• Title/Summary/Keyword: 내부기생

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양돈생산에 있어서 내부 기생충에 의한 피해

  • Choe, Jae-Jun
    • The Korea Swine Journal
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    • v.11 no.6 s.118
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    • pp.136-139
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    • 1989
  • 루이지아나대학의 스테왈트교수와 죠지아대학의 헤일교수는 미국의 양돈산업에 미치는 기생충의 피해에 대해 작년에 J. Animal Science지에 기고한 바 있다. 두 교수의 조사에 의하면 내부기생충은 양돈장에 경제적으로 많은 피해를 주고 있는 것으로 밝혀졌다. 이와같은 점은 우리나라도 예외는 아닐 것이다. 이 원고는 두 교수가 J. Animal Science지에 기고한 내용임을 밝힌다. 내부기생충 구제로 양돈생산성을 높이길 바란다.

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닭에 대한 내부기생충의 피해

  • 김영환
    • KOREAN POULTRY JOURNAL
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    • v.3 no.6 s.20
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    • pp.41-45
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    • 1971
  • 누구나 다 아는 내부기생충(회충)$\cdots$$\cdots$ 그러나 그피해는 당신이 모르게 갑자기 나타난다. 왜?$\cdots$$\cdots$1달 자란 회충 한마리가 하루 5,000여개의 알을 낳기 때문이다. 정상을 벗어난 높은 폐사율, 성장부진, 산란이 피크에 올라가지 않을때, 난중이 빨리 증가하지 않을때 여러분은 그 닭의 기생충 보유유무를 체크할 필요가 있다.

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Studies on the Natural Enemies of Protopulvinaria mangiferae(Green) (Homoptera : Coccidae) (담팔수깍지벌레의 천적에 관한 연구)

  • Kim, Jong-Kuk;Morimoto, Katsura
    • Journal of Forest and Environmental Science
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    • v.14 no.1
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    • pp.128-137
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    • 1998
  • In Fukuoka, the natural enemies of Protopulvinaria mangiferae were confirmed as six primary parasitoids, three hyperparasitoids, and six predators. Among the primary parasitoids, Aneristus ceroplastae, Microterys flavus, and Coccophagus yoshidae were relatively abundant in Fukuoka. Aneristus ceroplastae and Coccophagus yoshidae were solitary endoparasitoid, whereas Microterys flavus was a gregarious endoparasitoid. Tetrastichus sp. was a hyperparasitoid and solitarily ectoparasitic to the pupae of Aneristus ceroplastae and Microterys flavus. The seasonal fluctuation of parasitisim and adult emergence of the important parasitoids was investigated in Fukuoka. Among the predatorys, Rhyzobius forestieri and Chilocorus kuwanae were relatively abundant, and seasonal fluctuation of adult emergence and consumption of the host were studied. As the first record from Japan, Rhyzobius forestieri was collected on leaves of Elaeocarpus sylvestris with heavy infestation of Protopulvinaria mangiferae.

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A New Method for Determination the Parasitic Extrinsic Resistances of MESFETs and HEMTs from the Meaured S-parameters under Active Bias (측정된 S-파라미터에서 MESFET과 HEMT의 기생 저항을 구하는 새로운 방법)

  • 임종식;김병성;남상욱
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.6
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    • pp.876-885
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    • 2000
  • A new and simple method is presented for determining the parasitic resistances of MESFET and HEMT from the measured S-parameters under normal active bias without depending on additional DC measurements or iteration or optimization process. The presented method is based on the fact that the difference between source resistance(Rs) and drain resistance(Rd) can be obtained from the measured Z-parameters under zero bias condition. It is possible to define the new internal device including intrinsic device and 3 parasitic resistances by elimination the parasitic inductances and capacitances from the measured S-parameters. Three parasitic resistances are calculated easily from the fact that the real parts of Yint,11 and Yint,12 of intrinsic Y-parameters are zero theoretically and the relations between S-,Z-, Y-matrices. The calculated parasitic resistances using the presented method and successively calculated equivalent circuit parameters give modeled S-parameters which are in good agreement with the measured S-parameters up to 400Hz.

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A Study on Small-signal and Large-signal Equivalent Model for Diodes (다이오드의 소신호 및 대신호 등가모델에 관한 연구)

  • 최민수;양승인;전용구
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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    • pp.267-271
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    • 2001
  • 다이오드의 소신호 및 대신호 파라미터 추출은 DC 해석, 외부 기생 소자 추출, 마지막으로 5-파라미터에 의한 내부소자 추출로 이루어진다. DC IV-곡선과 S-파라미터의 curve-fitting으로 내부 파라미터를 구하였고 외부 기생소자는 바이어스에 따라 변하지 성질을 이용하였다. 사용된 소자는 Schottky diode는 SIEMENS사의 BAS125를, Varactor diode는 SONY사의 1t362를, PIN diode는 Hitachi사의 HVM14S를 모델로 사용하였다. 실측을 위해 사용된 소자는 각각 HP사의 HSMS-2822, SONY사의 1t362, HP사의 HSMP-3834을 이용하여 측정하였다.

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Polydnavirus Replication and Ovipositional Habit of Cotesia plutellae (프루텔고치벌(Cotesia plutellae) 폴리드나바이러스 복제와 산란 습성)

  • Kim Yonggyun;Bae Sangki;Lee Sunyoung
    • Korean journal of applied entomology
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    • v.43 no.3 s.136
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    • pp.225-231
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    • 2004
  • An endoparasitoid wasp, Cotesia plutellae, has been used for a biological control agent against the diamondback moth, Plutellae xylostella. It has a symbiotic polydnavirus in their reproductive tract, which is required for its successful parasitization. Here, we measured a specific replication time of the polydnavirus during female development of C. plutellae. We, also, analyzed the reproductive potentials of female C. plutellae under mating or different host conditions. At $25^{\circ}C$, pupal C. plutellae began to develop adult tissues such as compound eyes and wings since day 2. At day 5, all adult tissues including antennae were developed and were ready to emerge. With polyclonal antibody raised against C. plutellae polydnavirus, an immunobloting could confirm virus replication at day 4 during pupal stage. Virus particles could be visualized by transmission electron microscope in the oviduct lumen of day 5 pupae. After adult eclosion, venom gland and ovarian calyx increased in size, though ovarioles did not. Mated females layed large number of eggs (over $60\%$) at first 4 days during their mean longevity of ca. 8 days at $25^{\circ}C$. Unmated females showed less active ovipositional behavior, where all the eggs developed into males. C. Plutellae parasitized both P. xylostella and fall webworm, Hyphantria cunea. However, C. Plutellae developed faster and showed higher successful paarasitization in P. xylostella than in H. cunea.