• Title/Summary/Keyword: exotic

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Study on the Dynamics of Fish Community in the Lake Paldang (팔당호의 어류군집 동태)

  • Son, Yeong-Mok;Song, Ho-Bok;Byeon, Hwa-Kun;Choi, Jae-Seok
    • Korean Journal of Ichthyology
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    • v.9 no.1
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    • pp.141-152
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    • 1997
  • The dynamics of fish community was investigated in the Lake Paldang from September 1995 to August 1996. The collected fishes were classified into forty two species involving in eleven families. Dominant species was Erythroculter erythropterus (relative abundance : 27.96%) and subdominant species was Lepomis macrochirus (20.69%). Also, Squalidus japonicus coreanus (19.25%), Opsariichthys bidens (4.07%), Hemibarbus labeo (3.42%), Acheilognathus yamatsutae (2.68%) and Micropterus salmoides (2.68%) were numerous. Dominant species was L. macrochirus in spring and autumn and S. japonacus coreanus in summer. E. erythropterus was subdominated in all seasons. The still-water fishes increased after construction of Paldang Dam. Ten were endemic species in Korea. Four species were exotic, and they occupied 24.75% in relative abundance. Dominance index was high at St. 2, diversity and evenness at St. 5, and richness at St. 4. In these stations, collection was made with casting net and scoop net. In the stations where collection was made with fixed shore net, dominance index was high at St. 8, diversity and evenness at St. 14, and richness at St. 7. E. erythropterus showed a stable age structure, while L. macrochirus was composed of mainly 3~4 year classes.

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Distribution Aspect and Extinction Threat Evaluation of the Endangered Species, Rhodeus pseudosericeus (Pisces: Cyprinidae) in Korea (멸종위기어류 한강납줄개 Rhodeus pseudosericeus (Pisces: Cyprinidae)의 분포양상 및 멸종위협 평가)

  • Ko, Myeong-Hun;Han, Mee-Sook;Kwan, Sun-Man
    • Korean Journal of Ichthyology
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    • v.30 no.2
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    • pp.100-106
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    • 2018
  • The distribution aspect and extinction threat evaluation of the endangered species, Rhodeus pseudosericeus were investigated from 2012 to 2017 in Korea for the subject of this study. The number of appearance sites in the past literature of available and identified R. pseudosericeus was 26. During the study period, the samples of R. pseudosericeus were collected in 44 sites (Hangang River 35 sites, Sapgyocheon Stream 4 sites, Daecheoncheon Stream 5 sites) among the noted 214 sampling stations investigated. Among these, the newly appearance streams were Ilricheon Stream, Samsancheon Stream, Bangyecheon Stream and Hanpocheon Stream in the Hangang River. In addition, the habitats and populations in the upper Seomgang River (Hoengseong Dam), lower Heukcheon Stream, Muhancheon Stream and Daecheoncheon Stream decreased due to dam construction, river work, water pollution, and the spread of the exotic species Micropterus salmoides. The main habitat of R. pseudosericeus was the middle-upper stream of clean water with slow water velocity, sand-pebble bottoms and lots of aquatic plants. Given this evidence as noted for the 30.2% reduction in occupancy within 10 years, due to the qualitative decline of habitat, the overfishing risk of ornamental fish and the spread of M. salmoides, in this case R. pseudosericeus is considered to be Vulnerable (VU A2cde) based on the IUCN Red List categories and criteria.

Constructing a Heterotopia of Migrant Space: 'Weekend Flat' of Filipino Migrant Care-givers in Tel Aviv, Israel (헤테로토피아로서의 이주 공간: 텔아비브 필리핀 노인돌봄노동자들의 '주말아파트'를 중심으로)

