• 제목/요약/키워드: migration

검색결과 4,436건 처리시간 0.029초

바닷새 및 해양어류의 이동 연구 동향: 위치추적 기법과 연구 사례를 중심으로 (Research trends in seabird and marine fish migration: Focusing on tracking methods and previous studies)

  • 최진환;윤성호;홍미진;강기호;이후승
    • 환경생물
    • /
    • 제40권1호
    • /
    • pp.25-53
    • /
    • 2022
  • 본 연구에서는 오늘날 바닷새 및 해양어류의 이동 연구방법 및 내용의 동향을 고찰하고, 기존 동물 이동 연구의 기본 틀에 의거하여 향구 연구방향에 관하여 제언하였다. 연구방법론적 측면에서는 과학기술의 발달에 따라 전파추적 기법, 음향추적 기법, RFID, 위성추적 기법, 지오로케이터 등을 이용한 위치추적 기법이 바닷새 및 해양어류의 이동 연구에 널리 활용되고 있으며, 개체군의 분포 및 밀도조사, 안정성 동위원소 등 체내 물질 분석을 통한 연구도 이루어진다. 연구내용의 경우, 크게 환경요인이나 종간 경쟁 등의 외적 요인, 호르몬을 비롯한 체내 물질과 같은 내적 요인, 어업활동이나 해상풍력단지 건설 등의 인위적인 활동, 그리고 기후변화가 바닷새와 해양어류의 이동에 미치는 영향 등이 다루어지고 있다. 추후 연구에서는 내적 요인과 관련하여 이동과 분산에 영향을 주거나 유발하는 요인이 되는 체내 생리적 요인이나 변화를 규명하고, 이동 능력 분석을 위하여 자기장의 변화가 조류 및 어류의 이주 능력에 미치는 영향이나 종별 시공간적 이주 능력의 차이, 이주 정확성 및 성공률에 영향을 미치는 요인에 관한 연구가 필요할 것으로 제언한다. 또한 외부 환경적 요인과 관련해서는 어업활동이나 해상풍력 등의 방해요인과 기후변화가 해양동물들의 이주 및 분산 패턴에 미치는 영향에 대한 연구의 필요성이 대두되며, 마지막으로 여러 생태적 측면에서 서로에게 직·간접적인 영향을 미치는 바닷새와 해양어류에 대한 융합적인 연구가 요구된다.

Vertical Migration of Sound Scatterers in the Southern Yellow Sea in Summer

  • Lu, Lian-Gang;Liu, Jianjun;Yu, Fei;Wu, Wei;Yang, Xiaodong
    • Ocean Science Journal
    • /
    • 제42권1호
    • /
    • pp.1-8
    • /
    • 2007
  • Acoustic volume backscattering strength data were collected and Conductivity Temperature Depth (CTD) measurements were conducted in the southern Yellow Sea in summer 2005 and 2006. The high temporal and vertical resolution acoustic data measured with a 307 kHz Acoustic Doppler Current Profiler (ADCP) and a 250 kHz acoustic Doppler profile (ADP) had dominant diel variation, which resulted from vertical migration of sound scatterers. Some scatterers congregating in the bottom layer in the daytime migrated upward at dusk, and migrated downward into the bottom layer at dawn. The migration speeds were estimated. More than 33 days data show that the diel migration varies with time. The feature of migration measured with ADCP and ADP is consistent to some extent with what is described in the study on vertical migration of zooplankton in the southern Yellow Sea with conventional net samples.

다중 개체군 유전자 알고리즘의 새로운 이주 방식 (A New Migration Method of the Multipopulation Genetic Algorithms)

  • 차성민;권기호
    • 한국정보과학회논문지:소프트웨어및응용
    • /
    • 제28권1호
    • /
    • pp.26-30
    • /
    • 2001
  • 다중개체군 유전자 알고리즘은 일반 유전자 알고리즘의 변형된 형태로써, 일반 유전자 알고리즘의 단점을 보완하기 위해서 고안되었다. 다중 개체군 유전자 알고리즘의 핵심은 이주방식이라고 할 수 있다. 현재 적합도 기반 이주방식과 임의 이주 방식이 널리 쓰이고 있다. 이 가운데 개체의 다양성을 유지하는 임의 이주 방식이 보다 널리 쓰이고 있는 일반적인 이주 방식이다. 본 논문은 다중 개체군 유전자 알고리즘의 새로운 이주 방식을 제안하다. 일반적인 이주 방식에 비해서 수렴 속도를 향상시킬 수 있다는 장점이 있다. 제안하는 이주 방식을 일반적인 이주 방식과 비교해 보았다.

