• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1645-1654
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• 2007

The total methylotrophic population associated with rice plants from different cultivars was enumerated at three different stages: vegetative, flowering, and harvesting. The bacterial population in the leaf, rhizosphere soil, endophytic in the stem and roots, and epiphytic in the florets and grains were determined from four rice cultivars, Il-mi, Nam-pyeoung, O-dae, and Dong-jin, sampled from three different field sites. The methylotrophic bacteria isolated on AMS media containing 0.5% methanol as the sole carbon source uniformly showed three distinct morphologies, which were recorded as separate groups and their distribution among the various samples was determined using the ecophysiological index. The growth stage at the time of sampling had a more significant effect on the methylotrophic population and their distribution than the field site or cultivar. A similar effect was also observed for the PPFMs, where their population in different plant parts increased from V10 to R4 and then decreased towards stage R9. A canonical discriminant analysis of the PPFM population from different parts of rice showed clear variations among the cultivars, sampled sites, and growth stages, although the variations were more prominent among the growth stages.

• 한국인구학
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• 제8권1호
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• pp.65-86
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• 1985

Korean population is ecpected to reach about 50 million by year 2000. And per capita GNP might attain the $5,000 level. This is bound to have profound impact on housing. For one thing, population and income growth will accelerate new household formation thus increasing new housing needs. On the other, changes in the housing preference function in association with income growth and new way of life would mean increasing demand for better dwelling environment. In addition, by year 2000, there will be many more elderly households necessitating new approaches to housing. The question is whether or not Korea could cope with new housing perspectives. If Korean housing has made in the past some progress in housing quality, it has not been able to tackle the mounting housing shortage. This is attributable to the concentration of effective housing demand in the hands of upper income groups in association with skewed income distribution and sustained dwelling price hike. Korea needs some basic changes in housing policy. The public sector should produce much more small dwellings either for sales or renting. Second, mortgage loans should be expanded so as to increase the access to housing. Third, every thing must be done to cut down the dwelling price through tax cut, relaxation of some requlations, cyclical stabilization of dwelling construction and loan subsidies.

• ALGAE
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• 제18권4호
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• pp.289-294
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• 2003

The age growth pattern of Myagropsis mygroides (Cystoseiraceae, Phaeophyta)population were investigated at Tongyeong (128$^{\circ}$ 25' E and 34$^{\circ}$ 45' N) in South coast of Korea, from September 1998 to August 1999. Water temperatures varied from 7.7${^{\circ}C}$ to 26${^{\circ}C}$ during the survey period. Distinct seasonal changes were found in the plant legth and wet weight of plant, and their maximum length and wet weight were attained 70.5(${\pm}$ 20.9) cm and 191.8(${\pm}$ 135.0) g during April and May. The growth patterns were divided into four periods of slow growth (September-November), fast growth (December-February), maturing growth (March-May) and declining period (June-August). The Tongyeong population of M. myagroides was dominated by less than three-year old small plants with slower growth rates, shorter plant length, lighter plant weight than those of other locations in Korea.

• Food Science and Biotechnology
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• 제27권6호
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• pp.1865-1869
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• 2018

This study examined the effects of alfalfa seed germination on growth of Salmonella enterica. We investigated the population changes of S. enterica during early sprout development. We found that the population density of S. enterica, which was inoculated on alfalfa seeds was increased during sprout development under all experimental temperatures, whereas a significant reduction was observed when S. enterica was inoculated on fully germinated sprouts. To establish a model for predicting S. enterica growth during alfalfa sprout development, the kinetic growth data under isothermal conditions were collected and evaluated based on Baranyi model as a primary model for growth data. To elucidate the influence of temperature on S. enterica growth rates, three secondary models were compared and found that the Arrhenius-type model was more suitable than others. We believe that our model can be utilized to predict S. enterica behavior in alfalfa sprout and to conduct microbial risk assessments.

• The Journal of Asian Finance, Economics and Business
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• 제9권3호
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• pp.23-31
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• 2022

The study investigates the effect of trade openness on the economic growth of agricultural countries. The information of export, import, gross domestic product (GDP), Gross Fixed Capital Formation (GFCF), and population of 72 agrarian nations generated by the World Bank from 2011 until 2020 is used for data examination. Then, before panel data analysis, a preferred model is chosen from among common-effects, fixed-effects, and random effects. The best model turns out to be a fixed-effect model. The result reports that from 2011 to 2020; 16 out of 72 nations have succeeded in experiencing positive economic growth, the value of GFCF was US$ 2,859.04 billion, and later grew by 19 percent to US$ 3,393.73 billion, the population tends to increase continuously year by year, and 2 out of 72 countries experienced export plus import exceed their GDP. Moreover, trade openness is positively associated with economic growth, with a coefficient of 3.81. Besides that, an increase in GFCF may boost economic growth by approximately 3.32 percent. On the contrary, one percent additional population significantly delivers around 25.46 percent negative economic growth. To sum up, the higher intensity of products or services sold and bought abroad may enhance the economic performance.

