• Communications for Statistical Applications and Methods
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• 제22권3호
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• pp.255-264
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• 2015

This paper addressed the problem of estimation of finite population mean in double sampling for stratification. This paper proposed a generalized ratio-cum-product type estimator of population mean. The bias and mean square error of the proposed estimator has been obtained upto the first degree of approximation. A particular member of the proposed generalized estimator was identified and studied from a comparison point of view. It is observed that the identified particular estimator is more efficient than usual unbiased estimator and Ige and Tripathi (1987) estimators. An empirical study was conducted in support of the theoretical findings.

• 한국연초학회지
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• 제3권2호
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• pp.115-122
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• 1981

Data for this study were obtained from Burley 21 (Nicotiana tabacum L.) grown under various densities on the field in 1978 and 1979 at the Jeonju Experiment Station, Korea Ginseng & Tobacco Research Institute. Interrelations between yield and its components were statistically studied by correlation, regression, and pathway analysis. Correlation of yield with plant population was significant and positive. Quadratic functions for yield vs. plant population and the length of the largest leaf were fitted to the data. Multiple recession equation between yield and its components (leaf number ($X_1$), a leaf area ($X_5$), weight per unit leaf area ($X_9$), plant population ($X_14$)), was significant at the 5% level. Measuring the relative importance of its components on yield, plant population was 49.5%, weight per unit leaf area 25.3%, a leaf 15.6%, and leaf number 9.8%.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3693-3696
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• 2010

We experimentally measure the kinetic energy and angular distributions of photoelectrons of $N_2$ as a function of 410 nm femtosecond laser intensity by using velocity map imaging technique. The strong-field multiphoton ionization of molecules shares many of the characteristics with those of atoms. Electron kinetic energies are nearly independent of laser intensities. The independence suggests that the electron peaks in the photoelectron spectrum actually result from a two-step process, indicative of the occurrence of real population in the intermediate states. The relative amplitudes of electron peaks indicate that in the two-step process, nonresonant population transfer dominates for low intensities, while resonant population transfer dominates for higher intensities.

• 한국환경복원기술학회지
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• 제24권5호
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• pp.25-34
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• 2021

Increase in avian species richness is one of the important issues of urban biodiversity policies, since it can promote diverse ecosystem services such as seed dispersal, education, and pollination. However, though human disturbance can significantly affect avian species richness, there are limited studies on the way to reflect the dynamics of floating population. Therefore, this study analyzed the spatial relationship between avian species richness, floating population, and vegetation cover using telecommunications information to identify the areas that requiring targeted monitoring and restoration action. Bivariate Local Moran's I was applied to identify LISA cluster map that showing representative biotopes, which reflect significant spatial relationship between species richness and population distribution. Edge density and distribution of ndvi were identified for evaluating relative adequacy of selected biotopes to strengthen the robust biodiversity network. This study offers insight to consider human disturbance in spatial context using innovative big data to increase the effectiveness of urban biodiversity measures.

• 한국인구학
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• 제13권1호
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• pp.37-50
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• 1990

본 논문에서는 인구이동과 소득분배의 관계를 분석하기 위하여 상대적 박탈감 개념을 적용한 인구 이동모형을 바탕으로 개인과 사회의 분배요소가 인구이동과 어떤 상호연관성을 갖는가를 이론적으로 검토하였다. 인구 이동으로 인한 개인의 상대적 박탈감의 변화는 이동자와 비이동자의 이동 이전과이후의 상대적 위치와 그들의 준거집단이 누구를 포함하는가에 따라 증가할수 있다. 또한 각 개인의 상대적 박탈감의 변화에 따라 사회적 소득분배는 인구이동으로 인하여 더욱 악화될수 있다는것을 논의하였다.

• 지역연구
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• 제9권1호
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• pp.45-63
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• 1993

University enrollment has long been regarded as one of the major factors inducing population concentration in Seoul and the Capital Region of Korea. Consequently, since early 1980's increases in enrollment and new establishments of extention universities beyond the boundary of Seoul, has been promoted, while university enrollment quota in Seoul has been strictly controlled. The degree of actual population dispersal, however, resulting from such a university enrollment policy has not been empirically tested. This paper aims at: First, identifying the trend of population growth and evolution process of the university enrollment policy in the Capital Region; Second, comparing the degree of influence of university enrollment on population concetration factors; Third, measuring actual effect of the enrollment control on population dispersal out of Seoul and the Capital Region. Major findings are as follows: First, only a week correlation between population and university enrollment growth trends was found; Second, the relative degree of influence on population concentration in the Capital Region, were order, in the order of magnitude, the physical amenity factor, the socio-cultural amenity factor, the employment climate factor and the educational factor. Third, and most improtant, based on the comparison of spatial distribution of graduated high schools and current residence of the selected university students, the gap between the two distributions was revealed and the inter-regional student population movement was estimated. The result shows that in Seoul's case about one-half of and in Kyunggi Province's case about one-fifth of university enrollment size, contributes to population concentration into Seoul. Fourth, as to the universities outside of the Capital Region, little effect in the case of universities located within the commuting distance, and a little effect on population dispersal in the case of universities located beyond commuting distance, were found. In sum, it seems clear that university enrollment policy in the Capital Region, especially in Inchon/Kyunggi Province has not been effective on student population dispersal out of Seoul and the Capital Region. Therefore, it is strongly recommended that university enrollment policy be throughly re-examined from its goal to the implementation means.

