• Journal of the Korean Statistical Society
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• v.5 no.2
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• pp.119-127
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• 1976

By examining Table 1, it is confirmed that the two model fertility scheduels for 1960 and 1975 are close agreement with the census data in Korea. The declines of age-specific fertility are more remarkable among older women than among younger, as exhibited in Table 3 and Fig. 2. A merit of this fitted model schedule as compared to fitted conventional frequency distributions such as the Pearson Type III curve, is that the model schedule incorporates combinations of intuitively understandable demographic factors. The value of m, a measure of fertility control, increased remarkably from 0.531 in 1960 to 2.429 in 1975. Considering the fact that the average value of m for forty-three schedules shown in the 1965 Demographic Yearbook was 1.0, and the value of m in England and Wales for 1965 was 1.91, the recent level of fertility control in Korea may be considered higher than generally believed.

• Communications for Statistical Applications and Methods
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• v.22 no.1
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• pp.11-14
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• 2015

The Great Famine may have had a continued impact on the population structure of North Korea even after the crisis subsided ten years ago. However, there is a significant gap between what has been said about the country and what data indicates. This gap seems inevitable mainly because reliable data are seriously lacking and access is restricted for most scholars outside the country. Yet, it is only reasonable to question why most studies have failed to explain the causality between the Great Famine and accumulated changes in the population of North Korea. In this regard, a recent study conducted by Korean demographers (Jeon et al., 2015) have several implications on the importance of accurate and reliable data when the study involves such rare and scarce information. This paper explores the changing trends of the population structure in North Korea providing a review of recent studies on demographic issues associated with North Korea and offers suggestions on understanding the post-famine effect on the overall changes in the population of North Korea.

• Communications for Statistical Applications and Methods
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• v.22 no.1
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• pp.15-18
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• 2015

Reunification, (considered a 'bonanza'), is often expected to bring economic and social benefits as well as solutions to the population aging problem; consequently, the study on the population structure of North Korea is salient. This paper reviews and talks on the North Korean population and implications. In view of reliability and consistency, the North Korean population appears at an explicit change compared to the past, and shows significant differences from the South, implying that it needs significant resources to integrate during reunification. Therefore, it is opportune to discuss the North Korean population prior to the clamor for the reunification.

• Journal of Korean Society of Transportation
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• v.13 no.3
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• pp.5-17
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• 1995

One of interesting issues in urban land-use and transportation policy is about an unproven belief that imbalances between employment and residential sites strongly influence urban commuting patterns. The purpose of this study si to find how spatial distribution of jobs and housing affects commuting distances in Seoul Metropolitan Area using 1990 Census O-D Data. This study estimates cost-minimizing required commuting distance, given the actual distributions of jobs and housing , and compares required commuting distances with actual commuting distances. One of findings is that the standard urban economic theory explains only 1/3 of actual commuting in the case study area. The policy implication of this study is that jobs-housing balance policy will have only a minor effect on the actual commuting.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.4
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• pp.267-276
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• 2004

Much of previous attention on researches of the decision tree focuses on the splitting criteria and optimization of tree size. Nowadays the quantity of the data increase and relation of variables becomes very complex. And hence, this comes to have plenty number of unnecessary node and leaf. Consequently the confidence of the explanation and forecasting of the decision tree falls off. In this research report, we propose some decision tree algorithms considering the interaction of predictor variables. A generic algorithm, the k-1 Algorithm, dealing with the interaction with a combination of all predictor variable is presented. And then, the extended version k-k Algorithm which considers with the interaction every k-depth with a combination of some predictor variables. Also, we present an improved algorithm by introducing control parameter to the algorithms. The algorithms are tested by real field credit card data, census data, bank data, etc.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.73-81
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• 2012

For planning and developing rural regions, it is very important to understand and utilize regional characteristics including social, demographic, and economic aspects. The purpose of this study is to find effective analysis techniques and provide a procedure design for mining regional characteristics in South Korea through reviewing and analyzing 41 related studies. The engaged research methods can be classified into five categories (PCA+CA, PCA, CA, GIS, and PCA+GIS) with the combination of three methodologies: principal component analysis (PCA), cluster analysis (CA), and geographical information system (GIS). The combination of PCA and CA occupied about 40 % of research methods used in related studies. The analysis tool of Korean Rural Information Supporting System (KRISS) is designed based on the outcomes of this study and applied to classify the regional capacity of agriculture using agricultural census data (2000) for evaluating its applicability.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.225-236
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• 2000

To compile seasonally-adjusted statistics for Korean economic statistics accurately. it is necessary to develop a Korean seasonal adjustment program. In this paper. the Korean seasonal adjustment program BOK-X-12-ARIMA, developed through modification of the US. Bureau of the Census's X-12-ARIT\IA, is explained in detail.

• Animal Systematics, Evolution and Diversity
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• v.33 no.1
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• pp.37-44
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• 2017

The present census on freshwater bryozoans in the Han River, Geum River and in lentic water bodies in Gangwon Province revealed three gymnolaemate species. Two of them-Hislopia prolixa Hirose and Mawatari, 2011 and Victorella pavida Saville Kent, 1870 were recorded for the first time from South Korea. Paludicella articulata (Ehrenberg, 1831), on the other hand, had already been documented from a few sites since 1941. The bryozoans, all belonging to the order of Ctenostomata, were found on a variety of substrates in freshwater (H. prolixa and P. articulata) and brackish habitats (V. pavida). Hislopia prolixa had recently been established as a new species and this is the first record for an occurrence outside of Japan, where it had been newly described from Lake Biwa and nearby satellite lakes.

• Survey Research
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• v.11 no.2
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• pp.71-95
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• 2010

Base population, intercensal and postcensal population estimates, and population projections have been regularly published as official populations. Base population is usually made out based on census conducted every 5 or 10 years, and is most important from which intercensal, postcensal estimates, and population projections are derived. We investigate how base population in Korea is made out and then compare it with those of other countries. We also present problems arising from making out base population in Korea.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.41.1-41.1
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• 2014

Clusters of galaxies provide unique laboratories to study astrophysical processes on large scales, and are also important probes for cosmology. X-ray observations are still the best way to find and characterise clusters. The extended ROSAT-ESO flux-limited X-ray (REFLEX II) galaxy clusters form currently the largest well-defined and tested X-ray galaxy cluster sample, providing a census of the large-scale structure of the Universe out to redshifts of z-0.4. I will describe the properties of the survey and the X-ray luminosity function, which led to our recent cosmological constraints on omegaM-sigma8. They tighten the previous constraints from other X-ray experiments, showing good agreements with those from the Planck clusters, but some tension exists with the Planck CMB constraints. The second part of my talk will concern the structure of the local Universe, and the study of the first X-ray superclusters. The density of the clusters reveals an under-dense region in the nearby Universe, which has an interesting implication for the cosmological parameters. Using the X-ray superclusters, that are constructed with a physically motivated procedure, I will show environmental aspects that X-ray superclusters provide, and compare to cosmological N-body simulations.