  • PDF

사회네트워크 분석을 이용한 광주 전남지역의 공간 구조 변화 및 중심지 분석 (Analysis of Spatial Structures and Central Places of Gwangju and Jeonnam Region using Social Network Analysis)

  • 이지민
    • 농촌계획
    • /
    • 제23권2호
    • /
    • pp.43-54
    • /
    • 2017
  • When an age of low growth and population decline, population migration plays an important role in spatial structure of region. There have been many researches on migration and regional spatial structure. The purpose of this study is to examine the changes of Gwangju and Jeonnam region's spatial structure and central area using social network analysis methods. For analysis it was used that population and migration data and passenger OD(Origin and Destination) travel data released by Statistics Korea and Korea Transport Database(KTDB). Using Gephi 0.8.2, migration and passenger OD networks were visualized, and this describe network flow and density. The results of the network centrality analysis show that the most populated village is not always network center though population mass is an important factor of central places. The average eigenvector centrality of 2010 migration is the lowest during 2005-2015, and it means few regions have high centralities. When comparing migration and travel networks, travel data is more effective than migration data in determining the central location considering spatial functions.

도시민 농촌이주에 대한 주요쟁점과 시사점 (Reviews of Rural In-Migration Studies and Its Practical Implications)

  • 이민수;박덕병
    • 농촌지도와개발
    • /
    • 제18권1호
    • /
    • pp.1-33
    • /
    • 2011
  • In-migration has long been recognized as on important factor in rural development. Its impact can be expected to increase even further as the elderly population continues to grow. Recently with the retirement of baby boomers, postretirement moves have become increasingly important issue in rural Korea. Because the consequences of rural in-migration are often most pronounced at the local or regional level, rural planners are among the many scholars and practitioners seeking to understand the patterns and consequences of in-migration. At the same time, however, planners have sometimes overlooked basic research on the causes and determinants of mobility, and on the relationships between retirement migration and other socioeconomic processes. The papers aims to explore the reviews of rural in-migration studies and its practical implications, providing an interdisciplinary review of the most important studies published between 1990-2009. Through the literature review of in-migration, this study suggests that main arguments for rural in-imgration studies such as rural populations, counterurbanization, rural businesses incubator and rural amenity be emphasized to vitalize and diversify rural economies.

소망막내피세포에서 금 나노입자의 최종당화산물에 의한 세포 이동 및 침윤성 억제 효과 (Gold Nanoparticles Inhibit AGEs Induced Migration and Invasion in Bovine Retinal Endothelial Cells)

  • 채수철
    • 환경생물
    • /
    • 제28권1호
    • /
    • pp.8-13
    • /
    • 2010
  • 본 연구는 BRECs에서 AGEs로 유도된 세포의 이동 및 침윤에 있어서 AuNP의 역할에 관한 연구이다. 소 망막으로부터 내피세포를 분리하고, 세포 생존율은 MTT assay로 확인하였다. Wound migration assay는 BRECs의 이동력을 확인하기 위해 수행하였다. Tube formation은 on-gel system을 통해 확인하였다. AuNP의 apoptosis 유도는 caspase-3 assay를 통해 확인하였다. AGE-BSA은 세포증식 및 이동에 있어서 증가함을 보여주었다. 또한 AuNP는 AGE-BSA 존재 유무에 상관없이 세포의 증식, 이동, 신생혈관 형성을 억제하였고, caspase-3을 통해 apoptosis를 유도하였다. 이러한 결과, AuNP는 AGE로 유도된 신생혈관 형성 및 세포의 이동성을 억제하는 약재제로서, 당뇨성 합병증에 있어서 잠재적으로 중요한 분자가 될 것이다.

혼화재 혼입 콘크리트의 염화물 침투저항성에 관한 실험적 연구 (Experimental Study on the Chloride Invasion Resistance Properties of Concrete Containing Mineral Admixtures)

  • 유재강;김동석;이상수
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2003년도 학술.기술논문 발표회
    • /
    • pp.43-48
    • /
    • 2003
  • This paper investigate that the effect of the concrete containing mineral admixtures(pozzolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for 3~4 replacement ratios under W/B ratios ranged from 0.40 to 0.55. For the electrical migration test, Tang and Nilsson's method was used to estimate the migration coefficient of chloride ion. As a results, the W/B ratios, kinds of admixture and replacement ratios, water curing periods had a great effect on the migration coefficient of chloride ion, and the optimal replacement ratios of admixture had a limitation for each admixtures. Also, the addition of mineral admixtures by mass(replacement of OPC) enhanced the resistance of the mixture to chloride penetration compared with the plain concrete. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures. The compressive strength was shown related to the migration coefficient of chloride ion, the compressive strength increased with the decreasing migration coefficient of chloride ion. Below the 50MPa, the variation of migration coefficient of concrete added mineral admixtures was bigger than plain concrete.

