• Title/Summary/Keyword: Field study

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Study on Ti-doped LiNi0.6Co0.2Mn0.2O2 Cathode Materials for High Stability Lithium Ion Batteries (고안정성 리튬이온전지 양극활물질용 Ti 치환형 LiNi0.6Co0.2Mn0.2O2 연구)

  • Jeon, Young Hee;Lim, Soo A
    • Journal of the Korean Electrochemical Society
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    • v.24 no.4
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    • pp.120-132
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    • 2021
  • Although the development of high-Nickel is being actively carried out to solve the capacity limitation and the high price of raw cobalt due to the limitation of high voltage use of the existing LiCoO2, the deterioration of the battery characteristics due to the decrease in structural stability and increase of the Ni content. It is an important cause of delaying commercialization. Therefore, in order to increase the high stability of the Ni-rich ternary cathod material LiNi0.6Co0.2Mn0.2O2, precursor Ni0.6Co0.2Mn0.2-x(OH)2/xTiO2 was prepared using a nanosized TiO2 suspension type source for uniform Ti substitution in the precursor. It was mixed with Li2CO3, and after heating, the cathode active material LiNi0.6Co0.2Mn0.2-xTixO2 was synthesized, and the physical properties according to the Ti content were compared. Through FE-SEM and EDS mapping analysis, it was confirmed that a positive electrode active material having a uniform particle size was prepared through Ti-substituted spherical precursor and Particle Size Analyzer and internal density and strength were increased, XRD structure analysis and ICP-MS quantitative analysis confirmed that the capacity was effectively maintained even when the Ti-substituted positive electrode active material was manufactured and charging and discharging were continued at high temperature and high voltage.

Analysis on Types of Scientific Emoticon Made by Science-Gifted Elementary School Students and their Perceptions on Making Scientific Emoticons (초등 과학영재 학생의 과학티콘 유형 및 과학티콘 만들기에 대한 인식 분석)

  • Jeong, Jiyeon;Kang, Hunsik
    • Journal of The Korean Association For Science Education
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    • v.42 no.3
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    • pp.311-324
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    • 2022
  • This study analyzed the types of scientific emoticons made by science-gifted elementary school students and their perceptions on making scientific emoticons. To do this, 71 students from 4th to 6th graders of two gifted science education center in Seoul were selected. Scientific emoticons made by the students were analyzed according to the number and types. Their perceptions on making scientific emoticons were also analyzed through a questionnaire and group interviews. In the analyses for types of text in the scientific emoticons, 'word type' and 'sentence type' were made more than 'question and answer type'. And the majority of students made more 'pun using pronunciation type' and 'mixed type' than other types. They also made more 'graphic type' and 'animation type' than 'text type' in the images of the scientific emoticons. In the analyses for the information of the scientific emoticons, 'positive emotion type' and 'negative emotion type' of scientific emoticons were made evenly. The students made more 'new creation type' than 'partial correction type' and 'entire reconstruction type'. They also used scientific knowledge that preceded the knowledge of science curriculum in their grade level. The scientific knowledge of chemistry was used more than physics, biology, earth science, and combination field. 'Name utilization type' was more than 'characteristic utilization type' and 'principle utilization type'. Students had various positive perceptions in making scientific emoticons such as 'increase of scientific knowledge', 'increase of various higher-order thinking abilities', 'ease of explanation, use, memory, and understanding of scientific knowledge', 'increase of fun, enjoyment, and interest about science and science learning', and 'increase of opportunity to express emotions'. They were also aware of some limitations related to 'difficulties in the process of making scientific emoticons', 'lack of time', and 'limit that it may end just for fun'. Educational implications of these findings are discussed.

Optimal Transplanting Date for Rice Flour Cultivars to Avoid Occurrence of Pre-harvest Sprouting in Gangwon Province (강원지역 쌀가루용 벼의 이앙시기가 수발아 발생에 미치는 영향)

