• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.408-423
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• 2021

We established and monitored survey sites in seven regions of Mt. Jiri to investigate population decline and change of the Korean fir (Abies koreana) over a ten-year period from 2009 to 2018. With the exception of one site (Seseok), the six remaining ones all showed a four-layer stratification structure. The importance value of Korean firs in all of the survey areas decreased significantly by 28.5%, from 55.7% in 2009 to 39.8% in 2018. The average population of objects with a diameter at breast height (DBH) of 5cm or more in all survey sites was 711 objects/ha in 2018, and the cumulative death rate from 2009 to 2018 was 10.8%. Among the death types, DS (dead standing) was the most dominant, comprising 82.4% of the total survey area. However, in Banyabong 1, which had a high gradient of 35°, the death types other than DS accounted for 44.2%. We estimate that A. koreana can maintain a stable population as its distribution type for each diameter class in the Saeseokpyeongjeon site showed a reverse-J shape. The average annual ring growth in all survey sites was 1.09 mm/year, with the most abundant growth observed in the Seseokpyeongjeon site, which was formed mainly by a subtree layer. The growth ring survey showed the estimated average age of A. koreana population in the Byeoksoryeong and Banyabong 1 sites to be 102 and 91 years, respectively, a general downward trend of vitality since 2013.

• Animal Bioscience
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• v.34 no.7
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• pp.1123-1133
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• 2021

Objective: Shandong indigenous pig breeds are important Chinese pig resources. Their progressive population decline in recent decades has attracted attention towards their conservation. Conservation genetics of these indigenous breeds are essential for developing a conservation and utilization scheme. Methods: A high-density single nucleotide polymorphism (HD-SNP) chip-based comparative analysis of genetic characteristics was performed for seven Shandong indigenous pig breeds in the context of five Western commercial breeds. Results: The results showed that Shandong indigenous pig breeds varied greatly in genetic diversity, effective population size, inbreeding level, and genetic distance with the Western commercial breeds. Specifically, Laiwu and Dapulian displayed low genetic diversity, and had a genetically distant relationship with the Western commercial breeds (average F statistics [F_ST] value of 0.3226 and 0.2666, respectively). Contrastingly, the other five breeds (Yantai, Licha, Yimeng, Wulain, and Heigai) displayed high genetic diversity within breed and had some extent of mixture pattern with the Western commercial breeds, especially Duroc and Landrace (F_ST values from 0.1043 to 0.2536). Furthermore, intensive gene flow was discovered among the seven Shandong indigenous breeds, particularly Wulian, Licha, and Heigai, as indicated by the large cluster formed in the principal component analysis scatterplot and small population differentiation (average of 0.1253) among them. Conclusion: Our study advances the understanding of genetic characteristics of Shandong indigenous breeds and provides essential information for developing an appropriate conservation and utilization scheme for these breeds.

• Health Policy and Management
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• v.34 no.1
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• pp.38-47
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• 2024

Background: Korea's population of children and adolescents has decreased by 2.88 million over the past decade and is expected to decline further due to the unprecedented low birth rate. In the fee-for-service compensation system, the decline in the pediatric population relates directly to the profit decrease in the pediatric clinics. This study analyzed whether the worsening profits of pediatric clinics impacted their closure. Methods: We built annual data for pediatric and other department clinics (internal medicine, otolaryngology, and family medicine) using the status of medical institute and health insurance claims data from 2012 to 2022. Then, we analyzed whether institutional variables such as annual profit and regional variables (Herfindahl-Hirschman index, the number of clinics per 100,000, etc.) affected the closure of clinics. The methods used in this study are descriptive statistics and chi-square analysis. Odds ratios for each variable were estimated by generalized estimating equations (GEE). Results: The closure rate of pediatric clinics was 2.66%-7.04% in 2012-2022, which was consistently higher than those of internal medicine, otolaryngology, and family medicine clinics. The profit gap per institution between the pediatric and the other clinics grew from 126 million won in 2012 to 245 million won in 2019. In the GEE analysis, profit decrease compared to the previous year with lower profit was the main factor that increased the closure of pediatric and other department clinics. After adjusting profit-related variables, the decrease in the pediatric population itself did not relate to the closure of pediatric clinics. The number of pediatric clinics or monopolies also did not affect the closure of pediatric clinics. Conclusion: The worsening profit is the crucial factor for the closure of pediatric clinics, while the pediatric population is decreasing. For this reason, it is necessary to actively seek ways to maintain a stable treatment system for children and adolescents.

