• 제목/요약/키워드: Flare

검색결과 481건 처리시간 0.032초

Are EUV bright points flare loops?

  • Kwon, Ryun-Young;Chae, Jong-Chul
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권1호
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    • pp.59.4-60
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    • 2009
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Characteristics of Four SPE Classes According to Onset Timing and Proton Acceleration Patterns

  • Kim, Roksoon;Cho, Kyungsuk;Lee, Jeongwoo;Bong, Suchan;Park, Youngdeuk
    • 천문학회보
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    • 제40권1호
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    • pp.63.3-64
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    • 2015
  • In our previous work (Kim et al., 2015), we suggested a new classification scheme, which categorizes the SPEs into four groups based on association with flare or CME inferred from onset timings as well as proton acceleration patterns using multienergy observations. In this study, we have tried to find whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (>5000pfu) even if the associated flare and CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. For the former, the sites are very low (~1Rs) and close to the western limb, while the latter has a relatively higher and wider acceleration sites. (ii) When the proton acceleration starts from the higher energy, a SPE tends to be a relatively weak event (<1000pfu), in spite of its associated CME is relatively stronger than previous group. (iii) The SPEs categorized by the simultaneous proton acceleration in whole energy range within 10 minutes, tend to show the weakest proton flux in spite of strong related eruptions. Their acceleration heights are very close to the locations of type II radio bursts. Based on those results, we suggest that the different characteristics of the four groups are mainly due to the different mechanisms governing the acceleration pattern and interval, and different condition such as the acceleration location.

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재단 각도에 따른 세미 플레어 스커트의 외관 및 헴라인 드레이프 형상에 관한 연구 - 실제 착의와 i-Designer의 가상 착의 시스템을 중심으로 - (A Study on the Shape of Hem-line of Semi-Flare Skirts according to a Cutting Angle - Based on the Comparison between Real Clothing and 3D Virtual Clothing -)

  • 구미란;서미아
    • 복식문화연구
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    • 제17권3호
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    • pp.499-511
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    • 2009
  • As the demand of the consumer for high-sense clothing, relation with materials is becoming important even in clothing construction. Especially, the cutting angle of materials is becoming an crucial element in the formation of silhouette, and drape of Hem line, of skirts. Accordingly, in this study, Hem line shapes between real clothing and 3D virtual clothing of "i-Designer" were analyzed by manufacturing semi-flare skirts of polyester 100% according to a cutting angle, and the results are as follows. As a result of comparison of silhouette between the real clothing and the virtual clothing, the real and the virtual have a similar feeling regardless of a cutting angle. In case of drape shapes, both the front and the lateral side were represented in almost similar shapes. The back side, however, the real and the virtual showed a great difference in case of grain direction. And in the whole silhouette, the real and the virtual were represented similarly. It could be known that with regard to Hem-line drape shapes between the real clothing and the virtual according to a cutting angle, the real clothing is represented in a location farther from the body than the virtual clothing and, the location or number of node was similarly showed in the real and the virtual.

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STUDY OF SOLAR ACTIVE REGIONS BASED ON BOAO VECTOR MAGNETOGRAMS

  • MOON YONG-JAE;PARK YOUNG DEUK;YUN HONG SIK;CHO EUN-AH
    • 천문학회지
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    • 제32권2호
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    • pp.127-136
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    • 1999
  • In this study we present the study of solar active regions based on BOAO vector magnetograms and H$\alpha$ filtergrams. With the new calibration method we analyzed BOAO vector magnetograms taken from the SOFT observational system to compare with those of other observing systems. In this study it has been demonstrated that (1) our longitudinal magnetogram matches very well the corresponding Mitaka's magnetogram to the extent that the maximum correlation yields r=0.962 between our re-scaled longitudinal magnetogram and the Mitaka's magnetogram; (2) according to a comparison of our magnetograms of AR 8422 with those taken at Mitaka solar observatory their longitudinal fields are very similar to each other while transverse fields are a little different possibly due to large noise level; (3) main features seen by our longitudinal magnetograms of AR 8422 and AR 8419 and the corresponding Kitt Peak magnetograms are very similar to each other; (4) time series of our vector magnetograms and H-alpha observations of AR 8419 during its flaring (M3.1/1B) activity show that the filament eruption followed the sheared inversion line of the quadrupolar configuration of sunspots, indicating that the flare should be associated with the quadrupolar field configuration and its interaction with new filament eruption. Finally, it may be concluded that the Solar Flare Telescope at BOAO works normally and it is ready to do numerous observational and theoretical works associated with solar activities such as flares.

