• Title/Summary/Keyword: Theoretical

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Wind-induced random vibration of saddle membrane structures: Theoretical and experimental study

  • Rongjie Pan;Changjiang Liu;Dong Li;Yuanjun Sun;Weibin Huang;Ziye Chen
    • Wind and Structures
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    • v.36 no.2
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    • pp.133-147
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    • 2023
  • The random vibration of saddle membrane structures under wind load is studied theoretically and experimentally. First, the nonlinear random vibration differential equations of saddle membrane structures under wind loads are established based on von Karman's large deflection theory, thin shell theory and potential flow theory. The probabilistic density function (PDF) and its corresponding statistical parameters of the displacement response of membrane structure are obtained by using the diffusion process theory and the Fokker Planck Kolmogorov equation method (FPK) to solve the equation. Furthermore, a wind tunnel test is carried out to obtain the displacement time history data of the test model under wind load, and the statistical characteristics of the displacement time history of the prototype model are obtained by similarity theory and probability statistics method. Finally, the rationality of the theoretical model is verified by comparing the experimental model with the theoretical model. The results show that the theoretical model agrees with the experimental model, and the random vibration response can be effectively reduced by increasing the initial pretension force and the rise-span ratio within a certain range. The research methods can provide a theoretical reference for the random vibration of the membrane structure, and also be the foundation of structural reliability of membrane structure based on wind-induced response.

A biobehavioral theoretical framework based on the mechanism of cellular aging for nursing interventions to promote autonomic balance (자율신경균형 증진 간호중재를 위한 생행동적 이론적 기틀 구축: 세포노화 기전 기반으로)

  • Nahyun Kim;Jooyeon Park
    • Journal of Korean Biological Nursing Science
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    • v.26 no.2
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    • pp.99-110
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    • 2024
  • Purpose: This study reviewed the pathophysiological mechanisms of cellular aging caused by psychological stress and aimed to establish a biobehavioral theoretical framework for nursing interventions to promote autonomic balance based on these mechanisms. Methods: A comprehensive literature review was conducted. Results: A review of the literature showed that the stress response increases the secretion of catecholamines and glucocorticoids, resulting in a greater allostatic load. This load induces inflammatory reactions and oxidative stress, shortening telomere length and damaging mitochondrial DNA, which can lead to cellular aging. Based on this mechanism, a biobehavioral theoretical framework for nursing interventions was established. This framework focuses on delaying or inhibiting the cellular aging process by acting on the stress response stage and improving autonomic balance. Conclusion: According to the proposed biobehavioral theoretical framework, stress-relieving nursing interventions may act on the mechanism of cellular aging caused by stress responses. We believe that this framework could expand our understanding of the biobehavioral aspects of stress and would facilitate efforts to use biomarkers to evaluate the effectiveness of stress-related nursing interventions at the cellular level.

Theoretical Analysis of Levers in a Precision Stage for Large Displacement (정밀 스테이지에서 출력변위 확대를 위한 레버의 해석)

  • 황은주;민경석;송신형;최우천
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.720-723
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    • 2004
  • Lever mechanisms are usually employed to enlarge output displacement in precision stages. In this study, theoretical analysis of a lever is presented including bending effect and relation between dimension parameters and an objective function. The objective function is chosen as multiplication of magnification ratio and forcedisplacement transmission. Through theoretical analysis, this study presents optimal values for the parameters and the analysis is verified by finite element method.

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Yang Shangsan's contribution to the theory frame of traditional Chinese medicine (양상선대중의이론체계광가형성적공헌(杨上善对中医理论体系框架形成的贡献))

  • Qian, Huinan
    • Journal of Korean Medical classics
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    • v.26 no.4
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    • pp.191-194
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    • 2013
  • This paper discusses Mr. Yang Shangsan's contribution to the theory frame of traditional Chinese medicine. He advocated initially the classification of Huangdi Neijing, which took preliminary shape of TCM theoretical rudiment. His Huangdi Neijing Taisu drew the outline of the TCM theoretical system framework and had a profound historical significance.

