• Title/Summary/Keyword: 새들

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Prevalence of Anaplasma sp. in Thrushes (Family Turdidae) in Jeju Island, Republic of Korea (제주도와 마라도내 지빠귀과 조류에서 Anaplasma spp. 감염 조사)

  • Oh, Mi-Rae;Moon, Kyoung-Ha;Kim, So-Yeon;Kim, Yun-Gi;Choi, Chang-Yong;Kang, Chang-Wan;Kim, Hwa-Jung;Lee, Kyoung-Kap;Yun, Young-Min
    • Journal of Veterinary Clinics
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    • v.31 no.3
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    • pp.206-211
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    • 2014
  • Anaplasmosis is a rickettsial zoonosis mediated by blood-sucking arthropods, such as ticks, flies, and mosquitos. Migratory birds are common hosts of ticks that are mediators of anaplasmosis, in particular, the tick infection rate in thrushes (family Turdidae) has been known to be high. The main purpose of this study is to survey the occurrence and prevalence of Anaplasma spp. from the migratory thrushes in Jeju island. We collected blood samples from 6 thrushes rescued at the Jeju Wildlife Rescue Center and from 34 wild-caught thrushes on Mara island which is a satellite island of Jeju. As a result, the nested PCR confirmed that seven out of 40 individuals (17.5%) were infected by Anaplasma spp. and all of them were identified as A. phagocytophilum based on sequences obtained from partial 16S rRNA. All the infected birds were on their northward migration in spring, our results suggest that the Turdidae family, which is a common and abundant migrant group passing through Jeju island, may act a role as active reservoir and disperser of A. phagocytophilum causing potential influx of the zoonotic pathogens from its wintering grounds in lower latitude to the mainland Korea as well as Jeju.

A Study on Improvement of Structural Strength Evaluation Methods for Tank of Tank Car used for Carrying Hazard Materials (위험물 수송 철도차량 탱크의 구조강도 평가방법 개선연구)

  • Lim, Chung-Hwan;Goo, Byung-Choon
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.239-245
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    • 2008
  • In this study, we researched about characteristics of many kinds of tank cars for carrying hazard materials and performed structural strength evaluation using finite element analysis for tank of asphalt tank car to suggest the efficient analysis method that can develop accuracy regarding to characteristics of tank cars. For this, we analyzed the asphalt tank refer to JIS E 7102 (Design Method for Tanks of Tank Cars). As results, we could show that the maximum stress is applied at the area supported by saddle and the maximum stress is under a criterion suggested from JIS E 7102. Therefore we verified that this asphalt tank car had enough structural strength.

Topological View of Viscous Flow behind Transom Stern (트랜섬 선미 후방의 점성 유동장 Topology 관찰)

  • Kim, Wu-Joan;Park, Il-Ryong
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.4 s.142
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    • pp.322-329
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    • 2005
  • Viscous flows behind transom stern are analyzed based on CFD simulation results. Stern wave pattern is often complicated due to the abrupt change of stern surface curvature and flow separation at transom. When a ship advances at high speed, whole transom stern is exposed out of water, resulting in the so-called 'dry transom'. However, in the moderate speed regime, stern wave development in conjunction of flow separation makes unstable wavy surface partially covering transom surface, i.e., the so-called 'wetted transom'. Transom wave formation is usually affecting the resistance characteristics of a ship, since the pressure contribution on transom surface as well as the wave-making resistance is changed. Flow modeling for 'wetted transom' is difficult, while the 'dry transom modeling' is often applied for the high-speed vessels. In the present study CFD results from the RANS equation solver using a finite volume method with level-set treatment are utilized to assess the topology of transom flow pattern for a destroyer model (DTMB5415) and a container ship (KCS). It is found that transom flow patterns are quite different for the two ships, in conformity to the shape of submerged transom. Furthermore, the existence of free surface seems to after the flow topology in case of KCS.

Study for Field Inspection of Phase-Array Ultrasonic for Electro-fusion Joints of Polyethylene Gas Pipes (폴리에틸렌 가스배관 전기융착부 위상배열초음파검사 현장사례 연구)

  • Kil Seong-Hee;Kwon Jeong-Rock;Park Kyo-Shik
    • Journal of the Korean Institute of Gas
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    • v.10 no.2 s.31
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    • pp.61-67
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    • 2006
  • We developed the ultrasonic phased array technique for obtaining ultrasonic images of electrofusion joints of polyethylene piping. And we inspected 4 cases at fields with this technique. First case is for the 300 mm diameter polyethylene electrofusion joint by using 3.5 MHz phased array sensor, second is for the 350 mm diameter saddle electrofusion joint, third is for the 400 mm diameter electrofusion joints and the last one is for the 400 mm diameter piping joints which will be used at 300 kPa suppling pressure.