  • Lim, Anna
    • Journal of the Korean Geographical Society
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    • v.51 no.6
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    • pp.799-817
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    • 2016
  • This article aims to reveal the ways in which a "space of difference" is produced and interpret the space as a heterotopic space, drawing the case of Filipino elderly care-givers in Israel. The in-betweens and temporariness of the migrants'experiences in the Israeli society lead to the creation of a heterotopic space. Paying attention to their particular life rhythm as live-in care-givers, namely weekdays-workplace and weekend-flat, this article explores how the migrant care-givers build their own society through a variety of spatial practices and multiple social relations based on the flat. In making the flat a perfect form of a lifestyle for their own, the migrants inscribe their presence in the flat in unique ways for different purposes, in a way different to that which surrounds it. However, the structure of flat not only signifies the migrants' marginality but also reflects the challenging position. The flat has functions in relation to all other space that remains, even if such connection often creates effects of contrast and difference. In this light, the flat is not merely an alienated and circumscibed exotic migrant enclave but a heterotopic space which is dynamically constructed in relation to other sites in the wider societal order.

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Characteristics of Vegetation Structure on the Ridge of the Naknam-Jeongmaek (낙남정맥 마루금 일대의 식생구조 특성)

  • Oh, Koo-Kyoon;Kang, Hyun-Mi;Park, Seok-Gon
    • Korean Journal of Environment and Ecology
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    • v.28 no.6
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    • pp.725-740
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    • 2014
  • To figure out the vegetation situation in the ridge of the Naknam-Jeongmaek, six intensive survey sites were selected considering environmental factors and human interferences, 132 quadrats (area $100m^2$) were installed to survey appearing species of trees and major environmental factors, and the characteristics of vegetation structures were analyzed. The surveyed plots were divided into six groups according to the analysis of classification by TWINSPAN; Quercus mongolica-Q. variabilis community, Pinus densiflora-Q. dentata community, Chamaecyparis obtusa community, Q. mongolica-P. densiflora community, P. densiflora-P. thunbergii community, P. koraiensis community, Rhododendron spp.-Lespedeza cyrtobotrya community. P. densiflora-Q. dentata community, Q. mongolica-P. densiflora community, and P. densiflora-P. thunbergii community are expected to be succeeded by deciduous oaks because the power of deciduous oaks is strong in their lower layer. C. obtusa community, P. densiflora community, and Rhododendron spp.-L.cyrtobotrya community are artificial forests that were artificially formed and are expected to be maintained in the current state for some time because the dominance value of planted species of trees is high. Most vegetations in Naknam-Jeongmaek were secondary forests or artificial forests formed for forest tree production and forestation for erosion control. In particular the top regions and hilly sections of the mountain were mostly dominated by deciduous oaks such as Q. mongolica, Q. variabilis showed some P. densiflora community competing with deciduous oaks. On the other hand, low sections and regions adjacent to the city showed severe artificial interference since exotic species such as P. thunbergiil, C. obtusa, P. koraiensis, and Rhododendron spp. were planted.

Characteristics of Fish Fauna and Community Structure in Daecheon Stream in Boryeong, Korea (보령 대천천의 어류상과 어류 군집 특성)

  • Song, Mi-Young;Jung, Seung-Yoon;Kim, Kyung-Hwan;Baek, Jae-Min;Lee, Wan-Ok
    • Korean Journal of Environment and Ecology
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    • v.27 no.4
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    • pp.437-448
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    • 2013
  • The ichthyofauna and fish community were studied in Daecheon Stream from April to October 2012. During the survey period a total of 42 species belonging to 13 families were collected. Dominant species by number was Zacco platypus(32.3%) and Tridentiger brevispinis(12.8%). In biomass, the dominant species was Z. platypus(27.7%) and Chelon haematocheilus(11.9%). Also, eight Korean endemic fish species and one endangered species (Rhodeus pseudosericeus) were collected. In addition, two exotic species(Carassius cuvieri and Micropterus salmoides) and migration fish species(Anguila japonica) were observed. Based on the length-weight relationship of Z. platypus, the b value was 3.21~3.29, and the condition factor(K) was 0.89 on average with stable condition. According to similarity analysis, fish communities in Daecheon Stream were divided into three groups; the upper reaches near a reservoir(St. 1), the middle reaches (St. 2 to 4) and the lower reaches near a weir(St. 5). Dominant species at each group were Zacco koreanus(St. 1), Z. platypus(St. 2 to 4) and T. brevispinis(St. 5). This result suggested that artificial structures such as dam and a weir have a marked effect on the distribution of fish communities in Daecheon Stream.

