• 제목/요약/키워드: foraging

검색결과 202건 처리시간 0.029초

대장균의 주화성에 근거한 박테리아 협동 최적화 (Bacteria Cooperative Optimization Based on E. Coli Chemotaxis)

  • 정희정;정성훈
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
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    • pp.241-244
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    • 2007
  • 본 논문에서는 박테리아의 주화성에 기초한 Bacteria Cooperative Optimization(BCO) 알고리즘을 소개한다. BCO는 Ant Colony Optimization (ACO)처럼 자연계에 존재하는 생명체의 행동양식을 모방하여 만든 최적화 알고리즘으로 크게 초기화, 측정, 행동결정, 이동으로 구성된다. 우리는 먼저 BCO 알고리즘을 설명하고 2차원 함수 최적화 문제를 이용하여 BCO알고리즘과 Genetic Algorithm(GA) 그리고 Bacterial Foraging for Distributed Optimization(BFO)의 성능 측정 결과를 기술한다. 실험 결과 BCO의 성능이 GA나 BFO보다 우수함을 보였다.

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Human Vesicular Glutamate Transporters Functionally Complement EAT-4 in C. elegans

  • Lee, Dukgyu;Jung, Sunki;Ryu, Jungmin;Ahnn, Joohong;Ha, Ilho
    • Molecules and Cells
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    • 제25권1호
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    • pp.50-54
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    • 2008
  • The vesicular glutamate transporter (VGLUT) transports glutamate into pre-synaptic vesicles. Three isoforms of VGLUT have been identified in humans, but their functional differences remain largely unknown. EAT-4 is the only homologue of human VGLUT in C. elegans. Here we report that mutants of eat-4 exhibit hyperforaging behavior and that each of the isoforms of human VGLUT functionally rescues the defects in eat-4 worms.

일본 북해도 낙엽활엽수림의 산림한경구조와 번식 조류 군집과의 관계 (The Relationship between Breeding Bird Community and Forest Structure at a Deciduous Broad-leaved Forest in Hokkaido, Japan)

  • Lee, Woo-Shin
    • The Korean Journal of Ecology
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    • 제19권4호
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    • pp.253-261
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    • 1996
  • This study was conducted to clarify the relationship between bird community and forest structure from early May to mid June, 1988 in two sites which had different forest structures due to silvicultural practice, located in the Tomakomai Experimental Forest of Hokkaido University, Hokkaido, Japan. Quantitative ahbitat analysis was applied to elucidate difference between the two study sites, and territory mapping method and guild analysis were used for assessment of the bird community. Dominant tree species were Quercus mongolica, Magnolia obovata, Prunus sargentii, Acer mono and Tilia japonica. Unithinned site had more foliage coverage in upper and middle layers, but in lower layer had less coverage than thinned site. Thirty four species of birds were recorded and of them only 21 species occupied territories within the study area. Dominant species were Ficedula narcissina, Phylloscopus occipitalis, Parus major, Passer rutilans, Sitta europaea and Parus palustris in the study area. The unmber of breeding species of the two sites were equal, but the species composition of breeding bird communities was different between the sites. The number of species and pairs on hole-nesting guild were greater in the unthinned site, but those on ground-nesting guild were greater in the thinned site. Canopy-nesting guild showed no significant difference between the two sites. Silvicultural practice such as proper thinning appeared to be not inadequate to all of the forest birds, probably good to bush and ground nesting guild, and to tree & bush and ground foraging guild. The silvicultural practice also did not considerably affect the hole and canopy-nesting guild.

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도시숲 백로류의 잠재번식지 선정을 위한 서식환경 조사 - 군산 백로류 집단번식지를 중심으로 - (A Survey on the Family Ardeidae Habitat for the Selection of the Alternative Breeding Sites at the Urban Forest in Korea)

