• 제목/요약/키워드: Natural variability

검색결과 284건 처리시간 0.033초

The medium-band observation of the neutrino source, TXS 0506+056

  • Hwang, Sungyong;Im, Myungshin;Taak, Yoonchan;Paek, Insu;Choi, Changsu;Shin, Suhyun;Ji, Tae-Geun
    • 천문학회보
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    • 제44권1호
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    • pp.73.4-73.4
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    • 2019
  • The TXS0506+056 is a blazar and counterpart of the neutrino event IceCube-170922A. It is the first time that the neutrino event and flaring event in electromagnetic wave (EM) coincided. We observed TXS0506+056 with medium-bands in optical using 0.25m and 2.1m telescope at McDonald observatory about a month after the neutrino event. We tracked the variability of SED of the target for three weeks, and our observation showed no abrupt variability in optical range during this period. We concluded that a month after the neutrino event, the TXS0506+056 became less active and shows no feature of the energetic event. We also concluded that the medium-bands are well suited for tracking SEDs of objects. Our result demonstrates the potential of the wide-field 0.25m telescope (5.5 deg^2) for finding transient objects and track the variability of sources like AGNs.

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The Monitoring Comparative Results of Floodplain Ecosystems in Regulated and Natural Part of the Danube River (Geisling-Passau)

  • Kouzmina, Janna;Treshkin, Sergey;Henrichfreise, Alfons
    • The Korean Journal of Ecology
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    • 제27권4호
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    • pp.211-216
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    • 2004
  • The complex ecological researches were made in the broad-leaved forest zone of Central Europe in nature reserves and national parks located on the banks of the river (hydrology, vegetation, soils, unconfined ground waters). The natural conditions of terrestrial ecosystems and natural sites were compared along the course of the rivers. The significant negative influence of low-dammed (low-confined hydrotechnic) construction and small reservoirs on vegetation and soils of floodplain was revealed. On the basis of analysis of mean annual water level and flow trends on the multi-years series (60-100 years) of the hydrometric stations on the rivers under consideration the significant influence of natural long-term variability of watering on vegetation dynamics in the floodplains was revealed.

언양 자연 집단내 Drosophila melanogaster의 유해 유전자 빈도 분석 (Analysis of Frequencies of Deleterious Chromosomes in On-yang Natural Population of Drosophila melanogaster)

  • 김영필;최영현
    • 한국환경과학회지
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    • 제5권1호
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    • pp.1-6
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    • 1996
  • The genetic variabilities of second chromosomes of Drosophila melanogaster concealed in On-yang natural Population have been analyzed by the Cy/Pm method and an allelism test during two years(1993-1994). The mean frequencies of deleterious(lethal and semilethal) genes in On-yang natural population were estimated to be 23.97% in 1993 and 27.15% in 1994, respectively. The allelism rates between lethal genes in the population were 0.654%(1993) and 1.429%(1994). The mean values of elimination by frequencies of deleterious genes and allelism rates were 0.0004(1993) and 0.0010(1994), respectively. The frequencies of phenotypic sterility of males in 1994 were estimated to be 1.95%, and thoses of genotypic sterility of females and males were estimated to be 1.54% and 2.31%, respectively.

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Variability in the coat protein genes of two orchid viruses from Phlaenopsis orchids in Korea

  • Park, S.H.;H.R. Lim;G.D. Ye;K.H. Ryu
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.145.1-145
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    • 2003
  • This study was conducted to designing conserved regions of molecules for virus-derived resistance to transgenic Phlaenopsis orchids to protect against two major orchid viruses, Cymbidum mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV). Infected leaf samples of Phalaenopsis were randomly screened by the RT-PCR with specific primers to both of viruses. RT-PCR products of the viruses were cloned and their nucleotide sequences were determined. Multiple alignments of coat protein (CP) genes of the viruses revealed that over the 88 % and 94 % identities with CymMV and ORSV, respectively, were observed. These data can be useful for selection of highly conserved regions of CP gene of the viruses for transgenic orchid experiments.

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지구시스템 모형을 이용한 21세기 동중국해와 남해의 수온과 일차생산 변화 평가 (Assessment of Changes in Temperature and Primary Production over the East China Sea and South Sea during the 21st Century using an Earth System Model)

  • 박영규;최상화;김선동;김철호
    • Ocean and Polar Research
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    • 제34권2호
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    • pp.229-237
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    • 2012
  • Using results from an Earth System model, we investigated change in primary production in the East China Sea, under a global warming scenario. As global warming progresses, the vertical stratification of water becomes stronger, and nutrient supply from the lower part to the upper part is reduced. Consequently, so is the primary production. In addition to the warming trend, there is strong decadal to interdecadal scale variability, and it takes a few decades before the warming trend surpasses natural variability. Thus, it would be very hard to investigate the global warming trend using data of several years' length.

