• Title/Summary/Keyword: Astronomical Field

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The Effects of the 'Solar system and Stars' Unit Using Backward Design 2.0 on Science Academic Achievement, Performance Evaluation, and Science Class Satisfaction (백워드 설계 2.0을 활용한 '태양계와 별' 단원 수업이 과학 학업성취도와 수행평가 및 과학 수업 만족도에 미치는 효과)

  • Son, Junho;Kim, Hyunry
    • Journal of the Korean Society of Earth Science Education
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    • v.13 no.2
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    • pp.147-161
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    • 2020
  • In order to help elementary students understand the astronomical unit in depth, this study applied backward design 2.0 to check the effect on students' science academic achievement, performance evaluation, and science class satisfaction. As a result of the study, there was no statistically significant difference in the science achievement test, but the average score of the experimental group has improved. As a result of the performance evaluation test, there was a statistically significant difference because the feedback was well provided through the process-focused assessment and it helped in-depth understanding. As a result of the science class satisfaction test, there was a statistically significant difference in the areas of science curriculum and peer relation except for the science teacher area. This is because a differentiated science curriculum was designed through analysis of achievement standards, and various teaching methods of student-centered were implemented to reach achievement standards. We hope this study will focus on the impact of backward design 2.0 on learners in elementary science classes and help find ways to effectively apply backward design 2.0 in the field.

Laser Acceleration of Electron Beams to the GeV-class Energies in Gas Jets

  • Hafz, Nasr A.M.;Jeong, Tae-Moon;Lee, Seong-Ku;Choi, Il-Woo;Pae, Ki-Hong;Kulagin, Victor V.;Sung, Jae-Hee;Yu, Tae-Jun;Cary, John R.;Ko, Do-Kyeong;Lee, Jong-Min
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.8-14
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    • 2009
  • In a laser-plasma wakefield accelerator, the ponderomotive force of an ultrashort high intensity laser pulse excites a longitudinal wave or plasma bubble in a way similar to the excitation of a wake wave behind a boat as it propagates on the water surface. Electric fields inside the plasma bubble can be several orders of magnitude higher than those available in conventional RF-based particle accelerator facilities which are limited by material breakdown. Therefore, if an electron bunch is properly phase-locked with the bubble's acceleration field, it can gain relativistic energies within an extremely short distance. Here, in the bubble regime we show the generation of stable and reproducible sub GeV, and GeV-class electron beams. Supported by three-dimensional particle-in-cell simulations, our experimental results show the highest acceleration gradients produced so far. Simulations suggested that the plasma bubble elongation should be minimized in order to achieve higher electron beam energies.

Generation Y's Delivery Apps Choice Attributes and Their Consequences (Y세대의 배달앱 선택속성과 결과)

  • Lee, Jung-Won;Kim, Tea-Wan;Lee, Min-Jong;Lee, Sung-Hoon
    • The Korean Journal of Franchise Management
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    • v.9 no.1
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    • pp.27-39
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    • 2018
  • Purpose - Recently, the mobile application field has been receiving astronomical attention from the past few years due to the growing number of mobile app downloads and withal due to the revenues being engendered. Especially delivery apps by mobile service market is experiencing rapid growth and competition is intensifying. Therefore, delivery apps' choice attributes has become important as a strategy for survival of franchise firms. Based on previous studies, this research proposed the theoretical framework about the structural relationships among customer satisfaction, trust and revisit intention on delivery apps' choice attributes. Research design, data, and methodology - This study examines the structural relationship between choice attributes of using the delivery app, satisfaction, trust, and revisit intention. More specifically, this study has been examined from the perspective of Generation Y who is enjoying electronic commerce and shopping with mobile phone. In this model, choice attributes of delivery app consists of three sub-dimensions such as service quality, system quality, interaction quality. So as to test the purposes of this study, research model and hypotheses were developed. After excluding 24 invalid respondent questionnaires, 201 valid questionnaires were coded and analyzed using frequency, confirmatory factor analysis, correlations analysis, and structural equation modeling with SPSS 21 and SmartPLS 3.0. Result - The results of the study are as follows. First, service quality and interaction quality had positive effects on satisfaction, and interaction quality had positive effects on trust, but system quality did not have a significant effect on both satisfaction and trust. Second, satisfaction had positive effects on both trust and revisit intention. Third, trust had positive effects on revisit intention. Conclusions - The implications of this study are following as: From the theoretical perspective, this study confirms the effect of delivery apps' choice attributes on satisfaction, trust, and revisit intention. In addition, it is significant that we examined the influence of choice attributes of delivery apps on their attitudes and behaviors of Generation Y familiar with mobile environment. Through this study, we hypothesized that the attributes of service quality and interaction quality of delivery apps have a significant effect on customer satisfaction, and this can be expected to provide meaningful implications for the development of franchise restaurant industry. To encourage continuous repurchase through customer satisfaction, franchise companies need to establish various strategic alliances with delivery app companies and new growth engines by providing diverse and high-quality services to customers in the smart age.