  • 김정수;김상욱
    • 한국환경복원기술학회지
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    • 제20권2호
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    • pp.1-12
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    • 2017
  • This study aims to provide the basic habitat data for the alternative breeding sites of Family Ardeidae including Ardea cinerea, Egretta alba modesta, Egretta intermedia, Egretta garzetta, Bubulcus ibis and Nycticorax nyciticorax. Species numbers, flight directions for detecting foraging grounds and current vegetation structure were investigated nesting at Gunsan urban forest area. Data were collected over a period of 10 weeks, from 15 June - 31 August 2014. The total nest and population of Family Ardeida were 684 and 1,712 respectively. Percentage of birds observed flying in 8 major compass directions were as follows. 57.27% of all birds were observed flying northwest, 22.09% were observed flying south and 13.40% were flying north. For possible foraging areas, to the northwest, there are Geumgang river tidal flats, and to the south, paddy fields and streams within 2km. Flying directions by species (${\chi}^2=287.18$, P<.001, Cramer's V=0.12) and by seasons(${\chi}^2=839.94$, P<.001, Cramer's V=0.19) showed significant difference statistically. In relation between species and directions, 60.31% and 24.05% of Bubulcus ibis and 59.40% and 23.00% of Ardea cinerea were observed flying northwest and south respectively. Vegetation in the sites consist of an overstory of 3 to 7 species. At site 1, Pinus thunbergii was the dominant species and site 2, Chamaecyparis obtusa. Understory vegetation is composed of shrubs, saplings and small trees of Chamaecyparis obtusa, Quercus acutissima, Smilax china and Platycarya strobilacea. Egrets and herons usually nested at the dense population and canopy overlayed forest, and especially branches and leaves of smallwood with less than 10cm of breast height diameter were relatively severely damaged due to the nesting and excreta.

폭소노미에 따른 웹 분류 연구 - 이용자 태깅 행위 분석을 중심으로 - (A Qualitative Exploration of Folksonomy Users' Tagging Behaviors)

  • 박희진
    • 한국문헌정보학회지
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    • 제45권1호
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    • pp.189-210
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    • 2011
  • 본 연구는 실제 폭소노미를 사용하는 참여자의 태깅 경험, 태깅과 폭소노미에 대한 인식을 파악하며, 폭소노미에 따른 웹 분류의 의미에 대해 탐구하고자 한다. 세 개의 폭소노미 시스템 Connotea, CiteULike, Delicious의 12명 참여자와 함께 정성적 연구의 틀 내에서 웹 설문, 인터뷰, 일기연구를 수행하였다. 참여자들의 태깅 행위를 이루는 기본구성요소를 파악하고, 태깅활동에 참여하게 되는 동기와 그 태깅동기들이 참여자들이 사용하는 태그에 어떻게 반영되는지를 조사하였다. 또한 정보탐색(information foraging) 이론을 적용하여 참여자들이 태깅을 통해 참여하는 사회성과 상호작용성에 대한 경험과 인식을 분석하고, 정보냄새로서의 태그에 대하여 논의하였다. 이용자 참여를 기반으로 하는 본 연구의 실증적 연구결과들은 폭소노미를 활용한 웹 정보서비스를 다양한 각도에서 이해하는데 도움을 주고, 웹 정보자원의 분류와 조직에 있어서 폭소노미의 유용화를 연구하는 개념적 틀을 제시함으로써 폭소노미 현상의 연구 향상에 기여할 수 있을 것으로 기대한다.

먹이 종 감각 정보 제공에 따른 긴호랑거미(Argiope bruennichi)의 웹 건축 전략 (Web-Building Strategy of a Wasp Spider, Argiope bruennichi, under Sensory Information Emitted by a Prey Species)

  • 진우영;신현철;김길원
    • 생명과학회지
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    • 제21권7호
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    • pp.1009-1015
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    • 2011
  • 거미의 건축물인 웹의 구조는 먹이 포획을 위한 자원의 투자이자 그 자체가 포식 전략이다. 잠재적인 먹이종으로부터 제공되는 감각정보를 바탕으로 포식 전략을 수정하는 개체는 그렇지 못한 개체에 비해 더 높은 적응도를 가질 것이다. 본 연구는 공중에 둥근 웹을 건축하는 긴호랑거미(Argiope bruennichi)를 대상으로 자외선을 인식하는 비행성 곤충인 서양뒤영벌(Bombus terrestris)의 정보를 경험한 개체가 자신의 건축 행동을 수정하는지를 알아보기 위해 수행되었다. 서양뒤영벌(B. terrestris)의 정보를 제공받은 실험군의 개체가 건축한 웹의 구조를 대조군(정보 없음)의 웹과 비교하였다. 본 연구의 가설은 실험군 개체들은 웹과 흰띠줄 건축에 더 많은 투자를 할 것이라는 것이다. 실험 결과는 당초의 가설을 기각했다. 웹과 흰띠줄 건축은 실험군과 대조군 모두에서 전반적으로 감소하는 경향을 나타냈다. 개체는 꽃꿀채집자의 정보에도 불구하고 흰띠줄을 더 길게 만들지도 웹을 확장하지도 않았다.

