• Title/Summary/Keyword: 기하학적으로

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The study of a practical modeling method for the analysis of dynamic behavior by the mockup test of prestressed concrete girder (PSC I형 거더 실물 모형체 실험을 통한 동적거동특성 분석의 실용적 모델링 기법 연구)

  • Kim, Hyung-Kyu;Jang, Il-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.148-156
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    • 2018
  • The integrity assessment of the bridge behavior is generalized by field data of a static load-deformation curve and dynamic properties such as impact factors and natural frequencies. Evaluating it with numerical analysis is a reasonable method. The results of the mockup test and the numerical analysis are corresponded with each other since the behavior of service load proceeds in elastic region. In case of the dynamic behavior of structure, especially for the analysis of vibration, the result of the mockup test differs from the result of numerical analysis a little due to the geometric shape and non-homogeneous materials. In order to converge on these tolerances, this study suggested several numerical models, analyzed the sensitivity and finally offered a practical modeling method for the estimation of bridge on the basis of the result of mockup test. Based on the model substituted concrete section for strands section, the natural frequency of the model composed with axial stiffness of strands or the model applied the modified modulus of elasticity was closest with the result of the mockup test.

Anatomical Achievement and Thought of Leonardo da Vinci (레오나르도 다빈치의 해부학 업적과 사고)

  • Chai, Ok Hee;Song, Chang Ho
    • Anatomy & Biological Anthropology
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    • v.29 no.2
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    • pp.35-46
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    • 2016
  • Leonardo da Vinci is remembered as the greatest genius of the Renaissance. He left outstanding achievements as an artist, scientist and inventor, and contributes up to today's science. He ranks the best in a variety of fields, such as botany, mathematics, geology, astronomy, geometry and optics. It has well known that Leonardo is an artist, scientist, inventor and philosopher. And he was a great anatomist that dissected dead bodies and animals directly and left many anatomical drawings. He took an interest in anatomy from the point of view of the artist, which is why the human body structure and function to know the sakes were "ignorant of the anatomy should not be upset." Over time, he became interested in the structure and function of the body, even get the human body in a difficult environment; he dissected many the human bodies directly. His scientific inquiry and infatuation made him as an advanced pioneer for more than 100 years, and got enough level to surpass the artistry. Leonardo left about 1,800 anatomical figures of the muscular, skeletal, vascular, nervous and urogenital system, and they are also very scientific and high artistic achievements. The aim of this article is to take a look at Leonardo da Vinci's anatomical achievements and thoughts. In addition, the goal is to knowledge today's anatomists about Leonardo da Vinci's astonishing achievements as a great pioneer in anatomy.

Anti-tuberculosis effects of frankincense through immune responses of Mycobacterium tuberculosis-infected macrophages (결핵균이 감염된 대식세포의 면역반응을 통한 유향(Frankincense)의 항결핵효과)

  • Son, Eun-Soon;Lee, Sun Kyoung;Cho, Sang-Nae;Park, Hae-Ryoung;Lee, Jong Seok
    • Korean Journal of Food Science and Technology
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    • v.53 no.6
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    • pp.756-760
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    • 2021
  • Frankincense has been used as a traditional medicine for treating rheumatoid arthritis, dermatitis, and muscle pain. In this study, the anti-tuberculosis effects of Frankincense were evaluated in immune responses of macrophages. Frankincense methanol extract was not cytotoxic to the host. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay using human macrophage (THP-1) cells did not show cytotoxic effects or morphological changes with treatments of 31.3, 62.5, and 125 ㎍/mL Frankincense methanol extract (FRM). Inhibitory effects of Frankincense methanol extract on the growth of Mycobacterium tuberculosis in human macrophages were investigated. The immune response was measured by monitoring the levels of TNF-α and IL-1β in THP-1 cells with or without M. tuberculosis infection under Frankincense methanol extract treatment. Inflammatory cytokine levels and M. tuberculosis numbers were reduced in THP-1 cells treated with Frankincense methanol extract. Therefore, Frankincense methanol extract could be used as a potential anti-tuberculosis agent.

Herding Behavior of the Seoul Apartment Market (서울시 아파트시장의 군집행동 분석)

  • Kim, Jung Sun;Yu, Jung Suk
    • Korea Real Estate Review
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    • v.28 no.1
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    • pp.91-104
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    • 2018
  • In this study, the occurrence and degree of herding behavior as a market participant behavior in a housing market were analyzed. For the analysis method, the actual sales price was applied in the CSAD (Cross-sectional Absolute Deviation) model, which has been used the most of late for herding behavior analysis. For the analysis contents, these were subdivided into region, elapsed year, size, and market condition to analyze the regionality and the internal and external factors. For the study results, first, there was no herding behavior in the entire region of Seoul. By region, herding behavior occurred in the downtown, southeast, and northwest regions, which coincided with the results of the precedent study (Ngene et al., 2017). Second, in the market analysis by elapsed year, herding behavior was captured in dilapidated dwellings. By size, herding behavior was observed in small-scale ($60m^2$ or less) apartments and in $85m^2$ or higher and less than $102m^2$ national housing units. Third, during the time of the global financial crisis, herding behavior was not observed in all the regions, whereas when the market situations were in a boom cycle, it was observed in the northwest region. These results suggest that there is a difference from the stock market, where in a period of recession, herding behavior occurs intensively with the expanding fear of incurring losses. This study is significant in that it analyzed the market participant behaviors in the behavioral economic aspects to better understand the abnormal phenomenon in a housing market, and in that it additionally provides a psychological factor - market participant behavior - in market analysis.

