• Title/Summary/Keyword: study trends

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A Review of Recent Climate Trends and Causes over the Korean Peninsula (한반도 기후변화의 추세와 원인 고찰)

  • An, Soon-Il;Ha, Kyung-Ja;Seo, Kyong-Hwan;Yeh, Sang-Wook;Min, Seung-Ki;Ho, Chang-Hoi
    • Journal of Climate Change Research
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    • v.2 no.4
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    • pp.237-251
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    • 2011
  • This study presents a review on the recent climate change over the Korean peninsula, which has experienced a significant change due to the human-induced global warming more strongly than other regions. The recent measurement of carbon dioxide concentrations over the Korean peninsula shows a faster rise than the global average, and the increasing trend in surface temperature over this region is much larger than the global mean trend. Recent observational studies reporting the weakened cold extremes and intensified warm extremes over the region support consistently the increase of mean temperature. Surface vegetation greenness in spring has also progressed relatively more quickly. Summer precipitation over the Korean peninsula has increased by about 15% since 1990 compared to the previous period. This was mainly due to an increase in August. On the other hand, a slight decrease in the precipitation (about 5%) during Changma period (rainy season of the East Asian summer monsoon), was observed. The heavy rainfall amounts exhibit an increasing trend particularly since the late 1970s, and a consecutive dry-day has also increased primarily over the southern area. This indicates that the duration of precipitation events has shortened, while their intensity became stronger. During the past decades, there have been more stronger typhoons affecting the Korean peninsula with landing more preferentially over the southeastern area. Meanwhile, the urbanization effect is likely to contribute to the rapid warming, explaining about 28% of total temperature increase during the past 55 years. The impact of El Nino on seasonal climate over the Korean peninsula has been well established - winter [summer] temperatures was generally higher [lower] than normal, and summer rainfall tends to increase during El-Nino years. It is suggested that more frequent occurrence of the 'central-Pacific El-Nino' during recent decades may have induced warmer summer and fall over the Korean peninsula. In short, detection and attribution studies provided fundamental information that needed to construct more reliable projections of future climate changes, and therefore more comprehensive researches are required for better understanding of past climate variations.

Change in the Prevalences and Risk Factors of Atrophic Gastritis and Intestinal Metaplasia in Korea: Multicenter Clinical Trials (위축성 위염과 장상피화생의 유병률 변화 및 위험인자의 변화: 다기관 연구 비교)

  • Hwang, Young-Jae;Kim, Nayoung;Kim, Sung Eun;Baik, Gwang Ho;Lee, Ju Yup;Park, Kyung Sik;Joo, Young-Eun;Myung, Dae-Seong;Kim, Hyeon Ju;Song, Hyun Joo;Kim, Heung Up;Nam, Kwangwoo;Shin, Jeong Eun;Kim, Hyun Jin;Kim, Gwang Ha;Lee, Jongchan;Lim, Seon Hee;Seo, Geom Seog;Choi, Suck Chei
    • The Korean journal of helicobacter and upper gastrointestinal research
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    • v.18 no.4
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    • pp.247-257
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    • 2018
  • Background/Aims: The aim of this study was to analyze the trend of the prevalences of atrophic gastritis (AG) and intestinal metaplasia (IM) from 2011 to 2016~2017 in Korea. And, the risk factors of AG and IM were compared between 2011 and 2016~2017. Materials and Methods: A total of 4,023 subjects in 2011 and 2,506 subjects in 2016~2017 were enrolled. AG and IM were diagnosed on the basis of endoscopic findings. Multivariate analysis was performed for risk factors of AG and IM. Seventeen factors were analyzed. Results: The seroprevalence of Helicobacter pylori decreased from 2011 (59.8%; 2,407/4,023) to 2016~2017 (51.6%; 1,293/2,506; P<0.001). The prevalence of AG decreased from 2011 to 2016~2017 (P=0.018), but that of IM increased (P<0.001). The risk factors of AG in 2011 were male sex, old age, H. pylori immuoglobulin G (IgG) positivity, family history of gastric cancer (GC), and high-salt diet. For IM in 2011, the risk factors were male sex, old age, H. pylori IgG positivity, and family history of GC. Risk factors of AG in 2016~2017 were old age, H. pylori IgG positivity, and country of residence. For IM in 2016~2017, the risk factors were male sex, old age, family history of GC, high fasting glucose level (${\geq}126mg/dL$), H. pylori IgG positivity, and low income level. Conclusions: The difference in prevalence trends of AG and IM between 2016~2017 and 2011 could be the result of the different risk factors of AG and IM, such as decreased prevalence of H. pylori infection.

