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A Study on the Variation of River Vegetation by Seasonal Precipitation Patterns (계절별 강수 패턴에 따른 하천 식생 변화 양상 연구)

  • Hee-Jeong JEONG;Seung-Yeon YU;Eun-Ji CHO;Yong-Joo JI;Yong-Suk KIM;Hyun-Kyung OH;Jong-Sung LEE;Hyun-Do JANG;Dong-Gil CHO
    • Journal of the Korean Association of Geographic Information Studies
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    • v.26 no.2
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    • pp.1-19
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    • 2023
  • In Korea, excessive vegetation in rivers made up of sand and gravel is emerging as a nationwide problem, which is attributed to increased spring precipitation and decreased annual precipitation. Therefore, this study was conducted for the purpose of identifying the effect of changes in precipitation patterns on river vegetation in Namcheon, Gyeongju, and analyzing the area of vegetation and ecological characteristics. As a result of the study, the amount of monthly precipitation in the summer of Namcheon decreased after 2007, and the area of vegetation increased continuously compared to the area of the sandbank. The proportion of naturalized plants increased steadily when precipitation continued to a level that did not cause flooding, but the area occupied by naturalized plants was small. Also, when the water level is maintained, the species diversity is low due to the dominance of a single species, and the dominant species was mainly native plants. Dominance of native plants inhibited the growth of naturalized plants, but the vegetation area increased even more. Therefore, it is necessary to manage the spread of vegetation itself rather than the division of native plants and naturalized plants in order to eliminate the active growth and prosperity of river vegetation. High water levels and continuous flooding caused by torrential rains in summer disturbed the plant communities, and vegetation formed afterwards was mainly native plants. Such flooding in river ecosystems is a positive factor for the emergence of native plants and over-formed vegetation communities, so it should be considered when establishing a vegetation management plan.

Metatranscriptome-Based Analysis of Viral Incidence in Jujube (Ziziphus jujuba) in Korea (메타전사체 분석을 이용한 국내 대추나무의 바이러스 감염실태)

  • Hong-Kyu Lee;Seongju Han;Sangmin Bak;Minseok Kim;Jean Geung Min;Hak ju Kim;Dong Hyun Kang;Minhui Kim;Wonyoung Jeong;Seungbin Baek;Minjoo Yang;Taegun Lim;Chanhoon An;Tae-Dong Kim;Chung Youl Park;Jae Sun Moon;Su-Heon Lee
    • Research in Plant Disease
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    • v.29 no.3
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    • pp.276-285
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    • 2023
  • This work investigated the viral infection in jujube plants in Korea. A total of 61 samples with the symptoms of putative viral infection were collected from experimental fields and orchards. Thereafter, the samples were subjected to metatranscriptome analysis, Reverse transcription polymerase chain reaction analysis, and nucleotide sequence analysis. These analyses identified the presence of two DNA viruses, jujube-associated badnavirus (JuBV), jujube mosaic-associated virus (JuMaV), and one RNA virus, jujube yellow mottle-associated virus (JYMaV). All samples collected were confirmed to be infected by at least one of the three viruses, with most showed multiple infections. The detection rates of JuBV, JYMaV, and JuMaV were 100%, 90.2%, and 8.2%, respectively. Only three combinations of viral infections were found: 9.8% of samples showed single infection of JuBV, 82.0% showed double infection of JuBV+JYMaV, and 8.2% showed triple infection of JuBV+JYMaV+JuMaV. Sequence analysis of the three viruses showed very high homology with respective virus isolates reported in China. This study is predicted to provide fundamental data to produce virus-free jujube seedlings and represents the first report of JuBV and JuMaV infection in Korea.

Analysis of the Distribution of Rice Blast Pathogens in High-Altitude North Korea Border Areas and Domestic Rice Cultivars (고위도 북한 접경지역과 국내 벼도열병균 레이스 분포 분석)

