• Journal of Energy Engineering
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• v.8 no.4
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• pp.605-611
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• 1999

Conventional methods for assessing remaining life of critical high temperature components in fossil power plants rely on nondestructive inspection practices and accompanying life analysis based on fracture mechanics By using these conventional methods. It has been difficult to perform uninterrupted in-service inspection for life prediction. Thus, efforts have been made for developing on-line remaining life monitoring systems employing information on the shape of structures, operating variables and material properties. In thus study, a software for on-line life monitoring system which performs real-time life evaluation of a high temperature system headers was developed. The software is capable of evaluating creep and fatigue life usage from the real-time stress data calculated by using temperatures/stress transfer Green functions derived in advance for the specific headers. The major benefits of the developed software life in determining future operating schedule, inspection interval, and replacement plan by monitoring real-time life usage based on prior operating history.

• Journal of the Korean Magnetic Resonance Society
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• v.17 no.2
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• pp.67-75
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• 2013

ATP synthase produces ATP, a major energy source for metabolic processes in organisms, from ADP and inorganic phosphate in cellular membranes. ATP synthase is known as a rotary motor, in which the c-subunit ring functions as a rotor. In this work, we have tried to develop a more general preparation procedure of thermophilic $F_oc$-ring ($TF_oc$-ring) for NMR measurements. The expression of $TF_oF_1$ is easily affected by various experimental conditions such as temperature, shape and size of a flask, a volume of medium, and shaking rate of an incubator. Accordingly, we have tried to optimize the expression conditions of $TF_oF_1$. $TF_oc$-rings were purified from $TF_oF_1$ according to a reported method. We modified purification procedures to improve purity and yield of $TF_oc$. On top of them, we found a new combination of detergents for the purification at anion-exchange column chromatography. To examine the effect of lipid environments on the structure, the $TF_oc$-rings were reconstituted into two kinds of lipid bilayers, namely, saturated and unsaturated lipid ones. Then, we have compared characteristics of the $TF_oc$-ring structures in these membranes with solid-state NMR.

• Transactions of Materials Processing
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• v.31 no.6
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• pp.351-364
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• 2022

The yield criterion, or called yield function, plays an important role in the study of plastic working of a sheet because it governs the plastic deformation properties of the sheet during plastic forming process. In this paper, we propose a modified version of previous anisotropic yield function (Trans. Mater. Process., 31(4) 2022, pp. 214-228) based on J2 and J3 stress invariants. The proposed anisotropic yield model has the 6th-order of stress components. The modified version of the anisotropic yield function in this study is as follows. f(J₂⁰,J₃⁰) ≡ (J₂⁰)³ + α(J₃⁰)² + β(J₂⁰)^3/2 × (J₃⁰) = k⁶ The proposed anisotropic yield function well explains the anisotropic plastic behavior of various sheets such as aluminum, high strength steel, magnesium alloy sheets etc. by introducing the parameters α and β, and also exhibits both symmetrical and asymmetrical yield surfaces. The parameters included in the proposed model are determined through an optimization algorithm from uniaxial and biaxial experimental data under proportional loading path. In this study, the validity of the proposed anisotropic yield function was verified by comparing the yield surface shape, normalized uniaxial yield stress value, and Lankford's anisotropic coefficient R-value derived with the experimental results. Application for the proposed anisotropic yield function to AA6016-T4 aluminum and DP980 sheets shows symmetrical yielding behavior and to AZ31B magnesium shows asymmetric yielding behavior, it was shown that the yield locus and yielding behavior of various types of sheet materials can be predicted reasonably by using the proposed anisotropic yield function.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.57-63
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• 2021

This study dissected and three-dimensionally (3D) scanned the facial muscles of Korean adult cadavers, created a three-dimensional model with realistic facial muscle shapes, and reproduced facial expressions to provide educational materials to allow the 3D observation of the complex movements of cadaver facial muscles. Using the cadavers' anatomical photo data, 3D modeling of facial muscles was performed. We produced models describing four different expressions, namely sad, happy, surprised, and angry. We confirmed the complex action of the 3D cadaver facial muscles when making various facial expressions. Although the results of this study cannot confirm the individual functions of facial muscles quantitatively, we were able to observe the realistic shape of the cadavers' facial muscles, and produce models that would show different expressions depending on the actions performed. The data from this study may be used as educational materials when studying the anatomy of facial muscles.