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MAGNETIC HELICITY CHANGES OF SOLAR ACTIVE REGIONS BY PHOTOSPHERIC HORIZONTAL MOTIONS

  • MOON Y.-J.;CHAE JONGCHUL;PARK Y. D.
    • 천문학회지
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    • 제36권spc1호
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    • pp.37-44
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    • 2003
  • In this paper, we review recent studies on the magnetic helicity changes of solar active regions by photospheric horizontal motions. Recently, Chae(200l) developed a methodology to determine the magnetic helicity change rate via photospheric horizontal motions. We have applied this methodology to four cases: (1) NOAA AR 8100 which has a series of homologous X-ray flares, (2) three active regions which have four eruptive major X-ray flares, (3) NOAA AR 9236 which has three eruptive X-class flares, and (4) NOAA AR 8668 in which a large filament was under formation. As a result, we have found several interesting results. First, the rate of magnetic helicity injection strongly depends on an active region and its evolution. Its mean rate ranges from 4 to $17 {\times} 10^{40}\;Mx^2\;h^{-1}$. Especially when the homologous flares occurred and when the filament was formed, significant rates of magnetic helicity were continuously deposited in the corona via photospheric shear flows. Second, there is a strong positive correlation between the magnetic helicity accumulated during the flaring time interval of the homologous flares in AR 8100 and the GOES X-ray flux integrated over the flaring time. This indicates that the occurrence of a series of homologous flares is physically related to the accumulation of magnetic helicity in the corona by photospheric shearing motions. Third, impulsive helicity variations took place near the flaring times of some strong flares. These impulsive variations whose time scales are less than one hour are attributed to localized velocity kernels around the polarity inversion line. Fourth, considering the filament eruption associated with an X1.8 flare started about 10 minutes before the impulsive variation of the helicity change rate, we suggest that the impulsive helicity variation is not a cause of the eruptive solar flare but its result. Finally, we discuss the physical implications on these results and our future plans.

Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity

  • Oh, Suyeon
    • Journal of Astronomy and Space Sciences
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    • 제31권2호
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    • pp.145-148
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    • 2014
  • There was a research on the prolongation of solar cycle 23 by the solar cyclic variation of solar, interplanetary geomagnetic parameters by Oh & Kim (2013). They also suggested that the sunspot number cannot typically explain the variation of total solar irradiance any more. Instead of the sunspot number, a new index is introduced to explain the degree of solar activity. We have analyzed the frequency of sunspot appearance, the length of solar cycle, and the rise time to a solar maximum as the characteristics of solar cycle. Then, we have examined the predictability of solar activity by the characteristics of preceding solar cycle. We have also investigated the hemispheric variation of flare index for the periods that the leading sunspot has the same magnetic polarity. As a result, it was found that there was a good correlation between the length of preceding solar cycle and spotless days. When the length of preceding solar cycle gets longer, the spotless days increase. It is also shown that the shorter rise time to a solar maximum is highly correlated with the increase of sunspots at a solar maximum. Therefore, the appearance frequency of spotless days and the length of solar cycle are more significant than the general sunspot number as an index of declining solar activity. Additionally, the activity of flares leads in the northern hemisphere and is stronger in the hemisphere with leading sunspots in positive polarity than in the hemisphere with leading sunspots in negative polarity. This result suggests that it is necessary to analyze the magnetic polarity's effect on the flares and to interpret the period from the solar maximum to solar maximum as the definition of solar cycle.

