• 제목/요약/키워드: Modification period

검색결과 338건 처리시간 0.02초

지상원격탐사를 이용한 에어러솔 간접효과 연구 (Aerosol Indirect Effect Studies derived from the Ground-based Remote Sensings)

  • 김병곤;권태영
    • 한국대기환경학회지
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    • 제22권2호
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    • pp.235-247
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    • 2006
  • Aerosol indirect radiative forcing of climate change is considered the most uncertain forcing of climate change over the industrial period, despite numerous studies demonstrating such modification of cloud properties and several studies quantifying resulting changes in shortwave radiative fluxes. Detection of this effect is made difficult by the large inherent variability in cloud liquid water path (LWP): the dominant controlling influence of LWP on optical depth and albedo masks any aerosol influences. Here we have used ground-based remote sensing of cloud optical depth (${\tau}_c$) by narrowband radiometry and LWP by microwave radiometry to determine the dependence of optical depth on LWP, thereby permitting examination of aerosol influence. The method is limited to complete overcast conditions with liquid-phase single layer clouds, as determined mainly by millimeter wave cloud radar. The results demonstrate substantial (factor of 2) day-to-day variation in cloud drop effective radius at the ARM Southern Great Plains site that is weakly associated with variation in aerosol loading as characterized by light-scattering coefficient at the surface. The substantial scatter suggests the importance of meteorological influences on cloud drop size as well, which should be analyzed in the further intensive studies. Meanwhile, it is notable that the decrease in cloud drop effective radius results in marked increase in cloud albedo.

HLS를 이용한 텔레메트리 표준 106-17 LDPC 부호기 설계 (Telemetry Standard 106-17 LDPC Encoder Design Using HLS)

  • 구영모;이운문;김복기
    • 한국항공우주학회지
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    • 제48권10호
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    • pp.831-835
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    • 2020
  • HLS는 C/C++ 언어로 기술된 소스 코드로부터 자동으로 HDL 코드를 생성하므로 타이밍이나 제어가 간단하고 하드웨어 구조를 쉽게 변경할 수 있어 FPGA 시스템 개발 기간을 단축할 수 있는 장점이 있다. 본 논문에서는 Xilinx사의 Vivado HLS를 이용하여 텔레메트리 표준 106-17 LDPC 부호기를 설계할 때 간단한 코드 수정으로 목적에 맞는 구조 변경의 용이함을 보이고 Spartan-7 xc7s100 디바이스를 타겟으로 합성하여 throughput과 하드웨어 복잡도 등의 결과를 비교하였다.

녹농균과 진균류의 생물학적 상호작용에 의한 Aflatoxin 류의 생성능과 성질 변화에 대한 연구 (Studies on Changes of Aflatoxin Productivity and Properties by a Pseudomonad)

  • 이영남;김주덕
    • 한국균학회지
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    • 제8권1호
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    • pp.59-62
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    • 1980
  • Investigation on modification of aflatoxin structures by Pseudomonads was attempted as a biological detoxifiying process of mycotoxins. Firstly, when any variation of aflatoxin yield of Aspergillus parasiticus in a mixed culture with Pseudomonas aeruginosa was examined, there was no noticible effect by growth of Pseudomonads on aflatoxin yield of Asperillus sp. Secondly, when capacity of Pseudomonas aeruginosa utilizing aflatoxin as a carbon source for its growth was tested, there was some indication that aflatoxin might be used for growth of Pseudomonads. It was also noticed that the residual aflatoxin showed different migrating pattern compared with that of the intact aflatoxin by thin layer chromatography. Thirdly, the cell-free extract prepared from Pseudomonas aeruginosa grown in a glucose minimal medium supplemented with aflatoxin and the intact aflatoxins were incubated in the presence of $Mg^{++}$. After a certain length of incubation period, the reaction mixtures were applied on TLC plates. As a result, aflatoxins in the reaction mixture migrated differently as the control did. Such results may indicate that some changes of aflatoxin properties were induced by Pseudomonads.

