• Title/Summary/Keyword: BIOGEOGRAPHY

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Effect of Levy Flight on the discrete optimum design of steel skeletal structures using metaheuristics

  • Aydogdu, Ibrahim;Carbas, Serdar;Akin, Alper
    • Steel and Composite Structures
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    • v.24 no.1
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    • pp.93-112
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    • 2017
  • Metaheuristic algorithms in general make use of uniform random numbers in their search for optimum designs. Levy Flight (LF) is a random walk consisting of a series of consecutive random steps. The use of LF instead of uniform random numbers improves the performance of metaheuristic algorithms. In this study, three discrete optimum design algorithms are developed for steel skeletal structures each of which is based on one of the recent metaheuristic algorithms. These are biogeography-based optimization (BBO), brain storm optimization (BSO), and artificial bee colony optimization (ABC) algorithms. The optimum design problem of steel skeletal structures is formulated considering LRFD-AISC code provisions and W-sections for frames members and pipe sections for truss members are selected from available section lists. The minimum weight of steel structures is taken as the objective function. The number of steel skeletal structures is designed by using the algorithms developed and effect of LF is investigated. It is noticed that use of LF results in up to 14% lighter optimum structures.

Studies of Avian Species in the Islands of Korea based on the Theory of Island Biogeography (도서생물지리학 관점에서 본 우리나라 도서지역의 조류에 관한 연구)

  • Lee, Sang-Don
    • Journal of Environmental Impact Assessment
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    • v.19 no.6
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    • pp.547-552
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    • 2010
  • The theory of island biogeography has influenced strongly on the conservation and management issues of species diversity in the islands. The theory has not limited to islands in the ocean, but expanded to isolated and fragmented areas in the forests and urban. This study has a rare opportunity to explore the species diversity and abundance of birds in the islands of Korea. A total of 151 islands in the west and south areas in the Korean peninsula were examined. The number of species and the area of islands were highly significant (P<0.000) and the number of species and the distance from the mainland showed not so strong relationship. This indicated that bird species diversity has more influenced by the size of the islands not the distance. This can be from the study species of birds that can fly long distance, and also natural characteristics of migratory and resident status. Species-area curve showed that the z-value was 0.21 indicating the area and the bird species are strongly correlated. The long-term monitoring of bird species presence in the islands should be followed for a proper management plan.

A Comparative Study on a Macrobenthic Community Structure from the Theory of Island Biogeography (도서생물지리설의 관점에서 대형무척추동물 군집 비교)

  • Seo, In-Soo;Choi, Byoung-Mi;Kim, Mi-Hyang;Yun, Jae-Seong;Park, Jae-Yeong;Lee, Sang-Yeop
    • Korean Journal of Environmental Biology
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    • v.28 no.4
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    • pp.179-187
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    • 2010
  • The Theory of Island Biogeography describes that the number of species on an island affected by island area and distance from the mainland. This study was performed to compare and analyze the community structure of the macro-invertebrates in three isolated islands, around Korean waters in terms of the Theory of Island Biogeography. Macrobenthic animals were collected using a modified underwater quadrat in August 2009. A total of 104 macrobenthic species were sampled with a mean density of 399 individuals $m^{-2}$ and biomass of 1,506.70 g $m^{-2}$. Based on the abundance and biomass data, there were 10 dominant species accounting for approximately 67.17% of total individuals. The highest densities were found in the amphipoda Amphipoda spp., the bivalvia Modiolus agripetus and Mytilus coruscus, the Sipunculida Phascolosoma scolops and the polychaeta Syllidae unid.. On the contrary, the top ten species made up 95.66% of the total biomass while the three most abundant, the bivalves M. coruscus, Streostria circumpicta and M. agripetus. The conventional multi-variate statistics (cluster analysis and non-metric multi-dimensional scaling) applied to assess spatial variation in macrobenthic assemblages. Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity identified 2 station groups. The group 1 was consisted with Gageodo (except for lower station at Transect 2) and Dokdo station and was numerically dominated by the polychaetes Eunice antennata and Syllidae unid., the cirripedia Megabalanus rosa and the bivalvia M. coruscus. However, group 2 was associated with Sohwado station and was characterized by high abundance of the anomura Petrolisthes japonicus, the gastropoda Lirularia pygmaea and the brachiopoda Coptothyris grayi. In conclusion, these results suggested that the species diversity and community structure of macrobenthos in three isolated island seemed slightly related to island area and distance from the mainland.

