• The Korean Journal of Zoology
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• v.21 no.1
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• pp.19-27
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• 1978

This study has been carried out with the object of researching into the situation of the genetic isolation of a Korean population located near Seoul. The results obtained are summarized as follows: In general, the distribution of P.T.C. threshold values in the population is close to that of the Seoul population. But the nonataster frequency of male in the population is higher than that of female, and this is in agreement with the status of ankyloglossia frequency in male. However the relationship between the two traits has not been clarified. The gene frequencies of rolling and folding of tongue are slightly lower than that of the Seoul population. The gene frequency conditioning the ability to twist the tongue is lower in the male than in the female. The color-blindness is 6.21 percent, and it is slightly higher than that of other Korean population. All considered, the studied population might be regarded to have been kept in genetic isolation.

• Journal of Integrative Natural Science
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• v.15 no.1
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• pp.9-18
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• 2022

This research examines the power of bootstrap two-sample test, and compares it with the powers of two-sample t-test and Wilcoxon rank sum test, through simulation. For simulation work, a positively skewed and heavy tailed distribution was selected as a population distribution, the chi-square distributions with three degrees of freedom, χ²₃. For two independent samples, the fist sample was selected from χ²₃. The second sample was selected independently from the same χ²₃ as the first sample, and calculated d+ax for each sampled value x, a randomly selected value from χ²₃. The d in d+ax has from 0 to 5 by 0.5 interval, and the a has from 1.0 to 1.5 by 0.1 interval. The powers of three methods were evaluated for the sample sizes 10,20,30,40,50. The null hypothesis was the two population medians being equal for Bootstrap two-sample test and Wilcoxon rank sum test, and the two population means being equal for the two-sample t-test. The powers were obtained using r program language; wilcox.test() in r base package for Wilcoxon rank sum test, t.test() in r base package for the two-sample t-test, boot.two.bca() in r wBoot pacakge for the bootstrap two-sample test. Simulation results show that the power of Wilcoxon rank sum test is the best for all 330 (n,a,d) combinations and the power of two-sample t-test comes next, and the power of bootstrap two-sample comes last. As the results, it can be recommended to use the classic inference methods if there are widely accepted and used methods, in terms of time, costs, sometimes power.

• Communications for Statistical Applications and Methods
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• v.11 no.3
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• pp.513-518
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• 2004

The well-known mode-mean-median inequality for the unimodal population distribution does not always hold for the frequency distribution. But many elementary statistics text books just mention that the relative location of the mean and median can be used to determine whether a distribution is positively or negatively skewed. In this paper we introduce the method generating data that is positively skewed but mean

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.464-469
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• 2013

After city of Busan has been entered to the aging society in 2000, the city has the highest aging rate among 7 representative cities in 2011. Moreover, while entire population and number of average household are decreasing, over 65 years old of elderly population is rapidly increasing. So, it is possible to enter the super-aged society, where aging rate would be about 20% after 2020. The purpose of this study is that older housing-related analysis is consisted of dong-unit, and this led microscopic analysis has become necessary. Surveys from 2000 through 2010, census aggregate (output area) unit of spatial analysis was conducted. Take advantages of this, aging population and area, soaring area, high-density areas, such as the region of interest were primary extracted, and microscopic location and spatial distribution patterns were analyzed. Upon analysis, aging population is concentrated in the city and adjacent area, the highlands, and 10 years of increasing rate was more than 30 times in certain aggregate. Regarding the characteristic of these areas, the original city center, Busan, especially concentrated and intensified in aging population. Also, 2000 to 2010, the overall distribution pattern of Busan has identified aging population that is increasingly being distributed. This is the result, which is confronted with previous research result. Entering a super aged-society for the future is accordance with migration of social costs and improve the quality of life of elderly. And this could be the basic information to use the spatial dimension for the corresponding.

