• Title/Summary/Keyword: grazing-in

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Growth and Morphological Changes in Scenedesmus dimorphus Induced by Substances Released from Grazers, Daphnia magna and Moina macrocopa (동물플랑크톤 Daphnia magna와 Moina macrocopa에서 유도된 분비물질에 의한 Scenedesmus dimorphus의 형태변화)

  • Jang, Min-Ho;Joo, Gae-Jae;Takamura, Noriko;Ha, Kyong
    • Korean Journal of Ecology and Environment
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    • v.34 no.4 s.96
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    • pp.285-291
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    • 2001
  • Grazer-induced colony formation was examined using a green alga Scenedesmus dimorphus (T$\ddot{u}$rpin) K$\ddot{u}$tzing. Algae were cultured in a medium with or without filtered water taken from cultures of Daphnia magna Straus (300 ind./L) or Moina macrocopa Straus (500 ind./L). The exposure to zooplankton filtered water (ZFW)promoted colony formation in S. dimorphus, with the magnitude of this response being directly proportional to the relative volume of ZFW that was added to the culture medium. The number of cells/colony and mean particle biovolume of S. dimorphus increased between 24 and 72 hours after exposure to ZFW, most likely due to the influence of chemicals released from D. magna or M. macrocopa, and possily as a defense mechanism against zooplankton grazing.

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Rapid detection of Theileria sergenti by polymerase chain reaction (중합효소연쇄반응을 이용한 Theileria sergenti의 신속한 검출)

  • 최은진;강승원
    • Parasites, Hosts and Diseases
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    • v.35 no.2
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    • pp.111-118
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    • 1997
  • Four separate pairs of oligonucleotide primers within the coding region in a T sergenti 33-kDa surface protein gene were selected to detect T. sergenti by PCR. The specificity of PCR-amplified DNA was examined by digestion with restriction enzyme 3nd Southern blot hybridization using T. sergenti p33 DNA probe. PCR appears to be specific for T. sergenti, without detectable signals from uninfected erythrocytes, uninfected bovine leukocytes and other hemoparasites, including A. morginnle and 3. ouata. Although 46 of 71 specimens (64.8%) from grazing cattle were microscopically positive. PCR in this study showed that 64 specimens (88.7%) were positive. Therefore, PCR proves a useful diagnostic tool for detecting T sergenti-infected cattle. In addition, it is also revealed that PCR was significantly more sensitive than traditional microscopic examination using Giemsa's stain.

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Estimation of surficial sediment thickness using mid-frequency ocean acoustic bottom reflected signals measured in shallow water off Geoje island (거제 인근해역에서 측정된 중주파수 음향 해저면 반사 신호를 이용한 표층 해저면 두께 추정)

  • Kwon, Hyuckjong;Choi, Jee Woong;Son, Su-Uk;Cho, Sungho;Hahn, Jooyoung;park, Joung-Soo;Park, Kyeongju
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.6
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    • pp.419-426
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    • 2016
  • Measurements of bottom loss as a function of grazing angle (in range of $9{\sim}14^{\circ}$) at a frequency range of 4 ~ 8 kHz were conducted on an experimental site off Geoje island in October 2015. Geoacoustic inversion of the surficial sediment thickness is performed using the arrival time difference between the surficial layer and the sub-bottom layer reflected signal. To invert the thickness of surficial sediment, we used the grain size of $8{\sim}10{\phi}$ obtained by KIGAM (Korea Institute of Geoscience and Mineral Resources). The thickness of the surficial sediment was estimated to be 4 ~ 7 m. Finally, this inversion result was compared with the geoacoustic observation conducted by the KIOST (Korea Institute of Ocean Science & Technology) using sub-bottom profiler.

The Effects of Thermal Decomposition of Tetrakis-ethylmethylaminohafnium (TEMAHf) Precursors on HfO2 Film Growth using Atomic Layer Deposition

