• Title/Summary/Keyword: Population migration

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Polychlorinated Biphenyls (PCBs) in the Bio-geochemistry of Oceans

  • Kannan, Narayanan
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.4
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    • pp.201-208
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    • 2007
  • Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

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The Migration Scheme in the Multi-population Genetic Algorithms using Fuzzy Logic Controller (퍼지 논리 제어를 이용한 다 개체군 유전자 알고리즘의 이주 기법)

  • 전향신;권기호
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10a
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    • pp.76-78
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    • 2003
  • 다 개체군 유전자 알고리즘에서는 여러 개의 개체군을 사용하여 각 개체군을 독립적으로 진화를 시키는데, 이 논문에서는 퍼지 논리 제어를 이용하여 독립적으로 개체군을 진화시켜 집단으로 이주시키는 새로운 코딩방법을 제안한다. 이 퍼지 논리 제어는 최적화과정 동안 교배 비율과 돌연변이 비율을 적합하게 조절하여 수행하는 두 퍼지 논리 제어를 나타낸다. 제안하는 방식을 성능평가해서 기존의 방식과 비교해 보았다. 제안하는 방식이 수렴속도를 향상시킬 수 있다는 장점을 보여준다.

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The COVID-19 Pandemic and the 'stranded' Migrant Population: An Unequal pain

  • Ullah, AKM Ahsan;Chattoraj, Diotima;Ibrahim, Wan Zawawi
    • SUVANNABHUMI
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    • v.14 no.2
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    • pp.61-88
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    • 2022
  • This article aims to determine the vulnerability of migrant populations to COVID-19. Between March 2020 and November 2021, informal interviews with respondents who were stranded in various parts of the world were conducted through Skype and WhatsApp. COVID-19 endangers millions of individuals who were stranded between their homes and their destinations - and who were compelled to reside in overcrowded accommodation where the ideas of "stay home," "keep safe," and "social distancing" have little significance.

A Study on the Relation between the Hollowization and the Phenomenon of Decreasing and Aging Population in Rural Villages - Focused on Geumsan-gun - (농촌마을의 공동화와 과소·고령화 현상의 관련성 연구 - 충남 금산군을 중심으로 -)

  • Cho, Young-Jae;Kim, Du-han;Cho, Eun-Jung
    • Journal of Korean Society of Rural Planning
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    • v.21 no.4
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    • pp.85-94
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    • 2015
  • The purpose of this study is to investigate how the hollowization in rural villages which causes marginal villages appears in Korean rural villages and whether the hollowization has relation with decrease and aging of population or not. For achieving the research objective, survey was carried out focused on Geumsan-gun. As a result, it confirmed that rural out-migration and rural decline especially in 'people', 'land(economic situation)' and 'community' have being progressed. Also variance analysis and regression analysis were executed with using the number of population and the ratio of people over 65 as dependent variables and using each survey contents(variables) as independent variables. The results of analysis showed that the ratio of people over 65(+), the income level per household(-), the rate of fallow lands(+), the number of empty houses(+), programs for urban-rural interchange(+), and the implementing public projects(+), etc. have a relation with the number of population(-) and the number of population(-), the income level per household(-), the rate of fallow lands(+), the number of empty houses(+), activities of communities(+), and the implementing public projects(+), etc. have a relation with the ratio of people over 65(+) (+: increase, -: decrease). So the hollowization in people', 'land(economic situation)' and 'community' has direct relation with decrease and aging of population in rural areas.

The Logic of Vertical Density: Tall Buildings in the 21st Century City

  • Al-Kodmany, Kheir
    • International Journal of High-Rise Buildings
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    • v.1 no.2
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    • pp.131-148
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    • 2012
  • This paper attempts to summarize recent debates on tall buildings. It first explains the driving forces of constructing tall buildings including population increase, rural-to-urban migration, demographic change, agglomeration, and human aspiration. Next, it discusses disadvantages and challenging factors that are frequently raised in making a case against tall buildings including economics, environmental factors, historic context, public safety, and psychological issues. The paper concludes by affirming that tall buildings will persist in the $21^{st}$ century due to strong commitment to urban sustainability and significant population increase worldwide.

Study on the Military factors and previous information on the relationship between population characteristics (정보화된 군사시설이전요인과 주민특성과의 관계에 관한 연구)

  • Shin, Kwang-Shig;Kim, Haeng Jo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.10
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    • pp.1561-1571
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    • 2013
  • In the previous Department of Defense informed military is needed more than ever. Residents to come to the old military thinking is not good. Study the transfer of most of the residents feel good military and some of the residents were thinking negatively. In the present study refer to the Department of Defense to improve the relationship between citizens and the future if the military is thought to ease the migration.