Results and Trends of Research on Japanese Traditional Theatre 'Noh' in Korea and China (한중에서의 일본 고전극 노(能) 연구의 성과와 경향)

  • Kang, Choonae
    • Journal of Korean Theatre Studies Association
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    • no.52
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    • pp.189-228
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    • 2014
  • The purpose of this research was to summarize Korea and China's researches on Noh and to examine main domain in this field, by investigating the academic books and articles published in two countries. In 1960s, since Nohgaku has been introduced to China, academic articles on Zeami's theories and aesthetics have emphasized on aesthetic characteristics of Chinese plays and Japanese Nohgaku through the similarities of oriental plays. The number of researches on Kabuki is almost twice as that of researches on Noh in China. While most researches on Kabuki were compared with the styles and music of Pecking Opera and the theatrical theories of liyu[李漁], those on Noh has been highlighted the comparative studies on $Y{\bar{o}}kyoku$[謠曲], Chinese Noh plays. The main difference among the researches on $Y{\bar{o}}kyoku$ in Korea and China was the material regarding characters of Noh. Because song yuanzaju[宋 元雜劇]and Nohgaku in Chinese-Japanese plays were the mature form of the classic plays and those were representative of traditional nation plays, this researches tried to ascertain the cultural origins of two countries regarding the aesthetic characteristics by referencing lyrical and narrative features[曲詞] of yuanzaju[元雜劇]and the classic waka of Nohgaku. While the comparative studies on Noh and song yuanzaju and kunqu[昆劇] in China were prevalent, national researches have emphasized on the inner world of the main character and dramaturgy through the verbal description of Noh. Especially, this research tried to investigate the inner world of the main character and the intention of the writers through the verbal description of Noh authorized in the history of the works. Also, the researches on Buddhism in the Middle Ages and religious background were examined significantly. In addition, the $Y{\bar{o}}kyoku$ has influenced on European modern playwrights and the comparative studies between the materials of $Y{\bar{o}}kyoku$ and Western modern plays were concerned. In Korea, the comparative studies on Noh between Korea abd Japan has been most focused on the origin theory of Noh. The fact that appearance theory of Noh had originated from Sangaku was common opinion among Korean, Chinese, and Japanese scholars. However, they are agree with the opinion that according to the formation of the different genres, Noh's mainstream was different among three countries despite of the same origin. Yuan drama and Noh play have the same origin, but different branch. In relation to the Noh's origin theory, there are literature comparative studies in religious background, the studies presumed the origin of instrumental music related to those in mask plays, and the comparative studies between Korean mask plays and $ky{\bar{o}}gen$ of Nohgaku. Kyogen is the Comedy inserted among the stories in Nohgaku performed in just one day. Therefore, $ky{\bar{o}}gen$ must be discussed separately from the relations of 'shite[任手]'s inner action veiled with masks. This research figured out that the lacking points of the two countries' researches were the acting methods of Noh. Academic articles written by foreign scholars studying Korean and Chinese theatres should be included when this issue will be dealt with. In Korea and China, translation studies and writings regarding Nohgaku have studied by those who are major in Japanese literature or oriental literature. This case is the same in Korea in that scholars whose speciality is not theatre, but Japanese literature has studied. Therefore, this present study can give a good grasp of whole tendency on Nohgaku's research in theatre fields.

Changes in Composition and Structure of Forest Vegetation of Apsan Park, Daegu Metropolitan City (대구광역시 앞산공원 산림식생의 조성 및 구조 변화)

  • Oh, Jeong Hak;Kim, Jun-Soo;Kim, Hak Yun;Cho, Hyun Je
    • Journal of Korean Society of Forest Science
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    • v.108 no.2
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    • pp.177-188
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    • 2019
  • The aim of our study was to identify the changing trends in the composition, structure, and spatial distribution of forest vegetation in Apsan Park, a representative urban forest in Daegu, South Korea. A vegetation survey was conducted in 1997 and 2016 using phytosociological methods, and a detailed vegetation map was created using the physiognomic dominant species. There were 22 vegetation types in both 1997 and 2016, but two of those types increased and two decreased. The total coverage per unit area ($100m^2$) of the component vegetation species increased from 163% in 1997 to 182% in 2016, and natural vegetation tended to be more than twice that of artificial vegetation. The average number of species decreased by seven from 25 in 1997 to 18 in 2016. Species diversity (H') increased only slightly from 1,654 in 1997 to 1,680 in 2016, while species dominance (D) decreased by 9% from 0.304 in 1997 to 0.276 in 2016. The similarity in the composition of the forest vegetation was about 78%, which was nearly the same. The life form spectrums of vascular plants changed from '$G-R_5-D_4-e$' in 1997 to '$MM-R_5-D_4-e$' in 2016 and the central dormancy type changed from geophytes (G) to megaphanerophytes (MM). The spatial distribution of the forest vegetation was reduced by approximately four times that of artificial vegetation. The number of forest landscape elements (patches) increased from 269 in 1997 to 294 in 2016, while the average area decreased by 12% from 5.8 ha in 1997 to 5.1 ha in 2016.

