• Applied Microscopy
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• v.32 no.4
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• pp.329-337
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• 2002

The morphology and cellular characteristics of adventitious roots, viz aerial roots, in the epiphytic American Ivy were examined to reveal structural changes of the aerial root upon surface attachment. Immature aerial roots were composed of parenchyma cells with dense cytoplasm containing plastids, however, the upper and lower epidermis were not distinguished. At early development, electron-dense substances (EDS) were constituents of much of the aerial root tissue, but the distribution of EDS varied within the tissue. The deposits appeared most concentrated in the superficial cell layers, with lesser amounts in cell layers closer to the cortex. Electron micrographs revealed that EDS deposits were always found in the vacuole, and were mainly associated with the tonoplast. While most of them occurred in the vacuole as small spherical deposits adjacent to the tonoplast, some deposits were oddly shaped or larger in size. Many of the vacuoles eventually filled with EDS, but the EDS content in those vacuoles decreased substantially after initial attachment to the surface. When the vacuoles became almost empty, cells near the epidermis already exhibited irregularity in outline. Subsequent breakdown of cellular components took place in the cells while they were still attached to the surface. This study suggests the potential role of EDS as substances involved in the surface attachment of the plant, however, further studies must be conducted to reveal the nature of EDS and the effects of EDS storage within these vacuoles.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.552-557
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• 2007

In this study, we investigated the antimicrobial effects of anti-Salmonella gallinarum-specific IgY separated from egg yolk obtained from layers immunized by S. gallinarum. The comparison tests of vaccination, content of IgY and innoculation number were examined by microscopic observation, turbidity, and pH. The results show that the ratio of anti-S. gallinarum IgY in the total IgY was 23%. Also, the anti-S. gallinarum IgY had selectivity only to S, gallinarum. The 0.3% addition of anti-S. gallinarum-specific IgY resulted in agglutinating clusters of S, gallinarum cells, but the agglomeration didn#t occur in IgY from layers not immunized nor in the control group. Microscopic observation indicated agglomerative cells when IgY was added at 0.2% or higher, and the pH and turbidity examinations revealed that a suppression effect was remarkable in IgY at more than 0.1%. These results suggest the possibility that IgY extracted from eggs and obtained from layers immunized by S. gallinarum can be used to prevent fowl typhoid.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.493-497
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• 1988

Peroxide value (POV), acid value (AV), color and flavor of soybean oil packaged with polyethylene (PE) bottle and Tetra-pack were periodically checked at $60^{\circ}C,\;40^{\circ}C$ for 33 days. POV more quickly increased when the storage temperature became higher. Kinetics of POV was followed the zero-order reaction rate. $Q_{10}$ values of those were in 1.8 in PE bottle and 2.1 in Tetra-pack at $20-40^{\circ}C$. Sensory scores were stable in PE bottle and Tetra-pack $20-40^{\circ}C$ and in Tetra-pack at $60^{\circ}C$, but those reached to the critical sensory point of 5 in PE bottle at $60^{\circ}C\;after\;30^{\circ}C$ days storage. Therefore, shelf-life of soybean oil could be predicted as 14.1 months and 7.8 months in PE bottle and 32.6 months and 22.5 months in Tetra-pack at $15^{\circ}C\;and\;25^{\circ}C$ by reaction rates of POV, $Q_{10}$ values and sensory scores.