  • Jung Wook Yang;Eun Young Kim;Jin Kyo Jung;In Jeong Kang;Yul Ho Kim;Boyng Joo Kim;Un Ho Yang;Sunggi Heu;Hyunjung Chung
    • Research in Plant Disease
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    • v.29 no.3
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    • pp.243-250
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    • 2023
  • To explore the distribution and the resistance reaction of rice blast pathogens that may occur in North Korea, rice blast pathogens in the North Korean border regions of Dandong and Yeon-gil in China and the North Korean border region of Cheorwon in South Korea were analyzed. In addition, comparative analysis was conducted with rice blast pathogen in Suwon and Jeonju, inland regions of South Korea. Resistance reactions above average were observed in monogenic rice lines (IRBLzt-T, IRBL9-W, IRBL20-IR24, and IRBLta-CP1) in Jeonju, Suwon, and Cheorwon from 2018 to 2020. In Dandong and Yeon-gil, the monogenic lines IRBLz5-CA, IRBL12-M, and IRBL19-A consistently showed resistance reactions for three years. Notably, IRBL19-A exhibited strong resistance. Race distribution analysis in South Korea indicated a shift from KI to KJ dominance from 2018 to 2020, while in the North Korean border regions of Dandong and Yeon-gil, the KI race was dominant in 2021 and 2022. The race distribution of rice blast pathogens in China's North Korean border regions differed significantly from that in South Korea.

Exploration of Children's Age and Parental Emotional Supportiveness that Impact the Accuracy of Children's Memory (아동의 회상 보고 정확성에 아동의 연령, 양육자의 지지가 미치는 영향)

  • Lee, Seungjin
    • Korean Journal of Culture and Social Issue
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    • v.22 no.4
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    • pp.523-541
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    • 2016
  • Both the child's and defendant's testimonies play crucial roles in the court's ruling of a child abuse case. Thus, empirical studies examining a child's truthful report, that is, disclosure, of his or her experience and recantation of the disclosure have manifold practical implications. The objective of the present study was to examine how easily a child recants his or her testimony after witnessing and disclosing an adult engaging in a small mistake. Furthermore, this study examined whether the child's age and emotional support from his or her caregiver predict the recantation of the child's testimony. Children of age 5-8 years played with dolls with the experimenter and witnessed the experimenter breaking the doll mask. The experimenter asked the children to keep it a secret. Then the children had the first memory interview, during which the interviewer induced the child to disclose the incident. Based on the treatment conditions, some children were provided supportive feedback while other received unsupportive feedback from their primary caregivers (mother) regarding the disclosure, then were interviewed for the second time. First, the author of this study examined whether the children would recant their disclosure (whether they would deny the incident after telling the truth of about what happened to the doll), and also examined the features of the child's voluntary reports, that is, the degree of their honesty. The findings of the experiment indicated that there were age-specific differences in the frequency of recantation, meaning that older children (8-9-year-olds) showed a stronger tendency to maintain their recantation in the second interview than relatively younger children (6-7-year-olds). Furthermore, children who received supportive responses from their mothers regarding the disclosure demonstrated more honest reports compared to those who received unsupportive responses from their mothers. The findings of this study assist the understanding of the effects of social-motivational factors on the process of children disclosing the truth when voluntarily recalling a negative incident that they had experienced and provide practical implications in legal aspects.

Analysis of Climate, Weather, Solar Radiation and Solar Energy in Major Cities of Tajikistan (타지키스탄 주요 도시의 기후, 날씨, 일사량 및 태양에너지 분석)

  • Taeyoo Na;Jeongdu Noh;Hyeontae Kim;Seong-Seung Kang
    • The Journal of Engineering Geology
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    • v.33 no.3
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    • pp.389-401
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    • 2023
  • Climate, weather, insolation (solar radiation), and solar energy in major cities of Tajikistan were investigated prior to construction of infrastructure for the Dushanbe Solar Station. In Dushanbe city there was a 70% probability of sunny days from May 16 to October 23, a period of 5.2 months. August had the most sunny days of in the year, with 99% probability of a sunny, the cloudiest month was February with a 41% chance of being sunny. In major cities of the Sughd and Gorno-Badakhshan states, the average number of cloudy days per month was ~3.3, with Dzhauz having 53 day and Fedchnko Glacier 79 days. For the 18 major cities of Tajikistan, the average annual total solar radiation was 2,429 W/m2, and the average monthly solar radiation was 202 W/m2. The city with the lowest annual total and monthly average solar radiation was Shartuz in Sughd state, with values ~2.7% less than the national average. The cities with the highest annual total and monthly average solar radiation were Khorog and Jirgatol in Gorno-Badakhshan state, with values ~10% above the national average. The daily average incident shortwave solar energy in the cities Dushanbe, Karakul, and Jirgatol was ~7.8 kWh per 2.4 m2 during summer (May-August), and 2.7 kWh during winter (November-February), or ~35% that of summer.