  • Lee, Ji-Woo;Cho, Youn-Sang;Kim, Yong-Bok;Jung, Jung-Su;Jeong, Young-Pyeong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.67 no.1
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    • pp.17-26
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    • 2022
  • Rice is one of the three major grains globally, and has been used as a staple food in Asian countries for a long time. In recent years, with the increase in the use of processed rice, the development and distribution of rice flour varieties have become a research focus. However, rice flour varieties are susceptible to pre-harvest sprouting (PHS). In this study, the optimal transplanting date for rice flour varieties for maximum yield production with PHS avoidance was examined. Four rice flour varieties with different maturity types (early maturing type, Garumi2 and medium-late maturing type, Seolgaeng, Hangaru, and Singil) were selected. The field experiment was conducted in Chuncheon (Central Plain area) and Cheorwon (Northern Plain area), Gangwon Province, Republic of Korea, from 2017 to 2019. The transplanting dates used were May 10, May 20, May 30, June 10, and June 20 in Chuncheon and April 30, May 10, May 20, May 30, and June 10 in Cheorwon. In Chuncheon, late transplantation decreased PHS in Garumi2. In Cheorwon, PHS in Garumi2 decreased with transplantation dates after May 20. The PHS decreased in Seolgaeng, Hangaru, and Singil with late transplantation in Chuncheon and Cheorwon. The optimal transplanting date for maximum yield production while avoiding PHS for Garumi2 was estimated to be June 10 in Chuncheon and May 25 in Cheorwon; for Seolgaeng, the optimal transplanting dates were May 20 in Chuncheon and May 15 in Cheorwon; for Hangaru, it was estimated to be May 30 in Chuncheon and May 15 in Cheorwon; and for Singil, the optimal dates were May 25 in Chuncheon and May 15 in Cheorwon.

The Alterations of Geochemical Behavior of Arsenic in Stabilized Soil by the Addition of Phosphate Fertilizer (인산질 비료에 의한 안정화 적용 토양 내 비소의 지구화학적 거동 변화)

  • Jeon, Yong-Jung;Kim, Bun-Jun;Ko, Ju-In;Ko, Myoung-Soo
    • Economic and Environmental Geology
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    • v.55 no.2
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    • pp.209-217
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    • 2022
  • The purpose of this study was to confirm the dissolution of arsenic from the stabilized soil around abandoned coal mines by cultivation activities. Experimental soils were collected from the agricultural field around Okdong and Buguk coal mines, and the concentration of arsenic in the soil and the geochemical mobility were confirmed. The average arsenic concentration was 20 mg/kg. The soil with relatively high geochemical mobility of arsenic in the soil was used in the batch and column experiment. The limestone was mixed with soil for soil stabilization, and the mixing ratio was 3% of limestone, based on the soil weight. The phosphoric acid fertilizer (NH4H2PO4) was added to the soil to simulate a cultivation condition according to the Rural Development Administration's rules. Comparative soil without mixing limestone was prepared and used as a control group. The arsenic extraction from soil was increased following the fertilizer mixing amount and it shows a positive relationship. The concentration of phosphate in the supernatant was relatively low under the condition of mixing limestone, which is determined to be result of binding precipitation of phosphate ions and calcium ions dissolved in limestone. Columns were set to mix phosphoric acid fertilizers and limestone corresponding to cultivation and stabilization conditions, and then the column test was conducted. The variations of arsenic extraction from the soil indicated that the stabilization was effectible until 10 P.V.; however, the stabilization effect of limestone decreased with time. Moreover, the geochemical mobility of arsenic has transformed by increasing the mobile fractions in soil compared to initial soil. Therefore, based on the arsenic extraction results, the cultivation activities using phosphoric fertilizer could induce a decrease in the stabilization effect.

Choi Chi-won, the Originator of Jeongeup Museongseowon and Scholar Culture (정읍 무성서원과 선비문화 원류 최치원)

