• Title/Summary/Keyword: 사인

Search Result 51,117, Processing Time 0.081 seconds

Conjunction Assessments of the Satellites Transported by KSLV-II and Preparation of the Countermeasure for Possible Events in Timeline (누리호 탑재 위성들의 충돌위험의 예측 및 향후 상황의 대응을 위한 분석)

  • Shawn Seunghwan Choi;Peter Joonghyung Ryu;John Kim;Lowell Kim;Chris Sheen;Yongil Kim;Jaejin Lee;Sunghwan Choi;Jae Wook Song;Hae-Dong Kim;Misoon Mah;Douglas Deok-Soo Kim
    • Journal of Space Technology and Applications
    • /
    • v.3 no.2
    • /
    • pp.118-143
    • /
    • 2023
  • Space is becoming more commercialized. Despite of its delayed start-up, space activities in Korea are attracting more nation-wide supports from both investors and government. May 25, 2023, KSLV II, also called Nuri, successfully transported, and inserted seven satellites to a sun-synchronous orbit of 550 km altitude. However, Starlink has over 4,000 satellites around this altitude for its commercial activities. Hence, it is necessary for us to constantly monitor the collision risks of these satellites against resident space objects including Starlink. Here we report a quantitative research output regarding the conjunctions, particularly between the Nuri satellites and Starlink. Our calculation shows that, on average, three times everyday, the Nuri satellites encounter Starlink within 1 km distance with the probability of collision higher than 1.0E-5. A comparative study with KOMPSAT-5, also called Arirang-5, shows that its distance of closest approach distribution significantly differs from those of Nuri satellites. We also report a quantitative analysis of collision-avoiding maneuver cost of Starlink satellites and a strategy for Korea, being a delayed starter, to speed up to position itself in the space leading countries. We used the AstroOne program for analyses and compared its output with that of Socrates Plus of Celestrak. The two line element data was used for computation.

Comparative Analysis of Diversity Characteristics (γ-, α-, and β-diversity) of Biological Communities in the Korean Peninsula Estuaries (하구 순환 유지 여부에 따른 하구 주요 생물 군집별 다양성 특성 연구: 열린하구와 닫힌하구에서의 γ-, α- 및 β-다양성 비교)

  • Oh, Hye-Ji;Jang, Min-Ho;Kim, Jeong-Hui;Kim, Yong-Jae;Lim, Sung-Ho;Won, Doo-Hee;Moon, Jeong-Suk;Kwon, Soonhyun;Chang, Kwang-Hyeon
    • Korean Journal of Ecology and Environment
    • /
    • v.55 no.1
    • /
    • pp.84-98
    • /
    • 2022
  • Estuary is important in terms of biodiversity because it has the characteristics of transition waters, created by the mixing of fresh- and seawater. The estuarine water circulation provides a variety of habitats with different environments by inducing gradients in the chemical and physical environment, such as water quality and river bed structure, which are ultimately the main factors influencing biological community composition. If the water circulation is interrupted, the loss of brackish areas and the interception of migration of biological communities will lead to changes in the spatial distribution of biodiversity. In this study, among the sites covered by the Estuary Aquatic Ecosystem Health Assessment, we selected study sites where changes in biodiversity can be assessed by spatial gradient from the upper reaches of the river to the lower estuarine area. The α-, γ- and β-diversity of diatom, benthic macroinvertebrates, and fish communities were calculated, and they were divided into open and closed estuary data and compared to determine the trends in biodiversity variation due to estuarine circulation. As results, all communities showed higher γ-diversity at open estuary sites. The benthic macroinvertebrate community showed a clear difference between open and closed estuaries in β-diversity, consequently the estuarine transects were considered as a factor that decreases spatial heterogeneity of their diversity among sites. The biodiversity trends analyzed in this study will be used to identify estuaries with low γ- and β-diversity by community, providing a useful resource for further mornitoring and management to maintain estuarine health.