• 한국약용작물학회지
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• 제13권5호
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• pp.254-261
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• 2005

To evaluate the effects of cultivar, environment, age and cultivation times on ginsenoside content among 8 wild populations of American ginseng (Panax quinquefolium), the concentrations of 6 ginsenosides in root were determined at the time of collection (T0) of plants from the wild and 1 year after (T1) transplanting the roots to each of two different forest garden locations. Both location and population had significant effects on root and shoot growth. Overall, ginsenoside Rb1 was most abundant. The second most abundant ginsenoside were Re and Rg1, however the contents of them were not significantly different from each other. Concentrations of Rg1 and Re were inversely related. Ginsenoside Re was influenced by population and location. Ginsenoside Rg1, Rb1, Rc, Rb2 and Rd were influenced by population, location and age. Ginsenoside levels were consistently lower but growth was consistently higher at the more intensively managed garden location.

• 대한수학회논문집
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• 제38권4호
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• pp.1163-1173
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• 2023

In this paper, we prove the Hyers-Ulam stability and Mittag-Leffler-Hyers-Ulam stability of a differential equation of Logistic growth in a population by applying Laplace transforms method.

• 한국항만경제학회지
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• 제17권2호
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• pp.61-87
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• 2001

The purpose of this paper is to analyze the location, population growth. and cargo concentration of Korean port-cities. In the location theory, Sommer (1976) and McGee (1967) models are newly introduced, as are the Rimmer (1967), Bird (1965), Hoyle (1981) models. which were already introduced in previous studies from Korea. Analysis of population growth in the Korean port-cities is conducted using data from 1966 to 1998. Rimmer and Hoyle's concentration models are used to measure cargo concentration from 1966 to 2000. The main results of this paper are as follows: First, Korean ports are concentrated on the East Sea, the Southern Sea, and the West Sea. Their locations are closely related with the hinterland. the inland city, and growth of port-cities. In considering the foreign countrys' cases, Korean port-cities are similar to the models of Bird and Hoyle. Second, the populations of Ulsan and Pohang grew at the fastest rate in 1966-1998, while the port cities in the Honam and Jeiu region grew at much lower ratios. Most port cities are located near large industrial complexes. Third the growth rates of Gwangyang, Daesan, Pohang, Pyungtaeg, and Samchunpo increased, while those of Busan. Mukho, Masan, Mogpo, Yeosu, and Sokcho declined. Of particular note, the growth rate of Busan remained negative after the late 1980s. Fourth. empirical results using the Rimmer (1967) model indicate that Gwangyang, Daesan, Pyungtag, and Pohang have shown the concentration. But the deconcentration was shown from the Busan, Mukho, Janghang, Gunsan, Mogpo, Yeosu, Masan, Sokcho. and Jeju. Fifth, the concentration of ports located in West coast region has shown the mixed results between concentration and deconcentration except the concentration of early 1970s and 1990s. The concentration of ports located in East coast region has shown the concentration before the middle of 1980s. And deconcentration after the middle of 1980s have appeared. The Southern coast region has shown the continuous deconcentration except the partial concentration of early 1986. and 1991. Planners of Korean ports should find out the factors of concentration and deconcentration of each ports and should determine factors such as investment priority level. size and scope in order to ensure the balanced development of regional ports and port-cities.

• Journal of Plant Biology
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• 제18권3호
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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.

• 대한한방소아과학회지
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• 제18권1호
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• pp.221-246
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• 2004

Objective: The purpose of this study was to investigate the effects of Kamikwiryongtang (KKT) on the immune response and growth in a young mouse (3 weeks mice). Methods The viability of thymocytes and splenocytes in vivo and in vitro system, the population of helper T (Th) cells and cytotoxic T (Tc) cells in thymocytes and increased the population of T-lymphocytes and the population of Th cells in splenocytes, the production of ${\gamma}$ -interferon, interleukin-2 and interleukin-4 in splenocytes was investigated. KKT (500mg/kg) was administerd p.o. once a day for 7 days. Results: KKT increased the viability of thymocytes and splenocytes in vivo, but did not affect the viability of thymocytes and enhanced the viability of splenocytes in vitro system. In addition, KKT did not affect the population of helper T (Th) cells and cytotoxic T (Tc) cells in thymocytes and increased the population of T -lymphocytes and the population of Th cells in splenocytes. Also, KKT increased the production of ${\gamma}$-interferon, interleukin-2 and interleukin-4 in splenocytes. Furthermore, KKT increased the production of nitric oxide in vivo, but did not affect the production of nitric oxide in vitro system. KKT enhanced the phagocytic activity of peritoneal macrophages in vivo, but decreased the phagocytic activity in vitro system: KKT increased the body weight of a young mouse. Conclusions: KKT stimulates the specific immune response via increase of, the viability of thymocytes and splenocytes and the non-specific immune response via increase of phagocytic activity of peritoneal macrophages and stimulates the growth of a young mouse.