method, a variant of the interregional cohort-component method, is established as an alternative where in-migration and out-migration are separately considered and then are combined to produce a projection for the migration component. Predicated on the established method, population projections for Busan are undertaken for the period of 2005~2030 under three different scenarios. Considerably different projection results are obtained between the net migration and biregional methods; among others, the trend of population decline is more severe in the former than in the latter. An investigation of the temporal trend of the projected population shows that the proposed method is highly reasonable. In conclusion, the proposed method based on the biregional cohort-component method seems not only to be theoretically more robust than the net migration cohort-component method but also to be very effective in the real world application.

• Journal of the Korean housing association
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• v.22 no.1
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• pp.11-23
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• 2011

The purpose of this study is to explore cohort changes in first-time homeownership in Korea. The study collected qualitative data from individual interviews to explore the housing trajectories of different birth cohorts. As a result, Individual interviews facilitated an exploration of the decision making process of first-time homeowner with in a cohort context. The cohorts born in the 1950s seek a sense of security through homeownership, and have strong Korean sentiments of ownership. They tried various means to buy a house, and real estate market boom at that time played a role in the driving force. The cohorts born in the 1960s have less insecurity of tenure than the previous cohorts, but they still feel the need for homeownership. Since the currency crisis in 1997 caused the fluctuation of housing price, the 1960s cohort experienced a dramatic decline and rebound of assets while the previous cohorts had experienced a steady rise in housing prices. Finally, the attitude towards housing in the group of 1970s cohorts has changed from ownershiporiented to use-oriented.

• Genomics & Informatics
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• v.13 no.3
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• pp.70-75
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• 2015

MicroRNAs (miRNAs) have been demonstrated to play an important role in carcinogenesis. Previous studies revealed that miRNAs are present in human plasma in a remarkably stable form that is protected from endogenous RNase activity. In this study, we measured the plasma expression levels of three miRNAs (miR-21, miR-27a, and miR-155) to investigate the usefulness of miRNAs for gastric cancer detection. We initially examined plasma miRNA expression levels in a screening cohort consisting of 15 patients with gastric cancer and 15 healthy controls from Korean population, using TaqMan quantitative real-time polymerase chain reaction. We observed that the expression level of miR-27a was significantly higher in patients with gastric cancer than in healthy controls, whereas the miR-21 and miR-155a expression levels were not significantly higher in the patients with gastric cancer. Therefore, we further validated the miR-27a expression level in 73 paired gastric cancer tissues and in a validation plasma cohort from 35 patients with gastric cancer and 35 healthy controls. In both the gastric cancer tissues and the validation plasma cohort, the miR-27a expression levels were significantly higher in patients with gastric cancer. Receiver-operator characteristic (ROC) analysis of the validation cohort, revealed an area under the ROC curve value of 0.70 with 75% sensitivity and 56% specificity in discriminating gastric cancer. Thus, the miR-27a expression level in plasma could be a useful biomarker for the diagnosis and/or prognosis of gastric cancer.

• Journal of Sasang Constitutional Medicine
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• v.34 no.1
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• pp.46-57
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• 2022

Background Adherence to healthy diet acts as a key role to modify sedentary lifestyle in real life setting. Constitution type of traditional Korean medicine has been prediagnosed to risk factors of cardiometabolic diseases. This study aims to evaluate the associations between body composition and healthy eating status in Korean adults by their constitution type. Methods Of 4046 participants from Korean Medicine Daejeon Citizen Cohort study, Korean Medicine Daejeon Citizen Cohort (KDCC) study were included for analysis. Demographic, health-related behaviors and Korean Medicine (KM) type were surveyed based on a general health-related questionnaire. Anthropometric measurements and dietary factors by using Korean Healthy Eating Index (KHEI) were assessed only in the half of the original participants. Results 50.8% of Taeeum was observed from eligible 1967 participants (66.7%, women). The highest KHEI score was observed in soyang group (52.0±0.3, p=0.006) compared to other two groups. In taeeum group, lower appendicular skeletal muscle mass (ASM)(%)(Taeeum: 38.7±0.1 vs. Soeum/Soyang: 39.2±0.1, p < 0.05), and higher percent of body fat (PBF)(%) (Taeeum: 32.9±0.2 vs. Soeum/Soyang: 29.0±0.2, p < 0.05) by the lowest tertile (T1) of the KHEI score, respectively. When the KHEI score increased by 1 point in taeeum group, a positive relationship was observed, which increased by 0.015% of ASM, however, a negatively related to in which body fat mass (BFM) decreased by 0.022 kg and PBF decreased by 0.024%. Conclusion Customized nutritional management is required that could help maintaining physical health and diet by their constitution type.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.571-573
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• 2004

Speaker verification systems based on multilayer perceptrons (MLPs) have good prospects in reliability and flexibility required as a successful authentication system. However, the poor learning speed of the error backpropagation (EBP) which is representative learning method of MLPs is the major defect to be complemented to achieve real-time user enrollments. In this paper, we implement an MLP-based speaker verification system and apply the existing two methods of the omitting patterns in instant learning (OIL) and the discriminative cohort speakers (DCS) to approach real-time enrollment. An evaluation of the system on a Korean speech database demonstrates the feasibility of the system as a speaker verification system of high performance.

• Journal of Advanced Navigation Technology
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• v.5 no.1
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• pp.1-10
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• 2001

Speech has a good characteristics of which car drivers busy to concern with miscellaneous operation can make use in convenient handling and manipulating of devices. By utilizing this, this works proposes a speaker verification method for protecting cars from being stolen and identifying a person trying to access critical on-line services. In this, continuant phonemes recognition which uses language information of speech and MLP(mult-layer perceptron) which has some advantages against previous stochastic methods are adopted. The recognition method, though, involves huge computation amount for learning, so it is somewhat difficult to adopt this in speaker verification application in which speakers should enroll themselves at real time. To relieve this problem, this works presents a solution that introduces speaker cohort models from speaker verification score normalization technique established before, dividing background speakers into small cohorts in advance. As a result, this enables computation burden to be reduced through classifying the enrolling speaker into one of those cohorts and going through enrollment for only that cohort.

• Journal of Korean Medicine Rehabilitation
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• v.27 no.3
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• pp.117-124
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• 2017

Objectives Collaboration medicine means cooperate with western medicine and traditional korean medicine to treat the one disease. In Korea, Interest in collaboration medicine is increasing, But the number of studies is scare. Therefore we will conduct collaboration medicine study for the low back pain. Methods This study composes prospective cohort registry study. If the patients who need collaboration medicine by doctor come, we will ask regist this study. And patient select collaboration treatment group and single treatment group. Total 120 patients will recruit from collaboration pilot project hospitals. Each group patient will observed 4 weeks. Telephone research will conducted after 1 month from the last follow up. During the treatment, patients are treated usual treatment type of each medicine. Primary outcome is NRS and secondary outcomes are EQ-5D and ODI. We will analyze difference of 1 week and 4 week outcome result. Conclusions This study is the first large sample size study effect of collaboration medicine in Korea for low back pain. We check present collaboration system and improve collaboration system. Aim of this study is to find the effectiveness collaboration medicine for low back pain in the real condition. And we expect this pilot study will provide the clinical collaboration information and basis.