• Title/Summary/Keyword: Self-equilibrium state

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Inverse analysis of erection process for prismatic tensegrity structures with redundant cables

  • Pei Zhang;Huiting Xiong;Jingjing Yang;Jiayan Liu
    • Steel and Composite Structures
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    • v.49 no.2
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    • pp.125-141
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    • 2023
  • Firstly, a new kind of prismatic tensegrity structures with redundant cables is defined, the topology, geometry and forming conditions of which are introduced further. The development of its mechanical properties including self-stress states and structural stiffness with the increment of the twist angle is also investigated carefully. Combined with the topology of this kind of structures, a reasonable erection scheme is proposed, in which some temporary lifting points need to be set and two groups of vertical cables are tensioned in batches. Then, a simplified dynamic relaxation method is employed to track the erection process inversely, which aims to predict each intermediate equilibrium state during the construction, and give the key structural parameters that can effectively guide the construction. The removal of the active cables, the relaxation or tension of the passive cables are simulated by controlling their axial stiffness, so that the structural composition as well as the serial numbers of the elements always keep invariant regardless of the withdrawal of the slack cables. The whole analysis process is clear in concept, simple to implement and easy to popularize. Finally, several examples are given to verify the practicability and effectiveness of the proposed method further.

Form-finding of Tensegrity Structures with constraints by using Force Method (하중법을 이용한 텐세그리티 구조물의 자기평형 응력 탐색)

  • Chung, Woo-Sung;Lee, Jae-Hong;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.4
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    • pp.49-59
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    • 2011
  • This paper presents a new numerical method by using Singular Value Decomposition force method for form-finding of tensegrity structures with constraints. In order to maintain the tensegrity structures stable, state of self-equilibrium stress should be introduced. The existing force method has some advantages about form-finding of tensegrity structures. However, this method has complex formulation. In force density method, dummy members are required for form -finding of tensegrity structures with constraints. Therefore this study proposes new force method using Singular value decomposition. The proposed method is both having easy basic consept and simple computation than existing force method. A numerical example is presented to demonstrate the efficiency and robustness in searching initial single integral feasible self-stress mode for tensegrity structures with constraints.

Protonation State of Norfloxacin and Their Interaction with DNA (pH에 따른 Norfloxacin의 형태 및 DNA와의 상호작용에 관한 연구)

  • Yeo, Jeong-Ah;Son, Gwan-Su;Kim, Jong-Moon;Moon, Hyung-Rang;Jun, Eun-Duk;Cho, Tae-Sub
    • Journal of the Korean Chemical Society
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    • v.44 no.1
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    • pp.4-9
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    • 2000
  • We investigated the self-association and protonation state of norfloxacin, a member of quinokme antibiotics, using electric absorption and potentiom,etric titration. Both nitrogen at the piperazine ring and carboxylic acid were protonated at a low pH (cationic norfloxacin), and deprotonated at a high pH (anionic norfloxacin). In the intermediate pH range, a neutral species was dominant with the possibility of forming a zwitter ion. We also observed that nortloxacin molecules can be sracked to form a dimer at an intermediate pH, The equilibrium constant of the norfloxacin-DNA complex formation, which was measured by Stem-Volmermethod, increases as the pH of the system is lowered. This observation indicates that it is the cationic nortloxacin that forms a complex with DNA among various norfloxacin species in aqueous solution.

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Reconsideration about the Dong-Mu's Theory of Nature and Emotion (동무(東武) 성정론(性情論) 재고(再考))

