• 제목/요약/키워드: natural history

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Investigation of Dynamic Characteristcs Uninterruptible Power Supply System (UPS) Using Shaking Table Tests (무정전전원장치(UPS)의 진동대 실험 및 동적특성 분석)

  • Lee, Seung-Jae;Kim, Joo-Young;Choi, Kyoung-Kyu
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.11
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    • pp.129-136
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    • 2019
  • Non-structural elements are vulnerable to earthquake ground motion. In this study, an experimental study for the electrical non-structural element was performed using tri-axial shaking table tests. A 100kVA UPS(Uninterruptible Power Supply system) was used as the test specimen. The test specimen was anchored to the concrete slab using the conventional installation detail. The input acceleration were generated in accordance with ICC-ES AC156 code. Scale factors of the input acceleration with respect to the required response spectrum defined in ICC-ES AC156 were from 25% to 600%. Based on the test results, damage and dynamic characteristics of UPS were evaluated and analyzed including natural frequency, damping ratio, acceleration time history response, dynamic amplification factor and relative displacement.

Climate Change, Meteorological Vision, and Literary Imagination (기후변화·기상학적 비전·문학적 상상력)

  • Shin, Moonsu
    • Journal of English Language & Literature
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    • v.57 no.1
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    • pp.3-25
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    • 2011
  • As extremes of climate such as heavy storms, rainfalls, and droughts tend to be routine in recent years, global climate change becomes a serious concern not only for natural scientists but also for scholars of the human sciences. Efforts to tackle the anthropogenic climate change certainly require not only scientific knowledge about it but also a new sociocultural paradigm for valorizing and respecting nature in its own right. The huge casualties and mass destruction caused by recent climate disasters also remind us that nature has been an important factor to bring about changes in human history-a fact largely ignored in traditional history. This again validates the ecocritical request to prioritize place, physical setting, or the relationship characters hold with the natural world in understanding literary works. In this context this paper aims to demonstrate the importance of the meteorological vision in creating as well as understanding literary and cultural texts by examining such works as Shelley's "The Cloud," Byron's "Darkness," Keats's "To Autumn," all produced during the period of dramatic climate change including "the year without summer." It also briefly discusses Roland Emmerich's 2004 movie The Day after Tomorrow as a way of understanding recent cultural responses to the crisis of global warming.

FE model updating and seismic performance evaluation of a historical masonry clock tower

  • Gunaydin, Murat;Erturk, Esin;Genc, Ali Fuat;Okur, Fatih Yesevi;Altunisik, Ahmet Can;Tavsan, Cengiz
    • Earthquakes and Structures
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    • v.22 no.1
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    • pp.65-82
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    • 2022
  • This paper presents a structural performance assessment of a historical masonry clock tower both using numerical and experimental process. The numerical assessment includes developing of finite element model with considering different types of soil-structure interaction systems, identifying the numerical dynamic characteristics, finite element model updating procedure, nonlinear time-history analysis and evaluation of seismic performance level. The experimental study involves determining experimental dynamic characteristics using operational modal analysis test method. Through the numerical and experimental processes, the current structural behavior of the masonry clock tower was evaluated. The first five experimental natural frequencies were obtained within 1.479-9.991 Hz. Maximum difference between numerical and experimental natural frequencies, obtained as 20.26%, was reduced to 4.90% by means of the use of updating procedure. According to the results of the nonlinear time-history analysis, maximum displacement was calculated as 0.213 m. The maximum and minimum principal stresses were calculated as 0.20 MPa and 1.40 MPa. In terms of displacement control, the clock tower showed only controlled damage level during the applied earthquake record.

Generation of Artificial Time History Covering Design Response Spectrum by Two Modification Functions (이중 수정함수 적용을 통한 설계응답스펙트럼 포괄 인공지진파의 생성)

  • Park, Gun;Hong, Ki Nam;Han, Sang Hoon;Kim, Jae Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.1
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    • pp.1-11
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    • 2016
  • The domestic and foreign seismic design codes have specified that time history covers design response spectrum when the response spectrum, which calculated from the time history, is smaller than the design response spectrum at five points or less. In order to verify the design codes, time history analysis for a pier was performed by using five artificial time histories conforming design code with various characteristics and its member forces were evaluated according to them. It was confirmed from analysis results that, regardless of the conformity to design code requirement, seismic design using the artificial time histories could not guarantee earthquake resistant design if the response spectrum from them is lower than design response spectrum at the similar period to the natural frequency of structure. Thus, the time history generating method to make its acceleration response spectrum to be greater than design response spectrum at all period was proposed by two modification function in this study. It was also verified whether time histories from the proposed method satisfy the seismic design codes or not.