Korean Red Ginseng exhibits no significant adverse effect on disease activity in patients with rheumatoid arthritis: a randomized, double-blind, crossover study

  • Cho, Soo-Kyung;Kim, Dam;Yoo, Dasomi;Jang, Eun Jin;Jun, Jae-Bum;Sung, Yoon-Kyoung
    • Journal of Ginseng Research
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    • 제42권2호
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    • pp.144-148
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    • 2018
  • Background: Panax ginseng is a well-known immune modulator, and there is concern that its immune-enhancing effects may negatively affect patients with rheumatoid arthritis (RA) by worsening symptoms or increasing the risk of adverse effects from other drugs. In this randomized, crossover clinical trial, we evaluated the impact of Korean Red Ginseng (KRG) on disease activity and safety in RA patients. Methods: A total of 80 female RA patients were randomly assigned to either the KRG (2 g/d, n = 40) treatment or placebo (n = 40) groups for 8 wk, followed by crossover to the other treatment group for an additional 8 wk. The primary outcome was the disease flare rate, defined as worsening disease activity according to the disease activity score 28 joints-erythrocyte sedimentation rate (DAS28-ESR). The secondary outcomes were development of adverse events (AEs) and patient reported outcomes. Outcomes were evaluated at baseline and 8 wk and 16 wk. The outcomes were compared using the Chi-square test. Results: Of the 80 patients, 70 completed the full study. Their mean age was 51.9 yr, and most exhibited low disease activity (mean DAS28-ESR $3.5{\pm}1.0$) at enrollment. After intervention, the flare rate was 3.7% in each group. During KRG treatment, 10 AEs were reported, while five AEs were developed with placebo; however, this difference was not statistically significant (p = 0.16). Gastrointestinal- and nervous system-related symptoms were frequent in the KRG group. Conclusion: KRG is not significantly associated with either disease flare rate or the rate of AE development in RA patients.

가상착의 시스템을 통한 니트 플레어스커트의 드레이프 형상에 관한 연구 - 각도에 따른 플레어스커트를 중심으로 - (A Study on Knit Flare Skirts of Hem for 3D Virtual Clothing System - Focused on the Angle of Flare Skirt -)

  • 기희숙
    • 한국의상디자인학회지
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    • 제15권2호
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    • pp.77-89
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    • 2013
  • This study investigated the formation of silhouette and hemline shape of knit flare skirts according to the properties of knit material through virtual clothing with a 3D virtual clothing system called i-Designer of Technoa, thus building a database of the property data of knit material to reduce the number of sample making steps repeated and implemented several times in the process of clothes making. The results would help to estimate a silhouette in advance, offer assistance to the development of original knit wear, and explore ways to provide basic data for the development of the knit industry of the nation. The investigator made 12 kinds of experimental clothes to the angles(width of skirt: $90^{\circ}$ and $180^{\circ}$), gauge(7G, 12G, and 15G), and grain directions(wale and bias direction) of experimental clothes for virtual clothing. The dynamic characteristics of knit skirt samples according to each gauge were measured with the KES-FB system. Draper shapes were analyzed with the sectional shape data of hemline based on i-Designer. As for the measurements of the sectional shape of hemline and the formation of silhouette, the number of nodes, the average height of node mountains and valleys, and the hemline width right and left and before and after increased at the angle of $180^{\circ}$ than $90^{\circ}$. As gauges multiplied, the number of nodes, and silhouette angle dropping. When considering grain directions, the number of nodes and silhouette index increased in the wale direction at the angle of $90^{\circ}$ with the number of nodes and silhouette angle increasing in the wale direction at the angle of $180^{\circ}$.

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