• Child Health Nursing Research
• /
• v.26 no.4
• /
• pp.463-469
• /
• 2020

Reduction of the under-5 mortality rate is a target of the Sustainable Development Goals. Therefore, this study aimed to estimate under-5 child mortality rates in 52 low-migration countries using population data. The study utilized population data from the US Census Bureau from 1990 to 2015. The method involved first estimating mortality rates for countries with negligible net migration and then applying these rates to countries with matching mortality profiles, where it is reasonable to assume that migration is negligible for children under the age of 5 years. The highest child mortality was concentrated in the African region, followed by Asia and the Western region. However, steady progress in child mortality trends was concentrated in low-income countries. This simple method demonstrated that child mortality has significantly improved in high-income countries, followed by middle- and low-income countries. To reduce the under-5 mortality rates even further in these 52 countries, there is a need to accelerate equitable plans and policies related to child health to promote children's longevity and survival.

• Environmental Engineering Research
• /
• v.23 no.4
• /
• pp.406-419
• /
• 2018

In planning public service systems such as waterworks, the design population is very important factor. Owing to the limitations of the indirect method, two new models, which take into consideration urban characteristics, were developed to accurately predict external migration rate (EMR), which is an essential component in estimating reliably the design population. The root mean square error (RMSE) between the model values and observed values were 10.12 and 15.58 for the metropolitan cities and counties respectively and were lower compared to RMSE values of 27.31 and 28.79 obtained by the indirect method. Thus, the developed models provide a more accurate estimate of EMR than the indirect method. In addition, the major influencing factors for external migration in counties were development type, ageing index, number of businesses. On the other hand, the major influencing migration factors for cities were project scale, distance to city center, manufacturing size, population growth rate and residential environment. Future medium and long-term studies would be done to identify emerging trends to appropriately inform policy making.

• Journal of Environmental Science International
• /
• v.24 no.2
• /
• pp.229-236
• /
• 2015

In this study, the fish-migration ratios of rivers were analyzed, with the aim of proposing objective materials to help South Koreans to establish fish migration systems efficiently in the future. A total of 34,012 weirs have been built in the five major basins, with 5,081 fish-ways observed. Consequently, the fish migration ratio was considered low (14.9 %). According to the findings of the study analyzing the 5,081 fish-ways, standard-type fish-ways took up 68 % of the total while the non-standard types accounted for 32 %. The five major basins were observed to have a total fish-migration ratio of 21.4 %. Regarding tributaries, Tributary 1 accounted for 27.5 % of the fish-migration ratio, while Tributary 2 and 3 accounted for 19.8 % and 16.3 %, respectively. In conclusion, the study argues that any relevant field in the fishing industry of South Korea needs to improve their understanding of the fish-migration ratio. This would be expected, eventually, to help them maximize the efficiency of a minimum number of fish-ways. In addition, the study supports the need for those in relevant fields to study carefully the ecological needs of each fish species, before establishing priority standards for the building of fish-ways.

• Journal of the Korean association of regional geographers
• /
• v.15 no.5
• /
• pp.616-634
• /
• 2009

Criticizing the existing social science approaches to transnational migration for their ignorance of spatial perspectives and the resultant limits in the understanding of the concrete processes of international migration and settlement, this paper aims to examine how spatial perspectives and geographical epistemology can positively contribute to the understanding and conceptualization of transnational migration. In particular, it emphasizes that the processes of transnational migration cannot be solely understood in terms of 1) global capitalist restructuring and economic rationality, 2) the impacts of deterritoralized transnational networks, or 3) the operation of immigration regimes constructed at the national scale. Alternatively, this paper argues that the conceptualization of 'transnational space', which is based on the understanding of the socio-spatial dimensions - that is, place, territory, scale and networks - that affect the processes of transnational migration, could significantly contribute to the understanding of the transnational migration.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2004.11a
• /
• pp.32-32
• /
• 2004

• The Korean Journal of Applied Statistics
• /
• v.33 no.4
• /
• pp.421-437
• /
• 2020

