• The Korean Journal of Soil Zoology
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• v.1 no.1
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• pp.37-47
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• 1996

This research was carried out to investigate soil mictoarthropods fauna in Namsan and Kwangreung which were considered to receive different degreeds of environmental pressures. In basic environmental data, Namsan where under rather accelerated acidification by air contamination and acidic rain showed low pH, tardy decomposition and turnover rate. Population density of soil microarthropods was high in Kwangreung 17,169.8/\ulcorner\ulcorner(coniferous forests), 17,892.6/$\textrm{m}^2$(deciduous forests) than in Namsan, 12,143.8/$\textrm{m}^2$ (coniferous forests), 14,216$\textrm{m}^2$(deciduous forests). Biomass of soil microarthropods was 2,020.219mg/$\textrm{m}^2$ at coniferous forests and 4,270.172mg/$\textrm{m}^2$ at deciduous forests in Namsan, and 3,287.326mg/$\textrm{m}^2$ at coniferous forests and 4326.1mg/$\textrm{m}^2$ at deciduous forests in Kwangreung. Population density constantly showed high in spring, and seasonal fluctuations were correlated with seasonal precipitation. As far as vertical distribution is concerned, population density was concentrated in litter layer as 70% while 30% are in soil layer and also decreased with increasing depth.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1449-1454
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• 2013

There are many methods for measuring the difference between two location parameters. In this paper, statistics are proposed in order to estimate the difference of two location parameters. The statistics are designed not using the means, variances, signs and ranks, but with the cumulative distribution functions. Hence these are measured as the differences in the area between two univariate cumulative distribution functions. It is found that the difference in the area between two empirical cumulative distribution functions is the difference of two sample means, and its integral is also the difference of two population means.

• The Journal of the Korean Society for Microbiology
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• v.11 no.1
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• pp.87-91
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• 1976

It has been known that there are more than 50 species of mosquitoes in Korea but little study was done on distribution of summer mosquitoes species in Seoul. The author collected and investigated the species and seasonal distribution of mosquitoes in Seoul from 1967 to 1972. 1) The most abundant species of summer mosquitoe was A. vexans nipponii, $30{\sim}70%$ of total mosquito population. 2) The next abundant species was C. pipiens but there was wide frequencies according to different years. 3) C. tritaeniorhynchus, the vector of Japanese encephalities, was third in order, possesed about 9% of total mosquitoe population every year and reached peak in August and September. 4) It was found that there ware 7 species of mosquitoes commonly in Seoul City.

• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.139-145
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• 1999

The experiment was conducted to determine the effects of Plant growth and the microbial distribution in soils treated with microbial products, Mity-GroTM. The results from this experiment were as follows ; 1. Plant height of Tomato and Pepper were significantly increased at 30 days after planted in soils treated with Mity-GroTM. Therefore, treatment of microbial products, Mity-GroTM, was considered to contribute the plant growth at early stage. 2. Microbial distribution in soils treated with Mity-GroTM was significantly changed at specific mcirobial population. However, The ratio of bacteria/actinomycetes in the plot treated with Mity-GroTM was significantly enhanced.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.123-124
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• 1996

Snapshots of eight SA and standard fields from low to high galactic latitudes were made using the KPNO 0.9m 2K $\times$ 2K CCD with a limiting magnitude from 19 to 22.5. The purpose of this study is to determine the vertical distribution of stars with respect to Galactic latitude and z-distance in comparison with the model simulation between intermediate population to the 'thick disk' component of scale height of a few kpc. Comparison of the preliminary results between observed and model simulation for 3 of the S fields shows good agreement both in V-mag and B- V color distributions. A bimodal distribution in B- V at high galactic latitude seems to be represented by a halo and 'thick disk' dwarf in the blue and by a normal disk dwarf population in the red.

