• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.3
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• pp.222-229
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• 2005

This paper presents a self-organizing scheme for multi-agent swarm systems based on coupled nonlinear oscillators (CNOs). In this scheme, unicycle robots self-organize to flock and arrange group formation through attractive and repulsive forces among themselves. The main result is the maintenance of flexible and scalable formation. It is also shown how localized distributed controls are utilized throughout group behaviors such as formation and migration. In the paper, the proposed formation ensures safe separation and good cohesion performance among the robots. Several examples show that the proposed method for group formation performs the group behaviors such as reference path following, obstacle avoidance and flocking, and the formation characteristics such as flexibility and scalability, effectively.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.519-522
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• 2005

This paper presents a self-organizing scheme for multi-agent swarm systems based on coupled nonlinear oscillators (CNOs). In this scheme, unicycle robots self-organize to flock and arrange group formation through attractive and repulsive forces among themselves. It is also shown how localized distributed controls are utilized throughout group behaviors such as formation and migration. In the paper, the proposed formation ensures safe separation and good cohesion performance among the robots. Several examples show that the proposed method for group formation performs the group behaviors such as reference path following, obstacle avoidance and flocking, and the formation characteristics such as flexibility and scalability, effectively.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.635-641
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• 2020

In this study, phase equilibria and formation behaviors of methane hydrate containing mono-ethylene glycol (MEG) and salts (sodium chloride, NaCl; sodium bromide, NaBr; sodium iodide, NaI) are investigated. Equilibrium conditions of methane hydrate containing MEG and salts are measured in a temperature range 272~283 K and a pressure range 3.5~11 MPa. Hydrate inhibition performance in the presence of additives can be summarized as follows: methane hydrate containing (5 wt% NaCl + 10 wt% MEG) > (5 wt% NaBr + 10 wt% MEG) > (5 wt% NaI + 10 wt% MEG). Formation behaviors of methane hydrate with MEG and salts are investigated for analyzing the induction time, gas consumption amount and growth rate of methane hydrates. There are no significant changes in the induction time during methane hydrate formation, but the addition of MEG and salts solution during hydrate formation can affect the gas consumption amount and growth rate.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.6
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• pp.296-302
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• 2020

Magnesium alloys have been rapidly attracting as lightweight structural material in various industry fields because of having high specific strength and low density. It is well known that the crystallographic texture plays an important role in improvement of poor room temperature ductility of magnesium alloys. In this study, high-temperature plane strain compression deformation was conducted on extruded AZ80 magnesium alloy at 723K by varying the strain rates ranging from 5.0×10^-3s^-1 to 5.0×10^-2s^-1 in order to investigate the behaviors of texture formation. It was found that texture formation behaviors in three kinds of specimens were affected by continuous and discontiuous deformation mechanism.

• BMB Reports
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• v.49 no.12
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• pp.655-661
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• 2016

Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

• Corrosion Science and Technology
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• v.2 no.1
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• pp.12-17
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• 2003

The effects of Cr content and film formation potential on electronic behaviors of the passive film on Fe-Cr alloys were investigated in borate buffer solution. Influence of pH on passive films of both Fe-Cr and Fe-Cr-Mo alloys was also investigated. Mott-Schottky and cyclic voltammetry techniques were used to elucidate electronic behaviors of passive films and their electrochemical characteristics. AES analysis of passive films was carried out. Results showed that doping density decreased as Cr content and film formation potentials increased. The addition of Mo to Fe-Cr alloy had little influence on donor densities in pH 9.2 solution but some effects on the decrease in donor densities in pH 1.6 acidic solution.

• Journal of the Korean institute of surface engineering
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• v.43 no.5
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• pp.217-223
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• 2010

For an application as templates of high performance with proper pore size and shape, porous anodic alumina films were prepared by anodization in oxalic acid, and formation behaviors of anodic alumina layer as well as dissolution process in acid solution have been investigated. The surface characteristics on anodic alumina layer were shown to be dependent on the fabrication parameters for anodization. For the dissolution behaviors of anodic alumina, the thickness of the barrier-type alumina layer decreased linearly with the rate of 0.98 nm/min in $H_3PO_4$ solution at $30^{\circ}C$. The changes of the anodic alumina layers were analyzed by SEM and TEM.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.299-300
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• 2018

Electrochemical behaviors of Nb ion in the $LiCl-KCl-NbCl_5$ molten salt were examined. Cyclic voltammograms with different scan rates and scan range at $450^{\circ}C$ showed possible electrochemical redox reactions which were identified by comparison to the literature data. Peak potentials for each redox reaction were consistent with the literature, but some redox reactions were not clearly defined due to the formation of subchloride compound in chloride salt. The electrochemical behaviors of Nb ion related to the subchloride formation as well as Nb metal deposition will be investigated for the future work.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.351-361
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• 2015

External reactor vessel cooling (ERVC) for in-vessel retention (IVR) has been considered one of the most useful strategies to mitigate severe accidents. However, reliability of this common idea is weakened because many studies were focused on critical heat flux whereas there were diverse uncertainties in structural behaviors as well as thermal-hydraulic phenomena. In the present study, several key factors related to molten corium behaviors and thermal characteristics were examined under multi-layered corium formation conditions. Thereafter, systematic finite element analyses and subsequent damage evaluation with varying parameters were performed on a representative reactor pressure vessel (RPV) to figure out the possibility of high temperature induced failures. From the sensitivity analyses, it was proven that the reactor cavity should be flooded up to the top of the metal layer at least for successful accomplishment of the IVR-ERVC strategy. The thermal flux due to corium formation and the relocation time were also identified as crucial parameters. Moreover, three-layered corium formation conditions led to higher maximum von Mises stress values and consequently shorter creep rupture times as well as higher damage factors of the RPV than those obtained from two-layered conditions.

• Journal of Global Scholars of Marketing Science
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• v.5
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• pp.171-204
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• 2000

This paper intends to investigate the hierarchical effects of personality variables and values on pro-environmental product purchase and recycling behaviors mediated by 3 factor environmental attitudes. Previous literature review on pro-environmental behaviors has three categories of research trends. The first category generally done during 70's and early 80's is mainly focused on identifying pro-environmental consumer groups. Second stream of studies has focused on the mediating and moderating effects of variables, such as PCE, environmental knowledge, the perceived importance of behavioral consequences etc., on various pro-environmental behaviors. The last and latest trends of literature is focused on hierarchical and interactive effects of variables on behaviors. Following the trends of literature is review of such specific variables as social responsibility, community mindedness, locus of control, values, and environmental attitudes. The result shows that both locus of control and social responsibility have positive effects on two of environmental attitudes, harmony with nature and limits to growth, but community mindedness did not have effects on environmental attitudes. And social belonging value has positive effects on two of environmental attitudes, limits to growth and nature over human, and environmental value has positive effects on the formation of harmony with nature and limits to growth. But self-actualization has negative effects. And it's also suggested the positive effects of environmental attitudes on purchase and recycling behaviors. Specifically, all environmental attitude variables have positive effects on the formation of pro-environmental product purchase and recycling behaviors except in case of the effects of nature over human to recycling. And it's also revealed that pro-environmental product purchase is a preceeding behavior to recycling behavior, which suggest that consumers have to purchase environment friendly and recyclable products in order to engage in effective recycling behavior. Various applications of the results are discussed in the conclusion.