• Korea journal of population studies
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• v.29 no.2
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• pp.53-88
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• 2006

The major aim of this paper is to develop a hypothetical set of age-specific fertility rates which are logically derived and reasonably accurate in the projection of future population. The first procedure is to select a generalized log-gamma distribution model, which includes Coale-McNeil nuptiality model, in order to estimate and project a set of age-specific fertility rates by birth cohort and birth order. The second is to apply the log-gamma model with an empirical adjustment to the actual data to estimate and project the future fertility rates for relatively young birth cohorts who did not complete their reproductive career. This study reconstructs or translates a set of cohort age-specific fertility rates into a set of period age-specific fertility rates which must be hypothesized in order to establish the broader framework of future population projection. For example, the fertility at age 20 in the year of 2020 is the fertility at age 20 for the cohort born in 1990, while the fertility at age 21 in the year of 2020 is the fertility at 21 for the cohort born in 1989. In turn, once a set of age-specific fertility rates for the cohorts who were born up to the year of 2010, it is possible for one to establish an hypothetical set of period age-specific fertility rates which will be needed to project the future population until the year of 2055. The difference in the hypothetical system of age-specific fertility rates between this study and the 2005 special population projection comes from the fact that the fertility estimation/projection model used in this study was skillfully exploited to reflect better actual trend of fertility decline caused by rise in marriage age and increasing proportion of those who remain single until their end of reproduction. In this regard, this paper argues that the set of age-specific fertility rates derived from this study is more logical and reasonably accurate than the set of those used for the 2005 special projection. In the population projection, however, the fundamental issue of the hypothetical setting of age-specific fertility rates in relation to the fertility estimation/projection model is about how skillfully one can handle the period effects. It is not easy for one to completely cope with the problem of period effects except for the a minor period adjustment based on recent actual data, along with the given framework of a cohort-based fertility estimation/projection model.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.37-41
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• 2016

Purpose The importance of quality control by the error to a minimum, which for the purpose of enhancing the reliability of the examination is not be emphasized excess. Currently, most nuclear medicine laboratory are conducting the internal and external quality control, and they are applying the Levey-Jennings or Westgard Multi-Rules by using the commercialized quality control materials. The reliability of the nuclear medicine blood test which affects the diagnosis of patients and the treatment policy is being secured through this quality control activity. Therefore, researchers will evaluate the utility of the statistic quality control using the population distribution of the nuclear medicine blood test conducted targeting the checkup examinees by the additional technique of the reliability improvement. Materials and Methods A statistic analysis was performed about 12 items of the nuclear medicine blood test targeting 41,341 peoples who used the health screening and promotion center in Asan Medical Center from January, 2014 to December, 2014. The results of 12 items of the nuclear medicine blood test was divided into the monthly percentage of three groups: within reference values, over reference, and under reference to analyze the average value of the population distribution, standard deviation, and standard deviation index (SDI). Results The standard deviation of the population distribution mostly showed a result within ${\pm}2SD$ in all groups. However, When the standard deviation of the population distribution represented a result over ${\pm}2SD$, it was confirmed SDI was showing a result of SDI > -2 or SDI > 2. As a result of analyzing the population distribution of 12 items(AFP, CEA, CA19-9, CA125, PSA, TSH, FT4, Anti-Tg-Ab, Anti-TPO-Ab, Calcitonin, 25-OH-VitD3, Insulin) of the nuclear medicine blood part basic test, when SDI of the monthly percentage which deviated from the reference values was over ${\pm}2.0$, CA19-9 September was 2.2, Anti-Tg-Ab may was 2.2, Insulin January was 2.3, Insulin March was 2.4. It was confirmed these cases were attributed to the abnormality of the test reagent (maximum combination rate of isotope reagent declined) and the decline of the test response time. Conclusion The population distribution includes the entire attribute which becomes the study object. It is expected the statistic quality management using the population distribution which was conducted targeting the checkup examinees by dividing into three groups: within reference values, over reference, and under reference by means of this characteristics will be able to play a role of complementing the internal quality control program which is being carried out in the laboratory.

• Journal of the Korean Regional Science Association
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• v.9 no.2
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• pp.103-119
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• 1993

This research examines the spatial development of rural industrial estates (Nong-gong Jigu) in Chonbuk province and gives insight into the strategies for economic development in the entire region. Selected location factors which are likely to pull new investment into the estates are examined by using questionnaires. Few loction factors except nonlocal factors can be found in explaining why location choices are made. The irrelevance of the analysis based on location factors suggests that an alternative approach should analyze changes in the spatial development of the rural industrial estates. Such an alternative is to understand the dynamics of the spatial organization of production by focusing on characteistics of plant closing in the rural industrial estates. To take into account of the characteristics of plant closing we provide the hypothesized relationships between employment size, organizational structure, inter and intra industrial linkage, characteristics of production processes, and availability of local labor market and the likelihood of closing. A logit model is then made to identify the selected factors which might influence the probability of plant closing. The results from the logit analysis and their implications suggest that the policy should be more concerned with the characteristics of firms, such as size and ownership, as well as of the local labor markets. Given that the Chonbuk region has experienced rapid population decline, together with its poor industrial base, it seems that the success of the policy in the declined rural areas in less certain.