• The Korean Journal of Applied Statistics
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• v.33 no.1
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• pp.11-23
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• 2020

Sampling design should provide statistics to meet a given accuracy while saving cost and time. However, a large number of non-responses are occurring due to the deterioration of survey circumstances, which significantly reduces the accuracy of the survey results. Non-responses occur for a variety of reasons. Chung and Shin (2017, 2019) and Min and Shin (2018) found that the accuracy of estimation is improved by removing the bias caused by non-response when the response rate is an exponential or linear function of variable of interests. For that case they assumed that the error of the super population model follows normal distribution. In this study, we proposed a non-response bias adjusted estimator in the case where the error of a super population model follows the gamma distribution or the log-normal distribution in a business survey. We confirmed the superiority of the proposed estimator through simulation studies.

• Journal of Environmental Health Sciences
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• v.47 no.4
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• pp.303-309
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• 2021

Background: Humidifier disinfectant is a biocidal product used in the water tanks of humidifiers to prevent the growth of microorganisms. Although there are a huge number of cases of reported humidifier disinfectant-related health effects across the entire Korean population, their numbers are distributed differently depending on the region. Objectives: This study aimed to investigate the regional distribution of enrollment cases who reported humidifier disinfectant-related health effects. Methods: This study used data on 6,240 subjects who experienced humidifier disinfectant-related health effects and who enrolled their cases which is conducted by the Korea Ministry of Environment. We examined the regional distribution of the enrolled cases based on sixteen administrative divisions and assessed the: 1) crude number; 2) proportional rate; and 3) age-standardized proportional rate of enrollment by region. Results: When we examined the crude number of enrollments by region, the highest number were in Gyeonggi-do Province (n=1,896), followed in order by Seoul (n=1,405), Incheon (n=436) Busan, Daegu, Gyeongsangnam-do Province, Daejeon, Chungcheongnam-do Province, Gyeongsangbuk-do Province, Jeollabuk-do Province, Gwangju, Chungcheongbuk-do Province, Gangwon-do Province, Jeollanam-do Province, Ulsan, and Jeju-do. When we examined proportional rate of the regional enrollment (cases per 100,000 population), Daejeon (n=16.2) was the region with the highest rate, followed in order by Gyeonggi-do Province (n=16.1), Incheon-do Province (n=15.9), Seoul, Daegu, Gwangju, Jeollabuk-do Province, Chungcheongnam-do Province, Busan, Chungcheongbuk-do Province, Gangwon-do Province, Gyeongsanbuk-do Province, Gyeongsangnam-do Province, Ulsan, Jeju-do, and Jeollanam-do Province, which is inconsistent with the order in terms of crude numbers. However, when we examined the age-standardized proportional rate of regional enrollment (cases per 100,000 population), their ranked distribution is consistent with the crude rate. Conclusions: This study observed that the regional distribution of the enrolled cases who reported humidifier disinfectant-related health effects is inconsistent with the regional distribution of the proportional rate of enrollment cases, which may be caused in part by the volume of the inherent population of each region.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1433-1436
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• 2016

Background: Cholangiocarcinoma (CCA), a major problem of health in Thailand, particularly in Northeastern and Northern regions, is generally incurable and rapidly lethal because of presentation in stage 3 or 4. Early diagnosis of stage 1 and 2 could allow better survival. Therefore, this study aimed to provide a distribution map of populations at risk for CCA in BuaYai district of Nakhon Ratchasima province, Northeast Thailand. Materials and Methods: A cross-sectional survey was carried out in 10 sub-districts and 122 villages, during June and November 2015. The populations at risk for CCA were screened using the Korat CCA verbal screening test (KCVST) and then risk areas were displayed by using Google map (GM). Results: A total of 11,435 individuals from a 26,198 population completed the KCVST. The majority had a low score of risk for CCA (1-4 points; 93.3%). High scores with 6, 7 and 8 points accounted for 1.20%, 0.13% and 0.02%. The population at risk was found frequently in sub-district municipalities, followed by sub-district administrative organization and town municipalities, (F=396.220, P-value=0.000). Distribution mapping comprised 11 layers: 1, district; 2, local administrative organization; 3, hospital; 4, KCVST opisthorchiasis; 5, KCVST praziquantel used; 6, KCVST cholelithiasis; 7, KCVST raw fish consumption; 8, KCVST alcohol consumption; 9, KCVST pesticide used; 10, KCVST relative family with CCA; and 11, KCVST naive northeastern people. Geovisual display is now available online. Conclusions: This study indicated that the population at high risk of CCA in Bua Yai district is low, therefore setting a zero model project is possible. Key success factors for disease prevention and control need further study. GM production is suitable for further CCA surveillance and monitoring of the population with a high risk score in this area.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.275-285
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• 2020