• Journal of Distribution Science
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• v.17 no.4
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• pp.77-85
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• 2019

Purpose - Statistics of Traditional Market is the only source of information on traditional markets, shopping street, and underground shopping street. The government conducts a survey of traditional market conditions every year to look at the current status of traditional markets and provide effective support. Therefore, this study examines the necessity and validity of updating about the Survey Population of Traditional Market Research design, data, and methodology - This study investigated the necessity of updating about the Survey Population of Traditional Market through literature review. Therefore this study examined the necessity of the current population based on the review of the population related to the sample design, methods, and the sampling frame. Next, we examined the change patterns of the population and the sample by dividing the population and sample of the current survey of the traditional market survey into the market unit, the store unit within the market, and finally the individual store unit. Results - As a result, the population of traditional market changes about 4~6%. Next, the analysis of the store unit in the market shows that the number of stores is very variable even though the market is continuously included in the survey target. Finally, as a result of examining the characteristics of individual stores, the stores with less than one year were more than 6% of the total surveyed stores based on the traditional market. These results are generally inconsistent with the idea that stores in traditional markets will operate for a long time in one place. Next, we proposed the establishment of a management system, applying Citizen Generated Data, and circulation survey. Additionally, this study proposes to change the stratification variables at the regional level rather than the market unit. Conclusions - Therefore, in this study, it is suggested that a current population of traditional market is needed updating, and that a population survey should be updated at least four years. In addition, a system for investigating traditional markets and districts was established and a circulation survey was proposed for efficient use of budgets. Based on these research results and policy suggestions, the future research directions are suggested.

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.18-26
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• 2020

Echinosophora koreensis (Nakai) Nakai an endemic plant with limited distribution in some parts of the Korean Peninsula, is designated as "Endangered" species on the IUCN Red List. The species is under the threat of deterioration in nature due to various environmental changes causing loss of natural habitats. We investigated the distribution pattern and population structure of E. koreensis to serve as a basic reference for identifying the dynamics and persistence of natural populations of this species in the future. To determine the characteristics of the E. koreensis population, we laid two to three large plots sized 20m×30m on the ridgeline as the reference in Yanggu, Chuncheon, and Hongcheon and laid four to seven small quadrats sized 1m×1m on the transect. A total of 530 plots were laid, 10 each at 2m interval, to measure the number of the stems, the number of fruiting, height, and other factors. The collected distribution information was compared with the existing IUCN assessed categories by applying IUCN Red List ver 3.1 Criteria B. The average population density of the three surveyed areas was 3.47 stem/㎡; the density of each area was 3.95 stems/㎡ in Yanggu, 3.37 stems/㎡ in Chuncheon, and 2.87 stems/㎡ in Hongcheon. The number of fruiting per stem was 0.0038, indicating only 7 fruits out of 1,837 stems and that vegetative reproduction is likely to be more dominant than sexual reproduction. The distribution tendency of population density in the small plots in three surveyed areas showed that the density of E. koreensis tended to decrease toward the center of the forest with low crown openness and around the mountain ridge with high crown openness. It indicated that the quantity of light could be a very important factor for the growth of individuals of this species. The analysis of the heights of individuals present in the surveyed plots showed a range of 2.3 ~ 68.5cm and an average of 20.1cm. An analysis on the stage-structure of the E. koreensis population based on the sieve height found that the appearance frequency decreased with increasing height above 15 ~ 20cm and that the percentage of individuals lower than 10cm, which were presumed to be seedlings, was severely low, indicating a necessity of study on the population sustainability based on the monitored data. The occupied area calculated with the collected species distribution information was 200㎢, indicating the EN category according to the IUCN Red List Reference B.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.116-124
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• 2022