Life History of Locastra muscosalis (Walker) (Lepidoptera: Pyralidae) and Its Natural Enemies (벼슬집명나방의 생활사 및 천적 종류)

  • 박철하;이범영;이세표
    • Korean journal of applied entomology
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    • v.32 no.1
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    • pp.101-104
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    • 1993
  • The life history and host plants of Locastra muscosalis (Walker) which is a defoliating pest of walnut trees were studied mainly in Chungchongbuk-do province. Juglans nigra Linne, J. mandshurica Mixim., Carya illinoensis koch and Pterocarya stenoptera DC. were found to be new host plants. Locasta muscosalis (Walker) had one generation per year and the adults emerged form late June to late July with a peak emergence around July 10th. Females oviposited a mean of 560 eggs on the top surfaces of leaves. The duration of the egg stage was from 7 to 12 days. Young larvae fed on the leaves within webs that bound the leaves beginning in the middle of July. In the middle of September the fully matured larvae entered the soil -a cm below the soil surface, and the pupal period lasted 16 days on average. The natural enemies observed and/or reared from larvae of pupae were 3 species of parasitoids, 6 species of predators and an unidentified virus.

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Misunderstandings of Korean Beauty: Comparative Studies of the Theses of Ryoo Jong-yeol, Ko You-seup, and Yoon Hee-soon (한국적 미에 대한 오해 -류종열, 고유섭, 윤희순의 논고 비교분석-)

  • Oh, Beung-Ouk
    • The Journal of Art Theory & Practice
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    • no.1
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    • pp.23-48
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    • 2003
  • Art theorists support art productions by, introducing them to the public, explaining their meanings, and playing a crucial part in the development of art. These tasks seem like their opus. Because the principles of art production and the artistic languages are quite different from the ordinaries, we need 'interpreters' who can mediate us and the artists. Art works need interpretation. And the interpretation includes not only the characteristics of the given art work, but the customs, history, and the unique qualities of the race that produced the art work. The former director of the Korean National Museum, Choi Soon-woo wrote on the characteristics of Korean art as those that stem from the poised, arbitrary, and non-elaborate state of mind. The statement of the former Director of the National Museum has its weight far greater than just a personal opinion. In fact, we encounter the same resonance of this statement over and over reproduced in the mass media. The problem lies on that it deals with not only a single art work, but the entire Korean art. And going further, this kind of remarks are already infused into every sector of our thought on art appreciation. In this paper, I argue for a re-reading of the characteristics of Korean beauty based on two reasons. First, the characteristic of art work is contemporary, thus we cannot define the characteristics of entire Korean art in a few words without the context of the period of its making. Second, Director Choi defined the characteristics that I pointed out above as 'natural' and 'nature-friendly.' Nature or being natural is not an usual word that defines the characteristics of art work, which stands for the opposite side of the nature in the binary opposition of nature/culture. To delve into these misunderstandings of Korean beauty in the popular notions of Korean art, I suggest the re-reading of three major articles on Korean art: Ryoo Jong-yeol's "Korean race and its art," Ko You-seup's reiteration of Ryoo's thesis called "Discourses in Korean Art History and Aesthetics," and Yoon Hee-soon's antithesis of Ryoo Jong-yeol titiled "Studies on Korean Art History."

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Eggs Development and Early Life History of Spine Loach, Cobitis hankugensis (Pisces: Cobitidae), Endemic to Korea (한국 고유종 기름종개 Cobitis hankugensis의 난발생 및 초기생활사)

  • Ko, Myeong-Hun;Park, Jong-Young
    • Korean Journal of Ichthyology
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    • v.24 no.2
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    • pp.94-100
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    • 2012
  • The spine loach, Cobitis hankugensis endemic to Korea were collected at the Nokdong River, Unbong-eup, Namwon-si, Jeollabuk-do during June 2007 for study its eggs development and early life history. The eggs were obtained by injecting gonadotropin (LHRH-1) to female and were fertilized by dry method in the laboratory condition. The matured eggs were separative, demersal and light yellowish with $1.29{\pm}0.07mm$ in diameter average. Under $23{\sim}25^{\circ}C$, the eggs were hatched in 45~52 hours after fertilization, and just hatching larvae were $4.5{\pm}0.24mm$ in total length. On 5 days after hatching, they were $6.6{\pm}0.13mm$ in total length and their yolk sacs were completely absorbed. From 25 days after hatching, they became the juvenile stage with $9.0{\pm}0.49mm$ in total length. On the 100 days after hatching, their external forms and band patterns were similar to those of adults with average $27.3{\pm}2.82mm$ in total length.