Preparation of Silica Nanoparticles via Recycling of Silicon Sludge from Semiconductor Dicing Process and Electro-responsive Smart Fluid Application (반도체 다이싱 공정에서 발생하는 실리콘 슬러지를 재활용한 실리카 나노입자의 제조 및 전기감응형 유체로의 응용)

  • Yeon-Ryong Chu;Suk Jekal;Jiwon Kim;Ha-Yeong Kim;Chan-Gyo Kim;Minki Sa;Hyung Sub Sim;Chang-Min Yoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.31 no.3
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    • pp.15-25
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    • 2023
  • In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO2-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm-1. Such enhancement in ER performance of SiO2-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

A CF-based Health Functional Recommender System using Extended User Similarity Measure (확장된 사용자 유사도를 이용한 CF-기반 건강기능식품 추천 시스템)

  • Sein Hong;Euiju Jeong;Jaekyeong Kim
    • Journal of Intelligence and Information Systems
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    • v.29 no.3
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    • pp.1-17
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    • 2023
  • With the recent rapid development of ICT(Information and Communication Technology) and the popularization of digital devices, the size of the online market continues to grow. As a result, we live in a flood of information. Thus, customers are facing information overload problems that require a lot of time and money to select products. Therefore, a personalized recommender system has become an essential methodology to address such issues. Collaborative Filtering(CF) is the most widely used recommender system. Traditional recommender systems mainly utilize quantitative data such as rating values, resulting in poor recommendation accuracy. Quantitative data cannot fully reflect the user's preference. To solve such a problem, studies that reflect qualitative data, such as review contents, are being actively conducted these days. To quantify user review contents, text mining was used in this study. The general CF consists of the following three steps: user-item matrix generation, Top-N neighborhood group search, and Top-K recommendation list generation. In this study, we propose a recommendation algorithm that applies an extended similarity measure, which utilize quantified review contents in addition to user rating values. After calculating review similarity by applying TF-IDF, Word2Vec, and Doc2Vec techniques to review content, extended similarity is created by combining user rating similarity and quantified review contents. To verify this, we used user ratings and review data from the e-commerce site Amazon's "Health and Personal Care". The proposed recommendation model using extended similarity measure showed superior performance to the traditional recommendation model using only user rating value-based similarity measure. In addition, among the various text mining techniques, the similarity obtained using the TF-IDF technique showed the best performance when used in the neighbor group search and recommendation list generation step.

Analysis of the Pre-service Chemistry Teachers' Cognition of the Nature of Model in the Design and Development Process of Models Using Technology: Focusing on Boyle's Law (테크놀로지를 활용한 모델의 설계와 개발 과정에서 나타난 예비화학교사의 모델의 본성에 대한 인식 분석: 보일 법칙을 중심으로)

  • Na-Jin Jeong;Seoung-Hey Paik
    • Journal of the Korean Chemical Society
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    • v.67 no.5
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    • pp.378-392
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    • 2023
  • The purpose of this study is to analyze the pre-service chemistry teachers' cognition of the nature of model in process of designing and developing models using technology. For this purpose, 19 pre-service chemistry teachers' in the 3rd grade of a education college located in the central region observe experimental phenomena related to Boyle's law presented in the 7th grade science textbook and researchers required the design and development of a model related to the observed experimental results using technology. Based on previous studies, the nature of model were classified into two aspect: 'Representational aspect' and 'Explanatory aspect'. The 'Representational aspect' was classified into 'Representation', 'Abstraction', and 'Simplification', and the 'Explanatory aspect' was classified into 'Analysis', 'Interpretation', 'Reasoning', 'Explanation', and 'Quantification'. The pre-service chemistry teachers' cognition were analyzed by the classification. As a result of the study, the 'Representation' of the 'expressive aspect' was uniformized in the form of space that changes in volume, and the pressure was expressed as the Brightness inside the cylinder or frequency of color change of particles for 'Abstraction'. In the case of 'Simplification', the particle collision was expressed as a perfectly elastic collision, but there was a group that could not simply indicate the type of particle. In the 'Explanatory aspect', in the case of 'Analysis', volume was classified as a manipulated variable, and in the case of 'Interpretation', most groups analyzed the change in pressure through the collision of gas particles. However, the cognition involved in 'Reasoning' was not observed much. In the case of 'Explanation', there were groups that did not succeed in explanation because the area where the particles collided was not set or incorrectly set, and in the case of 'Quantification', there was a group that formulated the number of collisions per unit time, and on the contrary, there was a group that could not quantify the number of collisions because they could not be expressed in numbers.