• Journal of Life Science
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• 제10권1호
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• pp.14-19
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• 2000

Variation at 25 allozyme loci in Korean wateralder (Alnus hirsuta Rupr.) from nine distinct populations was measured to estimate the amount and pattern of genetic diversity and population structure. The mean genetic diversity within population was 0.166. Korean alder populations have slightly high levels of genetic diversity compared to those present in associated temperature-zone species and two Canadian alder species. Among population s genetic differentiation accounted for an significant 9% of the total variation. High gene flow(Nm=2.63) was observed. Analysis of fixation indices, calculated for all polymorphic loci in each population, showed a substantial deficiency of heterozygotes relative to Hardy-Weinberg expectations. The mean GST value A. hirsuta in Korea (GST = 0.087) is similar to those of A. rogosa in Canada (GST = 0.052). These low values of GST in two countries. reflecting little spatial genetic differentiation, may indicate extensive gene flow (via pollen and/or seeds) and/or recent colonization. These factors reduce the effect of geographic isolation of breeding and the chance for genetic divergence. A pattern of increasing is observed with increasing rainfall per year. Regression analysis indicates that 54% (F = 4.67) of the variability observed can be explained by this relationship.

• The Plant Pathology Journal
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• 제15권4호
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• pp.158-161
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• 1999

We determined threshold environmental factros to initiate infection of pepper plants by Botrytis cinerea, a fungal pathogen of pepper gray mold, in two greenhouse conditions. A new efficient spore-trapping method was developed to estimate population density of airborne conidia in the greenhouses, and spore release was measured using a Kerssies' selective medium. At a given day, spores were released greater during daytime (mostly from 7:30 am to 10:30 am and at 4:30 pm) than nighttime. Diurnal and nocturnal temperatures in the greenhouse-1 were about $25^{\circ}$ and $17^{\circ}$,and relative humidity was 100% for prolonged 24 h due to rain on December 17, 1997. Population density of air-borne conidia was 3.0$\times$103 conidia/ $0.5\textrm{m}^3$ after two days, and the initial infection occurred in ten days. During the same period of time in the greenhouse-2, diurnal temperature was about $25^{\circ}$ and nocturnal temperature was below $15^{\circ}$, and population density of air-borne conidia was 104 conidia/ $0.5\textrm{m}^3$. Under these conditions, the initial infection started in three days. This indicates that the early infection occurs under which diurnal temperature is approximately $25^{\circ}$, nocturnal temperature is maintained below $15^{\circ}$, and population density of air-borne conidia is 104 conidia/ $0.5\textrm{m}^3$ at saturated relative humidity condition.

• 한국환경보건학회지
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• 제35권4호
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• pp.249-258
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• 2009

The objectives of this study were to compare the relative risk of all-cause mortality and cause-specific mortality associated with Asian dust events, and especially to investigate the effects on the susceptible population such as the elderly and children, which were based on the data in Seoul from 2000 to 2006. Both of the study periods with/without Asian dust days, respiratory-cause mortality was the highest, followed by cardiovascular-cause mortality and all-cause mortality in sequence among mortality related to air pollution for all-aged group. As to susceptible group, the relative risk of mortality is the highest for +65 yrs group among all-cause mortality. According to comparison of mortality with/without Asian dust days, the relative risk of all-cause mortality is larger in the model with Asian dust days than the one in the model without Asian dust days among all age group (except for under 15 yrs group) and all air pollutants. The relative risk of cause-specific mortality (except for ozone in under 15 yrs group in case of respiratory-cause mortality, and ozone in all age group and over 65 yrs group in case of cardiovascular-cause mortality) per IQR increase of each pollutant is larger in the model without Asian dust days.

• 한국환경과학회지
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• 제32권11호
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• pp.767-775
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• 2023

This study was conducted to lay the foundation for considering the qualitative aspects of environmental resources by calculating the weight of each environmental resource to calculate the total amount of environmental resources in Jeju. By comparing and analyzing the results of the expert survey conducted in 2011 and the results of the expert survey conducted in 2011 and 2022, changes in experts' perceptions and implications over time were derived. In addition, based on the results of the recent survey, the weight according to the relative importance was calculated to lay the foundation for calculating the total amount of environmental resources in Jeju. The results of this study are expected to provide basic data necessary for the successful institutionalization of the total environmental resource system by providing a scientific basis for the calculation of the total environmental resource. As a result of comparing the survey conducted in 2011 to the survey conducted in 2022 to establish a total environmental resource management plan in Jeju Special Self-Governing Province, there was a difference in the relative importance of the environmental resource category. Although the ranking between categories did not change, it was confirmed that the relative importance of the natural and local resource environment decreased and the relative importance of the living environment field increased significantly. Over time, the importance of plants and wildlife increased, the importance of landscapes and topographic geology decreased, the importance of wetlands and caves increased, and the importance of Gotjawal, natural monuments, and cultural history decreased. In the living environment category, the importance of water pollution increased significantly, and in the humanities and social environment category, the importance of population increased and the importance of industry decreased. It is judged that most changes in item importance are largely influenced by changes in the background of the times and overall perception. It was confirmed that the importance of plants, wildlife, wetlands, and caves with relatively high awareness and the importance of water pollution, which is emerging as a regional problem, have all increased significantly due to structural problems of population age.