• Title/Summary/Keyword: solar activities

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GPS TEC Responses to Solar Flare Eruption and Geomagnetic Storm in 2011

  • Chung, Jong-Kyun;Lee, Chi-Na
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.27.2-27.2
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    • 2011
  • The Total Electron Content (TEC) measured from Global Positioning System (GPS) can be continuously or peculiarly increased (positive ionospheric storm) or decreased (negative ionospheric storm) with solar and geomagnetic activities as well as the chemical and dynamic processes with thermosphere in the mid-latitudes. The ionospheric storm is not easy to predict owing to its difficult mechanism, and the real-time GPS TEC monitoring may be useful to follow ionospheric response to solar and geomagnetic storms. Korea Astronomy & Space Science Institute has continuously monitor GPS TEC over Korea Peninsula in near real-time of 10 minutes to watch activities. In this presentation, we will report the variation of GPS TEC over Daejeon and JeJu in Korea during the period of solar flare eruption and geomagnetic storm events in 2011. These events in 2011 will be compared with the event in October 2003 and November 2004.

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Recent International Activity of KASI for Space Weather Research

  • Cho, Kyung-Suk;Park, Young-Deuk;Lee, Jae-Jin;Bong, Su-Chan;Kim, Yeon-Han;Hwang, Jung-A;Choi, Seong-Hwan
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.32.1-32.1
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    • 2010
  • KASI's Solar and Space Weather Research Group (SSWRG) is actively involved in solar and space weather research. Since its inception, the SSWRG has been utilizing ground-based assets for its research, such as the Solar Flare Telescope, Solar Imaging Spectrograph, and Sunspot Telescope. In 2007 SSWRG initiated the Korean Space Weather Prediction Center (KSWPC). The goal of KSWPC is to extend the current ground observation capabilities, construct space weather database and networking, develop prediction models, and expand space weather research. Beginning in 2010, SSWRG plans to expand its research activities by collaborating with new international partners, continuing the development of space weather prediction models and forecast system, and phasing into developing and launching space-based assets. In this talk, we will report on KASI's recent activities of international collaborations with NASA for STEREO (Solar Terrestrial Relations Observatory), SDO (Solar Dynamic Observatory), and Radiation Belt Storm Probe (RBSP).

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Studies on the Solar Activated Insecticidal Activities of Dihydroxyl Phosphorus(V) Triazatetrabenzocorrole Derivatives (Dihydroxyl Phosphorus(V) Triazatetrabenzocorrole 유도체의 광학 살충 활성 연구)

  • Oh, Hyun-Chul;Woo, Je-Wan
    • The Korean Journal of Pesticide Science
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    • v.15 no.2
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    • pp.87-96
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    • 2011
  • To study solar activated insecticide, three types of dihydroxyl phosphorus(V) triazatetrabenzocorrole derivatives ($P(OH)_2TBCs$) including H, 4'-methoxy phenoxy, 4'-tert butyl phenoxy substituents were synthesized. The results show that slightly red-shift with introducing substituents was observed and singlet oxygen was generated by the sunlight. Based on photochemical properties, solar activated insecticidal activity tests against Liriomyza trifolii (Burgess) were carried out. Overall insecticidal activities were 100~85.7% in the concentration of 500ppm, and especially in the case of compound $P(OH)_2TBC$ the insecticidal activities was 100%.

The Analysis of the Topside Additional Layer of Martian Ionosphere Using MARSIS/Mars Express Data

  • Kim, Eojin;Seo, Haingja;Kim, Joo Hyeon;Lee, Joo Hee;Kim, Yong Ha;Choi, Gi-Hyuk;Sim, Eun-Sup
    • Journal of Astronomy and Space Sciences
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    • v.29 no.4
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    • pp.337-342
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    • 2012
  • In this study, the transient second or third layer on the topside of the Martian ionosphere were investigated with the most recently released Mars advanced radar for subsurface and ionospheric sounding/Mars Express data obtained from January 2010 to September 2011 to study the correlation between these topside additional layers and surface magnetic fields, solar zenith angle and solar activities. When examining the zones where the topside layer appeared, the occurrence rate of the topside layer was low at the areas with a strong Martian crustal magnetic field as observed by the Mars global surveyor. The occurrence rate of additional layers on the Martian topside ionosphere decreases as the solar zenith angle increases. However, these layers appeared significantly near the terminator of which solar zenith angle is $90^{\circ}$. In comparison between F10.7 which is the index of solar activities and the occurrence rate of the topside layer by date, its occurrence rate was higher in 2011 than in 2010 with less solar activities. The result of this study will contribute to better understanding of the environments in the topside of the ionosphere through the correlation between the various conditions regarding the Martian ionosphere and the transient layer.

Decomposition of Organic Compound by Photo-Chemical Reaction on Ilmenite (일메나이트 상에서 광화학반응에 의한 유기물의 분해)

  • Choi, Im-Kyu;Ha, Baik-Hyon
    • Solar Energy
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    • v.8 no.2
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    • pp.39-45
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    • 1988
  • Photo-decomposition experiments to produce hydrogen from organic compound such as alcohols and organic acids were investigated using the Korean natural ilmenite, which was used as ore itself as well as the calcined in vacuum. The decomposition activities of alcohol on ore (30-60 mesh) which was not calcined did not decrease even if it was repeatedly used. But crushed ore which had newly formed ilmenite surface revealed enhanced activities. The ilmenite powder calcined in vacuum showed 3-8 times higher activies than the ore powder itself and also the decomposition activity of formic acid was much higher than that of alcohols.

