• Journal of the Korean Institute of Rural Architecture
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• v.11 no.4
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• pp.25-34
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• 2009

The modern philosophy of historic conservation focuses on the permanence of the material aspects of monuments as historic evidence of the artistic achievement of the past. However, so strongly are European attitudes to architecture and its conservation embedded in modern conservation, that it has skewed all conservation thinking towards the concept of the European-type monument which emphasizes visual beauty through its material substance. Thus, some basic ideas of modern conservation seem ill-suited to East Asian architecture which is conceived in a different spirit from its European counterpart. The purposes of the paper are to discuss the need for approaches which are different from the modern Western view of conservation for East Asian architectural heritage, and to make suggestions for developing conservation principles more suited to the unique values and aesthetic sense of East Asian culture and architecture. Conservation principles in the East Asian societies are determined in relation to the spiritual and naturalistic sensibilities of East Asian culture and architecture.

• Journal of Korean Medical classics
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• v.22 no.4
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• pp.261-264
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• 2009

Gi(氣) transformation theory is the foundation of Traditional Chinese Medicine[TCM]. This theory matured during the period of "Hwangjenaegyeong(黃帝內經)", and later in the history of TCM was a source of significant impact on the development process and direction of general medical theory. The concept of "gi transformation[氣化]" mainly originates from the definition of the three levels which are nature, the relationship between nature and human, and the body's own metabolism, and is used to describe the usage and the resulting changes of 'gi(氣)'. Gi transformation possesses six characteristics which are permanence, universality, representationalism, directional, variability, and orderliness. The research of the concept and characteristics of gi transformation[氣化] in "Hwangjenaegyeong" will help identify the important academic value and practical significance of the formation of the basic theory of TCM as the result of the gi transformation theory, and highlight the unique characteristics of TCM.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.556-561
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• 2005

The steel shows plastic deformation after the yield point exceeds. The plastic deformation due to overloads occurs at the interior support of a continuous bridge. The plastic deformation is concentrated at the interior support and the permanence deformation at the interior support remains after loads apply. Because local yielding causes the positive moment at the interior support, it is called 'auto-moment'. Auto-moment redistributes the elastic moment. Because of redistribution, auto-moment decreases the negative moment at the interior support of a continuous bridge. In this paper, the plastic rotation is evaluated using the moment-rotation curve proposed by Schalling and Beam-line method. Moreover, auto-moment is derived from the experiment curve.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.413-417
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• 2013

The organic Rankine Cycle (ORC) uses a kind of refrigerant as a working fluid that evaporates at relatively low temperature, as the Rankine Cycle uses superheated steam as the working fluid. A small scale ORC test bench was installed, and two different working fluids (R245fa and R134a) were injected into the test bench. The test bench was in operation with the two different working fluids under the same conditions. The effects against the system performance from the different working fluids were analysed, and root causes were identified. Other factors reflecting the power generation efficiency were also found. A conclusion was drawn, that R245fa makes the system perform better, than R134a.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.721-741
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• 2011

In this paper we have considered a dynamical mathematical model of the sub-populations of potential smokers (non-smokers), smokers, smokers who temporarily quit smoking, smokers who permanently quit smoking and a class of smoking associated illness by introducing time dependent parameters and distributed time delay to acquire smoking habit. Here, we have established some sufficient conditions on the permanence and extinction of the smoking class in the community by using inequality analytical technique. We have introduced some new threshold values $R_0$ and $R^*$ and further obtained that the smoking class in the community will be permanent when $R_0$ > 1 and the smoking class in the community will be going to extinct when $R^*$ < 1. By Lyapunov functional method, we have also obtained some sufficient conditions for global asymptotic stability of this model. Computer simulations are carried out to explain the analytical findings. The aim of the analysis of this model is to identify the parameters of interest for further study, with a view to informing and assisting policy-maker in targeting prevention and treatment resources for maximum effectiveness.

• Journal of applied mathematics & informatics
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• v.38 no.5_6
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• pp.375-406
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• 2020

The anti-predator factor due to fear of predator in eco- epidemiological models has a great importance and cannot be evaded. The present paper consists of a modified Lesli-Gower predator-prey model with contagious disease in the predator population only and also consider the fear effect in the prey population. Boundedness and positivity have been studied to ensure the eco-epidemiological model is well-behaved. The existence and stability conditions of all possible equilibria of the model have been studied thoroughly. Considering the fear constant as bifurcating parameter, the conditions for the existence of limit cycle under which the system admits a Hopf bifurcation are investigated. The detailed study for direction of Hopf bifurcation have been derived with the use of both the normal form and the central manifold theory. We observe that the increasing fear constant, not only reduce the prey density, but also stabilize the system from unstable to stable focus by excluding the existence of periodic solutions.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.880-883
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• 1996

Plasma Source Ion Implantation (PSII) technique was used for the hydrophilization or hydrophobization of polymer surfaces. Polymers were modified with different plasma gases such as oxygen, nitrogen, argon, and tetrafluoromethane, and for varying lengths of treatment time. Plasma ion treatment of oxygen, nitrogen, argon and their mixtures increased significantly the hydrophilic properties of polymer surfaces. More hydrophobic surfaces of polymers were formed after the treatment with tetrafluoromethane. A study of plasma source ion implanted polymers was performed using contact angle measurements and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The TOF-SIMS spectra and depth profile were used to obtain the information about the treated surfaces of polymers. The permanence of this technique could be evaluated with respect to ageing time. The surfaces treated with PSII gave better stability than other surface modification methods.

• Kyungpook Mathematical Journal
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• v.56 no.3
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• pp.831-844
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• 2016

In this paper, we consider a discrete predator-prey system with Watt-type functional response and impulsive controls. First, we find sufficient conditions for stability of a prey-free positive periodic solution of the system by using the Floquet theory and then prove the boundedness of the system. In addition, a condition for the permanence of the system is also obtained. Finally, we illustrate some numerical examples to substantiate our theoretical results, and display bifurcation diagrams and trajectories of some solutions of the system via numerical simulations, which show that impulsive controls can give rise to various kinds of dynamic behaviors.

• Korean Journal of Child Studies
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• v.23 no.3
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• pp.123-137
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• 2002

This study investigated children's cognitions of physically impossible events by characteristics of the events. The 67 subjects were 3-, 5-, and 7-year old children from one day care center and one elementary school in Seoul. Children's responses to questions regarding the events were taped and transcribed. Cognition of the events was measured by recognition of impossibility, possibility of replication, and reasons for the possibility of replication of the events. Data were analyzed by ANOVA(repeated measures), and Pearson's correlation. Children's recognition of the impossibility of the events varied by type of task : Recognition of gravity tasks was different from irreversibility tasks, but there were no differences between recognition of irreversibility and gravity and between irreversibility and object permanence. The possibility of replication correlated significantly with reasons given by the children.

• Journal of Educational Research in Mathematics
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• v.12 no.4
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• pp.457-472
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• 2002

In this paper, we deal with the algebraic thinking from the perspective of ‘process’ and ‘object’ aspects. Generally, mathematical concepts have come from the concrete process. We consider the origin of algebra as the arithmetic calculations. Also, the concept of school arithmetic is beginning from actions or procedures. However, in order to develop the alge- braic thinking and to apply this thinking, we have to see the history of algebraic thinking, and find this duality. Next we investigate various researches relating to the ‘process-object duality’. Theses studies suppose that the concept formation and thinking process should be stared from the process-object duality. Finally, we reinterprete many difficulties in algebra - equals sign, variables, algebraic expressions, and linear equations, the principle of permanence of form- from the perspective of the process-object duality.