• Journal of the Korean Geographical Society
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• v.49 no.5
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• pp.728-746
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• 2014

The purpose of this study is to analyze the influence of the selective migration of young age group and the stage migration which has proceeded through generations, on the transition of fertility and the population growth in the rural and urban in the case of Jeollabuk-do. For this, we use O-D matrix of 20-34 age group, the distribution of that group and women of child bearing age, and vital statistics in 1970-2010. The major findings of this study are as follows. First, the outflows from their birth place are common and dominant features of 20-34 age group in each time. Second, there is the stage migration which preceding generation moved from the rural areas to the cities in Jeollabuk-do and following generation has moved from the cities to Seoul metropolitan area. Third the selective outflow migration of young age group has leaded to reduction of the childbearing population, declining birthrate, aging and natural population decline. Due to the stage migration, these depopulation processes occurred in rural area in the past, and currently it expands to the cities with about 15 years time gap. In fact, there have been the natural population decrease which annual number of deaths exceed that of births from the late 1980s in the most rural areas and in the early 2000s, such a phenomenon has been confirmed also in urban areas. Therefore, this study concludes that the stage migration through generations is one of the crucial factor to the population growth in local cities and also brings out the step-wise population decrease in settlement hierarchies.

• Journal of Technology Innovation
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• v.31 no.2
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• pp.333-369
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• 2023

In this paper, the effect of government corporate support projects on corporate growth was analyzed, and the effect on corporate financial performance or non-financial performance was empirically analyzed by using the growth stage as a modulating variable in government support activities. As a result, it was analyzed that government corporate support had a significant effect on financial performance, non-financial performance, and use of government support, and that the moderating effect of the growth stage had a positive (+) effect on both financial and non-financial performance. Taken together, the research results showed that government corporate support had a positive effect on corporate performance, the growth stage had a positive (+) effect on both financial and non-financial performance, and the impact on financial performance was even greater. Accordingly, government support projects must be supported according to each company's growth stage, and during the decline, companies need to provide customized support according to the state of the company through industry and corporate analysis, and it is expected to be meaningful to improve the efficiency of the government's business support project.

• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.149-153
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• 2016

Objective : The aim of the present study is to estimate the incidence trend of head injury and the mortality based on traffic accident statistics and to investigate the impacts of rapid industrialization and economic growth on epidemiology of head injury in Korea over the period 1970-2012 including both pre-industrialized and post-industrialized stages. Methods : We collected data of head injury estimated from traffic accident statistics and seven hospital based reports to see incidence trends between 1970 and 2012. We also investigated the population structure and Gross National Income (GNI) per capita of Korea over the same period. The age specific data were investigated from 1992 to 2012. Results : The incidence of head injury gradually rose in the 1970s and the 1980s but stabilized until the 1990s with transient rise and then started to decline slowly in the 2000s. The mortality grew until 1991 but gradually declined ever since. However, the old age groups showed rather slight increase in both rates. The degree of decrease in the mortality has been more rapid than the incidence on head injury. Conclusion : In Korea during the low income stage, rapid industrialization cause considerable increase in the mortality and the incidence of head injury. During the high income stage, the incidence of head injury gradually declined and the mortality dropped more rapidly than the incidence due to preventive measures and satisfactory medical care. Nevertheless, the old age groups revealed rather slight increase in both rates owing to the large population structure and the declining birth rate.

• The Journal of Pediatrics of Korean Medicine
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• v.20 no.2
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• pp.101-114
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• 2006

Objective : In order to educate juveniles with proper sex education and to present advisable sexual culture among them, we researched the revelation age and duration period of secondary sex characteristics of 5th and 6th elementary student in Cheon-an, and compared them with their mother's case. Method : We did a survey among 5th and 6th grade elementary student in Cheon-an, which includes pictures presenting, different stages of breasts and pubic hair development. Results : Results show that in girls, average menarche age was 11.47 while the average of their mother's was 14.25. 3 years of decline was observed. On boys, average pubic hair development age was 11.42, similar to the average age of voice change, 11.43. Girls showed relatively earlier distribution of pubic hair manifestation age of 11.39, than in boys, which was 11.42. Concerning the sexual maturity, 99% of girls were over B2, while 43% of boys were over PH2. Almost all of the female participants manifested secondary sex characteristics, and half of them were in the stage of pubic hair development. Conclusion : We observed that the average age of manifesting secondary sex characteristic among elementary students is getting younger and especially, menarche age of young girls is significantly showing downward tendency compared to their mothers'. Sex education in elementary schools should be carried out considering the development stage of secondary sex characteristics among students.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.147-153
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• 2019

Recently, the perception of software education, which had been considered as a field of education for programmers in this field, is changing in response to recent changes with the trend of 4th industrial revolution. Major counties competitively invest in software education and the target age group for software education is also on the decline. However, the traditional text-based programing languages such as JAVA and Python, have a high entry barrier. To address the shortcoming, a variety of methods have been recently proposed for the effective software education for kindergarten and elementary school student. In this paper, we propose a robot-based coding education system with steps for coding education for effective software education. The proposed method is divided into three stages, depending on the level of the student being trained in the software coding education to interact with robots. The proposed stages consists of unplugged coding using a remote control, coding using a graphic-based programming language and text- based coding. We conducted an experiment with performing separate missions while providing propoer tutorials for each stage to verify the effectiveness of the proposed software education system.