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Adhesion of Human Osteoblasts Cell on TiN Thin Film Deposited by Cathodic Arc Plasma Deposition

  • Pham, Vuong Hung;Kim, Sun-Kyu;Le, Vinh Van;Kwon, Byoung-Se
    • 한국표면공학회지
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    • 제41권6호
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    • pp.264-268
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    • 2008
  • Interaction between human osteoblast and TiN films was conducted in vitro. TiN films were produced by cathodic arc plasma deposition. The surface was characterized by atomic force microscopy (AFM). TiN films, glass substrates and Ti films were cultured with human osteoblasts for 48 and 72 h hours. Actin stress fiber patterns and microtubules of osteoblasts were found slightly more organized and distributed on TiN films compared to those on the Ti films and the glass substrates. Human osteoblasts also showed slightly higher cell attachment, proliferation, and focal contact adhesion on TiN films compared to those on Ti films and glass substrates. Our results demonstrated that TiN films showed slightly better cellular adhesion of osteoblasts than Ti films and glass substrates in a short-time culture period.

Performance and Emissions Characteristics of a Diesel Engine with Some Bio-Oil Fuels

  • La, Woo-Jung;Ju, Eun-Sun;Kim, Byong-Hwa;Cho, Ki-Hyun;Kim, Jong-Chun
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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    • pp.359-368
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    • 1996
  • The performance and exhaust emissions of a diesel engine using light oil, heated, rice-bran oil , heated rice-bran oil treated with ultrasonic wave, used frying oil, use frying oil treated with ultrasonic wave, used frying oil, used frying oil treated with ultrasonic wave, methyl esters of rice-bran oil and used frying oil have been compared. All the fuels performed satisfactorily in a precombustion chamber-type diesel engine without injection pump recalibration or any engine modification at the range of engine speed from 1600 to 2800 rpm at its full load during a sort period , with the rice-bran oil and rice-bran oil treated with ultrasonic wave requiring somewhat preheating when ambient temperature was below 15$^{\circ}C$. General performance and emission characteristics of light oil and bio-oils were comparable , with the bio-oil based fuels giving very low SO$_2$ and lower smoke readings.

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한반도의 지진재해도 작성연구 (A Study on Seismic Hazard Map of Korea)

  • 김성균
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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    • pp.11-26
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    • 1997
  • It has knows that the seismicity of the Korean Peninsula is relatively inactive than those of adjacent northern China and southwestern Japan. Recently the review of long term historical records and recent seismicity. In addition, it is considered that the modern society is more vulnerable to seismic hazard because of high urbanization and industrialization. From this viewpoint, the improvement and modification of the present regulation for aseismic design is strongly proposed. The purpose of the present study is to prepare seismic hazard maps for Korea to be used in improving the present regulation. The present study was performed as a cooperative project of eight Korean seismologists. Each seismologist calculated independently seismic hazard value at the given grid points based on his own judgement about methodology and seismicity. Then the values are unified with equal weight to produce a seismic hazard map. Seven seismic hazard maps for peak acceleration with 10 percentile probability of exceedance in 5, 10, 20, 50, 100, 250, 500 years are presented. This probability of exceedancd in such years corresponds to return period of 48, 95, 190, 475, 950, 2373, 4747 years, respectively. It is recommended to use a hazard map to be selected on the basis of the importance and the design level of structures.

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황토와 석회의 혼합처리에 의한 정수 슬러지의 개질화에 관한 연구 (Loess and Lime Treatment for Modification of Waterworks Sludges)

  • 임성진;조재준;이재복
    • 상하수도학회지
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    • 제14권4호
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    • pp.318-327
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    • 2000
  • Sludge production from water treatment plants is increasing each year because water resources deterioration is proceeding and water supply facilities are growing due to water demand increase. Water treatment plant sludges can be modified to soil cover in sanitary landfilling site through the lime treatment and other alternatives. The compression strength of $1.0kg/cm^2$ is necessary for the dozer operation on soft son cover material at municipal landfilling site. Modified sludge was experimentally produced in this study with lime, bentonite, loess, and activated loess dosing. X-ray diffraction patterns of the limed water treatment plant sludge confirmed the presence of calcium carbonate and ettringite. Unconfined compression strength properties of modified sludges showed material property improvement applicable for soil cover alternatives. When adding 20-30% activated loess to water treatment plant sludges. the modified sludges could reach the compression strength for cover soil after 7 days solidification reaction, but decrease of compression strength was intentioned in 28 days reaction period. Solidification effect of the modified sludge with activated loess was observed through the scanning electron microscope.