Freshwater Fish Fauna and Community Structure of the Small Streams in Bogil Island, Korea (보길도 소하천 담수어류상 및 군집구조)

  • Han, Jeong-Ho;Park, Chan-Seo;An, Kwang-Guk;Paek, Woon-Kee
    • Korean Journal of Environment and Ecology
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    • v.31 no.1
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    • pp.72-80
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    • 2017
  • Fish fauna and community structures in freshwater were analyzed in the streams (12 stations) of the Bogil Island from May to September 2015. Total numbers of the sampled species and genus (9 families) were 21 and 17, respectively. Gobiidae was the most dominant taxa, which accounted for 47.6% (10 species) of the total species, and the relative abundance, based on the number of individuals, was 60.4% (1,157 individuals). Subdominant families were three taxa of Cyprinidae (3 species; 500 ind.), Mugilidae (2 species; 168 ind.) and Mugilidae (2 species; 128 ind.). The dominant species, based on the relative abundance, was Rhynchocypris oxycephalus (20.7%) and the subdominant species were Gymnogobius urotaenia (19.5%), Leucopsarion petersii (17.2%) and Chelon haematocheilus (8.5%). These species were composed of upstream-resident fish as well as migratory fishes, so the streams of the Bogil Island had unique characteristics in the fish compositions. Based on all the species sampled, 9 species (42.9%) were primary freshwater fishes, 11 species (52.4%) were peripheral fishes and 1 species (4.8%) was amphidromous fish. Korean endemic species and exotic species were not found in the streams of Bogil Island. According to the analysis of fish community structure, species richness index and species diversity index were highest (1.831, 1.957) in the Site 8 and lowest in the Site 4. In the meantime, the dominance index was highestin the Site 4 (1.00) and lowest in theSite 8 (0.17).

Spin-orbit Coupling Effect on the Structural Optimization: Bismuth Telluride in First-principles (스핀-궤도 각운동량 상호작용의 구조 최적화에 대한 효과: 비스무스 텔루라이드의 제일원리 계산의 경우)

  • Tran, Van Quang;Kim, Miyoung
    • Journal of the Korean Magnetics Society
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    • v.23 no.1
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    • pp.1-6
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    • 2013
  • Spin-orbit coupling (SOC) effect is known to be the physical origin for various exotic magnetic phenomena in the low-dimensional systems. Recently, SOC also draws lots of attention in the study on magnetically doped thermoelectric alloys to determine their properties as the thermoelectric application as well as the topological insulator via the exact electronic structures determination near the Fermi level. In this research, aiming to investigate the spin-orbit coupling effect on the structural properties such as the lattice constants and the bulk modulus of the most widely investigated thermoelectric host material, $Bi_2Te_3$, we carried out the first-principles electronic structure calculation using the all-electron FLAPW (full-potential linearized augmented plane-wave) method. Employing both the local density approximation (LDA) and the generalized gradient approximation (GGA), the structural optimization is achieved by varying the in-plane lattice constant fixing the perpendicular lattice constant and vice versa, to find that the SOC effect increases the equilibrium lattices slightly in both directions while it markedly reduces the bulk modulus value implying the strong orientational dependence, which are attributed to the material's intrinsic structural anisotropy.

Studies on Resource Plants of the Mireukbong and Manduksan in Jeollabuk-do (전라북도 만덕산과 미륵봉 일대의 자원식물상 연구)