조간대 갯벌에서의 도요·물떼새 서식지수용능력 추정 (Estimating Habitat Carrying Capacity of Shorebirds in the Intertidal Mudflat)

  • 문영민;김관목;유정칠
    • Ocean and Polar Research
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    • 제42권1호
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    • pp.21-31
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    • 2020
  • Shorebirds migrating along the East Asian-Australasian Flyway (EAAF) have been drastically decreasing due to continuous area loss and quality degradation of intertidal mudflats in the Yellow Sea. Evaluating the current habitat quality by means of habitat carrying capacity estimation could be effective in predicting the magnitude of impacts caused by habitat loss and provide better understanding to improve management strategies. In this study, we estimated the total biomass of Macrophthalmus japonicus, a main prey item of curlews in the Korea peninsular as habitat carrying capacity of the southern intertidal mudflat of Ganghwa Island, one of the key stopover sites for curlews in the EAAF. The result of the estimation took into account spatial differences of prey biomass and the available foraging time by tide patterns. Accordingly, it was found that curlew populations account for 30.26% of the habitat carrying capacity. When we calculated the mean biomass of the area and extrapolated it to the whole area to calculate the total biomass, it was found that the curlews have consumed 10.92% of the total biomass. The results show that the habitat carrying capacity of the southern intertidal mudflat of Ganghwa Island has decreased by 7.8% compared to a study conducted twenty years ago employing the same method. This study shows that there can be considerable differences in the results of habitat carrying capacity estimation between different methods, indicating that various environmental factors that affect the estimation results of habitat carrying capacity must be considered to achieve a more precise analysis and assessment.

Foraging Behavior of Helicoverpa armigera $H{\ddot{u}}bner$ (Lepidoptera: Noctuidae) First Instar Larvae on Selected Cotton Varieties

  • Amin, Md. Ruhul;Azad, H.M. Saifullah;Hossain, Md. Shamim;Suh, Sang Jae;Kwon, Yong Jung
    • Current Research on Agriculture and Life Sciences
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    • 제32권4호
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    • pp.185-188
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    • 2014
  • The movement, survival, and weight gain of Helicoverpa armigera $H{\ddot{u}}bner$ (Lepidoptera: Noctuidae) first instar larvae were studied on CB9, CB10 and SR05 cotton varieties under field conditions. The neonate H. armigera were released on the cotton varieties at the squaring stage of the plants and, after a period of 72 hours, the survival, weight gain, and final location of the larvae were observed. While the different cotton varieties had no effect on the survival and weight gain of the larvae, the release locations on the cotton varieties had a significant influence on the larval survival and weight gain. The larvae fed small squares of the cotton varieties were significantly heavier and showed a higher mortality than the larvae fed leaflets and mature leaves. For the cotton varieties in this study, the larvae released on leaflets showed a significantly higher rate of recovery compared to the larvae released on mature leaves and squares. This study also found that that the larvae on leaflets did not move up or downward unlike the larvae on mature leaves and squares. This information on the foraging behavior of larvae on cotton varieties will assist researchers to interpret field data and thereby help with the development of pest management decisions.

Dietary composition of two coexisting bat species, Myotis ikonnikovi and Plecotus ognevi, in the Mt. Jumbong forests, South Korea

  • Sungbae Joo;Injung An;Sun-Sook Kim
    • Journal of Ecology and Environment
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    • 제47권4호
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    • pp.168-176
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    • 2023
  • Background: Many insectivorous bats have flexible diets, and the difference in prey item consumption among species is one of the key mechanisms that allows for the avoidance of interspecies competition and promotes coexistence within a microhabitat. In Korea, of the 24 bat species that are known to be distributed, eight insectivorous bats use forest areas as both roosting and foraging sites. Here, we aimed to understand the resource partitioning and coexistence strategies between two bat species, Myotis ikonnikovi and Plecotus ognevi, cohabiting the Mt. Jumbong forests, by comparing the differences in dietary consumption based on habitat utilization. Results: Upon examining their dietary composition using the DNA meta-barcoding approach, we identified 403 prey items (amplicon sequence variants). A greater prey diversity including Lepidoptera, Diptera, Coleoptera, and Ephemeroptera, was detected from M. ikonnikovi, whereas most prey items identified from P. ognevi belonged to Lepidoptera. The diversity index of prey items was higher for M. ikonnikovi (H': 5.67, D: 0.995) than that for P. ognevi (H': 4.31, D: 0.985). Pianka's index value was 0.207, indicating little overlap in the dietary composition of these bat species. Our results suggest that M. ikonnikovi has a wider diet composition than P. ognevi. Conclusions: Based on the dietary analysis results, our results suggests the possibility of differences in foraging site preferences or microhabitat utilization between two bat species cohabiting the Mt. Jumbong. In addition, these differences may represent one of the important mechanism in reducing interspecific competition and enabling coexistence between the two bat species. We expected that our results will be valuable for understanding resource partitioning and the coexistence of bats inhabiting the Korean forests.