Effects of Different Light Wavelengths on the Growth of Olive Flounder (Paralichthys olivaceus) (빛의 파장이 넙치 Paralichthys olivaceus의 성장에 미치는 영향)

  • Benedict, Ndada Regina;Kim, Yeo-Reum;Kim, Jong-Myoung
    • Journal of Life Science
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    • v.29 no.3
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    • pp.311-317
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    • 2019
  • To investigate the effects of light on growth in fish, olive flounder (Paralichthys olivaceus) were reared under four kinds of monochromatic light-emitting diodes (LEDs) at violet (400 nm), blue (465 nm), green (508 nm), and red (635 nm) wavelengths, along with a white fluorescent lamp as control. The rearing experiments were carried out with 15 fish per tank under different wavelength illumination at the same intensity. After rearing the fish under a 12 hr:12 hr light:dark photoperiod for 60 days, percentage increases in weight gain of $269.92{\pm}13.02$, $363.21{\pm}3.74$, $433.22{\pm}4.83$, $290.17{\pm}11.83$, and $340.74{\pm}26.58%$ and increases in specific growth rates (SGR) of $2.18{\pm}0.06$, $2.56{\pm}0.07$, $2.79{\pm}0.01$, $2.27{\pm}0.05$, and $2.47{\pm}0.10$ were observed in fish grown under the illumination of red, blue, green, and violet LEDs and the white fluorescent light, respectively. The results show faster growth in fish reared under green LEDs, but slower growth in those reared under red light. Differences in most blood parameters were minor, aside from an increased level of glutamic oxaloacetic transaminase in the fish grown under red LED illumination. Histological analysis of the retina showed few changes in the ratio of photoreceptor layer thickness to total retina thickness in fish reared under the green LEDs compared to those in other illumination groups. These results indicate that green LED light can foster increased growth in olive flounder with no distinct harmful effects on their light-sensitive photoreceptor layers.

Recent Trends in Integrative Insect Nutrition: A Nutritional Geometry Perspective (통합곤충영양학에 관한 최신 연구동향: 영양기하학적 관점을 중심으로)

  • Lee, Kwang Pum;Jang, Taehwan;Rho, Myung Suk
    • Korean journal of applied entomology
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    • v.61 no.1
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    • pp.129-142
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    • 2022
  • Nutrition dictates nearly all biological processes and determines Darwinian fitness in all living organisms, including insects. Research on insect nutrition has a long history in the field of insect physiology and the importance of understanding insect nutrition has become increasingly apparent with the growing need for producing insects as food and feed. Nevertheless, it is only in recent years that we have witnessed a major breakthrough in our knowledge of insect nutrition. The multivariate, interactive, and dynamic nature of nutrition has long hampered our complete understanding of insect nutrition. However, the challenge posed by such nutritional complexity has been overcome with the advent of the Nutritional Geometry, which is an integrative and multidimensional framework that enabled us to model complex interactions between multiple nutrients. In this review, we introduce the basic concepts and principles of the Nutritional Geometry and describe how this innovative framework has revolutionized the field of insect nutrition and has placed nutrition in the centre of the interface between physiology, ecology, and evolution. We close this review by discussing potentially fertile research areas that can benefit tremendously from the application of this powerful nutritional paradigm in the future.

Ecological Niche Overlap Between Quercus acutissima and Q. dentata with Soil Moisture and Nutrient Gradients (상수리나무와 떡갈나무의 수분과 영양소 구배에 따른 생태지위 중복역)

  • Kyeong Mi Cho;Ara Seol;Yoon Kyung Choi;Se Hee Kim;Eui Joo Kim;Yoon Seo Kim;Jung Min Lee;Ju Seon Lee;Gyu Ri Kim;Ji Won Park;Jae Hoon Park;Young Han You
    • Journal of Wetlands Research
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    • v.25 no.2
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    • pp.159-165
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    • 2023
  • This study measured the ecological niche overlap between two deciduous oak species(Quercus acutissmia and Q. dentata) according to the change in growth responses after treating with the moisture and nutrient contents of the soil at four gradients, and interpreted the degree of competition between the two oak species by ordination method. In the moisture environment gradient, the ecological niche overlap of the two species was high in the photosynthesis-related leaf organs and low in plant architecture such as shoot length. In addition, in case of competition between two oaks, Q. dentata was remarkably dominant in soil moisture gradient, but Q. acutissimia slightly was slightly advantageous over Q. dentata in the soil nutrient gradient. These results show that even in a similar taxonomical group growing in a similar habitat, the response to the organ system of the plant varies depending on the type of environment factor, resulting in different competitive differences among plants.

