• Title/Summary/Keyword: 잠자리

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Feeding Ecology of the Endangered Endemic Species, Rhynchocypris semotilus (Pisces: Cyprinidae) in the Songhyeoncheon (Stream), Korea (송현천에 서식하는 멸종위기어류 버들가지 Rhynchocypris semotilus (Pisces: Cyprinidae)의 섭식생태)

  • Hyeok-Yeong Kwon;Hyung-Soo Seo;Myeong-Hun Ko
    • Korean Journal of Ichthyology
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    • v.36 no.1
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    • pp.68-76
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    • 2024
  • To reveal the feeding ecology of Rhynchocypris semotilus, the survey was conducted in Songhyeoncheon, Songhyeon-ri, Hyeonnae-myeon, Goseong-gun, Gangwon-do in April 2022. As a result of analyzing the contents of the stomach using the index of relative importance (IRI), the important prey organisms were mainly Trichoptera (46.6%), Ephemeroptera (27.6%), Diptera (12.6%), Odonata (9.7%), Plecoptera (2.8%), Coleoptera (0.6%), and Hemiptera (0.1%) of Class Insecta, Phylum Arthropoda in that order. As a result of analyzing the trend by calculating the index of relative importance (IRI) for each age, it was found that those born in the same year mainly feed on relatively small Ephemeroptera and Diptera, but the proportion of these gradually decreases as they grow. And the proportion of relatively large Trichoptera and Odonata gradually increased, turning them into the most important food source for those over 3 years old. Additionally, prey size was the smallest at 2.8±2.5 (0.6 to 9.0) mm for individuals born in the same year, but gradually increased to 5.1±6.1 (1.1 to 17.0) mm for individuals born more than 3 years. As a result of examining prey selectivity, Plecoptera (+0.78), Trichoptera (+0.66), (+0.66), Coleoptera (+0.66), and Hemiptera (+0.03) showed positive selectivity, while Amphipoda (-1.00), Ephemeroptera (-0.24), Odonata (-0.13) and Diptera (-0.05) showed negative selectivity.

V+관세 국제운임의 구성과 관세의 과세 - 운임은 항상 부담스러워 - 국제운임의 구성과 관세의 과세 -

  • Lee, Ji-Su
    • Venture DIGEST
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    • no.2 s.127
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    • pp.56-57
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    • 2009
  • 어느날 저녁 귀가 후 잠자리에 들 준비를 하고 있는데 예전에 알고 지냈던 S사장님이 전화를 하셨다. 격 없이 지내던 사이지만 시계는 11시를 가리키고 있었고 목소리도 뭔가 대단히 화가 나 있었다. 전화 내용은 이러했다. 국제특송으로 영국서 6만 원짜리 물건을 받았는데 운임이 물건 값의 두 배인 12만 원이 나왔다는 거다. 한 밤중에 전화기를 들만도 하다. 보통 운임이 물건 값을 넘게 되면 물건을 받는 사람은 화부터 난다. 그런데 막상 따지고 싶어도 운임으로 청구된 금액이 무엇인지를 몰라 답답하기 일수다. 이번 호에서는 운임의 구성에 대해 살펴보기로 하자.

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초고속 무선 데이터 전송을 위한 홈 네트워킹 기술 비교

  • 박지우;조성언;김재영;강희조;오창헌
    • The Magazine of Kiice
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    • v.5 no.1
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    • pp.57-64
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    • 2004
  • 홈 네트워킹(home networking)이란 용어는 가정(home)과 장비들 간의 통신이 가능하도록 하는 망구성(networking)이란 두 가지 용어가 합쳐진 말이다. 가정에 있는 모든 장비들을 연결해 서로 통신할 수 있도록 함으로써, 가족 구성원이 현재 위치에 관계없이(가정 내의 위치 또는 가정 밖의 위치에 무관하게) 가정 내 장비를 제어하거나 통신할 수 있도록 해주는 기술이다. 예를 들어, 거실에 앉아서 잠자리에 든 아이들 방의 불을 끈다거나, 외출하다가 도시 가스 밸브를 열어놓은 것이 생각나면 휴대폰으로 가스차단기를 작동시키는 등 일상생활에 즉시 적용할 수 있는 기술이다[1]. (중략)

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Community Structure of Aquatic Insects in Miryang-Dam Water System (밀양댐 수계의 수서곤충 군집에 대하여)