  • Oh, Nam Khen;Kim, Jin-Tae;Ahn, Jong-Ki;Kang, Goru;Kim, So Yeon;Yun, Ju-Young
    • Applied Science and Convergence Technology
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    • v.25 no.3
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    • pp.56-60
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    • 2016
  • The ALD process is an adequate technique to meet the requirements that come with the downscaling of semiconductor devices. To obtain thin films of the desired standard, it is essential to understand the thermal decomposition properties of the precursors. As such, this study examined the thermal decomposition properties of TEMAHf precursors and its effect on the formation of $HfO_2$ thin films. FT-IR experiments were performed before deposition in order to analyze the thermal decomposition properties of the precursors. The measurements were taken in the range of $135^{\circ}C-350^{\circ}C$. At temperatures higher than $300^{\circ}C$, there was a rapid decrease in the absorption peaks arising from vibration of $Sp^3$ C-H stretching. This showed that the precursors experienced rapid decomposition at around $275^{\circ}C-300^{\circ}C$. $HfO_2$ thin films were successfully deposited by Atomic Layer Deposition (ALD) at $50^{\circ}C$ intervals between $150^{\circ}C$ to $400^{\circ}C$; the deposited films were characterized using a reflectometer, X-ray photoelectron spectroscopy (XPS), Grazing Incidence X-ray Diffraction (GIXRD), and atomic force microscopy (AFM). The results illustrate the relationship between the thermal decomposition temperature of TEMAHf and properties of thin films.

Transmission and Reflection Characteristics Measurements at the 60GHz for the Various Obstacles (다양한 장애물에 대한 60GHz 대역에서의 투과 및 반사 특성 측정)

  • Song, Ki-Hong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.1
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    • pp.25-32
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    • 2008
  • This paper presents the reflection and transmission measurements conducted at the 60GHz suitable to provide a high speed wide band service. Mean received power and standard deviation are calculated and used to compare the characteristics of radio wave propagation to the various obstacles between transmitting and receiving antennas at the frequency. The results show that the transmitted signal strength by the steel door and copper plate are about 40dB lower than in free space, those by the rubber plate, glass and styroform are about 3dB lower than in free space. Also, the re(looted signal strengths at the 60 degree grazing angle show that in case by the partition is about 23dB lower, by the surface of a wall is about 6dB lower than by the copper plate. The presented results can be used for the design of 60 GHz picocell communication network that the reflected and transmitted waves affect to the service area.

Current Status of Forage Use on the Goat Farming in Mountainous Pasture (흑염소 방목초지의 사초생산성 및 사료가치 평가에 관한 연구)

  • Moon, Sang Ho;Kim, Sang Woo;Choi, Gi Jun;Jang, Se Young;Park, Jae Hyun;Jeon, Byong Tae;Kim, Myoung Hwa;Kim, Sung Jin;Oh, Mi Rae
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.35 no.2
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    • pp.112-118
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    • 2015
  • This study was carried out to offer basic information for the promotion of the goat industry and the improvement of mountainous-pasture management by investigating seasonal changes in forage and livestock productivity according to the grazing-pasture type. The forage productivity of rangeland was the highest (p < 0.05) in summer and decreased in autumn; but that of pasture was the largest (p < 0.05) in spring and had relatively stable productivity with minor seasonal differences, although it decreased slightly in autumn. The dry matter content was not seasonally different at pasture, but it was changeable from spring to autumn at rangeland. The crude protein content increased in autumn at pasture (p < 0.05), and decreased in summer and autumn compared with spring at rangeland. The crude fiber content was lower and the ether extract was higher at pasture compared with rangeland. The average daily gain of the goats was different depending on forage productivity and pasture type; consequently, the lowered forage productivity at rangeland compared with pasture means that rangeland needs to be changed or improved to a pasture type that provides a more effective grazing system for goats.

Small-Angle X-ray Scattering Station 4C2 BL of Pohang Accelerator Laboratory for Advance in Korean Polymer Science

  • Yoon, Jin-Hwan;Kim, Kwang-Woo;Kim, Je-Han;Heo, Kyu-Young;Jin, Kyeong-Sik;Jin, Sang-Woo;Shin, Tae-Joo;Lee, Byeong-Du;Rho, Ye-Cheol;Ahn, Byung-Cheol;Ree, Moon-Hor
    • Macromolecular Research
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    • v.16 no.7
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    • pp.575-585
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    • 2008
  • There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

Abundances and Bacterivory of Heterotrophic and Mixotrophic Nanoflagellates in and Estuarine System of the Mankyung and Dongjin Rivers, Korea (만경.동진강 염하구에서 종속영양성 및 혼합영양성 미소편모류의 수도(數度)와 박테 리아 섭식)

