• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.339.1-339
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• 1998

No Abstract, See Full Text

• Proceedings of the Korean Vacuum Society Conference
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• 2006.02a
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• pp.78-78
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• 2006

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.446.2-446.2
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• 2003

• Journal of radiological science and technology
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• v.11 no.2
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• pp.17-20
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• 1988

• Journal of radiological science and technology
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• v.16 no.1
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• pp.41-55
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• 1993

Recently, various screen film system have been introduced in diagnostic radiology. There are two kinds of screen film system : blue emitting $CaWO_4$ screen has been largely used in these days. However, it tends to be changed to use green emitting $Gd_2O_2S$ : Tb screen. In this study, photographic characteristics of $CaWO_4$ and $Gd_2O_2S$ : Tb screen were investigated with luminescence, spectroscopy. The morphology of $CaWO_4$ and $Gd_2O_2S$ : Tb were also observed by using scanning electron microscope. The result obtained were as follows : 1. There was small difference in the thickness of phosphor layers for the front and back screen of blue emitting system, but little difference in those of green emitting system. 2. There was no difference in the size of phosphor particles between the front and back screen for each screen. However, the particle size was different for the various kinds of screens. 3. The shape of phosphor particle was round with many faces for all the screens. 4. In the exposure of X-ray with the same intensity, luminescent intensity of a green emitting system was $6{\sim}7$ times larger than that of a blue emitting system. 5. The thickness of phosphor layers does not affect on the sensitivity of the screens exposed by X-ray.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.629-638
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• 2014

Objective of this study is to be utilized as foundational data of expression methods and to increase children's dream and imagination by researching and analyzing differences of imaginative reaction from patterns of imaginative activities and verbal response for the expressive methods of illustrations. Study subjects are 253 children aged from six to seven years old, and four different types of research tool of which are screens with simple pattern, realistic pattern, omitted pattern and indirect pattern has been used in the empirical survey conducted over two times. Result from provided research tools has shown that difference of diversity can be observed from patterns of imaginative activities and verbal reaction patterns. Especially, in terms of imaginative activities, structural and creative imagination responses can be observed from screens with simple, omitted patterns and indirect and metaphorical patterns compares to screens with simple patterns and direct, realistic patterns, and positive affection to children's dream and creativity and imagination can be found from the result of high imaginative response observed from patterns of verbal reaction.

• Journal of the korean society of oceanography
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• v.33 no.1-2
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• pp.35-40
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• 1998

In February and April 1997, three temporary interruptions of electric power production at the Uljin Nuclear Power Plant in the east coast of Korea were caused by the malfunction of the cool-ing-water supply unit. The clogging of the drum screens inside the unit caused by the surface swarm of the euphausiid Euphausia pacifica Hansen might be responsible for the malfunction. These incidents were of particular interest since such interruption of reactors' operation by krill swarms had not previously been reported. Using samples caught by the drum screens inside the cooling water-supply unit, we investigated the population structure of surface swarms. One occasion of nighttime and three occasions of daytime surface swarms were found in February and April 1997, respectively. The foreguts of more than 60% of E. pacifica in nighttime surface swarm were in full condition. This evidence suggests that E. pacifica aggregates to the surface water at night for feeding. In daytime surface swarms consisting of mature E. pacifica, however, foreguts in full condition were only found in less than 10eio of krill examined, suggesting that daytime surface swarms are closely related to breeding activity. During the study period, the growth rate of mature females was more than twice higher than that of mature males. Analyses of the sex-ratio and length-frequency data show a decrease in the portion of males with increasing size. There was a decline in the number of males of 19 mm in length. Energy loss during spermatophore transfer may result in the death of male E. pacifica, as found in male E. superba.

• Journal of Radiation Protection and Research
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• v.41 no.3
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• pp.216-221
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• 2016

Background: Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. Materials and Methods: A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of $^{11}C$-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. Results and Discussion: The size distribution for $^{11}C$-bearing aerosol particles was found to be ca. $70{\mu}m$ in geometric mean diameter. The size was similar to that for $^7Be$-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. Conclusion: The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.251-265
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• 2006

To investigate the impingement of fish on the traveling screens, fishes were collected from the traveling screens at Hadong Power Plant through the year of 1999. A total of 84 fish species were collected during the study period. The dominant species were Leiognathus nuchalis, Engraulis japonicus, Trichiurus lepturus and Takifugu niphobles. These four species accounted for 78.2% of the total number of individuals and 52.0% of total biomass collected. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The number of species and biomass were high in April and August, and the number of individuals was high in April and July. However, the number of fish species, number of individuals and biomass of fishes showed low values in winter.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.5
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• pp.1-7
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• 2012

본 연구의 목적은 국내에서 상용되고 있는 온실 피복재 및 보온재의 조합에 따른 관류열전달계수를 핫박스를 이용하여 평가하는 것이다. 온실용 일중 및 이중 피복재와 이중 보온재의 조합에 대하여 야간천공복사 차단여부에 따른 관류열전달계수를 핫박스를 이용하여 실외에서 측정하였다. 처리조건은 일중피복, 이중피복, 이중피복과 이중 마트보온재 및 이중피복과 이중 다겹보온재의 조합조건과 천공복사 유무에 따른 조건이며 총 8가지이다. 제작된 핫박스는 상시 변화하는 외부의 기상조건하에서도 내부온도를 설정된 온도로 일정하게 잘 유지할 수 있었다. 온실 피복재 및 보온재의 관류열전달계수를 측정하는 실내용 측정장치는 반드시 야간천공복사를 모의할 수 있는 측정장치가 되어야 할 것이다. 야간복사를 차단함으로서 온실의 열 손실을 줄여 보온효과를 얻을 수 있을 것으로 분석되었다. 모든 피복방식에 대해 야간복사 차단장치 유무에 관계없이 높은 풍속에서의 관류열전달계수가 낮은 풍속에서보다 더 큰 것으로 나타났다. 본 연구에서 사용된 측정기법을 사용하면 국내에서 생산되는 피복재 및 보온재의 관류열전달 특성을 정량적으로 비교할 수 있을 것으로 기대된다.