• Fashion & Textile Research Journal
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• v.20 no.6
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• pp.690-703
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• 2018

The purpose of this study is to help user understand the basic principles and interfaces of each program, and to provide a base material for the development of more efficient apparel CAD systems to compensate for each program's shortcomings by comparing the function of three apparel CAD systems: Yuka CAD, Opti-tex, and Style CAD. For this purpose, the skirt waistband and sleeve armhole line creation process were selected based on these two criteria. 1) There is a big difference between principle and method between CAD systems. 2) When CAD system is used rather than paper drawing process, the process is shortened and convenience is high. In this study, pros and cons and supplement point of each CAD system are suggested by comparing the functions of the CAD system performing the selected drafting process by four criteria: icon, key, method, and characteristic point. As a result of the study, it was confirmed that the three CAD systems differ in the basic principle and interface environment. As a result of analyzing the skirt waistband method function, it was confirmed that the band line is formed directly on the outline of the skirt and the band dart recognition function is the most efficient function and as a result of the analyzing the sleeve armhole line method function, it was confirmed that the curve generation function using the shape of the actual curve measure and the length adjustment function through the automation of the dimension calculation is the most efficient function.

• English & American cultural studies
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• v.16 no.2
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• pp.47-70
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• 2016

Under the inhumane oppression of imperialism, the Third World's political violence has been often represented as an immediate and explosive one with an instant, concentrated visibility. Yet the ecological and psychological exploitation of the Third-World countries by empires, as Rob Nixon insists, shows the relative invisibility of slow violence. This paper is to reveal this slow violence of the marginalized areas symbolized as the lowland. Although Arne Naess' deep ecology promotes the inherent worth of living beings regardless of their instrumental utility to human needs. this paper deals with three postcolonial ecological textbooks which criticize the white-centered deep ecology: Amitav Ghosh's The Glass Palace, Jhumpa Lahiri's The Lowland, and Barbara Kingsolver's The Poisonwood Bible. Through postcolonial critical study, this paper finds out that all these three works have some themes in common. First, these postcolonial works assume a shape of family saga which is parallel to the slow violence of ecological and psychological plundering of empires in the postcolonial countries. Second, like the mangroves which have a tenacious hold on life, these postcolonial people rather overcome the heterogenic challenge with the sturdy and tough mind than defeated. Third, the native people's ethics of earth functions as the stronghold for their respectable lifestyle in their indigenous historicity. Finally, as a big fat brother, the Americanized globalization or neoliberalism is warned as the neocolonialism which is often shown as the disguised pattern of greenwashing. Namely, the people's self-enhancement is always prior to the imperialistic development or neoliberalism in the postcolonial ecological texts which sharply contrast the native's life consciousness and the empire's development theory.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.59-70
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• 2022

Water distribution systems (WDSs) are a representative infrastructure injecting chlorine to disinfect the pathogenic microorganisms and supplying water from sources to consumers. Also, WDSs prescribe to maintain the usual standard (0.1-4.0 mg/L) of residual chlorine. However, the user's usage pattern, water age, network shape, and type affect the hydraulic features (i.e. nodal pressure, pipe velocity) and water quality features (i.e., the residual chlorine concentration). Therefore, this study developed an optimization approach for optimizing WDSs considering water quality-hydraulic factors using Multi-objective Harmony Search (MOHS). The design cost and the system resilience were applied as the design objective functions, and the nodal pressure and the concentration of residual chlorine are used as constraints. The derived optimal designs through this approach were analyzed according to network characteristics such as the network shapes and type. These optimal designs can meet the safety of economic and water quality aspects to increase user acceptance.

