• Title/Summary/Keyword: CME

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Development of Forecast Algorithm for Coronal Mass Ejection Speed and Arrival Time Based on Propagation Tracking by Interplanetary Scintillation g-Value

  • Park, Sa-Rah;Jeon, Ho-Cheol;Kim, Rok-soon;Kim, Jong-Hyeon;Kim, Seung-Jin;Cho, Junghee;Jang, Soojeong
    • Journal of Astronomy and Space Sciences
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    • v.37 no.1
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    • pp.43-50
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    • 2020
  • We have developed an algorithm for tracking coronal mass ejection (CME) propagation that allows us to estimate CME speed and its arrival time at Earth. The algorithm may be used either to forecast the CME's arrival on the day of the forecast or to update the CME tracking information for the next day's forecast. In our case study, we successfully tracked CME propagation using the algorithm based on g-values of interplanetary scintillation (IPS) observation provided by the Institute for Space-Earth Environmental Research (ISEE). We were able to forecast the arrival time (Δt = 0.30 h) and speed (Δv = 20 km/s) of a CME event on October 2, 2000. From the CME-interplanetary CME (ICME) pairs provided by Cane & Richardson (2003), we selected 50 events to evaluate the algorithm's forecast capability. Average errors for arrival time and speed were 11.14 h and 310 km/s, respectively. Results demonstrated that g-values obtained continuously from any single station observation were able to be used as a proxy for CME speed. Therefore, our algorithm may give stable daily forecasts of CME position and speed during propagation in the region of 0.2-1 AU using the IPS g-values, even if IPS velocity observations are insufficient. We expect that this algorithm may be widely accepted for use in space weather forecasting in the near future.

Inhibitory Effects of Complex of Mulberry Extract on Degenerative Arthritis (상심자추출물 등 복합물의 퇴행성관절염 억제효과)

  • Seo, Hyeong Ho;Jeong, Jong Moon
    • Korean Journal of Medicinal Crop Science
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    • v.22 no.4
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    • pp.262-269
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    • 2014
  • Complex of mulberry extract (CME) is composed of extracts of mulberry (Morus alba L.) fruit, mulberry leaves and black beans (Glycine max (L.) Merr.). In this study, we investigated prevention effects of CME on degenerative arthritis. The $SC_{50}$ value of DPPH radical scavenging by CME was $158.49{\pm}11.35{\mu}/mL$. We found that CME significantly reduced the production of nitric oxide (NO) and protein expression of cyclooxygenase-2 (COX-2) in RAW 264.7 cells which were activated by LPS. Experiments using animal model of degenerative arthritis showed that CME (400 mg/kg body weight) inhibited the production of TNF-${\alpha}$ (77.5%) and IL-$1{\beta}$ (95.0%). Furthermore, it was observed that CME reduced to 85.9% of paw edema induced by carrageenan. These results suggest that CME could improve degenerative arthritis.

Comparison of CME mean density based on a full ice-cream cone structure and its corresponding ICME one

  • Na, Hyeonock;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.54.1-54.1
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    • 2018
  • For space weather forecast, it is important to determine three-dimensional parameters of coronal mass ejections (CMEs). To estimate three-dimensional parameters of CMEs, we have developed a full ice-cream cone model which is a combination of a symmetrical flat cone and a hemisphere. By applying this model to 12 SOHO/LASCO halo CMEs, we find that three-dimensional parameters from our method are similar to those from other stereoscopic methods. For several geoeffective CME events, we determine CME mass by applying the Solarsoft procedure (e.g., cme_mass.pro) to SOHO/LASCO C3 images. CME volumes are estimated from the full ice-cream cone structure. We derive CME mean density as a function of CME height for these CMEs, which are approximately fitted to power-law functions. We find that the ICME mean densities extrapolated from the power law functions, are correlated with their corresponding ICME ones in logarithmic scales.

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Mass constraints of coronal mass ejection plasmas observed in EUV and X-ray passbands

  • Lee, Jin-Yi;Raymond, John C.
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.39.1-39.1
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    • 2011
  • Coronal mass ejection (CME) plasmas have been observed in EUV and X-ray passbands as well as in white light. Mass of CME has been determined using polarized brightness observed by the Large Angle and Spectrometric Coronagraph Experiment (LASCO) on board Solar and Heliospheric Observatory (SOHO). Therefore, this mass obtained from the LASCO observation indicates the total CME mass. However, the mass of CME plasma in different temperatures can be determined in EUV and X-ray passbands using observations by SOHO/EIT, STEREO/EUVI, and Hinode/XRT. Prominence/CME plasmas have been observed as absorption or emission features in EUV and X-ray passbands. The absorption features provide a lower limit to cold mass. In addition, the emission features provide an upper limit to the mass of plasmas in temperature ranges of EUV and X-ray. We determine the mass constraints using the emission measure obtained by assuming the prominence/CME structures. This work will address the mass constraints of hot and cold plasmas in CMEs, comparing to total CME mass.