A Study on the Characteristics of Ecosystem Change and Management in Urban Wetland - Focusing on the Dunchon-Dong Ecological and Scenery Conservation Area, Seoul - (도시 습지 자연생태계 변화 특성 및 관리방안 연구 - 서울시 둔촌동 생태·경관보전지역을 대상으로 -)

  • Han, Bong-Ho;Park, Seok-Cheol;Kim, Jong-Yup
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.51 no.3
    • /
    • pp.1-20
    • /
    • 2023
  • The present study has monitored the changes in the biodiversity of Dunchon-Dong ecological and landscape conservation area after the restoration of the wetland, identified and analyzed the threats to the ecosystem, and presented a management plan accordingly. In this area which was forests and rice paddies in the past, apartment reconstruction is currently underway, with some hinterland forests and wetlands remaining. When we look into the change in the floras, the total number of species was 193 in 2000 before the restoration, it decreased from 2004 to 2006, and as of 2019, it was 149, showing an increasing trend. The result of comparing the species that emerged before and after the restoration showed an increase in Cyperaceae herbs such as Carex maximowiczii and Carex dispalata growing in wetland areas within forests and Schoenoplectiella juncoides and Schoenoplectus tabernaemontani growing in areas within wetlands where shallow water is maintained. As a result of analyzing the change in the area ratio of each type of extant vegetation, the wetland native herbs formed the power at the highest ratio after the restoration. The change in the power of the wetland native herbs was on an increasing trend until 2007, after which it decreased much in 2010 and then gradually increased, showing values of 26.6% in 2000, 44.6% in 2002, 49.0% in 2005, 53.3% in 2007, 28.7% in 2010, and 37.3% in 2019. The cause of the decrease in 2010 was judged to be due to the vegetation management conducted to secure open water and remove organic matter in freshwater reservoirs. The amphibia which emerged from 2000 to 2019 was a total of 9 species including Hynobius leeshii, Bufo gargarizans, Kaloula borealis, and Rana uenoi. As a result of the changes in the emerging wild birds, the species diversity index before the restoration was 0.9922 in 2000, and the species diversity index after the restoration gradually increased to 1.2449 in 2005, 1.2467 in 2010, and 2.2631 in 2019. The amphibia and wild birds inhibiting in the Dunchon-Dong forest and wetland were judged to have increased through continuous wetland maintenance such as naturalized plant removal management, native plant maintenance, and open water securing management. For the ecosystem preservation management of the Dunchon-Dong ecological and landscape conservation area, it was suggested to minimize the impact of the Dunchon-Dong reconstruction project, reorganize the indiscriminate access roads adjacent to the wetland, and reorganize the main entrance to the wetland. For ecosystem restoration management, systematic restoration and ecological buffer planting were suggested to be carried out at the time of construction fence demolition.

Embryonic and Larval Development of Slender Catfish, Silurus microdorsalis Mori, 1936, Endemic to Korea (한국 고유종 미유기(Silurus microdorsalis Mori, 1936)의 난 발생 및 자치어 형태발달)

  • Kang-Rae Kim;Yeong-Ho Kwak;Mu-Sung Sung;Heon Yang;Seong-Jang Cho;Bong Han Yun;In-Chul Bang
    • Korean Journal of Ichthyology
    • /
    • v.35 no.2
    • /
    • pp.91-100
    • /
    • 2023
  • The early life history of Silurus microdorsalis living in Jahocheon Stream was studied by observing egg and morphological development. Live fish were captured in June 2018, then reared in a circulating filtration system under a 14L : 10D photoperiod with a water temperature of 18℃. To artificially induce spawning, females were injected with 0.5 mL of Ovaprim (Syndel, Nanaimo, BC, Canada) per kg of body weight, and males were injected with 10,000 IU/kg body weight of human chorionic gonadotropin. Approximately 15 h later, eggs were artificially inseminated by the dry method. Mature eggs were light pale yellow, which separated them from immature eggs. Fertilized eggs were 2.16±0.06 mm (n=8) in diameter and fully hatched at 181 h after fertilization. The fertilization rate was 63.1±2.2%, and 10.0±3.7% of the embryos were malformed at 18℃. The rates of development were 181 h at 18℃, 109 h at 21℃, and 76 h at 24℃. The larval size immediately after hatching was 4.64±0.22 mm (n=8), and the larvae displayed negative phototaxis at 1 day after hatching. The total larval length on 7 days after hatching was 12.47±0.53 mm, with 25~30 basal anal fin rays and 14~16 basal caudal fin rays observed. The total larval length was 14.13±0.51 mm on 9 days after hatching, and approximately 90% of the black endoplasmic reticulum was deposited on the head and body. The dorsal fin had formed, and a single basal body was observed. On 15 days after hatching, the total larval length was 16.69±0.31 mm; the number of basal caudal fin rays (18 poles) was an integer because 2 dorsal fin basal rays and 60~63 anal fin basal rays were observed. The total larval length was 28.96±1.10 mm on 50 days after hatching; the numbers of caudal fins (n=18), dorsal fins (n=3), pectoral fins (n=11), and anal fin basal rays (n=67~73) were integers.