  • 심재형;윤성화
    • 한국해양학회지
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    • v.30 no.5
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    • pp.413-425
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    • 1995
  • Abundances and bacterivory of heterotrophic and mixotrophic nanoflagellates were investigated fourtimes between October 1993 and March 1995 in an estuarine system of the Mankyung and Dongjin rivers to understand distributions of nanoflagellates and ecological significance of bacterivory of nanoflagellates. Bacterivory of nanoflagellates were measured with fluorescently labeled bacteria (FLB). Heterotrophic and autotrophic flagellates showed a rage of 438-4,159 cells ml/SUP -1/ (mean of 2,145 cells ml/SUP -1/, n=20) and 971- 4,935 cells ml/SUP -1/ (mean of 2,2226 cells ml/SUP -1/, n-20), respectively. These two groups of nanoflagellates generally showed similar distributions of abundance. Abundances of heterotrophic nanoflagellates, known as major grazers of bacteria, and those of autotrophic nanoflagellates with chloroplasts showed statistically significant correlations with bacterial abundance (respectively, r$^2$=0.51 and r $^2$=0.47, p>0.05). Mixotrophic nanoflagellates seemed to comprise at least 4-23% of autotrophic nanoflagellate populations. Individual predation rates of heterotrophic nanoflagellates ranged from 2.2 to 14.2 bacteria flagellate/SUP -1/ h/SUP -1/ (mean of 4.9 bacteria flagellate/SUP -1/h/SUP -1/, n=16), and those of mixotrophic nanoflagellates from 1.6 to 9.7 bacteria flagellate/SUP -1/ h/SUP-1/ (mean of 3.7 bacteria flagellate /SUP -1/ h/SUP -1/, n=16). Bacterivory by mixotrophic nanoflagellates comprised from 30 to 69% of total nanoflagellates grazing on bacteria, indicating the significant role of mixotrophic nanoflagellates as grazers on bacteria in the study area. The ratios of grazing rates on bacteria to bacterial secondary production ranged widely from 0.06 to 1.23. In June, when abundances of total nanoflagellates were low, removal of bacteria by bacterivory of nanoflagellates was also a small fraction (0.08${\pm}$ 0.01, n=4) of bacterial production. In other seasons, nanoflagellates usually grazed on bacteria in significant fraction (0.06${\pm}$0.37, n=9) of bacterial production. Both heterotrophic and mixotrophic nanoflagellates appear to be major grazers on bacteria, and might transfer bacterial secondary production to higher trophic level in an estuarine system of the Mankyung and Dongjin rivers.

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Depending on the angle of grazing procedure Analysis of relationship with look position by trend emotion (그레쥬에이션 시술 각도에 따른 트렌드 감성별 룩 포지션과의 관계 분석)

  • Son, Gwang Hyun;Park, Jang Soon
    • Journal of Digital Convergence
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    • v.16 no.9
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    • pp.497-502
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    • 2018
  • The purpose of this study is to investigate the correlation between female gradation angle and angles of female gradation according to the angle of the treatment. A total of 100 questionnaires were analyzed using questionnaires. The results showed that sophisticated images were observed at $5^{\circ}$, $31^{\circ}$, and $85^{\circ}$ of gradation, and elegance images were observed at $15^{\circ}$ and $65^{\circ}$, and modern images were observed at $50^{\circ}$. Through this study, we will be able to conduct in-depth follow-up research on female gradation cuts classified by the trend position of trends in Korean men, and it will be possible to use it as basic data for deeper haircut education at the same time as creating customer satisfaction.

Real-Time Rendering of a Displacement Map using an Image Pyramid (이미지 피라미드를 이용한 변위 맵의 실시간 렌더링)

  • Oh, Kyoung-Su;Ki, Hyun-Woo
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.5_6
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    • pp.228-237
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    • 2007
  • displacement mapping enables us to add realistic details to polygonal meshes without changing geometry. We present a real-time artifacts-free inverse displacement mapping method. In each pixel, we construct a ray and trace the ray through the displacement map to find an intersection. To skip empty regions safely, we traverse the image pyramid of displacement map in top-down order. Furthermore, when the displacement map is enlarged, intersection with bilinear interpolated displacement map can be found. When the displacement map is at distance, our method supports mipmap-like prefiltering to enhance image quality and speed. Experimental results show that our method can produce correct images even at grazing view angles. Rendering speed of a test scene is over hundreds of frames per second and the influence of resolution of displacement map to rendering speed is little. Our method is simple enough to be added to existing virtual reality systems easily.