A Review of Ecological Niche Theory from the Early 1900s to the Present (생태적 지위(Ecological Niche) 이론에 대한 검토 및 제언)

  • Koo, Kyung Ah;Park, Seon-Uk
    • Korean Journal of Environment and Ecology
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    • v.35 no.4
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    • pp.316-335
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    • 2021
  • This study reviewed the change of theory of ecological niche(concepts and definitions) over time to provide a theoretical basis for habitat-related studies of animals and plants. Accordingly, it analyzed and summarized the major discussion trends of ecological niche worldwide in each period from the 1900s to the present. Countries advanced in ecological studies, such as the EU and the USA, have conducted theoretical and empirical studies on the ecological niche since the early 1990s. The concept of the ecological niche was introduced in the early 1900s, developed in the mid-1900s, and advanced from the mid-1900s to the late 1900s. Since the 2000s, the advanced concept has diversified with new developments in technologies and research methods. The factors suggested by theoretical and empirical studies in defining the ecological niche of a species include 1) population dynamics of the target species, 2) all biotic conditions to sustain a population (food relationship and material flow in the food chain), 3) all non-biotic conditions to sustain a population (physical environmental conditions), 4) all direct and indirect interactions between these environmental factors, and 5) response and adaptation mechanisms that include the migratory ability of the target species or genetic diversity and adaptability to change. Unlike such international advancement, there have not been sufficient theoretical, philosophical, and empirical studies of ecological niche in Korea. The concepts and definitions by Greennell, Elton, and Hutchinson were selectively and partially borrowed for empirical studies without full description. Considering that the theory of ecological niche becomes the foundation for habitat-based species conservation and restoration, it is necessary to seek diversification and advancement of theoretical and empirical research and research methods and technological development. It will provide an important foundation for the academic advancement of ecology and for establishing and implementing policies to preserve and restore ecology and biodiversity effectively and successfully in Korea.

Changes in Literary Trend During the Late Joseon and Lee Yong-hyu's Writing (조선후기 문풍의 변화와 이용휴의 글쓰기)

  • Lee, Eun-bong
    • (The)Study of the Eastern Classic
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    • no.48
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    • pp.91-116
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    • 2012
  • Writing is a process and work of expressing one's own feelings and thoughts that are not contained in rigid forms; however, the literary trend and environment during the Late Joseon was not so tolerant. A revivalist approach to writing was dominant during this period, which was summarized in the expression that "Prose must be written in the style of Qin and Han; and Poetry in that of High Tang. "Hence, it was practically a taboo to express one's raw emotions and disregard the custom and regulations of writing. Nevertheless, literati, who got tired of the dogmatic rule of Neo-Confucianism at the time that refused to see the changing world and the pseudo-archaic writing that merely imitated the outside and was empty inside, attempted new styles of writing to escape from the model or example and what was familiar. Lee Yong-hyu, who was in the middle of such transformations, learned the trends of Late Ming and Early Qing through the newly imported Chinese books and created his own style that reflected his personality. His writings refused the Neo-Confucian system of thoughts, which was a dominant ideology of the time, paid attention to the human nature and emphasized the restoration of the self. His writing could be described as being anti-pseudo-archaic and criticized the pretentious trend of the time. He argued that in order to restore the true self, one must recover the innocent mind that was bestowed on human by heaven/nature (cheon-li, 天理), and for this purpose, one must straighten out one's mind (sim, 心). His argument is similar to that of "Yangming School of Mind," which could be represented by the phrase, "Mind is the Principle (心卽理)." Yangming School claimed that moral principle existed within one's mind; and this was in stark contrast with the Neo-Confucian idea that "principle (li)"was external and transcendent, and was spoken by the great Confucian masters and written down in Confucian Classics. By denying the externality of the principle and underscoring its immanence, the idea that centralized Confucian Classics and canons was dismantled. Lee Yong-hyu's writing styles that denied the model and emphasized the restoration of the self was influenced by such thoughts. However, one must neither hastily judge that he is an advocate of Yangming School of Mind, nor determine the anti-pseudo-archaic writers' ideological basis as the philosophy of Yangming School. Once it is rigidly defined, be it Zhu Xi's philosophy or Wang Yangming's philosophy, it becomes another model that one must abide by, and again the self disappears. Thus, Lee Yong-hyu defied any kind of model that claimed authenticity or precedence and wished that people would live independently as oneself, and left such claims and wishes in writing. That is the reason, after more than two hundred years later, we still read his writings.