The Materials on Korean Folk Religions in the Encyclopedic Literatures of Late Joseon Dynasty (조선후기 유서류(類書類)에 나타난 민속종교 자료)

  • Suh, Young-Dae
    • Journal of Korean Historical Folklife
    • /
    • no.33
    • /
    • pp.31-72
    • /
    • 2010
  • At first, I extract materials on folk religion from four encyclopedic literatures of late Chosun dynasty-Lee, Ji-Bong-Ryu-Seol(『芝峯類說』) by Soo-Kwang(李晬光), San-Lim-Kyung-Jae(『山林經濟』) by Hong, Man-Sun(洪萬選), Sung-Ho-Sa-Seol(『星湖僿說』) by Lee-Ik(李瀷), O-Ju-Yeon-Moon-Jang-Jun-San-Go(『五洲衍文長箋散稿』) by Lee, Kyu-Kyung(李圭景), and present these materials by tables. Second, I examined the contents and characters of these materials on folk religion. The conclusions from this research are as follows. ① There are common features and points of difference between these four encyclopedic literatures. One of common features are that all these four are encyclopedic works, but San-Lim-Kyung-Jae is more practical than another three. ② These encyclopedic literatures regard folk religion as a negative culture, because these literatures based on Confucianism. But they did not deny miraculous virtues of folk religion. ③ These encyclopedic literatures give us many informations on gods and spirits of Korean folk religion, i.e. city gods(城隍神)·Yup-Sin(업신)·spirits of disease, god Kim-Bu(金傅大王神)·god Jung-Duk-Yang(鄭得揚)·god of King Kuan-u(關王神)·god Bu-keun(付根神) etc. So I review these gods and spirits referenced in encyclopedic literatures. ④ These encyclopedic literatures show much interest in ghost in common. The reason of interest is that authors of these encyclopedic literatures are all scholars of Sung Confucianism and Sung Confucian was concern about ghost. The Sung Confucianism denied the ghost as personal being whom Korean folk religion regards to a kind of spirits. Instead of beliefs in ghost of folk religion, they insist on the ghost as Ki(氣), a kind of cosmic principle. But these encyclopedic literatures acknowledge some parts of folk religion's beliefs in ghost, because they admit the miraculous virtues of these parts. ⑤ There are many items on divination in these encyclopedic literatures. But they show dual attitude on divinations. The one is negative attitude to divinations on individual destiny and the other one is positive attitude to divinations on agriculture. ⑥ There are also many items on witchcrafts in these encyclopedic literatures. Through these items, I assumed pervasiveness of beliefs on witchcraft at that time. ⑦ Shamans, as religious specialist, are stand on a central position of Korean folk religion. So it is a matter of course that these encyclopedic literatures concerned on Korean shaman. As Confucians, authors of these encyclopedic literatures did not regards shamans as positive one. But they did not deny miraculous virtues of shamans. In spite of these encyclopedic literatures have negative view points to, and include false informations Korean folk religion, I would like to emphasis on importance of these encyclopedic literatures to understand Korean folk religions, especially Korean folk religions of late Yi Dynasty.

Entertainment History Perspective - Around the Grand Duchess to Appear in Movies 'Elizabeth' - (엔터테인먼트 관점에서 바라본 영화로 본 역사 - 영화 '엘리자베스'에 나와 있는 여성 통치자에 대한 관점을 중심으로 -)

  • Choi, Sun-Ah
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.6
    • /
    • pp.247-256
    • /
    • 2019
  • The importance of the convergence education is getting more and more emphasized. But the university convergence education has not yet met today's needs. So this study is focused on showing effective practice methods and finding development directions of the university convergence criticism education. One of a significant trend of the contemporary academic education of liberal arts is the tendency of the convergent and integrative studies. What is essential in the convergent and integrative studies creativity. The zeitgeist of knowledge-based society is change and innovation. In response to its request, college education is being asked to do convergence education, And general education as the basis of convergence education is strengthened.