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Study on Hydraulic Characteristis for Upstream Migration of Fish in a Pool-and-Weir Fishway (어족의 소상을 위한 계단식어도 수리특성에 관한 연구)

  • Kim, Jin-Hong;Kim, Chul
    • Water for future
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    • v.27 no.2
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    • pp.63-72
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    • 1994
  • In this study, hydraulic characteristics for upstream migration of fish in a pool-and-weir fishway were analyzed through experiment. The results showed that streaming flow was preferable to plunging flow for upstream migration of fish and it was not good to make an orifice beneath the septum since it generates turbulent jet and eddies. Protrusions on the side wall of fishway were preferable to grooves since they decelerate flow velocity and make upstream migration easy. A vertically movable septum was necessary for a flushing of deposited bed material, and net installing over fishway was also needed for birds not to approach the fishway and eat fish.

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Impact Structural Behavior by Bird Strike on Engine Inlet Nacelle (엔진 흡입구 나셀의 조류 충돌에 대한 충격 거동 해석)

  • Kong, Chang-Duk;Lee, Seung-Hyeon;Park, Hyun-Bum
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.04a
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    • pp.67-70
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    • 2007
  • It is well known that the aircraft engine inlet should be safely designed against the bird strike at the aircraft development stage. The aircraft accident is increasing for FOD(Foreign Object Damage), especially bird of runway circumference. The aircraft accident due to bird strike brings about economic loss and which is connected with the life of passengers. In this study, MSC/DYTRAN has been utilized to analyze the aircraft engine inlet against the bird strike. In order to validate the proposed method for the bird strike analysis, this study was performed with comparison of precedence study results.

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Energy-Efficient Uplink Power Control Based on the Flocking Model in Cellular Networks (셀룰러 네트워크에서 플로킹 모델 기반 에너지 효율적인 상향링크 전력 제어)

  • Choi, Hyun-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.10
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    • pp.1186-1189
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    • 2016
  • A distributed uplink power control algorithm based on flocking model is proposed to improve the energy efficiency of mobiles station (MS) in cellular networks. As each bird in a flock matches its velocity with the average velocity of the adjacent birds, each MS in a cell matches its uplink rate with the average uplink rate of the co-channel MSs in adjacent cells by controlling its transmission power. Results show that the proposed algorithm effectively reduces the power consumption in the MS, while maintaining a low outage probability, which eventually improves the energy efficiency of the MS.

Impact Structural Behavior by Bird Strike on Engine Inlet Nacelle (엔진 흡입구 나셀의 조류충돌에 대한 충격거동 해석)

  • Kong, Chang-Duk;Lee, Seung-Hyeon;Park, Hyun-Bum;Yoon, Jae-Huy
    • Journal of the Korean Society of Propulsion Engineers
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    • v.11 no.3
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    • pp.58-64
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    • 2007
  • It is well known that the aircraft engine inlet should be safely designed against the bird strike at the aircraft development stage. The aircraft accident is increasing for FOD(Foreign Object Damage), especially bird of runway circumference. The aircraft accident due to bird strike brings about economic loss which is connected with the life of passengers. In this study, MSC/DYTRAN has been utilized to analyze the aircraft engine inlet against the bird strike. In order to validate the proposed method for the bird strike analysis, this study was performed with comparison of precedence study results.

Effect of Degree of Ripeness and Size of Fruit on the Feeding Preference in Some Breeding Birds (식물의 종류와 열매의 크기 및 성숙도가 조류의 먹이선택에 미치는 영향)

  • Kim, Hyun-Woo;Cho, Sam-Rae;You, Young-Han
    • Korean Journal of Environmental Biology
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    • v.27 no.4
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    • pp.334-340
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    • 2009
  • In other to know the feeding preference over the degree of ripeness and size of fruits in birds, we gave them to three bird species in breeding condition, counted and analyzed the number of fruits by correspondence ordination technique. Chrysolophus pictus did not show a distinct preference in respect to degree of maturity or size of fruits of among three tree species. Columba rupestris preferred un-ripen fruits over ripen ones of Prunus yedoensis or Elaeagnus multiflora, but did not choose selectively in case of fruits of Malus sieboldii. Pavo muticus showed the reverse favorable pattern of Columba rupestris. Total feeding amounts eaten by birds were dependent on the initial feeding amounts of fruits. These results indicated that in feeding activity some birds chose differently in terms of species or maturity of fruits, but not in fruit size.

Distributed Transmit Power Control Algorithm Based on Flocking Model for Energy-Efficient Cellular Networks (에너지 효율적인 셀룰러 네트워크를 위한 플로킹 모델 기반 분산 송신전력제어 알고리즘)

  • Choi, Hyun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.10
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    • pp.1873-1880
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    • 2016
  • Most of the energy used to operate a cellular network is consumed by a base station (BS), and reducing the transmission power of a BS is required for energy-efficient cellular networks. In this paper, a distributed transmit power control (TPC) algorithm is proposed based on the flocking model to improve the energy efficiency of a cellular network. Just as each bird in a flock attempts to match its velocity with the average velocity of adjacent birds, in the proposed algorithm each mobile station (MS) in a cell matches its rate with the average rate of the co-channel MSs in adjacent cells by controlling the transmit power of its serving BS. Simulation results show that the proposed TPC algorithm follows the same convergence properties as the flocking model and also effectively reduces the power consumption at the BSs while maintaining a low outage probability as the inter-cell interference increases. Consequently, it significantly improves the energy efficiency of a cellular network.