  • An, Young-hoon
    • Journal of the Daesoon Academy of Sciences
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    • v.40
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    • pp.243-272
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    • 2022
  • Jeongeup, Jeollabuk-do, is an area that requires attention from those who study the history of Korean thought. In addition, Jeongeup is an area wherein many works were recorded for the first time in literary history. This is the case with Jeongeupsa as a style of Baekje songs and the lyrics of the noble families of the Joseon Dynasty, Sangchungok. Jeongeup is likewise the location where Choi Chi-won (857~?) was selected to serve as a local taesu (viceroy) and where a unique tradition of music and style were passed down. In this paper, the relationship between Choi Chi-won's role in the process of establishing a silent Confucian academy in Jeongeup and the emergence of scholar culture was examined. When Choi Chi-won left after his term in office, a birth shrine called Taesansa Temple was built to repay the selection of the villagers, and it became the source that led to the opening of the Confucian academy Museongseowon in the future. Jeongeup will be shown to be the location where Choi Chi-won realized his aspirations and honed his capabilities. In particular, Choi Chi-won's played a crucial role in the mid-Joseon Dynasty by supporting the construction and securing the name of Museongseowon. That is why Choi Chi-won was able to be revived as a symbolic figure in the region. In addition, it can be seen that the shape of Choi Chi-won was more sedentary- in the form of a Confucian scholar- and Confucian scholars emphasized the transfer of portraits at Museongseowon. Through the poetry written by Choi Chi-won, readers can learn about the worries and perceptions of scholars during those times. Although his value in the field of poetry is diverse, he can especially be recognized as a Confucian intellectual. In a large number of his works, he expresses his anxiety, agony, and critical inner consciousness all of which came from his encounter with the realities of his time. In fact, Choi Chi-won showed his qualities as a prominent literary figure of his time who had extraordinary aspirations and an admirable work ethic. However, he failed to overcome his regional and mental alienation as a poet in neighboring countries. Therefore, he internalized a sort of fierceness in terms of his perception of the world. However, it seems that it was rather a factor that made his work exhibit a strong lyrical style. In addition, Choi Chi-won's collection of writings includes a number of works that strongly criticized various forms of pathological phenomena caused by terminal phenomena of the time. He also highlighted the wrong in society by realistically depicting the lives poor and needy people and their eventual sacrifice via distorted relationships. This can be read encapsulating the agony of intellectuals of that time. The dictionary definition of a 'Confucian scholar' is "a Confucian term referring to a person or class that embodies Confucian ideology," and in its contemporary meaning it suggests " ⋯ an example of a personality, but not an identity, and the conscience of one's time period as a source of human morality inwardly and social order outwardly." In this respect, it could even be said that Choi Chi-won could be considered the originator of scholar culture.

Agronomic and End-use Quality Analysis of 'AromaT', a Black Rice (Oryza Sativa L.) Variety with Floury Endosperm (분질배유를 지니는 흑미, '아로마티'의 주요 농업형질 및 가공적성 평가)

  • Ha, Su Kyung;Mo, Young-Jun;Jeong, Jong-Min;Lee, Hyun-Sook;Kim, Jinhee;Seo, Woo-Duck;Jeong, Ji-Ung
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.67 no.1
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    • pp.9-16
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    • 2022
  • Rice is one of the most important staple foods in Wnju, Jeonbuk, South Korea. However, rice consumption has dramatically decreased as eating habits have diversified owing to rapid economic growth. Recently, floury endosperm rice varieties have been developed to invigorate the rice processing industry, because dry-milled rice flour is economically and environmentally suitable for massive rice flour distribution. The National Institute of Crop Science has developed 'AromaT', an early-maturing black rice with floury-endosperm, suitable for tea and dry milling. 'AromaT' was derived from a cross between 'Suweon542' as the floury endosperm source and 'Heugjinju' as the black and aromatic source. In this study, 'AromaT' and its parents, 'Suweon542' and 'Heugjinju', were analyzed for agronomic traits, anthocyanin content, and their major physicochemical properties by different planting date. The field experiment was conducted in Wanju, Jeollabuk-do Province, South Korea, in 2019. The transplanting dates were May 30 (ordinary season), June 25 (double-cropping season), and July 10 (late season). The yield performance of brown rice 'AromaT' was 330 kg/10 a in the double-cropping cultivation method and was the highest among the transplanting dates. The floury endosperm of 'AromaT' was derived from 'Suweon542' containing 'flo7', located on chromosome 5 and known to control floury endosperm. With the late planting date, the anthocyanin content of 'AromaT' was 570.5 mg/100 g, much higher than that of 'Heugjinju' (376.3 mg/100 mg). The brown rice of 'AromaT' also exhibited the pop-corn-flavoring 2-acetyl-1-pyrroline, exclusively detected in aroma rice varieties. The average particle sizes of 'AromaT' and 'Suweon542' were 67.12 ㎛ and 70.9 ㎛, respectively, lower than that of 'Heugjinju' (95.5 ㎛) with a black transparent endosperm. The average damaged starch content of 'AromaT' was 8.1%, lower than that of 'Heugjinju' (10.05%) and Suweon542 (9.5%). As a result, 'AromaT' with high anthocyanin content, fine particle size, and low damaged starch content is expected to provide a new rice material in various processing fields.

