• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.97-115
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• 2023

In recent years, the structure of the population has been changing rapidly, with a declining birthrate and aging population, and the inequality of population distribution is expanding. At this point, changes in population estimation methods are required, and more accurate estimates are needed at the subregional level. This study aims to estimate the population in 2040 at the 500m grid level by applying an explainable machine learning to Busan in order to respond to this need for a change in population estimation method. Comparing the results of population estimation by applying the explainable machine learning and the cohort component method, we found that the machine learning produces lower errors and is more applicable to estimating areas with large population changes. This is because machine learning can account for a combination of variables that are likely to affect demographic change. Overestimated population values in a declining population period are likely to cause problems in urban planning, such as inefficiency of investment and overinvestment in certain sectors, resulting in a decrease in quality in other sectors. Underestimated population values can also accelerate the shrinkage of cities and reduce the quality of life, so there is a need to develop appropriate population estimation methods and alternatives.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.1
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• pp.6-15
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• 2021

We investigated the taxonomic status of the Korean populations of Eurema hecabe (Linnaeus, 1758) based on morphology and nuclear triose phosphate isomerase (Tpi). Up to now, the Korean population of E. hecabe was classified into E. mandarina (de l'Orza, 1869) based on morphological characteristics. A previous study raised the possibility of the Jeju-do population to be E. hecabe based on the color of forewing's fringe. However, morphological examination showed that the Korean population found in southern areas (Gyeonsang and Jeolla provinces), including Jeju-do is E. mandarina. In particular, the external morphology of autumn seasonal type of the Korean population was almost same as the Japanese mainland population, which is known as E. mandarina. Furthermore, sequence analysis of Tpi gene from nine individuals of E. mandarina collected in South Korean localities including Jeju-do clearly showed that all Korean specimens truly belong to E. mandarina.

• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.25-34
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• 1989

The author performed on epidemiological study of the TMD in 189 elderly people and 195 young people with Helkimo index. The clinical dysfunction index was based on data from clinical examination and the anamestic dysfunction index was based on data from the interview with the investigated person. The results were as follows : 1. In the elderly population, 27.5% reported that they had subjectively symptom of TMD but 43.4% had sign and symptoms of TMD in clinical examination. 2. The mean values for maximal opening differed significantly between elderly and young populations, 47.22mm and 51.44mm (p<0.001) and less than a 40mm opening was observed 7.9% in elderly population, 0.5% in young population (p<0.001). 3. The mean values for lateral movement to the right and left did not differ with age, which were 8.56mm and 8.47mm in elderly population, 8.90mm and 8.81mm in young population, but the mean value for protrusion differed significantly between elderly and young populations, 6.89mm and 7.64mm (p<0.01). 4. A higher incidence of TMJ noise was recorded in the elderly and young populations than young population, especially crepitus, but a higher incidence of clicking was recorded in young population (p<0.05).

• Journal of Environmental Science International
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• v.23 no.4
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• pp.697-705
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• 2014

The exposed population of a vulnerable group to high ozone episodes (exceeding 60 ppb/8h) was estimated in Busan metropolitan city from 2000 to 2010. The frequency of high ozone days at monitoring sites and the number of the population aged over 65 were used to calculate the accumulated (total, seasonal, and yearly) number of the exposed older population (EOP) to high ozone episodes during the study period based on administrative areas, by interpolation and zonal mean methods in ArcGIS software. The older population in this city had increased significantly from 2000 to 2010 (representing over 10% of the total population in 2010). The vulnerable areas (e.g. the eastern area of the city) of the EOP to high ozone episodes were different from the areas with frequent high ozone episodes (e.g., the western area) due to the increase of the older population in particular areas. The difference was more significant in spring than in any other season, and in 2010 than in previous years (2000 and 2005).

• Korea journal of population studies
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• v.32 no.1
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• pp.113-137
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• 2009

This article uses genealogical information to estimate fertility, mortality, and population growth in Korea during the eighteenth and nineteenth centuries. Upper class males' probability of dying as estimated from genealogies was converted into that for the whole male population drawing upon information on colonial mortality and model life tables, which indicated male life expectancy at birth was 23 years. Age-specific marital fertility rates for upper class females as calculated from genealogies were combined with estimates of age at first marriage and information on colonial fertility to derive age-specific fertility rate for the whole female population, which implied a total fertility rate of 6.81. Finally, the estimated indices of mortality and fertility were inserted into equations describing stable populations to find that the Korean population grew 0.62% p.a. during the eighteenth and nineteenth centuries.