THEORETICAL CONSIDERATIONS ON THE VARIABILITY OF ACTIVE GALACTIC NUCLEI

  • PARK SEOK JAE
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.97-98
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    • 1996
  • Variability of active galactic nuclei is now a well-known phenomenon. This remains to be fully explained by a theoretical model of the central engine. Time scales of AGN variability seem to range continuously from hours up to months. The short time scale variability must be related to the phenomena on the event horizon of the black hole, while the long one to those in the accretion disk or surrounding matter. Based on the axisymmetric, nonstationary model of the central engine, we discuss theoretical considerations on the variability of active galactic nucleus.

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Solution of Klein Gordon Equation for Some Diatomic Molecules with New Generalized Morse-like Potential Using SUSYQM

  • Isonguyo, Cecilia N.;Okon, Ituen B.;Ikot, Akpan N.;Hassanabadi, Hassan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3443-3446
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    • 2014
  • We present the solution of Klein Gordon equation with new generalized Morse-like potential using SUSYQM formalism. We obtained approximately the energy eigenvalues and the corresponding wave function in a closed form for any arbitrary l state. We computed the numerical results for some selected diatomic molecules.

A Study on the Present Condition of the Coffee and Vision of 21C in Korea (한국 커피시장 현황과 21세기의 비전)

  • 진양호
    • Culinary science and hospitality research
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    • v.5 no.2
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    • pp.5-28
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    • 1999
  • The main propose of this study was to present condition of the Coffee and Vision of 21C in Korea. To achieve the propose of this study, Theoretical and empirical approaches were used. In review of theoretical background, basic concepts and characteristics of Coffee. Based on the theoretical studies and previous studies, vision of 21C in Korea. First, we'll have to a national enterprise of coffee. Second, Instant coffee was export to china and east asia in 21C. Third, our Coffee culture was diversity, so wording is more easy. Fourth, coffee meeting will prosper

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Theoretical & Experimental Study on the Air-Type Nonmetallic Collectors. (비금속 공기식 집열기의 이론 분석 및 성능실험)

  • Lee, Dong-Won;Lee, Jong-Ho
    • Solar Energy
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    • v.6 no.1
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    • pp.77-86
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    • 1986
  • In this study, theoretical & Experiemental Analysis on three different air type solar collectors (One of metallic material: AI, two of non-metallic materials; GIWA & Slate) are performed. The results of three different collectors show the similiar performance in spite of different absorber material. The results of experiment are coincided with the theoretical results, and thus it is possible to estimate the performance of collector for the other experiment measuring variables. As a result, the thermal conductivity has no influence on the collector efficiency, because air, heat transfer medium, flows through over the whole surface of absorber plate.

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Exploratory discussions on an integrated approach to mathematics education (수학교육의 통합적 접근에 대한 탐색적 논의)

  • Yu, Chung Hyun
    • East Asian mathematical journal
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    • v.32 no.2
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    • pp.291-300
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    • 2016
  • The integration of mathematics education is required Fundamentally discussion about the nature and purpose of mathematics education. After the theoretical discussion of that, Practical approach of that can be correctly realized. However, It is the impression that theoretical discussions and practical action about the current discourse about integration in mathematics education are the wrong order. To understand the practical action for the integrated approach in mathematics education, theoretical discussion of the integrated approach of mathematical education is properly required.

A Theoretical Analysis of Thermic Endfire Interstitial Applicator

  • Park, Jong-Kweon;Eom, Hyo-Joon
    • Journal of electromagnetic engineering and science
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    • v.1 no.1
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    • pp.60-62
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    • 2001
  • A novel approach for modeling the thermic endfire interstitial applicator is presented. A hypothetical semi-infinite circular cylinder is added in the endfire direction in order to facilitate the theoretical modeling approach. The Fourier transform and mode-matching technique is utilized to obtain a solution in fast-convergent series Numerical computations for the input impedance are performed to check the Validity of the theoretical model.

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