  • Lee, Jun-Hee;Lee, Eui-Ju;Koh, Byung-Hee
    • Journal of Sasang Constitutional Medicine
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    • v.21 no.2
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    • pp.11-26
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    • 2009
  • 1. Objectives : This research was purposed to reconsider the Dong-Mu's Theory of Nature and Mind(生情論). 2. Methods : The Dong-Mu's interpretation on the first chapter of "The Doctrine of Mean(中庸)", and the related contents of Nature and Emotion(性情) in his literature such as "Gyukchigo(格致藁)", "Donguisusebowon-Sasang chobongyun(東醫壽世保元四象草本卷)" and "Donguisusebowon(東醫壽世保元)" were reviewed. 3. Results and Conclusions : 1. Dong-Mu reinterpreted the concepts about 'Providence(天命) and Human Nature(人性)', 'Not-yet-intentional state(未發) and Intentional state(已發)', 'Nature and Mind(性情)' and 'Equilibrium and Harmony(中和)' in "The Doctrine of Mean", and used these concepts as logical tools in explanation of his thoughts of Human being and medical theory. 2. The generating principle of Nature and Mind(性情) presented as sorrow, anger, joy and pleasure is 'the Principle of Human nature(性理)', which is embodied as 'the Principle of Organ(臟理)' in "Donguisusebowon". The Principle of Organ(臟理) is originated from Heart and lie at lung, spleen, liver and kidney as the form of Four Virtue(四德). 3. The Principle of Organ(臟理) has the position of superintendence and is the generating principle of Nature and Emotion(性情), by which the structural and functional variations between different constitutional types are formed. 4. Dong-Mu's newly established concept of Nature and Emotion(性情) is the core logic in his idea of physiology, pathology and self-cultivation.

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Seed-dependent Accelerated Fibrillation of ${\alpha}$-Synuclein Induced by Periodic Ultrasonication Treatment

  • Kim, Hyun-Jin;Chatani, Eri;Goto, Yuji;Paik, Seung-R.
    • Journal of Microbiology and Biotechnology
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    • v.17 no.12
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    • pp.2027-2032
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    • 2007
  • [ ${\alpha}$ ]-Synuclein is the major component of Lewy bodies and responsible for the amyloid deposits observed in Parkinson's disease. Ordered filamentous aggregate formation of the natively unfolded ${\alpha}$-synuclein was investigated in vitro with the periodic ultrasonication. The ultrasonication induced the fibrillation of ${\alpha}$-synuclein, as the random structure gradually converted into a ${\beta}$-sheet structure. The resulting fibrils obtained at the stationary phase appeared heterogeneous in their size distribution, with the average length and height of $0.28\;{\mu}m{\pm}0.21\;{\mu}m$ and $5.6\;nm{\pm}1.9\;nm$, respectively. After additional extensive ultrasonication in the absence of monomeric ${\alpha}$-synuclein, the equilibrium between the fibril formation and its breakdown shifted to the disintegration of the preexisting fibrils. The resulting fragments served as nucleation centers for the subsequent seed-dependent accelerated fibrillation under a quiescent incubation condition. This self-seeding amplification process depended on the seed formation and subsequent alterations in their properties by the ultrasonication to a state that accretes the monomeric soluble protein more effectively than their reassociation of the seeds back to the original fibrils. Since many neurodegenerative disorders have been considered to be propagated via the seed-dependent amyloidosis, this study would provide a novel aspect of the significance of the seed structure and its properties leading to the acce]erated amyloid formation.

Finite Element Analysis of the Tire Contact Problem (타이어 접지문제의 유한요소 응력해석)

  • Han, Y.H.;Kim, Y.H.;Huh, H.;Kwak, Y.K.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.5
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    • pp.820-830
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    • 1989
  • The tire inflation and contact problem has been solved by a finite element method. The finite element formulation is derived from the equilibrium equations by the principle of virtual work in the form of an updated Lagrangian formulation for incremental analysis. Then, a contact formulation is added to the finite element formulation to calculate stress state of tire in contact with flat rigid road under the load due to the self-weight of a vehicle. In the finite element analysis, equations of effective material properties are introduced to analyze a plane strain model of the shell-like tire by considering the bending effect of reinforced steel cords. The proposed equations of effective material properties produced stress concentration around the edge of belt layers, which does not appear when other well-known equations of material properties are adopted. The result from the above algorithm demonstrates the validity of the formulation and the proposed equations for the effective elastic constants. The result fully interprets the cause of separation between belt layers by showing the stress concentration.