• STI Policy Review
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• v.6 no.2
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• pp.1-23
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• 2015

This study aims to contribute to the debate over the age-productivity relationships in scientific and technological research. For this purpose, we conducted an empirical experiment employing a time-series cross-section dataset derived from the KRI of the NRF containing data on individual researchers of fifty major universities in Korea covering the period of 2008-2013. This study has found that: (1) there exists an inverse U-shaped age-productivity relationship at the level of individual researchers; (2) the impact of the average age of a research group on the productivity of individual researchers varies across fields; (3) male and female researchers move along different age-productivity curves; and (4) the inverse U-shaped age-productivity relationship also holds at the level of organizations. The results suggest that the aging of researchers in Korea will soon reach the stage where serious losses in research productivity become a reality. Yet, it is not so clear whether the observed decline in the performance of older researchers is due to declining cognitive capability, which is an unavoidable result of aging, or to declining motivation, which results from an institutional system that discourages older researchers' research activities (such as reduced access to research opportunities or mandatory retirement). What is clear is that it is inevitable for the Korean science system to change the current seniority- and age-based organizational system into one of higher adaptability.

• Research in Plant Disease
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• v.8 no.4
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• pp.245-249
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• 2002

Monosporascus cannonballus, a soilborne ascomycetes is recently described in Korea that causes root rot/vine decline of cucurbits. The effect of Monosporascus root rot disease on photosynthetic activity and growth was studied on oriental melon plants. At harvest stage, photosynthetic activity of diseased oriental melon plants was lower and stomatal resistance was higher than healthy plants, while xylem exudates were not observed in diseased plants. There was no difference in mineral contents of the leaves and stems between diseased and healthy plants. Leaf area, fresh and dry weights, and fruit weights of the plants were markedly decreased in diseased plants compared to those of healthy plants.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.343-350
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• 2016

Membrane distillation (MD) is a novel separation process that have drawn attention as an affordable alternative to conventional desalination processes. However, membrane fouling and pore wetting are issues to be addressed prior to widespread application of MD. In this study, the influence of ultrasonic irradiation on fouling and wetting of MD membranes was investigated for better understanding of the MD process. Experiments were carried out using a direct contact membrane distillation apparatus Colloidal silica was used as a model foulants in a synthetic seawater (35,000 mg/L NaCl solution). A vibrator was directed attached to membrane module to generate ultrasonic waves from 25 kHz (the highest energy) to 75 kHz (the lowest energy). Flux and TDS for the distillate water were continuously monitored. Results suggested that ultrasonic irradiation is effective to retard flux decline due to fouling only in the early stage of the MD operation. Moreover, wetting occurred by a long-term application of ultrasonic rradiation at 75 kHz. These results suggest that the conditions for ultrasonic irradiation should be carefully optimized to maximize fouling control and minimize pore wetting.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.355-358
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• 2015

We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group galaxy M33. The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The pulsating giant stars (AGB and red supergiants) are identified and their distributions are used to derive the star formation rate as a function of age. These stars are also important dust factories; we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry. The mass-loss rates are seen to increase with increasing strength of pulsation and with increasing bolometric luminosity. Low-mass stars lose most of their mass through stellar winds, but even super-AGB stars and red superginats lose ~40% of their mass via a dusty stellar wind. We construct a 2-D map of the mass-return rate, showing a radial decline but also local enhancements due to agglomerations of massive stars. By comparing the current star formation rate with total mass input to the ISM, we conclude that the star formation in the central regions of M33 can only be sustained if gas is accreted from further out in the disc or from circum-galactic regions.

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.17-24
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• 2008

The aim of this paper is to report our preliminary results of investigating the spatial focalization of Zen-meditation EEG (electroencephalograph) in alpha band (8-13 Hz). For comparison, the study involved two groups of subjects, practitioners (experimental group) and non-practitioners (control group). To extract EEG alpha rhythm, wavelet analysis was applied to multi-channel EEG signals. Normalized alpha-power vectors were then constructed from spatial distribution of alpha powers, that were classified by Fuzzy C-means based algorithm to explore various brain spatial characteristics during meditation (or, at rest). Optimal number of clusters was determined by correlation coefficients of the membership-value vectors of each cluster center. Our results show that, in the experimental group, the incidence of frontal alpha activity varied in accordance with the meditation stage. The results demonstrated three different spatiotemporal modules consisting with three distinctive meditation stages normally recognized by meditation practitioners. The frontal alpha activity in two groups decreased in different ways. Particularly, monotonic decline was observed in the control group, and the experimental group showed increasing results. The phenomenon might imply various mechanisms employed by meditation and relaxation in modulating parietal alpha.