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Relationship Between Solar Proton Events and Corona Mass Ejection Over the Solar Cycle 23 (태양 주기 23 기간 동안 태양 고에너지 양성자 이벤트와 코로나 물질 방출 사이의 상관관계)

  • Hwang, Jung-A;Lee, Jae-Jin;Kim, Yeon-Han;Cho, Kyung-Suk;Kim, Rok-Sun;Moon, Yong-Jae;Park, Young-Deuk
    • Journal of Astronomy and Space Sciences
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    • v.26 no.4
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    • pp.479-486
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    • 2009
  • We studied the solar proton events (SPEs) associated with coronal mass ejections (CMEs) during the solar cycle 23 (1997-2006). Using 63 SPE dataset, we investigated the relationship among SPE, flare, and CME, and found that (1) SPE rise time and duration time depend on CME speed and the earthward direction parameter of the CME, and (2) the SPE peak intensity depends on CME speed and X-ray Flare intensity. While inspecting the relation between SPE peak intensity and the direction parameter, we found there are two groups: first group consists of large six SPEs (> 10,000 pfu at > 10 MeV proton channel of GOES satellite) and shows strong correlation (cc = 0.65) between SPE peak intensity and CME direction parameter. The second group has a weak intensity and shows poor correlation between SPE peak intensity and the direction parameter (cc = 0.01). By investigating characteristics of the first group, we found that all the SPEs are associated with very fast halo CME (> 1400km/s) and also they are mostly located at central region and within ${\pm}20^{\circ}$ latitude and ${\pm}30^{\circ}$ longitude strip.

Relations Among Sunspots, CMEs and Geomagnetic Storms in Solar Cycle 23 (태양주기 23의 흑점, CME 및 지자기폭풍의 빈도간 상관관계 연구)

  • Rho, Su-Lyun;Chang, Heon-Young
    • Journal of Astronomy and Space Sciences
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    • v.26 no.1
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    • pp.9-24
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    • 2009
  • We compare the relation among the annual distribution of sunspots: coronal mass ejections (CMEs) and geomagnetic storms and North-South asymmetry during solar cycle 23. For this purpose, we calculate correlation coefficients between (i) annual distribution and N-S asymmetry of CMEs - sunspots (ii) distribution of CMEs - occurrence number of geomagnetic storms (iii) distribution of sunspots - occurrence number of geomagnetic storms. We find that (i) the annual distribution of total CMEs has good correlation with distribution of annual average of sunspots but poor correlation with N-S asymmetry of sunspots, N-S asymmetry of CMEs has good correlation with N-S asymmetry of sunspots: (ii) total and N-S asymmetry of CMEs have poor correlation with occurrence number of geomagnetic storms, it's, however, well correlated with the classified groups of CMEs (Ap, Dst and an indices vs. fast CMEs($\upsilon$ > $1000kms^{-1}$), Dst index vs. Halo CMEs), and (iii) sunspot numbers and area are correlated with occurrence number of geomagnetic storms. We conclude that annual distribution of CMEs and sunspots have well correlated with geomagnetic storms, N-S asymmetry of CMEs and sunspots have poor correlated with the geomagnetic storms.

Protective Effect of Gryllus Bimaculatus Methanol Extract on UVB-induced Photoaging in Human Skin Fibroblasts (UVB로 손상된 피부 섬유아세포에서 쌍별귀뚜라미 메탄올 추출물의 보호효과)