• The Southeast Asian review
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• v.20 no.3
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• pp.147-182
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• 2010

The purpose of this study is to examine the population changes in the nine Southeast Asian countries, including Cambodia, Lao People's Democratic Republic, Philippine, Indonesia, Malaysia, Myanmar, Singapore, Vietnam, and Thailand. According to the demographic transition theory which described the transition from high birth and death rates to low birth and death rates, the demographic changes in less developed countries, including the Southeast Asian countries, follow the general pattern of the population changes that the Western countries had experienced. However, this theory does not consider the fact that the demographic behaviors such as fertility and mortality tend to be ethnocentric (or particular). Therefore, I examine in this paper both the generality and particularity of the population changes in the Southeast Asia . The analytic results are consistent with my assumptions. Every country in the Southeast Asia will soon reach the third phrase of the demographic transition and meet population ageing process. However, the timings arriving at the third phrase can differ. Singapore which is the most developed country had firstly passed through the demographic transition and the highest level of population ageing. Cambodia and Lao People's Democratic Republic, the least developed countries, will lastly arrive at the third phrase and the ageing society. In addition, among the three countries which had experienced war or civil war, only Cambodia had experienced babyboom.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.335-352
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• 2023

When solving multi-objective optimization problems, the blindness of the evolution direction of the population gradually emerges with the increase in the number of objectives, and there are also problems of convergence and diversity that are difficult to balance. The many- objective optimization problem makes some classic multi-objective optimization algorithms face challenges due to the huge objective space. The sine cosine algorithm is a new type of natural simulation optimization algorithm, which uses the sine and cosine mathematical model to solve the optimization problem. In this paper, a knee-driven many-objective sine-cosine algorithm (MaSCA-KD) is proposed. First, the Latin hypercube population initialization strategy is used to generate the initial population, in order to ensure that the population is evenly distributed in the decision space. Secondly, special points in the population, such as nadir point and knee points, are adopted to increase selection pressure and guide population evolution. In the process of environmental selection, the diversity of the population is promoted through diversity criteria. Through the above strategies, the balance of population convergence and diversity is achieved. Experimental research on the WFG series of benchmark problems shows that the MaSCA-KD algorithm has a certain degree of competitiveness compared with the existing algorithms. The algorithm has good performance and can be used as an alternative tool for many-objective optimization problems.

• The Korean Journal of Food & Health Convergence
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• v.9 no.5
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• pp.1-5
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• 2023

As the elderly population is rapidly increasing not only domestically but also globally, convenience foods for the elderly population are receiving attention. Therefore, the senior food market continues to grow rapidly both domestically and overseas. In relation to this, this study seeks to explore convenience food preferences through the growth status of the convenience food market and the demand for convenience food among the elderly population. We would like to consider various factors that influence the increase in convenience food consumption among the elderly population. This study uses meta-analysis and systematic literature research to find ways to revitalize the convenience food market targeting the elderly population. As a result of the analysis, it was mentioned that in order to revitalize the convenience food market for the elderly population, it is important to develop products with high nutritional value, suitable for the physical characteristics of the elderly population, and low price, and to consider convenience and accessibility. Through a multifaceted approach, we aim to increase the need for convenient food products that meet the needs of the elderly population, contribute to improving the health and well-being of the elderly, and further efficiently manage the health of the elderly nationally and globally.

• Korean System Dynamics Review
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• v.12 no.2
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• pp.127-151
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• 2011

The purpose of this study is to examine measures to improve government's supply oriented housing policy in population declining cities. For this purpose, system dynamics simulation method was used to build urban-housing model and different sets of housing policies were tested to see their impact on local housing problems. Simulation result shows that there is no best set of housing policies that can solve all housing problems in population declining cities. It also indicates that housing policy that solve one type of problems can worsen other type of problems. Housing policy that increases population size has negative effect of housing oversupply. It also increases proportion of old houses in population declining cities. However, housing policy that makes city younger with newer houses tends to increase housing shortage and housing price. So, policy choice needs to be made with clear understanding of trade off between different policies. The result also shows it is difficult to expect a full scale effect of housing policy on local housing problems unless it is executed with regional economic development policy because local housing problems are so closely related with local economic problem in population declining local cities.

• Journal of Korean Library and Information Science Society
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• v.44 no.1
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• pp.49-71
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• 2013

Public Libraries should be open at times when the community can make the most effective and convenient use of library collections and services. In other words, public library must provide adequate open hours for local residents. In this respect, this study analyzed the minimum opening hours per week in public library standards of international organizations(IFLA/UNESCO) and major countries (USA, Canada, UK, France, Australia, China, Taiwan, Japan, Korea) and suggested a desirable minimum standards(under 10,000 population-45 hours ; over 10,000~20,000 population-50 hours ; over 20,000~50,000 population-55 hours ; over 50,000~100,000 population-60 hours ; over 100,000~300,000 population-65 hours ; over 300,000 population-70 hours) for opening hours per week of public library based on population size in Korea.