Site Selection for Geologic Records of Extreme Climate Events based on Environmental Change and Topographic Analyses using Paleo Map for Myeongsanimni Coast, South Korea (고지도 기반 환경변화연구 및 지형분석을 통한 명사십리 해안의 제4기 연안지대 이상기후 퇴적기록 적지선정)

  • Kim, Jieun;Yu, Jaehyung;Yang, Dongyoon
    • Economic and Environmental Geology
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    • v.47 no.6
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    • pp.589-599
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    • 2014
  • This study selected optimal sites in Myeongsasimni located in west coast of Korea for stratigraphic research containing extreme climate event during quaternary period by spatio-temporal analyses of changes in sedimentary environment and land use employing 1918 topographic map, 2000 digital terrain map, 1976 and 2012 air photographies. The study area shows no significant changes in topographic characteristics that hilly areas with relatively large variations in elevation are distributed over north and south part of the study area, and sand dues are developed along the coast line. Moreover, flat low lying areas are located at the back side of the sand dues. The movement of surface run off and sediment loads shows two major trends of inland direction flow from back sides of sand dunes and outland direction flow from high terrains inland, and the two flows merge into the stream located in the center of the study area. Two sink with individual area of $0.2km^2$ are observed in Yongjeong-ri and Jaryong-ri which are located in south central part and south part of the study area, respectively. In addition, sea level change simulation reveals that $3.4km^2$ and $3.64km^2$ are inundated with 3 m of sea level rise in 1918 and 2000, respectively, and it would contribute to chase sea level change records preserved in stratigraphy. The inundated areas overlaps well with sink areas where it indicates the low lying areas located in south cental and south part of the study area are identical for sediment accumulation. The areas with minimal human impact on sediment records over last 100 years are $3.51km^2$ distributed over central and south part of the study area with the land use changes of mud and rice field in 1918 to rice field in 2012. The candidate sites of $0.15km^2$ in central part and $0.09km^2$ in south part are identified for preferable locations of geologic record of extreme climate events during quaternary period based on the overlay analysis of optimal sedimentary environment and land use changes.

A study of conception of pyo(標).bon(本).joong(中) in the part of woongihak(運氣學) in negeong(內徑) (내경(內徑) 운기편(運氣篇)의 표(標).본(本).중(中) 개념에 대한 연구(硏究))

  • Baik, You Sang;Park, Chan-Guk
    • Journal of Korean Medical classics
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    • v.11 no.2
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    • pp.114-134
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    • 1998
  • The conception of pyo(標) bon(本) joong(中) in the part of woongihak(運氣學) of negeong(內徑) one of the important thing that decides the relation between six gi(六氣) and samyum and samyang(三陰三陽) or between each other's of samyum and samyang itself, it says that the relation of Pyo-rce(表裏). So this conception from the ancient times have been used to explain the theory of meridian(經絡) and organs(五臟六腑) and in other important field of oriental medicine - Sanghannon(傷寒論), it became basis of explanation of pcthoiogical principles in the system of six kyung(六徑). At first, the subject or this study is limited to the rament of $\ll$Somun(素問)$\gg$ in order to find the accurate and original meanings of pyo(標) bon(本) joong(中). And the meanings are studied by the way of expanding it's meaning with basic conceptions of woongihak(運氣學) and astronomy included in negeong(內徑). In this study, the results are summarized as the followings. 1. The contents of - the 68th chapter of negeong(內徑), concerning pyo(標) and joong(中) come under chogi(初氣) and joonggi(中氣) of the same chapter, after consideration of astronomical knowledge. And they become active during the period that last about 30days, a haft of one step(一步) of kaekgi(客氣). 2. Bon(本) as a kind of six gi(六氣) that is revealed from internal principle of something, that is to say Ohhaeng(五行), comes mainly under the kaekgi(客氣) of woongihak(運氣學) with the meaning of 'sign' is thai the specific properties of six gi(六氣) are revealed to our sight, so we can feel that through the change of nature, Joong(中) is the other property hidden in the inside of six gi(六氣), that is a portion of original nature(本性) like the bon(本). 3. The relation of pyo(標) and bon(本) is like that bctween the principle hidden inside in all things(理) and it's expression into the real world(氣) also similar to thai of yumyang(陰陽) and ohhaeng(五行). Therefore bon(本), though it means one of the six gi(六氣), hale the property of ohhaeng(五行) and pyo(標) is revealed, with an appearance of samyum-samyang(三陰三陰). 4. pyo(標) and joong(中) are also the both sides of yum(陰) and yang(陰) that revealed under the change of yumyang-ohhaengl(陰陽五行) in the nature. For example, if the one is yang(陰), the other is yum(陰). In the process that the change of all things is revealed out, first the property of pyo(標) appears strongly and then that of joong(中) appears comparatively weakly. But, in spite of the inhibitive relation of yumyang(陰陽), pyo(標) and joong(中) promote each other. 5. Under the course of change. It happens according to the bon(本), the property of ohhaeng(五行) in the case of soyang(少陽) and taeyum(太陰), because the effect of moisture(濕) and fire(火) that makes hyung(形) and gi(氣) is very strong in the universe. In the case of taeyang(太陽) and soyum(少陰), it happens according to the bon(本) and pyo(標) because they hare the polarity of water and fire(火水), at the same time, are not separated each other. In the case of yangmeong(陽明) and gualyum(厥陰), the change appears only according to the joong(中), but not strongly because the phase of yangmeong(陽明) and gualyum(厥陰) is a lull phase processing to the next one.