  • Park, Yeon-Kyu;Park, Hyean-Cheal
    • Journal of Wetlands Research
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    • v.2 no.2
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    • pp.133-146
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    • 2000
  • An ecological survey was performed in Miryang dam water system during the period of June 5~6, 2000. The fauna collected from 7 sites consisted of total 67 species, 49 genus, 25 families, in 7 orders of aquatic insects. These included 29 species of Ephemeroptera, 22 species of Trichoptera, 7 species of plecoptera, 6 species of Diptera, 1 species of Megaloptera, Odonata and Coleoptera repectively. The relative abundance of Ephemeroptera, Trichoptera, Plecoptera, Diptera, and Coleoptera was 71 %, 11.2%, 5.1%. 11.9% and 0.6% respectively. The primary dominant species of tatal level was Epeorus aesculus, and second dominant species was Epeorus latifolium. The primary dominant species were Heptagenia kihada at site 1, Ecdyonurus dracon at site 2,3,4 and Epeorus aesculus at site 5, Epeorus latifolium at site 6,7. Dominance indices were ranged from 0.30 to 0.55, and species diversity indices from 3.11 to 4.25(mean=3.71). Saprobic system based on species diversity indicated that whole sites were oligosaprobic.

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The relation of fatigue, stress with quality of sleep among nursing students (간호대학생들의 피로, 스트레스와 수면의 질 관계)

  • Chung, Eunja;Lee, Yumi
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.4
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    • pp.311-316
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    • 2020
  • The purpose of this study is to compare fatigue, stress and quality of sleep between good sleep quality and poor sleep quality. Fatigue, stress and quality of sleep were assessed using three questionnaires; fatigue severity scale(FSS), Perceived stress scale(PSS), and Pittsburgh sleep quality index(PSQL). As a result of the study, the higher stress(22.2 vs. 19.0, p=.000) and poorer quality of sleep(11.2 vs. 5.7, p=.000) were observed between good sleep quality and poor sleep quality groups. Our finding show that time of going to bed and stress level influenced quality of sleep.

A taxonomic study of Korean Platanthera with a special reference to external morphology (한국산 제비난초속(Platanthera)의 분류학적 검토: 외부형태학적 형질을 중심으로)

  • Lee, Jin-Sil;Choi, Byoung-Hee
    • Korean Journal of Plant Taxonomy
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    • v.35 no.1
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    • pp.25-46
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    • 2005
  • External morphology focusing on the flower structure of Korean Platanthera was examined. The genus Tulotis was included to the genus Plathanthera as previously suggested by many workers, because the diagnostic character to distinguish the two genera was not distinct enough. It is revealed that the taxon previously recognized as P. metabifolia was the misidentification of P. chlorantha and P. neglecta should be treated as a distinct species from P. mandarinorum. In result, Korean Platanthera were rearranged into 8 species; P. chlorantha, P. mandarinorum, P. neglecta, P. hologlottis, P. japonica, P. ophrydioides, P. ussuriensis, and P. fuscescens. A key to the species of Korean Plathanthera and taxonomic discussion of each species were provided.

An Electron Microscopy of Spermiogenesis in the Dragonfly, Crocothemis servilia Drury (고추잠자리의 精子完成의 電子顯微鏡的 硏究)

  • Paik, Kyong Ki;Choi, Choon Keun;Lee, Kuk Bum
    • The Korean Journal of Zoology
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    • v.15 no.3
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    • pp.133-147
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    • 1972
  • Ultrastructures of spermiogeneis in other invertebrates were investigated by several workes (Anderson, et al., 1967; Bloch, et al., 1964; Christen, 1961; Gatenby, et al., 1959; Paik, et al., 1968; Silveira, 1964; Yasuzumi, 1957) but spermiogenesis of dragonfly has not been reported previously. Testes and vass deferentia of the Korean dragonfly, Crocothemis servilia, were used for electron microscopic study of spermiogenesis. Materials were prefixed for 1-2 hours at $3^{\circ}C$ in 1.25% glutaraldehyde buffered to pH 7.2 with 0.2M sodium cacodylate buffer. Fixed tissue was washed twice in 0.2M cacodylate buffer and was subsequently postfixed for 2 hours at $3^{\circ}C$ in 1% osmium tetroxide buffered to pH 7.2 with 0.4M sodium cacodylate buffer solution. Specimens were dehydrated in graded ethyl alcohol, and finally embedded in epoxy Epon resin. Thin sections prepared from all the blocks were doubly stained; first in uranyl acetate and then in lead citrate. All thin sectios were examined with a Hitachi HS-7S electron microscope. The results of this study were summarized as follows. 1. Along the condensation of chromatin in nucleus, the shpae of nucleus was changed from spherical shpae to ellipse and cone cell type. 2. During the elongation of nucleus and the migration of cytoplasm, the nucleus removed to the one side of spermatid and began to invaginate from the posterior portion of nucleus. 3. There are ring centrioles in invaginated portion and axial filaments derived from centriole extend to the tail through the tailward half of spermatid. 4. In the cross sections the axial filament consisted of a central sheath, a central fibril, and 9 peripheral doublets.