  • Kim, Young-Ha;Beon, Mu-Sup;Oh, Hyun-Kyung
    • Korean Journal of Plant Resources
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    • v.19 no.4
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    • pp.447-458
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    • 2006
  • The resource plants at the Manduksan and Mireukbong was listed 550 taxa: 107 families, 339 genera, 481 species, 1 subspecies, 65 varieties and 3 forms. Among 550 taxa listed was confirmed 323 taxa of edible plants (58.7%), 384 taxa of medicinal plants (69.8%), 267 taxa of ornamental plants (48.5%) and 268 taxa of the others (48.7%). Based on the list of the rare plants by the Forest Research Institute, 4 taxa were recorded in the studied areas; Lilium distichum (Preservation priority order: No. 159), Tricyrtis dilatata (No. 97), Aristolochia contorta (No. 151), Prunus yedoensis (No. 110) and based on the list of Korean endemic plants, 11 taxa were recorded; Cephalotaxus koreana, Carex okamotoi, Lilium amabile, Populus tomentiglandulosa, Salix purpurea var. japonica, Pseudostellaria multiflora, Prunus yedoensis, Forsythia koreana, Paulownia coreana, Weigela subsessilis, Aster koraiensis. Specific plant species by floral region were total 30 taxa; Prunus yedoensis in class V, Wistaria floribunda in class IV, 3 taxa (Spiraea salicifolia, Acer palmatum, Asperula lasiantha) in class III, 3 taxa (Potentilla dickinsii, Viola tokubuchiana var. takedana, Caryopteris incana) in class II, 22 taxa (Pinus koraiensis, Hosta capitata, Chloranthus japonicus, Salix glandulosa, Juglans mandshurica, etc.) in class I. This site needs urgent countermeasures, because there have increased many man-made damages like planting exotic plants, picking wild plants and soil compaction induced by human trampling.

A Study on the mobile Augmented reality of game Pokemon Go (모바일 증강현실 게임 포켓몬Go의 특성 연구)

  • Joo, Eun-Ryeong;Chung, Jean-Hun
    • Journal of Digital Convergence
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    • v.17 no.12
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    • pp.473-480
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    • 2019
  • Recently, local game companies have been increasingly producing PC-based game that were popular with users among the existing commercialized games into mobile games through remakes. In this paper, we studied how console-based game influenced mobile augmented reality game . Through this process, we extracted five characteristics of mobile augmented reality, then interpreted and classified the meaning of this. Based on released in 2016, the scope of research is limited to console and mobile games previously released. According to the analysis, showed 50 characteristics and borrowed 78% from its existing Pokemon, 22% from its new production, and contained 24% reality. We also found that the Pokemon game series , and the exotic series had much influence on production. Based on this research data, we hope that augmented reality games for mobile will be made more active using existing game contents. It is also hope that such activities will lead to the growth of the home and abroad game industry.

Freshwater Fish Fauna of the Yeosu Peninsula and Geumo Islands, Korea (여수반도와 금오열도의 담수어류상)

  • Chae, Byung-Soo;Yoon, Hee-Nam
    • Korean Journal of Ichthyology
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    • v.19 no.3
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    • pp.225-235
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    • 2007
  • The freshwater fish fauna and physical characteristics of streams in Yeosu peninsula and Geumo Islands were surveyed at thirty nine stations in the period of 2003 and 2005. Most of the streams were short in length and narrow in flowing water width. Main materials of riverbed in most stations were cobble, pebble and gravel; those in the stations adjacent river mouth gravel and sand. In the river type, eighteen stations out of surveyed stations were upstream type: Aa. Thirty nine fish species belonging sixteen families were caught in this survey region. Among them twenty seven species were primary freshwater fishes and nine were peripheral. In the species composition of each family, there were the most species in Cyprinidae and Gobiidae, twelve and ten species, respectively. Endemic species of Korean peninsula in this region were eight species. One exotic fish species, Lepomis macrochirus was found in Yeosu peninsula. Dominant species in each district was Zacco temminckii in Yeosu peninsula, Rhinogobius brunneus in Dolsan Island, Leucopsarion petersii in Geumo island and Oryzias latipes in Gae island. In the analysis of community structure, it was appeared that the community of Yeosu peninsula was the most diverse and stable in this region; as the size of island became smaller, diversity and richness of community decreased. Kichulchoia brevifasciata did not caught in this survey, and it is possible that the species was extincted in this island. Acanthorhodeus gracilis and L. petersii were reported firstly in this region.