Balance of Power and the Relative Military Capacity - Empirical Analysis and Implication to North East Asia - (세력균형(power balance)에서의 군사력 수준과 동북아시아에 주는 함의)

  • Kim, Myung-soo
    • Strategy21
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    • s.38
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    • pp.112-162
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    • 2015
  • This study began to confirm or review the balance of power theory by applying scientific methods through experiential cases. Though there are several kinds of national power, this study supposes military power as a crucial power when it comes to war and peace. This research covered balance and imbalance through comparing relative military power between nations or nations' group. Comparison of relative military power can be achieved by statistically processing the values of which has been converted into the standard variables in same domain, then calculating the values of nation's power which has been synthesized different experiential factors. In addition, the criteria of experiential experiment is highly dedicated to European countries, USA, Japan prior to 1st and 2nd World War, as well as USA, Soviet Union and North East Asia during Cold War era. In addition, the balance of power theory has been redefined to review the action of the state upon the changes of power as mentioned in the theory. To begin with, the redefined theory states that relative level of military power between nations defines the consistency of peace and balance of power. If military power is enough to be on the range of level required to keep the power in equilibrium, peace and balance can be achieved. The opposite would unbalance the military power, causing conflicts. While the relative military level between nations change, nations seek to establish 'nations group' via military cooperation such as alliance, which also shift relative military power between nations group as well. Thus, in order to achieve balance of power, a nation seeks to strengthen its military power(self-help), while pursuing military cooperation(or alliance). This changes relative military power between nations group also. In other words, if there exists balance of power between nations, there is balance of power between nations group as well. In this theory, WWI and II broke out due to the imbalance of military force between nations and nations group, and reviewed that due to the balance of military force during the Cold War, peace was maintained. WWI was resulted from imbalance of military cooperation between two powerful states group and WWII was occurred because of the imbalance among the states. Peace was maintained from cooperation of military power and balance among the states during the Cold War. Imbalance among continental states is more threatening than maritime states and balance of power made by army force and naval force also is feasible. Also the outcomes of two variables are found military power balanced ratio of military power for balance is 67% when variable ratio of balance is 100% and standard value for balance is 0.86. Military power exists in a form of range. The range is what unstabilized the international system causing nations to supplement their military powers. These results made possible the calculation and comparison between state's military power. How balance of power inflicted war and peace has been studied through scientific reviews. Military conflict is highly possible upon already unbalanced military powers of North East Asian countries, if the US draws its power back to America. China and Japan are constantly building up their military force. On the other hand, Korean military force is inferior so in accordance to change of international situation state's survival could be threatened and it is difficult to achieve drastic increase in military force like Germany did. Especially constructing naval force demands lots of time; however but has benefit that naval force can overcome imbalance between continental states and maritime states.

From Trauma To growth: Posttraumatic Growth Clock (외상 후 병리에서 성장으로: 외상 후 성장 시계)

  • Lee, Hong-Seock
    • Korean Journal of Cognitive Science
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    • v.27 no.4
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    • pp.501-539
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    • 2016
  • The human mind is a self-evolving system that develops along a multidimensional hierarchical pathway in response to traumatic stimulus. In absence of trauma, a mind integrated in conflict-free state is called monistic. When the monistic mind responses to a traumatic stimulus, a response polarity forms toward stimulus polarity within the mind, turning it into a bipartite structure. Dialectical interaction between the two opposites, originating from their incompatibility, creates a new third polarity in the upper dimension. Thereby, the mind turns into a trinity structure. When the interaction among the three polarities becomes optimized, the plasticity of the mind gets maximized into the "far-from-equilibrium state," and the function of three polarities is synchronized. Through this recalibration, the mind returns back to its monistic structure. If the mind with the recurred monistic structure responds to another traumatic stimulus, this cycle of hierarchical transformation repeats itself in this cyclical and fractal growth process through synchronization of basic trinity system. Applying this concept to the process of post-traumatic growth (PTG), this paper explores how the mind transforms traumatic experiences into PTG and proposes a 'PTG Clock' that shows a fundamental sequence in the development of the human mind. The PTG Clock consists of seven hierarchical phases, and each of the first six phases has two opposite sub-phases: shocked/numbed, feared/intrusive, paranoid/avoidant, obsessional/explosive, dependent/depressive, and meaningless/searching for meaning. The seventh, the synchronization phase, completes one cycle of the mind's transformation, realizing a grand trinity system, where the mind synchronizes its biological, social, and existential dimensions. At that point, the mind becomes more susceptible to not only the stimulus of its own traumatic experience but also the pain of others. Thereby, the PTG Clock sets out on a journey to another cycle of transformation in higher dimensions. The validity of this transformational process for the PTG Clock will be examined by comparing it to Horowitz's theory of stress response syndrome.