PRELIMINARY STUDY OF WATER CONTENTS AND SIGNAL BEHAVIOR IN FINGERNAIL/EPR DOSIMETRY

  • Choi, Hoon;Choi, Sul A;Lee, Byungil
    • Journal of Radiation Protection and Research
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    • 제38권4호
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    • pp.185-188
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    • 2013
  • Heating method using electric heater was used to reduce water content in fingernail clippings. Authors found that low water content is helpful to measure EPR signal of fingernail sample with enhanced variability. Generally, natural dehydration happens in normal room condition at least one month and needs much time for using in experiment. So, artificial heating method is applied in this study for time savings. Fingernail samples were tested to find effect of water content to the EPR signal on microwave power levels for dosimetry. Low water content in fingernail reduced variability of EPR signal and makes it possible to measure accurate EPR signal. It also made it possible to measure constant movement of EPR signals on several microwave power levels. Although this method was difficult to apply directly in fingernail/EPR dosimetry, we, authors, believe that this heating method would be useful to differentiate MIS2 and RIS which are generally located at the same g-factor and almost impossible to be identified with each other.

지반조사 데이터의 통계처리기법 (Statistical Representation Methods of Ground Data)

  • 이규환;윤길림
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.85-110
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    • 2008
  • Ground investigation data to be used as a basis for geotechnical analysis and foundation design are usually troubled with large uncertainty, due to natural variability and limited number of data. Statistical methods can be a rational tool for handling such uncertain ground data, in particular with a view to the selection of characteristic values for estimating ground design parameters used in design. The characteristic values of soil properties for use in geotechnical design have oftenly based on not only a subjective judgment but also engineer's past acumulated experience. This paper discussed some statistical methods which can handle such intrinsic ground uncertainty data with a case design in a rational manner.

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Sensitivity of Flow Metrics to Climate Variability and Extremes in Korea

  • Kim, Jong-Suk;Jain, Shaleen;Yuk, Ji Moon;Moon, Young-Il
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2016년도 학술발표회
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    • pp.117-117
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    • 2016
  • The natural hydrologic regime is intimately tied to the structure and function of stream and riparian ecosystems. Consequently, understanding the nature and extent of perturbations to the hydrologic regime, stemming from episodic-to-seasonal and longer-term climatic variations, as well as anthropogenic influences is an important starting point for developing an improved understanding of the coupled human-environmental systems. Herein, we pursued to explicate sensitivity of ecologically relevant flow metrics to climate variability and extremes in the five major river basins, Korea.

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Variability in Environmental Flow Metrics to Hydroclimatic Extremes

  • Kim, Jong-Suk
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2017년도 학술발표회
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    • pp.195-195
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    • 2017
  • The patterns of occurrence of typhoons in North Pacific region are constantly changing with the increase of temperature in sea surface and the occurrence of El Nino and La Nina and changes of their development caused by global warming. In addition, alterations of flow regimes caused by large-scale hydraulic construction projects in the past few years and changes in precipitation patterns caused by climate change have imposed increased stress on hydroecology while the indiscreet utilization of water resources has a negative environmental impact on the water flows in the natural rivers and streams and hydroecological structures. The purpose of this study is to explore the impact of altered hydrologic regime on stream and riparian ecosystems that are most vulnerable to climate variability and extremes such as typhoons.

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Does Inhaled Peppermint Essential Oil Affect Blood Pressure?

  • Park, Sah-Hoon;Kim, Kun-Hee;Park, Jong-Seong
    • 통합자연과학논문집
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    • 제14권3호
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    • pp.95-98
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    • 2021
  • By far, studies on the effect of oral administration of peppermint essential oil on blood pressure are not consistent, increasing or decreasing. And the effect of inhalation of peppermint essential oil on blood pressure was not reported. This study was designed to clarify the effect of peppermint essential oil inhalation on the blood pressure and autonomic nervous system. Blood pressure and heart rate variability (HRV) as an indicator of autonomic nervous system activity were measured. The systolic and diastolic blood pressure was not changed significantly by inhalation of peppermint essential oil. Standard deviation of normal to normal (SDNN), a parameter of total activity of autonomic nervous system also was not changed significantly. High frequency (HF) power level, an indicator of parasympathetic nervous system activity was not changed by peppermint. These results indicate that action mechanism of peppermint essential oil on blood pressure is different by the method of administration, oral or inhalation.