A Study on the Iron Seated Buddha at Bowonsa Temple in Seosan (서산(瑞山) 보원사(普願寺) 철조여래좌상(鐵造如來坐像) 고찰(考察))

  • Kang, Kunwoo
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.100
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    • pp.22-49
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    • 2021
  • Bowonsa Temple (普願寺) is located to the north of Gayasan Mountain in Unsan-myeon, Seosan-si, Chungcheongnam-do Province. The cultural properties it enshrines were produced during the late Unified Silla and early Goryeo periods, and include an Iron Seated Buddha. The Japanese Government-General of Korea Museum planned a survey on historical remains in Chungcheongnam-do Province during the early Japanese colonial era, and a field survey was conducted at the Bowonsa Temple site in 1916 (Taishō 5). During this survey, the sculpture of the Iron Seated Buddha (knee: width 212 cm x thickness 167 cm) was found enshrined in a hut. The sculpture was moved to Gyeongbokgung Palace in the following year. However, it is clear that the colossal Iron Seated Buddha was being housed at the Bowonsa Temple site at the start of the Japanese colonial era. This Iron Seated Buddha is presumed to have been produced in 955 by State Preceptor Beopin Tanmun (法印國師 坦文, 900-975). Tanmun was born into an influential family that produced many high officials. He became a leading figure in the Hwaeom (Flower Garland) school of Buddhism under the patronage of King Taejo. He also led Buddhist events at the Goryeo royal court during the reigns of King Hyejong (惠宗, r. 943-945) and King Jeongjong (定宗, r. 945-949). With the emergence of Gyunyeo (均如, 923-973), who was sponsored by Queen Daemok (大穆王后, dates unknown) of the Hwangbo clan (皇甫氏), Tanmun was transferred to Bowonsa Temple far from Kaesong. However, even while there Tanmun strengthened his ties with his supporters under the patronage of the Chungju Yu clan. He appears to have produced this colossal sculpture of Iron Seated Buddha as a prayer for longevity and a happy life for King Gwangjong (光宗, r. 949-975). The inscription on the Stele of State Preceptor Beopin at Bowonsa Temple Site that reads "[I] created a Buddha triad in gold" also suggests the Iron Seated Buddha was produced at Bowonsa Temple. This Iron Seated Buddha is thought to have been enshrined originally in a hall at Building Site No. 3 within the Bowonsa Temple precinct. Since excavations at the temple site have revealed that the temple's main hall was erected in the Joseon period, the Iron Seated Buddha might have been enshrined in a different hall at the time of its creation. It is likely that the sculpture was placed in a hall at Building Site No. 3 since Goryeo-era roof tiles and porcelain have been frequently excavated there and the remains of a square Buddhist altar have survived at the site. At the time of its creation, the Iron Seated Buddha was likely enshrined in a Goryeo-era hall at Building Site No. 3 but was transferred to the main hall during a rebuilding project undertaken at Bowonsa Temple in the Joseon period.

The Interrelationship between Riparian Vegetation and Hydraulic Characteristics during the 2020 Summer Extreme Flood in the Seomjin-gang River, South Korea (2020 여름 섬진강 대홍수시 하안식생과 수리 특성의 상호관계)

  • Lee, Cheolho;Lee, Keonhak;Kim, Hwirae;Baek, Donghae;Kim, Won;Kim, Daehyun;Lee, Hyunjae;Woo, Hyoseop;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.8 no.2
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    • pp.79-87
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    • 2021
  • Because active interactions occur among vegetation, hydrology, and geomorphology in riparian systems, any changes in one of these factors can significantly affect the other two. In this study, we evaluated these interactions at four sites (two in Gajeong and two in Hahan) along the Seomjin-gang River that was substantially devastated by an extreme flood in 2020. We examined the relationship between the riparian vegetation and the hydraulic characteristics of the flood using remote sensing, hydraulic modeling, and field surveys combined. The evaluation results showed that the floods caused a record-breaking rise of up to 43.1 m above sea level at the Yeseong-bridge stage gauge station (zero elevation 27.4 m) located between the Gajeong and Hahan sites, with the shear stress being four times higher in Hahan than in Gajeong. Additionally, the water level during the flood was estimated to be a maximum of 1 m higher depending on the location in the presence of riparian plants. Furthermore, both sites underwent extensive biological damage due to the flood, with 78-80% loss in vegetation, with preferential damage observed in large willow species, compared to Quercus acutissima. The above findings imply that all plant species exhibit different vulnerabilities towards extreme floods and do not induce similar behavior towards events causing a disturbance. In conclusion, we developed strategies for effectively managing riparian trees by minimizing flood hazards that could inevitably cause damage.