A Management Plan of Wastewater Sludge to Reduce the Exposure of Microplastics to the Ecosystem (미세플라스틱의 환경노출을 최소화하기 위한 하·폐수 슬러지 관리방안)

  • An, Junyeong;Lee, Byung Kwon;Jeon, Byong-Hun;Ji, Min-Kyu
    • Clean Technology
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    • v.27 no.1
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    • pp.1-8
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    • 2021
  • Due to the negative impacts of microplastics (MPs) on the ecosystem, the investigation of its occurrence and its treatment from sewage and wastewater treatment plants (WWTPs) have received a lot of attention in the recent years. Most MPs are precipitated and removed with the sludge during the treatment process. Proper sludge management is immensely necessary to avoid MP exposure in the environment. However, the domestic research on this aspect is limited. This study reviews appropriate sludge management approaches to decrease environmental MP exposure. This can be achieved through investigating sludge generation and treatment, regulation laws and government policy trends with an emphasis on WWTPs. The ratio of sludge in sewage treatment plants has been observed to be highest in recycling followed by incineration and landfills. Recycling is the highest in fuel followed by construction materials and composting. For WWTPs, the highest ratio is in recycling followed by fuel and landfills, and recycling is confirmed in the following order: incineration > after composting > after solidification > earthworm breeding. Treatment approaches that can increase the exposure of MPs to the ecosystem are considered to be used in landfills and agricultural fields. However, this method is not appropriate given the insufficient capacity of domestic landfills and the sufficient supply of existing chemical and animal manure fertilizers. Instead, it would be rational in terms of environmental preservation to expand the use of fuel and energy in connection with the new and renewable energy policy, and to actively seek the use of sub-materials for construction materials. In order to secure the basic data for the effectiveness of future planning and revision of related laws, it is required to perform an in-depth investigation of the sludge supply and demand status along with the environmental and economic effects.

Trends in QA/QC of Phytoplankton Data for Marine Ecosystem Monitoring (해양생태계 모니터링을 위한 식물플랑크톤 자료의 정도 관리 동향)

  • YIH, WONHO;PARK, JONG WOO;SEONG, KYEONG AH;PARK, JONG-GYU;YOO, YEONG DU;KIM, HYUNG SEOP
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.3
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    • pp.220-237
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    • 2021
  • Since the functional importance of marine phytoplankton was firstly advocated from early 1880s massive data on the species composition and abundance were produced by classical microscopic observation and the advanced auto-imaging technologies. Recently, pigment composition resulted from direct chemical analysis of phytoplankton samples or indirect remote sensing could be used for the group-specific quantification, which leads us to more diversified data production methods and for more improved spatiotemporal accessibilities to the target data-gathering points. In quite a few cases of many long-term marine ecosystem monitoring programs the phytoplankton species composition and abundance was included as a basic monitoring item. The phytoplankton data could be utilized as a crucial evidence for the long-term change in phytoplankton community structure and ecological functioning at the monitoring stations. Usability of the phytoplankton data sometimes is restricted by the differences in data producers throughout the whole monitoring period. Methods for sample treatments, analyses, and species identification of the phytoplankton species could be inconsistent among the different data producers and the monitoring years. In-depth study to determine the precise quantitative values of the phytoplankton species composition and abundance might be begun by Victor Hensen in late 1880s. International discussion on the quality assurance of the marine phytoplankton data began in 1969 by the SCOR Working Group 33 of ICSU. Final report of the Working group in 1974 (UNESCO Technical Papers in Marine Science 18) was later revised and published as the UNESCO Monographs on oceanographic methodology 6. The BEQUALM project, the former body of IPI (International Phytoplankton Intercomparison) for marine phytoplankton data QA/QC under ISO standard, was initiated in late 1990. The IPI is promoting international collaboration for all the participating countries to apply the QA/QC standard established from the 20 years long experience and practices. In Korea, however, such a QA/QC standard for marine phytoplankton species composition and abundance data is not well established by law, whereas that for marine chemical data from measurements and analysis has been already set up and managed. The first priority might be to establish a QA/QC standard system for species composition and abundance data of marine phytoplankton, then to be extended to other functional groups at the higher consumer level of marine food webs.