An Analysis on Landscape Architecture in Korean Seowon from 16th to 19th Century and its Historic Significance (조선 시대 서원 조경의 특징과 역사적 의미 연구)

  • Lee, Younghoon-Hayden;Sung, Jong-Sang
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.2
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    • pp.1-10
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    • 2023
  • This study aims to explore the significance of historic changes and cultural characteristics of landscape architecture in Korean Seowon. Seowon refers to educational private institutes that also served as Confucian shrines and were prevalent during the mid-to-late Joseon dynasty. Seowon comprised three distinct functional spaces: a shrine, a school, and a garden. The concept of Seowon's garden extended beyond designed landscapes to include the surrounding natural environment. The importance of landscape architecture in Seowon is rooted in its connection to the educational philosophy of these institutes. During the Joseon dynasty, scholars revered nature as a manifestation of Confucian ideals, and they believed that close engagement with nature was integral to self-discipline and learning. This research investigated fifteen relatively well-preserved garden in South Korea and conducted a comprehensive analysis of their gardens. The analysis revealed two key findings. Firstly, gardens in Seowon were actively designed and constructed during the early phase of Seowon culture but gradually diminished after the 17th century. This can be attributed to the shift in Seowon's purpose, with a greater emphasis on its religious function over education. Consequently, the significance and presence of landscape architecture in Seowon, which was closely related with its Confucianist education, declined. Secondly, the study explored the historical backgrounds of each Seowon's landscape architecture and found that many of them were designed or influenced by individuals who were later memorialized and deified in the Seowon's shrines. The landscape architecture created by these predecessors was carefully preserved by the faculties and students as a form of respect. Therefore, landscape architecture in Korean Seowon not only conveys the institutional purpose as an educational hub for the local society but also reflects the institute's strong relationship with the figures they worship as shrines.

The Meaning of Key Passages in The Canonical Scripture that Chronologically Record the Life of Kang Jeungsan: In Comparison to Jeungsan Cheonsa Gongsagi (연대기(年代記)로 본 강증산의 생애에 대한 『전경(典經)』 구절의 양상과 의미 - 『증산천사공사기(甑山天師公事記)』와 관련하여 -)

  • Ko Nam-sik
    • Journal of the Daesoon Academy of Sciences
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    • v.44
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    • pp.213-261
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    • 2023
  • The purpose of this article was to examine whether the parallel passages from The Canonical Scripture and Jeungsan Cheonsa Gongsagi (甑山天師公事記 Records of the Reordering Works of Celestial Master Jeungsan), the first full-length record related to the life of Kang Jeungsan compiled by Lee Sang-ho, indicate the same chronology. A comparison of the contents between The Canonical Scripture and Jeungsan Cheonsa Gongsagi revealed the following. The contents of The Canonical Scripture are categorized by a table of contents. By way of contrast, the contents of Jeungsan Cheonsa Gongsagi, is organized year by year. When parallel passages appear, the two texts tend to indicate the same year for specific events, but the chronology of some events do not match. A comparison of the contents of The Canonical Scripture and the first edition of Daesoon Jeongyeong (大巡典經 The Canonical Scripture of the Great Itineration) shows the following. Once again, the contents of The Canonical Scripture are organized via a table of contents. The contents of the first edition of the Daesoon Jeongyeong are also indicated through a table of contents. When lined up for comparison, most of the passages show the same content to have occurred in matching years. However, new contents are contained in this record that were absent in Jeungsan Cheonsa Gongsagi. All of these texts contain a summary of the life of Kang Jeung-san; however, they are organized differently. Jeungsan Cheonsa Gongsagi presents that summary chronologically (year by year with some gaps in years). Daesoon Jeongyeong and The Canonical Scripture both feature a table of contents wherein chapters are based around specific themes. One key takeaway is that different passages appear in the contents of each text. Also, The Canonical Scripture and the first edition of the Daesoon Jeongyeong contain some parallel passages wherein the two texts disagree on what year some events took place. Despite the different style of organization, Jeungsan Cheonsa Gongsagi and The Canonical Scripture can still be compared and such comparison shows the same pattern as comparison between The Canonical Scripture and Daesoon Jeongyeong. As a result of organizing and comparing the contents of the table of contents with the chronological record, the parallel passages wherein chronology is disputed can be highlighted and the introduction of new passages can also be shown.