A 40-year History of the Asia Pacific Journal of Small Business : Small and Medium Venture Business Policy and Strategic Management of Small and Medium Venture Businesses (중소기업연구 40년의 역사: 중소벤처기업정책 및 중소벤처기업의 전략적 경영)

  • Seo, Won-Seok;Lee, Sang-Myung
    • Korean small business review
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    • v.42 no.3
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    • pp.101-121
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    • 2020
  • Marking the 40th anniversary of the founding of The Korean Association of Small Business Studies, this paper was carried out to shed light on the historical trend of 40 years of small and medium business research through the papers published in the Asia Pacific Journal of Small Business and to consider the direction of future small and medium business research. In particular, we will focus on small and medium venture business policies and strategic management aspects of small and medium venture businesses to analyze the contents of published papers related to the subject and contribute to finding implications and future research directions. In order to analyze the research trends of small and medium venture business policies and strategic management sectors of small and medium venture companies covered in the Asia Pacific Journal of Small Business from 1979 to 2019, the analysis was divided by time and item based on research subjects, research methods, researchers, etc., and the primary analysis results are as follows: First, out of a total of 1,056 research papers, research papers on small and medium venture enterprise policy and strategic management showed a ratio of about 14% and 11% of the total research. Second, in terms of research subjects, the proportion of policy research on funds and start-ups and ventures was high in the field of small and medium venture enterprise policy, and the research on internationalization strategy was carried out the most in the area of strategic management. Third, qualitative research was more prominent until the 1980s, but the proportion of quantitative research began to increase after the 1990s, and since then, quantitative research has been carried out more than qualitative research. Fourth, over the past 40 years, Hanyang University, Kyungpook National University, Konkuk University, etc. were the institutions that presented research papers most actively in the areas of small and medium venture business policy and strategic management, and the research institute's participation was somewhat insufficient. The main implications of this study for the continuous development of the Asia Pacific Journal of Small Business are as follows. First, it is necessary to enhance the link between research on policy research and strategic management of small and medium venture companies in terms of research subject matter. Second, more diversity should be pursued in terms of research methods. Third, it is necessary to increase the participation rate of public and private research institutes related to small and medium venture enterprises in academic societies.

Comparison of the Video Dramas Based on Yoon Sim-duk, Kim Woo-jin and Reconsidering the Movie Praise of Death(1991) (윤심덕과 김우진 소재 영상물 비교 및 영화 <사의 찬미>(1991) 재론)

  • Chung, Woo-Suk
    • Journal of Popular Narrative
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    • v.26 no.4
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    • pp.43-76
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    • 2020
  • After comparing three video dramas based on Yoon Sim-duk and Kim Woo-jin, this paper intensively explores the movie Praise of Death(1991), which has the most meaningful traits in embodying the characters, focusing on the relationship with the previous works of the director or an actress. The movie Yoon Sim-duk(1969) focuses on meiodramatic narrative around the issue like love triangle or a relationship between out-of-wedlock woman and the wife of one man. The TV drama Praise of Death(2018) is pursuing ideal youth genre between attractive two lovers adorning even the suffering of the Japanese occupation with customary visual image. In comparison, the movie Praise of Death(1991) focuses on visual beauty, while overlaps the agony of two characters as pioneering artists with frustrated love narrative. In the process, this film reveals two-sided characteristics, especially the heroine, compared to the other two. She shows a rift between the passivity for the salvation of man and the activity of choosing even the fall of her own life. In order to examine this trait, we have to explore the other works which affect the movie Praise of Death. This came from the tendency director Kim Ho-sun and actress Jang Mi-hee had built in 1970s films. It also relates in the movies Jang Mi-hee had worked with director bae Chang-ho in the 1980s. The tendency to show a pursuit of classical cultures in the field of popular movies, and to overlap the problems of desire, including sexuality, with mental and intellectual issues, continues from the previous films to the movie Praise of Death for shaping a main female character. This study results in examining the movie Praise of Death in two contexts. One is the context of three video dramas having same materials, Yoon Sim-duk and Kim Woo-jin. And other is the context of the works that director Kim Ho-sun and actress Jang Mi-hee have continued together, or the works that Jang Mi-hee have continued with director Bae Chang-ho. Until now, Yoon Sim-duk and Kim Woo-jin has been used as a material for cultural contents in the various genres over and over again. Under this circumstance, by looking at this movie, one of representative case dealing with Yoon and Kim, in the complex context, it can reaffirm the effect and difficulty in fictionalisation of them as a subject matter.