A Study on the Trend of Stone Industry and Residue (석재 산업 및 부산물 동향 조사)

  • Chea, Kwang-Seok;Lee, Young Geun;Koo, Namin;Youn, Hojoong;Lim, Jong-Hwan
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.1
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    • pp.1-12
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    • 2022
  • Stone has been used for various purposes, such as for building stones, megaliths, ornamental stones, hunting and grinding throughout history. The global stone production amounted to around 153 million tons in 2018 excluding quarry waste, up 0.8% on year. Of them, stone residues accounted for 71%. The worldwide stone trading decreased 1.5 million tons to 56.5 million tons in 2018. The average price of stone was 34.1 USD per square meter, down 2.5% from the previous year. It's down 7% when only considering trading between the world's top twelve exporters. But in the three leading countries, Italy, Greece and Brazil, the price saw a sharp increase. In 2018, stone imports and exports totaled 815 million square meters, raising over 20 billion USD of revenue. Imports were largely led by six countries: China, Italy, Turkey, India, Brazil, Spain and Portugal, from largest to smallest.) In terms of stone use per 1,000 population, it was 117 square meters in 2001, and it increased to 264 square meters in 2017 and 266 square meters in 2018. The volume more than doubled during the period, but it has been declining slightly in recent years. China, India, Saudi Arabia and Belgium were the only countries that the stone use per 1,000 population exceeded 1,000 square meters. The increase rate was steepest in China, India and the United States, from largest to smallest. The global stone production is likely to grow to 69.85 million tons by 2025, despite the global economic downturn.

A Study on the Understanding of Yang Xiong (揚雄) Held by Korean Confucian Scholars in the Joseon Dynasty (조선조 유학자들의 양웅(揚雄) 이해에 관한 연구)

  • Jo, Min-hwan
    • Journal of the Daesoon Academy of Sciences
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    • v.37
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    • pp.297-328
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    • 2021
  • This paper aims to find out from what perspective Joseon Dynasty Confucian scholars evaluated and understood Yang Xiong's guiding principles and literature at the micro level and to reveal the academic trends of Joseon Dynasty Confucian scholars. This topic is approached as follows: first, an evaluation of Yang Xiong's way of living as a 'senior state official of Wang Mang (the controversial Emperor of the short-lived Xin Dynasty)'; second, Yang Xiong's literary character and his literary works; third, Yang Xiong's writing style; and fourth, Yang Xiong's view of good and evil. These can be summarized in three main ways: One is to agree with Zhu Xi's criticism of Yang Xiong as a 'senior state official of Wang Mang' and dismiss his guiding principles, academic achievements, literature, and other accomplishments. Most of these negatives have been found in Confucian scholars who are especially enthusiastic about theology. Examples include Hong Jikpil, Wi Baekgyu, Kim Wonhaeng, and Lee Sangjeong. In the case of kings such as King Yeong-Jo, the assessment of Yang Xiong is quite similar. The following assessments of Yang Xiong are positive though. Positive assessments are presented from two different views. One is a balanced approach that covers both the positive and negative aspects of Yang Xiong. For example, Heo-Kyun's understanding. Another positive view can be analyzed from three perspectives. The first case is when the scholars assessing Yang Xiong were not deeply influenced by Zhu Xi's criticism of him. Seo Geojeong and Seong-Hyeon are examples. The second case are those that broke away from theology or adhered to Silhak [Practical Studies]. Yi-Ik is an example. Third, assessments from scholars who posited that truth was of a pluralistic nature. Jang-Yu is an example of such scholars. Regarding theories of human nature; however, there was consensus among Confucian scholars that Mengzi held that human nature is good, and thereby it was common to criticize Yang Xiong's theory that human nature was a mixture of good and evil. From an ideal micro perspective, Joseon Dynasty Confucian scholars' different assessments of Yang Xiong show that their understanding and evaluation of Yang Xiong differed in accordance with their own differing worldviews and ideas.