• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3229-3232
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• 2012

In this study, cancer incidence data were assessed to provide various rates of five year age groups for a given year, lying between two census years. The individual exponential growth rate method is most useful in both population-based and non-population cased cancer registries in India to estimate the population by five yearly age groups and also find the rates of crude rates, age standard rates and cumulative rates. This method has been shown to endure from bias and often results sacrificing the overall growth rate and correction factor must be needful in five year age group population to maintain it. A second method, the difference distribution method is also able to maintain the overall growth rate and overcome the bias in estimation of five yearly age group populations. From this point of view these methods serving a new technique for population estimation by five yearly age groups for inter census years.

• Economic Analysis
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• v.26 no.1
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• pp.133-166
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• 2020

Since the mid-1990s, Korea has been aging rapidly. At the same time, real interest rates have declined sharply. This paper studies whether population aging has contributed to the real interest rate decrease in Korea. We first present empirical evidence that increases in life expectancy and the old-age-dependency ratio, and a fall in population growth, i.e., the population aging, decrease real interest rates. Then we calibrate a life-cycle model to capture the features of the old-age-dependency ratio and population growth in Korea, and show that population aging accounts for about one third of the fall in real interest rates between 1995 and 2018. Furthermore, according to simulation results, increased life expectancy is more important than decreased population growth in affecting the real interest rate decrease during the period.

• Ocean Science Journal
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• v.41 no.4
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• pp.211-219
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• 2006

A comparison was made of population of the economically important cockle Anadara (=Scapharca) broughtoni (Bivalvia, Arcidae) inhabiting different areas of the Razdolnaya River estuary at the head of Amurskii Bay (Peter the Great Gulf, East Sea). Also, changes in cockle population density and structure, as well as in cockle growth rates during the last 20 years were studied. In all years of investigation, the morphometrical parameters and growth rates of cockles were smaller at the sites located close to the River mouth than farther down-estuary. The differences can be attributed to higher concentration of suspended particulate matter, decreased salinity and water temperature, as well as a longer exposure to these unfavorable environmental factors at sites located close to the River mouth, compared to farther sites. For two decades, cockle population density had decreased by almost 30 times at some sites in the River estuary. The main reason for this population decline is commercial over-fishing of the cockle. Besides, for the last 20 years, linear parameters of the cockles in the population decreased approximately by 30% and weight parameters, almost two times. Cockle growth rates also decreased for this period. Evidently, these facts are due to the damaging effect of dredging.

• Journal of Plant Biology
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• v.18 no.3
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• pp.101-108
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• 1975

The nitrogen economy and primary production of a Helianthus annuus "Manchurian" population were studied with special reference to the pattern of seasonal changes of vertical distributions of dry matter and nitrogen quantities, and its quantitative significance was discussed in relation to the pattern of the plant population growth, distribution ratios among organs, and turnover rates of dry matter and nitrogen. The population was established in plant density of 11.1plant/$m^2$ at the experimdntal field of Kyungpook National University, Daegu. During the period of population developemnt (April-September, 1973), the annual inflow rates and outflow rates of dry matter and nitrogen were 5560 gDM/$m^2$/year and 89 gN/$m^2$/year, respectively. The distribution ratios of dry matter and nitrogen to leaves were 28% and 45%, to stems 48% and 18%, to roots 13% and 5%, and to flowers and seeds 11% and 32%, respectively. The maximum turnover rates of inflow of dry matter and nitrogen were attained in May-June, and were 216%/month and 210%/month, respectively. The amount of nitrogen demand was 52gN/$m^2$/year (58%) for the foliage growth, 13 gN/$m^2$/year(15%) for the stem growth, 20 gN/$m^2$/year(23%) for the reproductive organs, and 4 gN/$m^2$/year(4%) for the growth of the underground parts. The amount of nitrogen supply by the nitrogen withdrawn from senescing leaves and stems was 25gN/$m^2$/year(28%) and the amount of nitrogen absorption by the root from the environmental soil was 64 gN/$m^2$/year(72%). The ratiio of the a mount of produced dry matter to that of assimilated nitrogen during a year was calculated for this annual plant population as 60, which can be used as the nitrogen utility index.ity index.

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.319-324
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• 2007

To investigate the impacts of transgenic rice on freshwater organisms, we conducted two life table experiments using Daphnia magna for fifteen and twenty days, respectively. We examined life history traits such as population growth rates (r), reproductive rates ($R_0$), generation times, and survivorship. In the first experiment, we used non-drought-stressed transgenic and non-transgenic rice harvested in 2005. In the second study, we used non-transgenic and transgenic rice harvested in 2006 following drought stress. Each experiment involved three treatments in which D. magna neonates were fed with Selenastrum capricornutum (control treatment) and S. capricornutum with 5% aqueous extracts of non-transgenic rice (N-T) and transgenic rice (T). In the first experiment, D. magna showed reduced population growth rates and lowered fecundity in the N-T and T treatments. In the second experiment, D. magna receiving both transgenic and non-transgenic rice extracts showed very high mortality, low population growth rates and reproduction rates. We could not detect any significant negative effects of extracts from transgenic rice on D. magna life history traits at 95%.