A Study on the Environmental Instruction focused on ethical inquiry in elementary school (윤리적 탐구 중심의 초등 도덕과 환경수업)

  • Song, Youngmin
    • The Journal of Korean Philosophical History
    • /
    • no.28
    • /
    • pp.87-116
    • /
    • 2010
  • In elementary, environmental education have been doing in various subjects. The features of environmental instruction would be reflected on contents of environmental education and characteristics of each subjects. These contents of environmental education might be contained normative contents, and it is moral subject that treats these normative contents systematically. Then environmental instruction of moral subject in elemental school should be approach and inquire teaching contents related to environment education. In elementary school curriculum of moral subject, teaching contents related to environment are 'preciousness of life' and 'right views of Nature and protection of the environment'. By these contents, moral instruction can approach to life of animal and plants centered on the reason to take them preciously and relation between nature and humans centered on the moral consideration. It is a difference that approaches to the environmental education not by factual understanding but by normative understanding in moral instruction. It must be focused on ethical inquiry for normative approach and reserving identity of moral subject. Necessary conditions for ethical inquiry to the environmental instruction are moral status of things besides humans. For the ethical inquiry to the moral status of nature environments, teachers could be set the logic of instruction based on the developments of environmental ethics. Formal cohesiveness of environmental instruction could be developed in sequence of ethical inquiry on moral status to the life of animal, life of plants, and whole system of nature. For this, teacher could reflect on their instruction focused on some explanations. That is, it is explanation to the animal life based on the individual-extended human oriented ethics for human, plants life based on the individual-non human oriented ethics, whole natural system based on the holistic-non human oriented ethics. When teachers reflect these explanation, they can compose their instruction as 'finding something in common with humans and animals', 'reflection on the attitude to the commons', 'thinking about reasons on the different attitudes to the commons', 'the things that disappear as plants die', 'thinking on values about non organism'. These plan of instruction could be critically reconstruct by other teachers. But environmental consciousness by ethical inquiry should be hold on instruction to the environment reflected on identity of moral subject.

Woodam Jeong Si-han's Understanding of Toegye (우담(愚潭) 정시한(丁時翰)은 퇴계(退溪)를 어떻게 이해하였는가? - 『사칠변증(四七辨證)』을 중심으로 -)

  • Kang, Heui Bok
    • The Journal of Korean Philosophical History
    • /
    • no.29
    • /
    • pp.33-54
    • /
    • 2010
  • Woodam(愚潭) Jeong Si-han(丁時翰, 1625-1707) played an important role in the formation and development of the Toegye School. This writing explores the way Woodam understood the thought of Toegye(退溪, 1501-1570) as presented in The Book of Four-Seve Demonstration(四七辨證) The 17th century that Woodam lived in was the period in which monism and dualism coexisted. Woodam's understanding of Toegye's thought can be summarized as follows: 1) Woodam followed Toegye's li(理)-qi(氣) defense and his view on the origin of nature and emotion, acknowledging Toegye as the orthodox transmitter of Zhu Xi's teachings, 2) Woodam considered that the difference between the past and the contemporary teachings was simply caused by the difficulty of comprehending the character "li (principle) ". Thus he criticized Yulgok(栗谷, 1536-1584)'s claim that "that which rises is qi (material force), and that which gives rise to qi is li," and followed instead Toegye's views of the entivity, dynamism, and ultimacy of li and its substantial function. Yet, Woodam further developed Toegye's thought and asserted that "in the midst of the marvelous unity of li and qi, li is always dominant and qi is always ancillary." 3) Woodam criticized Yulgok's thought and advocated Toegye's doctrine of the mutual motion of li and qi(理氣互發說), thereby following Toegye's insistence that difference can be observed in sameness and sameness can be observed in difference, that integrative thinking is needed to constructively embrace both analytic and synthetic judgments. In conclusion, Woodam understood profoundly and correctly Toegye's views on the relationship between li and qi and between nature and emotion, and explained them more concretely. In so doing, he endeavored to live the life by the teachings of Toegye.