• Transactions of Materials Processing
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• v.31 no.4
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• pp.214-228
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• 2022

The yield criterion, or called yield function, plays an important role in the study of plastic working of a sheet because it governs the plastic deformation properties of the sheet during plastic forming process. In this paper, we propose a novel anisotropic yield function useful for describing the plastic behavior of various anisotropic sheets. The proposed yield function includes the anisotropic version of the second stress invariant J₂ and the third stress invariant J₃. The anisotropic yield function newly proposed in this study is as follows. F(J₂)+ αG(J₃)+ βH (J₂ × J₃) = k^m The proposed yield function well explains the anisotropic plastic behavior of various sheets by introducing the parameters α and β, and also exhibits both symmetrical and asymmetrical yield surfaces. The parameters included in the proposed model are determined through an optimization algorithm from uniaxial and biaxial experimental data under proportional loading path. In this study, the validity of the proposed anisotropic yield function was verified by comparing the yield surface shape, normalized uniaxial yield stress value, and Lankford's anisotropic coefficient R-value derived with the experimental results. Application for the proposed anisotropic yield function to aluminum sheet shows symmetrical yielding behavior and to pure titanium sheet shows asymmetric yielding behavior, it was shown that the yield curve and yield behavior of various types of sheet materials can be predicted reasonably by using the proposed new yield anisotropic function.

• Textile Coloration and Finishing
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• v.34 no.4
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• pp.241-249
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• 2022

As for military backpacks in Korea, utility backpack products equipped with various functions along with comfort and convenience are being developed. As a result, the volume and weight of the backpack increase, and many lightweight studies of the materials forming the backpack are being conducted. This study is a basic study on frame lightweight using fiber-reinforced composites to deal with aluminum, a back frame that maintains the shape of a backpack and provides stability when worn by combatants. As is known, only fiber-reinforced composites have sufficient light weight and mechanical properties, but the mechanical properties were reviewed by drilling holes to maximize the light weight. Tensile strength and flexural strength were measured by drilling 6mm, 12mm, 18mm, and 24mm holes, and the tensile strength and flexural strength were measured when 1, 3, 5, and 7 holes of 12mm were increased. As a result, even when the number of holes was increased, tensile strength did not change significantly, and the flexural strength showed to be higher in the case of 3 holes and 5 holes than in the case of 1 hole.

• Structural Engineering and Mechanics
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• v.86 no.3
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• pp.291-309
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• 2023

This paper addresses the finite element modeling of functionally graded porous (FGP) beams for free vibration and buckling behaviour cases. The formulated finite element is based on simple and efficient higher order shear deformation theory. The key feature of this formulation is that it deals with Euler-Bernoulli beam theory with only three unknowns without requiring any shear correction factor. In fact, the presented two-noded beam element has three degrees of freedom per node, and the discrete model guarantees the interelement continuity by using both C⁰ and C¹ continuities for the displacement field and its first derivative shape functions, respectively. The weak form of the governing equations is obtained from the Hamilton principle of FGP beams to generate the elementary stiffness, geometric, and mass matrices. By deploying the isoparametric coordinate system, the derived elementary matrices are computed using the Gauss quadrature rule. To overcome the shear-locking phenomenon, the reduced integration technique is used for the shear strain energy. Furthermore, the effect of porosity distribution patterns on the free vibration and buckling behaviours of porous functionally graded beams in various parameters is investigated. The obtained results extend and improve those predicted previously by alternative existing theories, in which significant parameters such as material distribution, geometrical configuration, boundary conditions, and porosity distributions are considered and discussed in detailed numerical comparisons. Determining the impacts of these parameters on natural frequencies and critical buckling loads play an essential role in the manufacturing process of such materials and their related mechanical modeling in aerospace, nuclear, civil, and other structures.