Background: In Korea, Symplocos prunifolia Siebold. & Zucc. is only found on Jeju Island. Conservation of the species is difficult because little is known about its distribution and natural habitat. The lack of research and survey data on the characteristics of native vegetation and distribution of this species means that there is insufficient information to guide the management and conservation of this species and related vegetation. Therefore, this study aims to identify the distribution and vegetation associated with S. prunifolia. Results: As a result of field investigations, it was confirmed that the native S. prunifolia communities were distributed in 4 areas located on the southern side of Mt. Halla and within the evergreen broad-leaved forest zones. Furthermore, these evergreen broad-leaved forest zones are themselves located in the warm temperate zone which are distributed along the valley sides at elevations between 318 and 461 m. S. prunifolia was only found on the south side of Mt. Halla, and mainly on south-facing slopes; however, small communities were found to be growing on northwest-facing slopes. It has been confirmed that S. prunifolia trees are rare but an important constituent species in the evergreen broad-leaved forest of Jeju. The mean importance percentage of S. prunifolia community was 48.84 for Castanopsis sieboldii, 17.79 for Quercus acuta, and 12.12 for Pinus thunbergii; S. prunifolia was the ninth most important species (2.6). Conclusions: S. prunifolia can be found growing along the natural streams of Jeju, where there is little anthropogenic influence and where the streams have caused soil disturbance through natural processes of erosion and deposition of sediments. Currently, the native area of S. prunifolia is about 3300 ㎡, which contains a confirmed population of 180 individual plants. As a result of these low population sizes, it places it in the category of an extremely endangered plant in Korea. In some native sites, the canopy of evergreen broad-leaved forest formed, but the frequency and coverage of species were not high. Negative factors that contributed to the low distribution of this species were factors such as lacking in shade tolerance, low fruiting rates, small native areas, and special habitats as well as requiring adequate stream disturbance. Presently, due to changes in climate, it is unclear whether this species will see an increase in its population and habitat area or whether it will remain as an endangered species within Korea. What is clear, however, is that the preservation of the present native habitats and population is extremely important if the population is to be maintained and expanded. It is also meaningful in terms of the stable conservation of biodiversity in Korea. Therefore, based on the results of this study, it is judged that a systematic evaluation for the preservation and conservation of the habitat and vegetation management method of S. prunifolia should be conducted.

• Asian Journal of Business Environment
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• v.9 no.4
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• pp.23-28
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• 2019

Purpose - With rapid population aging in Korea, changes in the population structure will result in a rise in the fiscal burden. This paper investigates the effects of population aging on fiscal spending based on Korea's province data and country panel data from the OECD. Research design, data, and methodology - We use province-level fiscal data from Local Finance Integrated Open System and the Korean Statistical Information Service and also collect country panel data from the OECD. To investigate the relationship between population aging and fiscal expenditures, our analysis uses the fixed effects model. Results - The empirical analysis based on Korean local finance and country panel data show that population aging has a positive impact on social welfare expenditures and it also has a positive impact on spending related to children and the elderly, implying that population aging may lead to an increase in fiscal spending via an increase in social welfare expenditures and spending related to children and the elderly. Conclusion - These empirical results suggest that countries like Korea that expect to experience rapid population aging need to pay more attention to prepare for the expected increase in age-related spending in the near future.