In this study, waste air containing ethanol and hydrogen sulfide, was treated by an integrated hybrid system composed of two alternatively-operating UV/photocatalytic reactor-process and biofilter processes of a biofilter system having two units with an improved design (R reactor) and a conventional biofilter (L reactor). Both a pressure drop (△p) per unit process of the integrated hybrid system and a microbe-population-distribution of each biofilter process were observed. The △p of the UV/photocatalytic reactor process turned out very negligible. The △p of the L reactor was observed to increase continuously to 4.0~5.0 mmH₂O (i.e., 5.0~6.25 mmH₂O/m). In case of R reactor, its △p showed the one below ca. 16~20% of the △p of the L reactor. Adopting such microbes-carrying biofilter media with high porosity as waste-tire crumb media, and the improved biofilter design, contributed to △p of this study, reduced by ca. 37~50% and 40~53%, respectively, from the reported △p of conventional biofilter packed with biofilter media of the mixture (50:50) of wood chip and wood bark. In addition, the △p of R reactor in this study, reduced by ca. 80% from the reported △p of conventional biofilter packed with biofilter media of the mixture (75:25) of scoria with high porosity and compost, was mainly attributed to adopting the improved biofilter design. On the other hand, in case of L reactor, the CFU counts in its lowest column was analyzed double as much as those in any other columns. However, in case of R reactor, its CFU counts were bigger by 50% than the one of L reactor and its microbes were evenly distributed at its higher and lower columns of R_dn reactor and R_up reactor. This phenomena was attributed to an even moisture distribution of 50~55% of R reactor at its higher and lower columns. Therefore, R reactor showed superb characteristics in terms of both △p and microbe-population-distribution, compared to L reactor.

• School Mathematics
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• v.12 no.3
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• pp.273-299
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• 2010

The purpose of the study is designing and implementing 'Sampling Distributions Simulation' to help students to understand concepts of sampling distributions. This computer simulation is developed to help students understand sampling distributions more easily. 'Sampling Distributions Simulation' consists of 4 sessions. 'The first session - Confidence level and confidence intervals - includes checking if the intended confidence level is actually achieved by the real relative frequency for the obtained sample confidence intervals containing population mean. This will give the students clearer idea about confidence level and confidence intervals in addition to the role of sampling distribution of the sample means among those. 'The second session - Sampling Distributions - helps understand sampling distribution of the sample means, through the simulation method to make comparison between the histogram of sampling distributions and that of the population. The third session - The Central Limit Theorem - includes calculating the means of the samples taken from a population which follows a uniform distribution or follows a Bernoulli distribution and then making the histograms of those means. This will provides comprehension of the central limit theorem, which mentions about the sampling distribution of the sample means when the sample size is very large. The forth session - the normal approximation to the binomial distribution - helps understand the normal approximation to the binomial distribution as an alternative version of central limit theorem. With the practical usage of the shareware 'Sampling Distributions Simulation', we expect students to have a new vision on the sampling distribution and to get more emphasis on it. With the sound understandings on the sampling distributions, more accurate and profound statistical inferences are expected. And the role of the sampling distribution in the inferences should be more deeply appreciated.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.337.2-337
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• 1995

No Abstract, See Full Text

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.2
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• pp.1-16
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• 2020

The current status of geographical distribution range of Deutzia paniculata, one of the korean endemic plants, was investigated based on the species distribution information. The information of the geographical range used for analysis includes all the published references to the distribution of D. paniculata, herbarium specimens in Korea National Arboretum (KH) including its online database: http://www.nature.go.kr, and field research. Although, D. paniculata was firstly recorded in Wonsan, Hamgyeongnam-do, North Korea, this research revelaved that D. paniculata is mainly distributed in Gyeongsangbuk-do and Gyeongsangnam-do, southern regions of the Korean Peninsula. According to the distribution map, this species was estimated on distribution edge of in Anyang region of Gyeonggi-do, Mt. Naejang of Jeollabuk-do and Mt. Taebaek of Gwangwon-do on the distribution edge. However, it was made use of intensive field survey to identify the natural population of the species in these regions. D. paniculata habitat was mainly distributed between 290 meters and 491 meters in altitude, but it was also found ranged from 936 to 959 meters in Gun-wi, Gyeongsangbuk-do, South Korea. The distribution slope was 5° to 35° and the north, N, NE and NW in the aspect. The flora of vascular plants in D. paniculata habitats was listed in 137 taxa: 54 families, 103 genera, 120 species, 2 subspecies, 12 varieties and 3 forms while Korean endemic plants were found in three taxa, Stewartia koreana, Weigela subsessilis and D. Paniculata. Based on a collection of non-biological environment and biological environment data, D. paniculata population were discussed to make strategy and basic research methods for sustainable preservation.