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특집 - 남성 당뇨병환자의 성기능장애

  • Gang, Jeong-Yun
    • The Monthly Diabetes
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    • s.209
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    • pp.16-18
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    • 2007
  • 5년 전부터 경구혈당강하제를 먹고 있는 56세 남자로 발기부전을 주소로 비뇨기과 외래를 방문했다. 약 3$\sim$4년 전부터 성기의 강직도가 좀 떨어졌지만, 부부관계를 끝까지 할 수는 있었는데, 최근 1년 전부터는 관계 도중에 사정을 하지도 않았는데 발기가 소실되어 버리는 경우가 생겨 당황하게 되기도 하였다. 급기야는 발기가 제대로 되지 않아 부부관계를 전혀할 수가 없어서 몇 번 시도 하다가 실패한 후로는 시도조차하지 않고 지내고 있다고 한다. 정력에 좋다는 건강보조식품을 먹어도 별로 도움이 되지 않는 것 같아서, 친구에게서 얻은 비아그라를 한알 먹어 보았는데, 효과를 보지는 못했다고 한다. 간혹 새벽발기도 되는 때가 있고, 이전 같지는 않지만 마음이 동할때도 있지만, 몇 번의 좌절을 겪은 후라 선뜻 시도하기가 두렵다고 하였다. 성기능을 평가하는 설문인 국제발기능지수로 보았을 때 11점으로 중등도의 발기부전이었고, 기본적인 혈액검사와 남성호르몬 수치는 정상이었다. 위와 같은 경우가 당뇨병에 의한 발기부전의 가장 흔한 예 중 하나인데, 대개 발기력의 약화가 서서히 진행되고, 성관계의 실패로 몇 번 당황한 후로는 의기소침 해져서 잠자리를 멀리하게 된다. 남성호르몬 수치가 정상이고 새벽발기도 간혹 되므로 경구용 발기부전 치료제가 우선적으로 선택될 수 있다. 이전에 친구에게서 얻어 먹은 비아그라는 약이 진짜인지 가짜인지가 불분명 하고, 무엇보다 복용법을 정확히 지키지 않아서 효과가 없을 수 있다.

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Visualization Study of Dragonfly Type Wing : Reduced Frequency (잠자리 유형 날개의 가시화 연구 : 무차원 진동수)

  • Kim Song Hak;Chang Jo Won
    • 한국가시화정보학회:학술대회논문집
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    • 2004.11a
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    • pp.14-17
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    • 2004
  • A purpose of this visual experiment is to investigate the effect of reduced frequency qualitatively by examining wake pattern change for insect flying motion. Insect is composed of two pair wing with forewing and hindwing, flying motion of insect is performed pitching and plunging so it makes a separation over the wings. The separation affects at the wake pattern and changed wake pattern has an influence on lift, drag and propulsion. This experiment is conducted by using a smoke wire technique and a camera is fixed at hindwing to take a photograph of wake. An electronic device is mounted below test section to find exact the mean positional angle of wing. The reduced frequency in experiment is 0.15, 0.3 and 0.45. We obtained the result which that reduced frequency is closely related to wake pattern that determines flight efficiency.

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Visualization Study on a Reduced Frequency of a Dragonfly type wing (잠자리 유헝 날개의 무차원 진동수에 따른 가시화 연구)

  • Kim Song Hak;Chang Jo Won
    • Journal of the Korean Society of Visualization
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    • v.2 no.2
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    • pp.58-65
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    • 2004
  • The purpose of this visualization study is to investigate the effect of reduced frequency qualitatively by examining wake patterns for dragonfly flight motion. Dragonflies have two pairs of wing (a forewing and hindwing) and flight is achieved by a pitching and plunging, so it makes a separation over the wings. The separation affects the wake pattern and changed wake pattern has an influence on lift, drag, and propulsion. This experiment was conducted by using a smoke wire technique and a camera fixed above the test section used to take a photograph of the wake. An electronic device is mounted below the test section to find the exact mean positional angle of the wing. The reduced frequency in the experiment is 0.15, 0.3 and 0.45. Results show that reduced frequency is closely related to the wake pattern that determines flight efficiency.

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