• Korea journal of population studies
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• v.10 no.2
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• pp.82-98
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• 1987

The urban population in Asia more than doubled between 1960 and 1985, growing by 3.0 percent per annum on average. Yet during that period, the proportion of the total population living in urban areas increased only from 21 to 27 percent. This seeming paradox is explained by the relatively high rates of rural population growth in Asia, which averaged 1.8 percent over the same period. The Republic of Korea has experienced the most rapid rate of urbanization in Asia during the past century. The proportion urban jumped from 28 percent in 1960 to 65 percent in 1985. There is a clear association between economic growth and the pace of urbanization in Asia. Currently natural increase accounts for about 60 percent of urban growth, but the speed of urbanization is projected to increase after 1990, and migration, reclassification and annexation will comprise about half of urban growth, Seoul is currently the fourth largest urban agglomeration in Asia, and its population is projected to be over 13 million by the end of the century. It is argued that policies to deconcentrate urban population will not be generally successful in Asia and that governments should attempt to manage the growth of large metropolitan areas more efficiently.

• The Korean Journal of Ecology
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• v.26 no.2
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• pp.82-86
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• 2003

We investigated the variation in adaptation to growth for four ecotypically-differentiated population of Taraxacum officinale found naturally in temporal environmental heterogeneity. Seeds collected from the four seasons were germinated in incubators and were grown for four months in greenhouse to test genetic variation among biotypes. Biotypes, segregated by seeds collected seasonally, were the part of natural population in Mokpo, South Korea. Each biotype was different in total dry weight of seeds, biomass, and leaf area, confirming previous finding. Differences between biotypes grown under a common environment indicated a genetic basis to their distinct demographic rates. Therefore, biotypes with similar annual rates of growth and contrasting seasonal rates should persist in the population. This differential response suggests that temporal variation in environment may be responsible, in part, for the maintenance of genetic variation within populations.

• Korea journal of population studies
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• v.12 no.1
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• pp.74-85
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• 1989

Ascertaining the actual growth rate of the population is an issue that has generated a lot of arguments amongst various scholars in the process of determining the actual census count. As such, this has had a pronounced effect in the determination of the actual growth rates for different urban populations in the country. But the effect centres much when it comes to accurately determining the major components or the factors contributing to the rapid growth of urban populations. The problem of rapid population growth centres much on its effects on the available basic social services and amenities provided for the people in these areas. Factors such as levels of medical knowledge and services, nutrition, quantity and quality of housing etc. to some extent influence the quality and duration of lives of the people. As such, their importance cannot be overemphasized when dealing with the issue of population growth. The study aims to examine the rate of population growth in the Federal Capital City, Abuja with respect to the available public provision of basic social services among other objectives. The findings from the data obtained from the Population Survey conducted in the city in 1985 show that the health care facilities available in the capital city are grossly inadequate to serve the entire inhabitants of the city. Moreso, the volume of in-migration into the city also compounds the health problems facing the city. The conclusion is that there is need for more resources to be allocated to the health sector to guarantee adequate and functional health care services in the city.

• The Journal of the Petrological Society of Korea
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• v.5 no.2
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• pp.161-167
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• 1996

The CSD (crystal size distribution) of diopside crystals in the calc-silicate hornfels of the Hwanggangni Formation intruded by the Cretaceous Daeyasan granite shows the patterns of continuous nucleation and growth. There is correlation between the distance from the intrusion contact and the slopes from the linear part of log(population density) vs. size diagrams. In the log(population density) vs. size diagrams of the samples systematically collected from the intrusion contact, two different groups are recognized; the slopes for the samples near the intrusion contact (horizontal distance from the contact less than 50m) are gentler (1500$cm^{-1}$) than those for the samples away from the intrusion contact (2500$cm^{-1}$, distance from the contact greater than 100 m). These differences may reflect the differences in growth rates and crystallization time, or the differences in diopside-forming reactions. All of the log(population density) vs. size diagrams show depletion of smaller crystals. The observed depletion may be due to Ostwald ripening or the changes in nucleation rates as the reactant phases diminishes. Similar grouping is also possible for the observed degree of depletion of smaller crystals; the depletion decreases with increasing distance from the intrusion contact, suggesting temperature-dependent rates of Ostwald ripening.

• ALGAE
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• v.26 no.1
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• pp.73-77
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• 2011

A dominant planktonic bloom-forming species, Mallomonas elongata was isolated from a small shallow eutrophic pond. The growth characteristics of this species on variable silicate concentrations and light intensities were investigated in laboratory unialgal cultures. In culture condition of $15^{\circ}C$, the maximum population growth and the highest growth rate of M. elongata occurred at a light intensity of $80\;{\mu}mol\;m^{-2}s^{-1}$, and in culture condition of $18^{\circ}C$, it exhibited the maximum population growth and the highest growth rates at a light intensity of $50\;{\mu}mol\;m^{-2}s^{-1}$. Silicate concentration had no effect on the population growth and growth rate of M. elongata.