• Korean Association for Visual Culture
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• v.19
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• pp.189-221
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• 2012

This thesis investigates the development of optical instruments in the 19th century, before the birth of the cinema, and the principle of the perception of moving images. For this purpose it traces the development stages of the optical instruments which demonstrated 'illusion of movement' from 1820s when the 'persistence of vision' had begun to be researched by scientists. Then, it examines the theory of the 'persistence of vision' or 'afterimage effect' known as the principle in the perception of illusion of movement produced from moving images. The optical instruments in the 19th century that presented the illusion of movement began with the Thaumatrope (double-sided picture disc), and appeared from the Phenakistiscope/Stroboscope (revolving disc), the Zoetrope (revolving drum) and the Praxinoscope (mirror-reflexive revolving drum), and in 1892 the Projection-Praxinoscope presented firstly the moving pictures (animation) on the screen. According to the research of psychology and physiology in the early 20th century it has been recognized that the 'afterimage effect' theory is not sufficient to explain the perception of illusion of movement from the moving images which is closely related to the particularity of the visual perception system of the human eyes. Since then, the Phi-phenomenon suggested 1912 by the Gestalt psychologist, Max Wertheimer (1880-1943), is regarded as the most persuasive theory until now, although it is still imperfect.

• Korean Association for Visual Culture
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• v.17
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• pp.65-92
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• 2011

This thesis investigates the complex functions of the magic lantern in illusionism and enlightment which was the most popular visual media and the direct ancestor of cinema. Especially, the thesis focuses on the characteristics of magic lantern's images which had been varied with the scientific and technological development. During the early period of the magic lantern, from the late 18th century to the beginning of the 19th century, it frightened viewers by showing magic images with ghosts and spectres, 'phantasmagoria', and wondered with images of natural catastropes and interesting stories like fables and fairy tales, which fulfilled the entertainment function. Since the mid 19th century the magic lantern began to show not only pictures of the 'scientific themes' on the earth, nature and human, but also them of the ethnological on the far, exotic worlds like Africa, Amazon and Syberia etc. from the European perspective. These contents conducted the educative function and contributed to the process of Enlightment to the peoples in the pre-modern age. The two functions of the magic lantern such as entertainment and education had been neither historically followed, nor clearly divided, but the one was predominant according to the development of lantern techniques as well as the changes of the world view and the culture of the time. The entertainment function of the magic lantern based on the visual fantacy did exist in the late 19th century further, and also in the late industrial society, even in the age of highly developed science and technology, viewers want rather 're-enchantment' by illusionism than facts and truths on the reality. This is an essential characteristic of the moving image media, as it had already been presented in the images of the magic lantern.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.49-54
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• 1970

In an effort of determine the metabolism and bio-synthesis of nitrogen, was studied at variance of souble nitrogens, free amino acids and total alcohol soluble amino acids during the growth of younger soybean plants, and saybean divides into cotyledon and embryonic organ (shoot and root system) in this experiment. 1. In the soluble nitrogen of soybean, ratio of increase and decrease in the amino acids of them was displayed the near phenomena both cotyledon and embryonic organ of soybean. But, in the 17th days after seed germination, that is the developmeatal stage of adult leaf of soybeans, was appear the maximum value. It has been suggested that the stage of first half period of growth as boundary the stage of adult leaf development which indicated clear morphologically, at the younger soybean plants, is the step that nitrogen assimilation. 2. It was investigated the amino acids of seventeen kinds in the seed state, but at the third days after seed germination, was investigated the amino acids of nineteen kinds. Ultimately, it appears the translocation from cotyledon to embryonic organ in the distribution of amino acid, the nineth day which differentiation begining day of embryonic organ, then after, it happen the variation of number of inspected amino acid in the cotyledon and embryonic organ but only the variance changes in the distribution and quantitative aspects. Especially, the most conspicuous fact was indicated the accumulation of Asparagine, that is the phenomena of Asparagine-accumulation was constitute, not with standing no fertilization from outside. It may be concluded from the results of this investigation that the difference of special phenomena of soybean from the embryo of other plans. 3. In the initial stage of differentiation at embryonic organ number of inspected amino acid was very few, and then, it was slightly appeared the increase-phenomena in the number of them. It was that the amino acid inspecting the initial stage was translocated from the cotyledon. It is suggested that the intermediate-metabolism of amino acid was constituted on the basis of above the result. 4. The phenomena of increase and decrease of total alcohol soluble amino acid were essentially identical to the water soluble amino acid of soybean, but it was appeared the severe difference of amounts in both of them.