This paper implemented a method to predict the fertility rate, mortality rate, and international migration rate using the R program, which has been widely used in recent years, that calculates population projection by substituting the results into the Leslie matrix. In particular, the generalization log gamma model for the fertility rate by Kaneko (2003), LC-ER model for mortality rate by Li et al. (2013), and functional data model for international migration rates proposed by Ramsay and Silverman (2005) and Hyndman and Booth (2008), Hyndman et al. (2013) can be directly demonstrated with R programs. Demography and bayesPop have been introduced as a representative demographic package implemented in R; however, it can be analyzed only for data uploaded to Human Mortality Database (HMD) and Human Fertility Database (HFD) with data changes and modifications requiring application of other data. In particular, in Korea, there is a limitation in applying this package because it is provided only for short-term data in HMD. This paper introduces an R program that can reflect this situation and the different patterns of low fertility, aging, migration of domestic and foreigners in Korea, and derives a population projection for the year 2117.

• International Journal of Concrete Structures and Materials
• /
• v.4 no.2
• /
• pp.105-108
• /
• 2010

In order to determine the effect of the use of limestone sand on chloride ion ingress in mortar, specimens were cast with two different sands: siliceous sand (used as reference) and limestone crushed sand (used for this study). To compare and assess the resistance of this mortar to chloride penetration, two different diffusions tests were employed: slow migration and rapid migration (AASHTO test). In this study, calculation of the effective diffusion coefficient is proposed using a model based on Nernst. Planck equation. The diffusion coefficients from each sample were compared. The results for all tests show that the diffusion coefficients for siliceous sand mortar are larger than those obtained with limestone sand. It appears also that the diffusion coefficient varies as a function of the W/C ratio.

• Journal of Information Technology Applications and Management
• /
• v.15 no.3
• /
• pp.1-25
• /
• 2008

IT platform migration to open systems (IPMO) bears a great deal of risk over all the associated processes, in terms of a major IT investment. Hence it requires empirical data and references for decision making. Although there have been a number of published papers encouraging or discouraging IPMO, the studies that deliver useful empirical evidence for IPMO decisions are rare. The obvious first step to resolve this problem would be to gain lessons from the organizations who experienced IPMO. Based on the Delphi study, we examine both the pre and post evaluations on IPMO benefits and risks and analyze the underlying reasons of different evaluations from different stages. Our results identify the most important factor the organizations should seriously consider, and which factor is easy to neglect at the ex-ante appraisal stage.

• International Journal of Concrete Structures and Materials
• /
• v.8 no.4
• /
• pp.269-278
• /
• 2014

When concrete is being transported through a pipe, the lubrication layer is formed at the interface between concrete and the pipe wall and is the major factor facilitating concrete pumping. A possible mechanism that illustrates to the formation of the layer is the shear-induced particle migration and determining the rheological parameters is a paramount factor to simulate the concrete flow in pipe. In this study, numerical simulations considering various rheological models in the shear-induced particle migration were conducted and compared with 170 m full-scale pumping tests. It was found that the multimodal viscosity model representing concrete as a three-phase suspension consisting of cement paste, sand and gravel can accurately simulate the lubrication layer. Moreover, considering the particle shape effects of concrete constituents with increased intrinsic viscosity can more exactly predict the pipe flow of pumped concrete.

• Journal of the Economic Geographical Society of Korea
• /
• v.12 no.4
• /
• pp.295-318
• /
• 2009

This paper explores micro-contexts of transnational migration and decision-making process of foreign migrants in Korea with four types, that is, married immigrants, immigrant workers, professional immigrants, and foreign students, analyzing dates of questionaries and interviews. Some findings can be summarized as follows. First, married immigrants and immigrant workers show relative lower level of micro-environments than professional immigrants and foreign students. Secondly, immigrants workers fill closest in geographical contiguity among immigrants' types, while married immigrants recognize more different in cultural comparison than the former. Both immigrants workers and foreign students think living environments of Korea better than other types, but immigrants workers consider relatively higher the level of technology, while foreign students evaluate lower that of education in Korea than other types. Thirdly, married immigrants give a relatively low score to the easiness of immigration, while both immigrant workers and professional immigrants give a high score to the job environment of Korea. Finally, all types of immigrants show a high portion in a self-decision making for international migration, while professional immigrants have much more experiences on visiting other countries than other types, and both married immigrants and foreign students seem to have utilized their networks with family members who live abroad.