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A Study on the Special Technician Byeolganyeok(別看役) and the Statues of Auspicious Animals(Seosusang, 瑞獸像) : the Scale-covered animal form(鱗獸形) in Gyeongbokgung Palace(景福宮) (경복궁 인수형(鱗獸形) 서수상(瑞獸像)의 제작시기와 별간역(別看役) 연구)

  • Kim, Min-Kyu
    • Korean Journal of Heritage: History & Science
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    • v.47 no.1
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    • pp.66-81
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    • 2014
  • Burnt down during the Imjin War(壬辰倭亂) of 1592, Gyeongbokgung Palace(景福宮) remained in ruins until 1865, when in the second year of King Gojong's(高宗) reign, reconstruction work began. At the time, a royal protocol(uigwe, 儀軌) for the reconstruction was not produced. Instead, the Gyeongbokgung Palace Construction Diary(Gyeongbokgung yeonggeon ilgi, 景福宮營建日記) records the reconstruction process from June to September of 1865. The contents of this diary reveal that the stone used in the construction was obtained from Ganghwa(江華), the Yeongpung field(映楓亭) just beyond Dongdaemun, and Samcheongdong(三淸洞), among other sites. In addition, selected stone remaining from the original Gyeongbokgung Palace site - such as that from the palace astronomical observatory(ganuidae, 簡儀臺) - as reused, while a number of buildings and stonework from Gyeonghuigung Palace(慶熙宮) were moved to Gyeongbokgung Palace. As a result, a number of $17^{th}$ and $18^{th}$ century stonework are currently located at Gyeongbokgung Palace. The Gyeongbokgung Palace Construction Diary contains a record indicating that the bronze dragon(靑銅龍) excavated from the lotus pond at the palace's Gyeonghoeru Pavilion(慶會樓) was created by special technician byeolganyeok(別看役) Kim Jae-su(金在洙) in 1865 for the symbolic purpose of protecting the palace from fire. The diary also reveals that among Kim Jae-su and the other special technicians(byeolganyeok) tasked with the installation and oversight of the palace stonework was Lee Se-ok(李世玉) - aid to have created the haechi statue at Gwanghwamun Gate. This indicates that there were men of court painter(hwawon, 畵員) background among the construction special technicians(byeolganyeok). Moreover, the diary records the names of the stoneworkers(seokjang, 石匠) who worked under these special technicians to actually carve the stonework. These included Jang Seong-bok(張聖福), who participated in the creation of the Geunjeongjeon Hall(勤政殿); and Kim Jin-myeong(金振明), who took part in the construction of Gwanghwamun Gate(光化門). Based on these results, it is possible to identify a number of special iconographic features of the scale-covered animal form(insuhyeong, 鱗獸形) auspicious animal statues at Gyeongbokgung Palace. These include a protruding mouth and large nose, formalized ears, and a mane along the back. Comparing these iconographic features with those found in the stonework of Joseon tombs makes it clear that these palace statues were created in the latter half of the $19^{th}$ century - the period corresponding to Gojong's palace reconstruction. This study was able to confirm that this iconography was taken up by the Gyeongbokgung Palace construction special technicians(byeolganyeok) and stoneworkers(seokjang) as they worked on tomb stonework earlier in their careers.