• The Magazine of the IEIE
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• v.29 no.6
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• pp.76-80
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• 2002

'Liquid Crystal의 상전이(相轉移)와 광학적 이방성(異方性)이 1888년과 1889년 F. Reinitzer와 O. Lehmann에 의해 Monatsch Chem.과 Z.Physikal.Chem.에 각각 보고된 후 부터 제2차 세계대전이 끝난 뒤인 1950년대 까지는 Liquid Crystal을 단지실험실에서의 기초학문 차원의 연구 대상으로만 다루어 왔다. 1963년 Williams가 Liquid Crystal Device로는 최초로 특허 출원을 하였으며, 1968년 RCA사의 Heilmeier등은 Nematic 액정(液晶)에 저주파(低周波) 전압(電壓)을 인가하면 투명한 액정이 혼탁(混濁)상태로 변화하는 '동적산란(動的散亂)'(Dynamic Scattering) 현상을 이용하여 최초의 DSM(Dynamic Scattering Mode) LCD(Liquid Crystal Display)를 발명하였다. 비록 150V 이상의 높은 구동전압과 과소비전력의 특성 때문에 실용화에는 실패하였지만 Guest-Host효과와 Memory효과 등을 발견하였다. 1970년대에 이르러 실온에서 안정되게 사용 가능한 액정물질들이 합성되고(H. Kelker에 의해 MBBA, G. Gray에 의한 Cyano-Biphenyl 액정의 합성), CMOS 트랜지스터의 발명, 투명도전막(ITO), 수은전지등의 주변기술들의 발전으로 인하여 LCD의 상품화가 본격적으로 이루어지게 되었다. 1971년에는 M. Shadt, W. Helfrich, J.L. Fergason등이 TN(Twisted Nematic) LCD를 발명하여 전자 계산기와 손목시계에 응용되었고, 1970년대 말에는 Sharp에서 Dot Matrix형의 휴대형 컴퓨터를 발매하였다. 이러한 단순 구동형의 TN LCD는 그래픽 정보를 표시하는 데에는 품질의 한계가 있어 1979년 영국의 Le Comber에 의해 a-Si TFT(amorphous Silicon Thin Film Transistor) LCD의 연구가 시작되었고, 1983년 T.J. Scheffer, J. Nehring, G. Waters에 의해 STN(Super Twisted Nematic) LCD가 창안되었고, 1980년 N. Clark, S. Lagerwall 및 1983년 K.Yossino에 의해 Ferroelectric LCD가 등장하여 LCD의 정보 표시량 증대에 크게 기여하였다. Color화의 진전은 1972년 A.G. Ficher의 셀 외부에 RGB(Red, Green, Blue) filter를 부착하는 방안과, 1981년 T. Uchida 등에 의한 셀 내부에 RGB filter를 부착하는 방법에 의해 상품화가 되었다. 1985년에는 J.L. Fergason에 의해 Polymer Dispersed LCD가 발명되었고, 1980년대 중반에 이르러 동화상(動畵像) 표시가 가능한 a-Si TFT LCD의 시제품(試製品) 개발이 이루어지고 1990년부터는 본격적인 양산 시대에 접어들게 되었다. 1990년대 초에는 STN LCD의 Color화 및 대형화(大型化) 고(高)품위화에 힘입어 Note-Book PC에 LCD가 본격적으로 적용이 되었고, 1990년대 후반에는TFT LCD의 표시품질 대비 가격경쟁력 확보로 인하여 Note-Book PC 시장을 독점하기에 이르렀다. 