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전기-경련 시술후의 혈장 HGH 반응 (A Study on the Human Growth Hormone Response Following Electro Convulsion Therapy)

  • 김동주;성호경;이상돈
    • The Korean Journal of Physiology
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    • 제10권1호
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    • pp.67-71
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    • 1976
  • Effect of Electro Convulsion Therapy (ECT) on the Human Growth Hormone (HGH) response was observed in 32 cases of various mental illness. The patients were fasting overnight and ECT was induced in the morning by application of $90{\sim}120V$ for a period of $0.1{\sim}0.5\;sec$. In all patients, venous blood samples were taken prior to simultaneously with 1 and 4 hours after the ECT. Plasma was immediately seperated and stored in $-20^{\circ}C$ refrigerator. HGH concentrantion was determined by means of radioimmunoassay Results were as follows: 1. Application of electric current was not followed by a significant change in mean plasma HGH of 52 cases. 2 Increases of plasma HGH following ECT were observed in about half cases showing low initial level but in 20 other cases with high initial level of plasma HGH, reasonable decreases after therapy were not found. 3. Plasma concentration of HGH one hour after application of current were always higher than just after the current. 4. There were no differences between HGH responses to a 1st, 2nd or 5th ECT. 5. Discussions were made on the possible modification of HGH response following ECT by the autoregulatory control mechanism.

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Lysosomal acid phosphatase mediates dedifferentiation in the regenerating salamander limb

  • Ju, Bong-Gun;Kim, Won-Sun
    • Animal cells and systems
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    • 제14권2호
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    • pp.73-81
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    • 2010
  • In this study, monoclonal antibodies against lysosomal acid phosphatase (LAP) of a salamander, Hynobius leechii, were used to determine the spatial and temporal expression of the LAP in the regenerating limbs. The Western blot and immunohistochemical analysis in the limb regeneration revealed that LAP was highly expressed at the dedifferentiation stage, especially in the wound epidermis and dedifferentiating limb tissues such as muscle and cartilage. With RA treatment, the LAP expression became upregulated in terms of both level and duration in the wound epidermis, blastemal cell and dedifferentiating limb tissues. In addition, in situ activity staining of LAP showed a similar result to that of immunohistochemistry. Thus, the activity profile of LAP activity coincides well with the expression profile of LAP during the dedifferentiation period. Furthermore, to examine the effects of lysosomal enzymes including LAP on salamander limb regeneration, lysosome extract was microinjected into limb regenerates. Interestingly, when the lysosome extract was microinjected into limb regenerates with a low dose of RA($50\;{\mu}g/g$ body wt.), skeletal pattern duplication occurred frequently in the proximodistal and transverse axes. Therefore, lysosomal enzymes might cause the regenerative environment and RA plays dual roles in the modification of positional value as well as evocation of extensive dedifferentiation for pattern duplication. In conclusion, these results support the hypothesis that dedifferentiation is a crucial event in the process of limb regeneration and RA-evoked pattern duplication, and lysosomal enzymes may play important role(s) in this process.

억양이 과장된 원어민 발화를 통한 영어 억양 교육과 평가 (Evaluation of Teaching English Intonation through Native Utterances with Exaggerated Intonation)

  • 윤규철
    • 말소리와 음성과학
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    • 제3권1호
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    • pp.35-43
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    • 2011
  • The purpose of this paper is to evaluate the viability of employing the intonation exaggeration technique proposed in [4] in teaching English prosody to university students. Fifty-six female university students, twenty-two in a control group and the other thirty-four in an experimental group, participated in a teaching experiment as part of their regular coursework for a five-and-a-half week period. For the study material of the experimental group, a set of utterances was synthesized whose intonation contours had been exaggerated whereas the control group was given the same set without any intonation modification. Recordings from both before and after the teaching experiment were made and one sentence set was chosen for analysis. The parameters analyzed were the pitch range, words containing the highest and lowest pitch points, and the 3-dimensional comparison of the three prosodic features [2]. An AXB and subjective rating test were also performed along with a qualitative screening of the individual intonation contours. The results showed that the experimental group performed slightly better in that their intonation contour was more similar to that of the model native speaker's utterance. This appears to suggest that the intonation exaggeration technique can be employed in teaching English prosody to students.

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