Heterotrophic Euglenids from Marine Sediments of Cape Tribulation, Tropical Australia

  • Lee, Won-Je
    • Ocean Science Journal
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    • v.41 no.2
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    • pp.59-73
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    • 2006
  • This paper presents new data on free-living heterotrophic euglenids (Euglenozoa, Protista) that occurred in the marine sediments at Cape Tribulation, Queensland, Australia. Twenty-nine species from 9 genera are described with uninterpreted records based on light microscopy, including one new taxon: Notosolenus capetribulationi n. sp. There was little evidence for endemism because the majority of heterotrophic euglenid species encountered here have been reported or were found from other habitats.

Some Free-Living Heterotrophic Flagellates from Marine Sediments of Tropical Australia

  • Lee, Won-Je
    • Ocean Science Journal
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    • v.41 no.2
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    • pp.75-95
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    • 2006
  • The diversity of heterotrophic flagellates was examined at marine sediments around Cape Tribulation, Australia. The species described belong to the Alveolates, Apusomonadiae, Cercomonadida, Choanoflagellida, Cryptomonadida, Diplomonadida, Euglenozoa incertae sedis, Kathablepharidae, Kinetoplastida, Pedinellids, Stephanopogonidae, Stramenopiles, Stramenopiles incertae sedis, Thaumatomonadidae and Protista incertae sedis. Among the 51 species from 38 genera encountered in this study is one new taxon: Glissandra similis n. sp., and two new names are introduced: Goniomonas abrupta (Skvortzov 1924) nomen nodum and Cercomonas skvortzovi (Skvortzov 1977) nomen nodum. There was little evidence for endemism because most flagellates including one new taxon described here have been reported.

Two Corbicula (Corbiculidae: Bivalvia) mitochondrial lineages are widely distributed in Asian freshwater environment

  • Park, Joong-Ki;Kim, Won
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.05a
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    • pp.377-377
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    • 2003
  • We investigated the biogeography of Asian Corbicula using mitochondrial gene sequence variation for Corbicula members sampled from 24 localities of 8 Asian regions. A total of 210 individuals were genetically characterized by examining sequence variations of a 614 bp fragment of the mitochondrial cytochrome oxidase I (COI) gene. Phylogenetic analyses of the COI dataset revealed that Corbicula members are subdivided into two well-supported clades: estuarine and freshwater. (omitted)

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Phylogenetic Relationships of Ulva and Enteromorpha Inferred from nrDNA Internal Transcribed Spacer2 Sequences

  • Kang, Sae-Hoon;Lee, Ki-Wan
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.10a
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    • pp.303-304
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    • 2001
  • The family Ulvaceae species are difficult to distinguish from one another on the basis of morphological and cytological criteria alone. ITS2 sequences are hewn to evolve quickly and have been reported to be useful for the study of intraspecific and interspecific variation and biogeography in algae (Bakker et al., 1992). We will here describe the basic characteristics of the ITS2 sequences in Ulva and Effteromorpha to compare our result with the above previous studies. (omitted)

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Some Free-living Heterotrophic Flagellates from Marine Sediments of Inchon and Ganghwa Island, Korea

  • Lee, Won-Je
    • Animal cells and systems
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    • v.6 no.2
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    • pp.125-143
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    • 2002
  • Heterotrophic flagellates occurring in the marine sediments of Inchon and Ganghwa Island are reported. Fifty-six species from 38 genera were encountered in this survey and two new taxa were recorded: Cyranomonas australis sp. nov. and Gweamonas unicus sp. nov. There was little evidence for endemism because all flagellates including the two new taxa described here have been found from other habitats in Australia which are geographically remote from Korea. This study supports the model that free-living heterotrophic flagellates have a world-wide distribution.

The Record of Erysiphe azaleae(Erysiphales) from Poland and Its Anamorph

  • Shin, Hyeon-Dong;Mulenko, Wieslaw
    • Mycobiology
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    • v.32 no.3
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    • pp.105-109
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    • 2004
  • Erysiphe azaleae, a powdery mildew fungus on Rhododendron spp., was originally described from North America, and has only recently been recorded in Germany, England, Switzerland and Poland. The present paper records plentiful collections of this species from Poland, and provides additional information of its anamorphic state for taxonomic purposes.