이후로는 TFT LCD의 대형화가 중요한 쟁점으로 부각되고 있고, 1995년 삼성전자는 당시 세계최대 크기의 22' TFT LCD를 개발하였다. 또한 LCD의 고정세(高情細)화를 위해 Poly Si TFT LCD의 개발이 이루어졌고, 디지타이져 일체형 LCD의 상품화가 그 응용의 폭을 넓혔으며, LCD의 대형화를 위해 1994년 Canon에 의해 14.8', 21' 등의 FLCD가 개발되었다. 대형화 방안으로 Tiled LCD 기술이 개발되고 있으며, 1995년에 Sharp에 의해 21' 두장의 Panel을 이어 붙인 28' TFT LCD가 전시되었고 1996년에는 21' 4장의 Panel을 이어 붙인 40'급 까지의 개발이 시도 되었으며 현재는 LCD의 특성향상과 생산설비의 성능개선과 안정적인 공정관리기술을 바탕으로 삼성전자에서 단패널 40' TFT LCD가 최근에 개발되었다. Projection용 디스플레이로는 Poly-Si TFT LCD를 이용하여 $25'{\sim}100'$사이의 배면투사형과 전면투사형 까지 개발되어 대형 TV시장을 주도하고 있다. 21세기 디지털방송 시대를 맞아 플라즈마디스플레이패널(PDP) TV, 액정표시장치 (LCD)TV, 강유전성액정(FLCD) TV 등 2005년에 약 1500만대 규모의 거대 시장을 형성할 것으로 예상되는 이른바 '벽걸이TV'로 불리는 차세대 초박형 TV 시장을 선점하기 위하여 세계 가전업계들이 양산에 총력을 기울이고 있다. 벽걸이TV 시장이 본격적으로 형성되더라도 PDP TV와 LCD TV가 직접적으로 시장에서 경쟁을 벌이는 일은 별로 없을 것으로 보인다. 향후 디지털TV 시장이 본격적으로 열리면 40인치 이하의 중대형 시장은 LCD TV가 주도하고 40인치 이상 대화면 시장은 PDP TV가 주도할 것으로 보는 시각이 지배적이기 때문이다. 그러나 이러한 직시형 중대형(重大型)디스플레이는 그 가격이 너무 높아서 현재의 브라운관 TV를 대체(代替)하기에는 시일이 많이 소요될 것으로 추정되고 있다. 그 대안(代案)으로는 비교적 저가격(低價格)이면서도 고품질의 디지털 화상구현이 가능한 고해상도 프로젝션 TV가 유력시되고 있다. 이러한 고해상도 프로젝션 TV용으로 DMD(Digital Micro-mirror Display), Poly-Si TFT LCD와 LCOS(Liquid Crystals on Silicon) 등의 상품화가 진행되고 있다. 인터넷과 정보통신 기술의 발달로 휴대형 디스플레이의 시장이 예상 외로 급성장하고 있으며, 요구되는 디스플레이의 품질도 단순한 문자표시에서 그치지 않고 고해상도의 그래픽 동화상 표시와 칼라 표시 및 3차원 화상표시까지 점차로 그 영역이 넓어지고 있다. <표 1>에서 보여주는 바와 같이 LCD의 시장규모는 적용분야 별로 지속적인 성장이 예상되며, 새로운 응용분야의 시장도 성장성을 어느 정도 예측할 수 있다. 따라서 LCD기술의 연구개발 방향은 크게 두가지로 분류할 수 있으며 첫째로는, 현재 양산되고 있는 LCD 상품의 경쟁력강화를 위하여 원가(原價) 절감(節減)과 표시품질을 향상시키는 것이며 둘째로는, 새로운 타입의 LCD를 개발하여 기존 상품을 대체하거나 새로운 시장을 창출하는 분야로 나눌 수 있다. 이와 같은 관점에서 현재 진행되고 있는 LCD기술개발은 다음과 같이 분류할 수 있다. 1) 원가 절감 2) 특성 향상 3) New Type LCD 개발.