Life History, Seasonal Occurrence and Natural Enemies of Caloptilia theivora (Lepidoptera: Gracillariidae) at Tea Tree Plantation (동백가는나방(Caloptilia theivora)의 생활사, 발생소장 및 천적의 종류)

  • 이승찬;김상수;김도익
    • Korean journal of applied entomology
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    • v.34 no.3
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    • pp.229-233
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    • 1995
  • The life history, seasonal occurrence of larval population and natural enemies of Tea leaf roller (Caloptilia theivora (Walshingham) were investigated in field-age. C. theivora had 6 generations a year. The developmental periods from egg to adult emergence were 32.1~38.6 days in spring and fall, and 24.8~32.7 days in summer. The average longevities of adults were 8.4~14.5 days in spring and fall, and 6.3~8.6 days in summer. The average number of eggs laid by a female were 55~71 throughout the season. Larval population density of C. theivora showed 3~4 peaks from middle may in 1992 and 1993. However, population density of 194 was pretty low in early season and exhibited a peak in late September-early October. C. theivora overwintered in pupal stage on the leaves. Four hymenopterous parasitoids of C. theivora larvae were identified ; they are Stenomesius japonicus (Ashmead), Sympiesis ringoniellae Kamijo, Elasmus sp., and S. dolichogaster Ashmead which is dominant.

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STUDY ON FEMINITY AND THE IDEAL BEAUTY OF BODY IMPLIED IN THE FASHION AND THE ANTI-FASHION MOVEMENT IN THE VICTORIAN PERIOD (II) (빅토리아시대 유행복식과 반유행복식 운동에 나타난 여성성과 인체미에 관한 연구 (II))

  • 김정선;김민자
    • Journal of the Korean Society of Costume
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    • v.51 no.6
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    • pp.5-24
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    • 2001
  • This paper is intended to explore femininity the ideal beauty of body and the features in fashion pursued in the Fashion system and the Anti-Fashion Movement in the Victorian period, on which the modern fashion is based. For the informative facts needed in this paper, books on history, fashion history, feminism, art history of aestheticism and the ideal beauty of body are referred to. On the part Ⅱ of this paper, the femininity and the ideal beauty of body implied in the Aesthetic Movement and Rational Dress Movement as the anti-fashion movement in the Victorian period will be reviewed. Following are the conclusion : First, the works in Aesthetic Movement mainly include the image of sensual female. The essence of femininity is categorized by cultural value, poetic spirit. appetite for sex and self-expression. The ideal beauty of body pursued in this movement is the beauty of immatured body, which means rejection of maternity as well as appetite for sex in the form of metaphor of the power and enthusiasm of female. The features of Aesthetic Movement emphasize the image of sensual and characteristic woman. These features are expressed in the natural waist line and the vertical H silhouette of high waist, natural exposure of body by means of drapery, simplicity and decency by design without fixed forms and seemingly faded colors. Second, Rational Dress Movement attempted to evaluate the femininity in a different way and ultimately pursued masculinity. Therefore, morality, liberty, intelligence, spirituality, self-control, willingness, which had been believed to exclusively belong to male, are added to the categories of femininity. The ideal beauty of body is expressed in the form of Venus Coelestic which is refined and strong. This symbolizes woman's freeing from the fate of reproduction and subordinate relationship with male, morality, decision of one's own and willingness. The features of Rational Dress Movement represent the image of strong-willed and moral woman in its internal meaning. The features of its fashions represent the concealment of the body, emphasis on activeness in pants without decoration and simplicity in its external form. All these features resulted from the pursuit of masculinity.

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From a Young Mathematics Professor to a Great Mathematics Teacher: Considering Characteristic Features of the Education of Pure Mathematics in the Social, Institutional and Interdisciplinary Contexts of UCL (드 모르간이 위대한 수학 교육자가 되기까지 : UCL의 사회적, 제도적, 간학문적 맥락 속에서 순수 수학 교육 바라보기)

  • Cho, Su-Nam
    • Journal for History of Mathematics
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    • v.24 no.3
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    • pp.109-143
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    • 2011
  • Augustus De Morgan became to be deeply interested in the education of pure mathematics since he came to teach in UCL because of the specific nature of natural philosophy lectures, the academical knowledge and reasoning powers of the students, and the negative attitudes of London society on mathematics. During his long tenure, he really tried his best to make his students understand the important concepts and the principles of pure mathematics, and logically explain the processes of inducing and proving the laws of pure mathematics. When he could not stay as a mere researcher, he had to concern himself with and pay attention to the problems of educating students. And then his teaching style was constructed in a specific way by the various attitudes about mathematics, the boundary relationship between the adjacent academical branches, and the social and systematic nature of UCL.