• Plant Biotechnology Reports
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• v.5 no.2
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• pp.107-120
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• 2011

The ability to feed an expanding world population poses one of the greatest challenges to mankind in the future. Accompanying the increased demand for food by the expected nine billion inhabitants of Earth in 2050 will be a continual decrease in arable land area, together with a decline in crop yield due to a variety of stresses. For these formidable challenges to be met, future crops should not only by high-yielding, but also stress-tolerant and disease-resistant. In this review, we highlight the importance of genetic engineering as an indispensable tool to generate just such future crops. We briefly discuss strategies and available tools for biotechnological crop improvement and identify selected examples of candidate genes that may be manipulated so that current biological maxima in yield may be surpassed by comfortable margins. Future prospects and the necessity for basic research aimed at identifying novel target genes are also discussed.

• Journal of the Korean housing association
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• v.24 no.2
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• pp.53-60
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• 2013

Recently, in Korea, single- or two-person households (50.5%) are becoming the primary family type due to increasing divorce rates, population aging, personal code of values and so on. Hence, small families will lead to a sudden increase of single- or two-person households. People searching for small houses are increasing because of the provision of officetels, one room and urban-life housing as well as economic recession. However, this has led to habitability problems, such as parking, storage space and decline in safety. In this study, we obtain the proper contents from LQI indicators of advanced research and use the indicators to evaluate the residential environment quality. We conduct a post-occupancy-evaluation (POE) survey and compare the habitability satisfaction level of apartment and officetel residents. According to the survey, officetel residents' satisfaction levels are low for the following factors in the order listed: ventilation, storage space, management expenses and facilities for children and the elderly.

• Journal of Preventive Medicine and Public Health
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• v.47 no.1
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• pp.64-71
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• 2014

Objectives: Physical activity behavior begins to decline during adolescence and continues to decrease throughout young adulthood. This study aims to explain factors that influence physical activity behavior in a sample of female adolescents using a health promotion model framework. Methods: This cross-sectional survey was used to explore physical activity behavior among a sample of female adolescents. Participants completed measures of physical activity, perceived self-efficacy, self-esteem, social support, perceived barriers, and perceived affect. Interactions among the variables were examined using path analysis within a covariance modeling framework. Results: The final model accounted for an $R^2$ value of 0.52 for physical activity and offered a good model-data fit. The results indicated that physical activity was predicted by self-esteem (${\beta}$=0.46, p<0.001), perceived self-efficacy (${\beta}$=0.40, p<0.001), social support (${\beta}$=0.24, p<0.001), perceived barriers (${\beta}$=-0.19, p<0.001), and perceived affect (${\beta}$=0.17, p<0.001). Conclusions: The findings of this study showed that the health promotion model was useful to predict physical activity behavior among the Iranian female adolescents. Information related to the predictors of physical activity behavior will help researchers plan more tailored culturally relevant health promotion interventions for this population.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.616-622
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• 2011

This study evaluated the fermentation characteristics and protein degradation dynamics of wet green tea grounds (WGTG) silage. The WGTG was ensiled with distilled water (control), or lactic acid bacteria (LAB), enzyme (E), formic acid (FA) and formaldehyde (FD) prior to ensiling. Three bag silos for each treatment were randomly opened at 0, 3, 7, 14, 28 and 60 days after anaerobic storage. For all the treatments, except for FA, there was a rapid decline in pH during the first 7 days of ensiling. LAB treatment had higher lactic acid content, lower ammonia-N ($NH_3$-N) and free-amino nitrogen (FAA-N) contents than other treatments (p<0.05). E treatment had higher lactic acid, water-soluble carbohydrates (WSC) and non-protein nitrogen (NPN) content than the control (p<0.05). FA treatment had higher $NH_3$-N and FAA-N content than the control (p<0.05). FD treatment had lower NPN and FAA-N content than the control, but it did not significantly inhibit the protein degradation when compared to LAB treatment (p>0.05). Results indicate that LAB treatment had the best effect on the fermentation characteristics and protein degradation of WGTG silage.