Confucian Cultivation of Mind and Meditation - The Care Model of Cultivation Applied by Toe-gye' 『The Method on Preservation of Human mind (活人心方)』 (유가 공부론과 명상 - 퇴계 활인심방(活人心方)을 응용한 수양치료 모형 -)

  • Lee, Yun-do
    • The Journal of Korean Philosophical History
    • /
    • no.28
    • /
    • pp.363-386
    • /
    • 2010
  • The purpose of this study is to examine the relationship between theory of Confucian moral cultivation and meditation. Recently our community is more interested in 'a disease of mind'. A view of world, life, values which derived from the distorted perception of 'a disease of mind' can not be treated by psychiatric methods. In this sense, 'a disease of mind' is different from psychiatric illness. In this reason, alternative therapies applying philosophy, literature, arts, and humanities are attracting attention. Meditation is also one of them. In general, Meditation has been developed in Buddhism, but its method is closely related with Confucianism. Buddhist meditation has a pessimistic view of the reality in human life, but that of Confucian philosophy has laid stress on the reality and ego in human life. At this point, the Confucian meditation could provide a clue of solution for us in treatment of a disease of human mind. So Confucian moral cultivation and meditation have a great significance for the treatment of this disease as a methodology. In general, mental healing or psychotherapy has been proceeded by way of dialogue. 'Talking Cure' was conceived to let clients themselves recognize their current situation and find out the problem: "what happened and what's wrong" in their minds. But it does not have a high possibility of successful cure for subjects who are in the state of frustration, confusion, and lost of value. And also it is very difficult to apply to special institutions such as correctional institutions and military soldier who are targeted by current application of Humanities therapy. On this sense, it seems to be valuable to apply Confucian cultivation of mind and meditation which have emphasized the importance of mind-control for this. This study tries to examine theoretically how to relate the Confucian cultivation of mind with meditation, and to suggest a model of Humanities therapy that could be applied by Toe-gye's 『The Method on Preservation of Human mind(活人心方)』. Although Confucian cultivation of mind could present a meaningful theory for curing the disease of mind, it is very difficult to put the theory into practice. It is because Confucian cultivation of mind in itself is a kind of instruction that you need to do in all of your life, and essentially it is difficult to expect a temporary effect by performance or practice. So a cure model of Confucian cultivation of mind will be suggested on this assumption and limitations. This model is attempted on the main purpose of Humanities therapy in accordance with the development of a Korean model.

Korean nation-centralism and Confucianism(I) - the reflection of controlled modern rationality (한국의 국가 중심주의와 유교(I) - 통제적 근대 합리성에 관한 성찰 -)

  • Lee, Sang-bong;Rhee, Myung-su
    • The Journal of Korean Philosophical History
    • /
    • no.28
    • /
    • pp.237-266
    • /
    • 2010
  • This thesis is to check whether the modernization, promoted mainly in 1960-1970 of Korea may have the relations with Confucian values or have a gap between this and that, and have the question about the idea of the appearance of modernity under Park Jung-hee's government, which is based on the viewpoint that Confucianism would have been made ill use of or have contribution to the nation-directing modernity, especially to the modernization of people. In a sense this thesis demands the overcome of the modern ills such as social dichotomy, leaving out matters of locals, and neglecting the diversities and singularities of creatures, resulted from efficiencies and uniformity caused by nation-centralism. At first Confucianism have represented humanism with a view to finding the mean between the two of locals, affairs, and men. As such it has seek to find centrality, which means my real mind for meeting outward things or the optimum as the mean, the best state between of the two. The political doctrines modified from Confucian learnings including chung, hyo, samgang, and oryun worked as the mechanism for finding nation-directing modernity. As a result we have lived in the modernity, strengthened by nation-centralism. And the leading concepts in related with Neo-Confucianism had people lose their spaces of desire for their own future or got them to be narrow. Accordingly the modernization of Korea means not an integral space in which we can achieve what we want in various aspects, but a deficient space to be complemented, resulted from the centralization of all conditions of life, dichotomous way of approaching matters by nation-centralism, far from being the essence of Confucianism. In the end the rapid modernization by the leaders in Korea has given rise to the concentration politics, economy, and so forth on Seoul as the center. Then we should deeply reflect the deficiency state of centralism like this and how Confucianism would have been responsible for it and will give how to relieve the unequal centralism of nation. Now for this matter we would like to expect our study in the future.v