  • Jeong, Taekyoung;Yu, Myeongnam;Heo, Huijin;Yang, Jinwoo;Jeong, Heonsang;Lee, Junsoo
    • Journal of the Korean Society of Food Culture
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    • v.35 no.5
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    • pp.478-482
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    • 2020
  • We evaluated the protective effects of cricket methanol extract (CME) on ultra-violet B (UVB)-induced photoaging in human skin fibroblasts. The fibroblast cells were treated with 10, 50, and 100 ㎍/mL of CME for 24 h, and then exposed to UVB (30 mJ/㎠). CME showed a dose-dependent cytoprotective effect without any observable cytotoxicity. CME reduced UVB-induced production of reactive oxygen species (ROS) by 34.4, 34.9, 40.6% at concentrations of 10, 50, 100 ㎍/mL respectively. CME inhibited the release of matrix metalloproteinase (MMP) 1 and 3. Furthermore, CME also reduced UVB-induced collagen degradation in the fibroblast cells. Taken together, our data suggests that CME has a significant protective effect on UVB-induced photoaging of the skin. This benefit occurs through multiple mechanisms. The results also suggest a potential role for CME as an ingredient in anti-photoaging cosmetic products in the future.

Performance Analysis of Maximum Zero-Error Probability Algorithm for Blind Equalization in Impulsive Noise Channels (충격성 잡음 채널의 블라인드 등화를 위한 최대 영-확률 알고리듬에 대한 성능 분석)

  • Kim, Nam-Yong
    • Journal of Internet Computing and Services
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    • v.11 no.5
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    • pp.1-8
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    • 2010
  • This paper presentsthe performance study of blind equalizer algorithms for impulsive-noise environments based on Gaussian kernel and constant modulus error(CME). Constant modulus algorithm(CMA) based on CME and mean squared error(MSE) criterion fails in impulsive noise environment. Correntropy blind method recently introduced for impulsive-noise resistance has shown in PAM system not very satisfying results. It is revealed in theoretical and simulation analysis that the maximization of zero-error probability based on CME(MZEP-CME) originally proposed for Gaussian noise environments produces superior performance in impulsive noise channels as well. Gaussian kernel of MZEP-CME has a strong effect of becoming insensitive to the large differences between the power of impulse-infected outputs and the constant modulus value.

CME and radio characteristics of making large solar proton events

  • Hwang, Jung-A;Cho, Kyung-Suk;Bong, Su-Chan;Kim, Su-Jin;Park, Young-Deuk
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.33.2-33.2
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    • 2010
  • We have investigated a relationship among the solar proton events (SPEs), coronal mass ejections (CMEs) and solar flares during the solar cycle 23 (1997-2006). Using 63 SPE dataset, we found that SPE rise time, duration time, and decrease times depend on CME speed and SPE peak intensity depends on the CME earthward direction parameter as well as CME speed and x-ray flare intensity. While inspecting the relation between SPE peak intensity and the CME earthward direction parameter, we found that there are two groups: first group consists of large 6 SPEs (> 10,000 pfu at >10 MeV proton channel of GOES satellite) and shows a very good correlation (cc=0.65) between SPE peak intensity and CME earthward direction parameter. The second group has a relatively weak SPE peak intensity and shows poor correlation between SPE peak intensity and the CME earthward direction parameter (cc=0.01). By investigating characteristics of 6 SPEs in the first group, we found that there are special common conditions of the extremely large proton events (group 1); (1) all the SPEs are associated with very fast halo CME (>1400km/s), (2) they are almost located at disk region, (3) they also accompany large flare (>M7), (4) all they are preceded by another wide CMEs, and (5) they all show helmet streamer nearby the main CME. In this presentation, we will give details of the energy spectra of the 6 SPE events from the ERNE/HED aboard the Solar and Heliospheric Observatory (SOHO), and onset time comparison among the SPE, flare, type II burst, and CME.

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Estimation of Zero-Error Probability of Constant Modulus Errors for Blind Equalization (블라인드 등화를 위한 상수 모듈러스 오차의 영-확률 추정 방법)

  • Kim, Namyong
    • Journal of Internet Computing and Services
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    • v.15 no.5
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    • pp.17-24
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    • 2014
  • Blind algorithms designed to maximize the probability that constant modulus errors become zero carry out some summation operations for a set of constant modulus errors at an iteration time inducing heavy complexity. For the purpose of reducing this computational burden induced from the summation, a new approach to the estimation of the zero-error probability (ZEP) of constant modulus errors (CME) and its gradient is proposed in this paper. The ZEP of CME at the next iteration time is shown to be calculated recursively based on the currently calculated ZEP of CME. It also is shown that the gradient for the weight update of the algorithm can be obtained by differentiating the ZEP of CME estimated recursively. From the simulation results that the proposed estimation method of ZEP-CME and its gradient produces exactly the same estimation results with a significantly reduced computational complexity as the block-processing method does.