Characteristics of Population Dynamics and Habitat Use of Shorebirds in Rice Fields during Spring Migration (봄철 논습지에 도래하는 도요·물떼새의 서식지 이용과 개체군 변동)

  • Choi, Seung-Hye;Nam, Hyung-Kyu;Yoo, Jeong-Chil
    • Korean Journal of Environmental Agriculture
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    • v.33 no.4
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    • pp.334-343
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    • 2014
  • BACKGROUND: Shorebirds use a variety of wetlands as their stopover sites to replenish energy and nutrient reserves along the migration route. It is increasingly important to understand how birds use the remaining available habitats during migration period, because shorebird stopover sites are often altered and destroyed. Rice fields serve as a major inland stopover site for migrating shorebirds. However, the information on habitat use patterns of shorebirds in rice fields is very limited in Korea. Therefore, we studied the patterns of shorebird abundance and their habitat use in rice fields during spring migration period in western-central Korea. METHODS AND RESULTS: Surveys were conducted at interval of 2-3 days during the spring migration period of 2014 at rice fields of mid-western Korea. We recorded the location of the observed birds on the rice field map according to the local habitat type. The habitat types were divided by physical structure and cultivation methods. Fifteen shorebird species and 7,852 individuals were recorded during the survey period. The number of shorebird species and their abundance began to increase from the beginning of flooding in late-April, and reached a maximum in early-May. After rice transplantation, the number of shorebird species and their abundance dramatically declined. Shorebirds selectively used paddy and levee rather than road and ditch and most species used shallow depth field type. Plowed field types were less attractive to most species. CONCLUSION: Flooding rice fields were functioned as stopover sites for a variety of shorebird species during spring migration period. Furthermore, these results provide that the appropriate agricultural practices can be improving the habitat quality for shorebirds.

The Structure of Interrelationship Among the Influential Factors of Migration Using Path Analysis (경로분석을 이용한 인구이동 결정요인들 간의 인과구조)

  • Lee, Hee-Yeon;Park, Jung-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.2
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    • pp.123-141
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    • 2009
  • Interregional migration is viewed as the most important component in regional population change in Korea. The purpose of this study is to analyze the structure of interrelationship among influential factors of interregional migration from the macro-viewpoint. During the period of 2000-05 the correlation between immigration and outmigration among 223 shi gun gu spatial unit was over 0.95, indicating that regions with high outmigration received high immigration. In this study the hypothesized cause-and-effect relationship among six influential factors of total migration flow was analyzed using path analysis. Based on the direct effect culturalwelfare environment has the biggest impact on immigration, while education environment and new housing environment are somewhat less and industrial-job opportunity environment the smallest impact. However based on the indirect effect, fiscal environment has the biggest impact on immigration, while industrial-job opportunity environment and infrastructure environment are somewhat less and new housing environment the smallest impact. If we consider the total effect, fiscal environment and cultural-welfare environment have the most significantly influenced on immigration. In particular, the influence of fiscal environment was remarkable in migration process through nonrecursive path and feedback loop.

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Migration Pattern of the Oriental Honey Buzzard Pernis ptilorhynchus at Hongdo Island in Korea (전남 홍도를 통과하는 벌매(Pernis ptilorhynchus)의 이동 양상)

  • Choi, Young-Bok;Chae, Hee-Young;Kim, Sung-Hyun
    • Korean Journal of Environment and Ecology
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    • v.23 no.1
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    • pp.50-55
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    • 2009
  • To understand the status of the migrating Oriental Honey Buzzard(Pernis ptilorhynchus) in Korea, we carried out a preliminary study on the number and local movements of the Honey Buzzard from September 2005 to October 2007 at Hongdo Island, Jeonnam Province, Korea. A total of 702 Honey Buzzards in 2005, 404 individuals in 2006, and 659 individuals in 2007 were recorded during the fall migration season, but during the spring migration season only two and eight birds were observed in 2006 and 2007 respectively. The migrating Honey Buzzard showed peak numbers from 20 September to 5 October at the study site. According to observation of arrival time of538 Honey Buzzard in October 2007, a total of 2l6 birds(40.l %) were passing over Hongdo Island between 7:00 AM to 8:00 AM, rising skyward on columns of warm air. This suggests the use of thermal currents and avoidance of nocturnal movement for crossing water. They preferred moderate winds(<5 m/s in speed) from northwest, but the migrating number apparently decreased in case of strong winds (${\geqq}5 m/s$). This suggests that wind speed and direction are important environmental factors for migration of the Oriental Honey Buzzard. At present, it is unclear which breeding population(from north-eastern China or Japan) passes over Hongdo Island. Moreover, it is difficult to prove migration route and to understand migratory behaviors of the Oriental Honey Buzzard in Korea. To prove the breeding sites and routes of the migrants over the study site, we need more detailed and further studies such as satellite tracking researches.