• Atmosphere
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• v.20 no.4
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• pp.467-482
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• 2010

In this study, characteristics of various stability indexes (SI) and environmental parameters (EP) for the lightning are analysed by using 5 upper air observatories (Osan, Gwangju, Jeju, Pohang, and Baengnyeongdo) for the years 2002-2006 over South Korea. The analysed SI and EP are the lifted index, K-index, Showalter stability index, total precipitable water, mixing ratio, wind shear and temperature of lifting condensation level. The lightning data occurred on the range of -2 hr~+1 hr and within 100 km based on the launch time of rawinsonde and observing location are selected. In general, summer averaged temperature and mixing ratio of lower troposphere for the lightning cases are higher about 1 K and $1{\sim}2gkg^{-1}$ than no lightning cases, respectively. The Box-Whisker plot shows that the range of various SI and EP values for lightning and no lightning cases are well separated but overlapping of SI and EP values between lightning and no lightning are not a little. The optimized threshold values for the detection of lightning are determined objectively based on the highest Heidke skill socre (HSS), which is the most favorable validation parameter for the rare event, such as lightning, by using the simulation of SI and EP threshold values. Although the HSS is not high (0.15~0.30) and the number and values of selected SI and EP are dependent on geographic location, the new threshold values can be used as a supplementary tool for the detection or forecast of lightning over South Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.1-11
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• 2007

Light is an environmental component inevitably regulating photosynthesis and photo-morphogenesis, which are involved in the plant growth and development. Studies were conducted at the International Rice Research Institute, Philippines in 2004 and 2005, with aims to investigate 1) morphological responses of rice plants to low radiation, 2) morphological alteration of shade-grown plants when exposed to high light intensity, and 3) photosynthetic responses of shade-grown rice plants. Reduction in solar radiation by 40% induced increases in the area on a single leaf basis, biomass partitioning to leaves, and chlorophyll meter readings but brought about retardation of tiller development and decrease in above-ground biomass production of rice varieties. When the shade-grown plants from two weeks of transplanting to panicle initiation were exposed to full solar radiation after panicle initiation, they demonstrated less increase in chlorophyll meter readings and more decrease in leaf nitrogen concentrations from panicle initiation to flowering than control plants that were grown under the ambient solar radiation for whole growth period after transplanting. Shade-grown rice plants exhibited lower carbon assimilation rates but higher internal $CO_2$ concentrations on a single leaf basis than control plants, when measurements for shade-grown rice plants were made under the shading treatments. But when the measurements for shade-grown plants were made under the full solar radiation, light-saturated carbon assimilation rates were similar to control plants. Response of photosynthetic rates to varying light intensities was not considerably different between shading treatments and control. Yield reduction was observed in the shading treatments from panicle initiation to flowering and from flowering to physiological maturity, mainly by less spikelets per panicle and poor grain filling, respectively.

• Journal of the Korea Concrete Institute
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• v.15 no.4
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• pp.549-556
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• 2003

Various researches on the application of polymer dispersions to the cement mortar and concrete have been practised in many countries like America, Japan and Germany and so on because of high performance and good modification effect of these. In this study, SBR, Polymer dispersion that widely used in situ is employed that the self-flowability may be induced in the cemen mortar. In order to comprehend and investigate the modification of cement mortar with self-flowability by SBR and properties and fracture mode of adhesive strength in tension of that, experimental parameter was set as SBR solid-Cement ratio(S/C) and Cement:Fine aggregate(C:F) and the experiments such as Unit weight, Flow, Consistency change, Crack resistance and Segregation that inform on the general properties have been done. In addition of that, Adhesion in tension is measured with a view to comprehending the properties and fracture mode in tensile load. Consistency change of cement mortar modified by SBR did grow better as the ratio of SBR solid-Cement increased and was much superior to that of resin based flooring such as polyurethane and epoxy which recorded the loss of consistency in 90min. after mixing. Adhesive strength in tension increased with continuity in the curing age and showed the maximum in case of C:F=1:1 and S/C=20%. As the increase of curing age, the fracture mainly happened in the concrete substrate and the interface between the specimen and concrete substrate.