  • PDF

An Energy Efficient Distributed Approach-Based Agent Migration Scheme for Data Aggregation in Wireless Sensor Networks

  • Gupta, Govind P.;Misra, Manoj;Garg, Kumkum
    • Journal of Information Processing Systems
    • /
    • 제11권1호
    • /
    • pp.148-164
    • /
    • 2015
  • The use of mobile agents for collaborative processing in wireless sensor network has gained considerable attention. This is when mobile agents are used for data aggregation to exploit redundant and correlated data. The efficiency of agent-based data aggregation depends on the agent migration scheme. However, in general, most of the proposed schemes are centralized approach-based schemes where the sink node determines the migration paths for the agents before dispatching them in the sensor network. The main limitations with such schemes are that they need global network topology information for deriving the migration paths of the agents, which incurs additional communication overhead, since each node has a very limited communication range. In addition, a centralized approach does not provide fault tolerant and adaptive migration paths. In order to solve such problems, we have proposed a distributed approach-based scheme for determining the migration path of the agents where at each hop, the local information is used to decide the migration of the agents. In addition, we also propose a local repair mechanism for dealing with the faulty nodes. The simulation results show that the proposed scheme performs better than existing schemes in the presence of faulty nodes within the networks, and manages to report the aggregated data to the sink faster.

Mouse Melanoma Cell Migration is Dependent on Production of Reactive Oxygen Species under Normoxia Condition

  • Im, Yun-Sun;Ryu, Yun-Kyoung;Moon, Eun-Yi
    • Biomolecules & Therapeutics
    • /
    • 제20권2호
    • /
    • pp.165-170
    • /
    • 2012
  • Cell migration plays a role in many physiological and pathological processes. Reactive oxygen species (ROS) produced in mammalian cells influence intracellular signaling processes which in turn regulate various biological activities. Here, we investigated whether melanoma cell migration could be controlled by ROS production under normoxia condition. Cell migration was measured by wound healing assay after scratching confluent monolayer of B16F10 mouse melanoma cells. Cell migration was enhanced over 12 h after scratching cells. In addition, we found that ROS production was increased by scratching cells. ERK phosphorylation was also increased by scratching cells but it was decreased by the treatment with ROS scavengers, N-acetylcysteine (NAC). Tumor cell migration was inhibited by the treatment with PD98059, ERK inhibitor, NAC or DPI, well-known ROS scavengers. Tumor cell growth as judged by succinate dehydrogenase activity was inhibited by NAC treatment. When mice were intraperitoneally administered with NAC, the intracellular ROS production was reduced in peripheral blood mononuclear cells. In addition, B16F10 tumor growth was significantly inhibited by in vivo treatment with NAC. Collectively, these findings suggest that tumor cell migration and growth could be controlled by ROS production and its downstream signaling pathways, in vitro and in vivo.

혼화재 혼입 콘크리트의 염화물 침투저항성에 관한 실험적 연구 (Experimental Study on the Chloride Invasion Resistance Properties of Concrete Containing Mineral Admixtures)

  • 유재강;김동석;이상수
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2003년도 학술.기술논문발표회
    • /
    • pp.43-48
    • /
    • 2003
  • This paper investigate that the effect of the concrete containing mineral admixtures(pozzaolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for 3∼4 replacement ratios under W/B ratios ranged from 0.40 to 0.55. For the electrical migration test, Tang and Nilsson's method was used to estimate the migration coefficient of chloride ion. As a results, the W/B ratios, kinds of admixture and replacement ratios, water curing periods had a great effect on the migration coefficient of chloride ion, and the optimal replacement ratios of admixture had a limitation for each admixtures. Also, the addition of mineral admixtures by mass(replacement of OPC) enhanced the resistance of the mixture to chloride penetration compared with the plain concrete. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures. The compressive strength was shown related to the migration coefficient of chloride ion, the compressive strength increased with the decreasing migration coefficient of chloride ion. Below the 50MPa, the variation of migration coefficient of concrete added mineral admixtures was bigger than plain concrete.

  • PDF