Exploring the Reliability of an Assessment based on Automatic Item Generation Using the Multivariate Generalizability Theory (다변량일반화가능도 이론을 적용한 자동문항생성 기반 평가에서의 신뢰도 탐색)

  • Jinmin Chung;Sungyeun Kim
    • Journal of Science Education
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    • v.47 no.2
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    • pp.211-224
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    • 2023
  • The purpose of this study is to suggest how to investigate the reliability of the assessment, which consists of items generated by automatic item generation using empirical example data. To achieve this, we analyzed the illustrative assessment data by applying the multivariate generalizability theory, which can reflect the design of responding to different items for each student and multiple error sources in the assessment score. The result of the G-study showed that, in most designs, the student effect corresponding to the true score of the classical test theory was relatively large after residual effects. In addition, in the design where the content domain was fixed, the ranking of students did not change depending on the item types or items. Similarly, in the design where the item format was fixed, the difficulty showed little variation depending on the content domains. The result of the D-study indicated that the original assessment data achieved a sufficient level of reliability. It was also found that higher reliability than the original assessment data could be obtained by reducing the number of items in the content domains of operation, geometry, and probability and statistics, or by assigning higher weights to the domains of letters and formulas, and function. The efficient measurement conditions presented in this study are limited to the illustrative assessment data. However, the method applied in this study can be utilized to determine the reliability and to find efficient measurement conditions for the various assessment situations using automatic item generation based on measurement traits.

Punching Shear Failure in Pile-Supported Embankments (말뚝으로 지지된 성토지반 내 펀칭전단파괴)

  • Hong, Won-Pyo;Song, Jei-Sang;Hong, Seong-Won
    • Journal of the Korean Geotechnical Society
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    • v.26 no.3
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    • pp.35-45
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    • 2010
  • The mechanism of load transfer by punching shear in pile-supported embankments is investigated. Based on the geometric configuration of the punching shear observed in sand fills on soft ground, a theoretical analysis is carried out to predict the embankment loads transferred on a cap beam according to punching shear developed in pile-supported embankments. The equation presented by the theoretical analysis was able to consider the effect of various factors affecting the vertical loads transferred on the cap beam. The reliability of the presented theoretical equation is investigated by comparing it with the results of a series of model tests. The model tests were performed on cap beams, which had two types of width; one is narrow width and the other is wide width. Sand filling was performed through seven steps. Two types of loading pattern were applied at each filling step; one is the long-term loading, in which sand fills at each filling step were kept for 24 hours, the other is the short-term loading, in which sand fills at each filling step were kept for 2 hours. The vertical loads measured in all model tests show good agreement with the ones predicted by the theoretical equation. Finally, the predicted vertical loads also show good agreement with the vertical loads measured in a well-instrumented pile-supported embankment in field, where cap beams were placed on too wide space.

The Analysis of Patients in Oral Medicine and the Evaluation of Oral Medicine as a Special Field (내원경로 분석을 통한 전문과목으로서의 구강내과의 역할)

  • Chung, Tae-Yong;Ryu, Ji-Won;Kang, Jin-Kyu;Ahn, Hyung-Joon;Choi, Jong-Hoon
    • Journal of Oral Medicine and Pain
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    • v.30 no.4
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    • pp.391-400
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    • 2005
  • Special Practitioner exists based on the need for special fields that are required to manage difficult patients with specialized skills distinguished from General practitioner. The purpose of dental specialist system is to manage patients who are not treatable by general practitioner by training doctors specializing in one specific field, thereby, enhancing health of the public. Oral Medicine deals with orofacial pain, oral soft tissue disease, forensic dentistry, oral diagnosis. In these days, living environments of city life bring about increase in stress which ultimately lead to increase in prevalence of temporomandibular disorder, oral soft tissue disease, neuropathies such as trigeminal neuralgia, and hence, the number of patients seeking help of those symptoms tend to increase. The purpose of this study was to analyze the rate of referrals and the routes of patients seeking help by investigating 3,707 patients who visited Department of Oral Medicine, College of Dentistry, Yonsei University, from August, 2004 to April, 2005. The results were as follows: 1. The types of disease referred to the Department of Oral Medicine were orofacial pain, oral soft tissue disease, forensic dentistry, oral diagnosis. 2. The rate of referrals was 58.51% which implies that more than half of the patients visiting the Department of Oral Medicine were referred. 3. The types of institution which made referrals were analyzed, and as a result, dental clinics made most of the referrals with the rate of 83.23%, while that from medical or oriental medical institutions was 16.78%. 4. Among the patients who visited the Department of Oral Medicine on their own, 30.52% gained the information about the Department of Oral Medicine from internet and mass media, and from neighbors. From the above results, most of the patients visiting the Department of Oral Medicine were found to be referred not only from the field of dentistry but also from the field of medicine. These suggest that Oral Medicine manages patients who are not treatable by general dental practitioners, and medical specialists tend to cooperate with the Department of Oral Medicine to manage diseases associated with Oral Medicine. Therefore, the role of Oral Medicine can be considered to be important as a special field, and the results of this study should be considered when working out a policy of Dental specialist system on demand and supply of residents in the future.