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Revaluation of Solar Radiation Resources in Korea (국내 태양에너지 자원의 재평가)

  • Jo, Dok-Ki;Kang, Yong-Heack
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.153-156
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    • 2006
  • The domestic solar radial ion data have been measured at 16 different sites all over the country since the beginning of 1980. It is very important that the fundamental data for the estimation and assessment of local solar radiation can be secured this project. In order to estimate available energy resource from solar radiation, it is necessary to have enough data, more than 30 years In any country. However since we have collected solar radiation(global radial ion including direct normal radiation) data only for 10 years we still need to measure insolation to secure the reliability and standardization of measured local solar radial ion data. In brief, the major activities on this R&D include rout me maintenance of the national network for insolation data measurement, evaluation of the collected data, and reliability enhancement for assessing the quality of solar radiation data as well.

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Study on Status of Solar Astronomy in North Korea

  • Kim, Sujin;Yang, Hong-Jin;Chung, Jong-Kyun;Yim, Insung
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.63.1-63.1
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    • 2021
  • We present status of solar astronomy in North Korea through analysis of research papers written by North Korea scientists. For the study, we collected 42 papers published in North Korea and international journals. We have analyzed the papers statistically according to three criteria such as research subject, research field, and research members. The main research subjects are the sunspot (28%), observation system (21%), and space environments (19%). The research fields are distributed with data analysis (50%), numerical method (29%), and instrument development (21%). There have been 25 and 9 researchers in the solar astronomy and space environment, respectively since 1995. North Korea's solar research activities were also investigated in three area: instrument, solar physics, and international research linkage. PAO(Pyongyang Astronomical Observatory) has operated two of sunspot telescope and solar horizontal telescope for spectroscopy and polarimetry, but there is no specific information on solar radio telescopes. North Korea has cooperated in solar research with Europe and China. We expect that the results of this study will be used as useful resource in supporting astronomical cooperation between South and North Korea in the future.

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SOLAR OBSERVATIONAL SYSTEM OF KYUNGHEE UNIVERSITY (경희대학교 태양관측시스템)

  • KIM IL-HOON;KIM KAP-SUNG
    • Publications of The Korean Astronomical Society
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    • v.13 no.1 s.14
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    • pp.39-54
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    • 1998
  • We have developed solar observational system in the department of Astronomy & Space Sciences of KyungHee University, in order to monitor solar activities and construct solar database for space weather forecasting at maximum of 23rd solar cycle, as well as an solar education and exercise for undergraduate students. Our solar observational system consists of the full disk monitoring system and the regional observation system for H a fine structure. Full disk monitoring system is made of an energy rejection filter, 16cm refractor, video CCD camera and monitor. Monitored data are recorded to VHS video tape and analog output of video CCD can be captured as digital images by the computer with video graphic card. Another system for regional observation of the sun is made of energy rejection filter, 21cm Schmidt-Cassegrain reflector, H a filter with 1.6A pass band width and $375\times242$ CCD camera. We can observe H a fine structure in active regions of solar disk and solar limb, by using this system. We have carried out intense solar observations for a test of our system. It is found that Quality of our H a image is as good as that of solar images provided by Space Environmental Center. In this paper, we introduce the basic characteristics of the KyungHee Solar Observation System and result of our solar observations. We hope that our data should be used for space weather forecasting with domestic data of RRL(Radio Research Laboratory) and SOFT(SOlar Flare Telescope).

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A Study on Developing Designs and the Practical Use of Outdoor Backpacks Equipped with Solar Cells

  • Park, Jinhee
    • Journal of Fashion Business
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    • v.17 no.6
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    • pp.88-97
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    • 2013
  • 'Smart Clothes', which incorporate topnotch digital technology into fashion, are a leading fashion runner in this digital era. The purpose of the study is to first help develop a practical design for outdoor backpacks which are equipped with eco-friendly solar cells that facilitate recharging diverse smart devices during outdoor activities; and, secondly, to offer some practical data from the actual appropriation tests that will be used for manufacturing such products. This trial study finds out how to conjoin some practical IT devices with fashion items and mainly focusses on designing outdoor backpacks which are loaded with solar cells for recharging electric devices, and, later, experiments on designed backpacks with some smart phones to see how it works. According to the desired purposes of backpacks, all the features can be adjusted and modified such as the kinds of solar cell panels, materials, sizes, positions of attachment, weights, etc. Smart Clothes are highly functional and fashionable items that satisfy both practical and emotional purposes, and are being actively developed to serve consumers. This study proves that Smart Clothes or Smart Wear will have practical uses for outdoor activities and will possibly lead our smart lifestyles.

Survey of Solar System Objects using KMTNet

  • Yang, Hongu;Ishiguro, Masateru;Lee, Hee-Jae;JeongAhn, Youngmin;Moon, Hong-Kyu;Choi, Young-Jun
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.63.1-63.1
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    • 2019
  • Solar system small bodies are unusual objects in astronomical survey data in that they are moving on the celestial sphere. In addition, even in a normal status, their magnitudes are changing over time, firstly because their relative positions with respect to the Sun and Earth are continually changing, secondly because they are rotating bodies with non-spherical shapes. Furthermore, some of them might exhibit unexpected activities, which could be caused by mass ejection or disintegration. Detections and observations of such activities are challenging due to their abrupt nature. Therefore, continuous monitoring observations of large number of Solar system small bodies are required to systematically obtain detailed/transient information about them. Since 2018/2019 winter, we have launched a new project using Korea Microlensing Telescope Network (KMTNet) for detecting such transient phenomena of Solar system objects. Our main goal is to monitor the magnitudes and detect sudden brightness changes. We also plan to discover interesting new objects, and monitor rotational brightness oscillations of asteroids. We intend to monitor the magnitudes of ~ 20,000 known Solar system small bodies per night, and acquire lightcurves of ~ 1,000 asteroids.

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