• International Journal of Concrete Structures and Materials
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• v.9 no.4
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• pp.453-462
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• 2015

A critical review on existing creep theories in calcium-silicate-hydrate (C-S-H) is presented with an emphasis on several fundamental questions (e.g. the roles of water, relative humidity, temperature, atomic ordering of C-S-H). A consensus on the rearrangement of nanostructures of C-S-H as a main consequence of creep, has almost been achieved. However, main disagreement still exists on two basic aspects regarding creep mechanisms: (1) at which site the creep occurs, like at interlayer, intergranular, or regions where C-S-H has a relatively higher solubility; (2) how the structural rearrangement evolutes, like in a manner of interlayer sliding, intra-transfer of water at various scales, recrystallization of gelled-like particles, or dissolution-diffusion-reprecipitation at inter-particle boundary. The further understanding of creep behavior of C-S-H relies heavily on the appropriate characterization of its nanostructure.

• Journal of Magnetics
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• v.10 no.2
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• pp.44-47
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• 2005

The oscillatory interlayer exchange coupling (IEC) has been shown in pinned $[CoFe/Pt(t_{pt})/CoFe]/IrMn$ multi-layers with perpendicular anisotropy. The period of oscillation corresponds to about 2 monolayers of Pt. The oscillatory behavior of IEC depending on the nonmagnetic metallic Pt thickness is thought to be related the antiferromagnetic ordering induced by IrMn layer. Oscillatory IEC as function of insulating NiO thickness has been observed in $[Pt/CoFe]_4/NiO(t_{NiO})/[CoFe/Pt]_4$ multilayers. The effect of N (number of bilayer repeats) upon the magnetic property of [Pt/CoFe]N/IrMn is also studied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.353-356
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• 1999

The electrical characteristics of fatty acid LB films were investigated to develop the gas sensor using Langmuir-Blodgett(LB) films which have high ordered orientation and ordering structure. The deposition status of fatty acid LB films were verified by the measurements of UV absorbance. The conductivity of fatty acid LB films for horizontal direction at room temperature was about $10^8[S/cm]$,/TEX>, which was correspond to semiconductor material. The activation energy for fatty acid LB films with respect to variation of temperature was about l.O[eV]. The response characteristics for organic gas were confirmed by measuring the response time, recovery time, and reproducibility of the fatty acid LB films to each organic gas. Also, the penetration and adsorption behavior of gas molecule were confirmed through the organic gas response characteristics of fatty acid LB films with respect to temperature.

• Journal of Intelligence and Information Systems
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• v.1 no.1
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• pp.61-72
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• 1995

Dynamic and explicit ordering of strategies is a key process in modeling knowledge-level problem-solving behavior. This paper addressed the important problem of howl to make the scheduler more knowledge-intensive in a way that facilitates the acquisition, integration, and maintenance of the scheduler control knowledge. The solution a, pp.oach described in this paper involved formulating the scheduler task as a heuristic classification problem, and then implementing it as a classification expert system. By doing this, the wide spectrum of known methods of acquiring, refining, and maintaining the knowledge of a classification expert system are a, pp.icable to the scheduler control knowledge. One important innovation of this research is that of recursive heuristic classification : this paper demonstrates that it is possible to formulate and solve a key subcomponent of heuristic classification as heuristic classification problem. Another key innovation is the creation of a method of dynamic heuristic classification : the classification alternatives that are selected among are dynamically generated in real-time and then evidence is gathered for and aginst these alternatives. In contrast, the normal model of heuristic classification is that of structured selection between a set of preenumerated fixed alternatives.

• International Journal of Reliability and Applications
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• v.2 no.2
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• pp.81-97
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• 2001

Lifetesting problems have been the subject of investigations for over three decades. Most suggested approaches are markedly different from those used in the related but wider goodness of fit problems. In the current investigation, it is demonstrated that a goodness of fit approach is possible in many lifetesting problems and that It results in simpler procedures that are asymptotically equivalent or better than standard ones. They may also have superior finite sample behavior. Several perennial classes are addressed here. The class of increasing failure rate (IFR) and the class of new better than used (NBU) are addressed first. In addition, we provide testing for a newer and practical class of new better than used in convex ordering (NBUC) due to Cao and Wang (1991). Other classes can be developed similarly and this point is illustrated with the classes of new better than used in expectation (NBUE) and harmonic new better than used in expectation (HNBUE).

• Polymer(Korea)
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• v.27 no.6
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• pp.521-527
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• 2003

It was found that polypropylene shows rearrangement of crystal structure during the melting process. For the analysis of recrystallization behavior, the change of dynamic mechanical property, crystallinity, and crystal structure were studied by DSC, FT-IR, SAXS, and DMA. Melt-recrystallization-remelting behavior of iPP was clearly observed when iPP was cooled down kom the melt more rapidly. Elastic modulus of iPP increased during the recrystallization process but crystallinity of iPP shows constant value. Furthermore, the full width of half mean of SAXS pattern decreased about 30%, and intra-lamella ordering of iPP increased during the melt process but is was not found for sPP.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.159-168
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• 2022

This study was conducted to classify segmental group based on the factors of foodservice motivation and then conducted a survey for one month from July 15 to August 14, 2021 to analyze the influence of demographic characteristics, usage behavior, and motivation on eating out choice behavior. A total of 310 copies were used for empirical analysis. The result is as follows. First, males showed higher task type than females, and females showed higher number of change type, gastronomic type, and fit type. Second, in demographic characteristics, all groups showed strong motivation for foodservice in married people aged 31-40 and 41-50. Third, in the restaurant selecting behavior difference between the segmental groups according to the motivation for foodservice the most preferred menu was korean food for fit type, gourmet type, duty type and western food was the highest in the change type. Fourth, in the ordering method of difference in restaurant selecting behavior among segmental groups, all four groups showed higher order type than unlimited type or buffets type. The limitations of this study are limited to the food field and analysis should be done, but the results of the study on specific food items have not been obtained. Therefore, it is hoped that the future research will be conducted by designating specific food fields.

• Progress in Superconductivity
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• v.14 no.2
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• pp.110-115
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• 2012

Samples with nominal compositions of $RuSr_2(Eu_{1.34-x}Tb_xCe_{0.66})Cu_2O_z$ (x = 0, 0.67) were prepared and their superconductivity and magnetic properties were compared to shed light on the effect of Tb substitution for Eu. X-ray diffraction measurements indicate that the Tb substitution resulted in a decrease in both a and c lattice parameters in consistent with ionic size difference between Eu and Tb. Contrary to the Tb-free sample, no superconducting transition behavior is observed in the Tb-sustituted sample. It is also found that the Tb substitution for Eu significantly increases the weak-ferromagnetic component of the field-cooled magnetic susceptibility as well as an increase in the magnetic ordering temperature. These results suggest that the magnetic state of the Ru sublattice is significantly affected by the Tb substitution for Eu.

• Asia pacific journal of information systems
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• v.13 no.4
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• pp.229-255
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• 2003

This article attempts to examine the well-known law that the increasing returns to scale(IRS) is effective in the Internet business. The effect of IRS is one of the hottest issues in the Internet business sector. Many cases and survey studies support the fact that the IRS phenomenon exists in the Internet business. Executives in Internet business generally give a deep trust on this theory. As the Internet business grows, however, the boundary of the business becomes widened and complicated. And each category of Internet business is characterized with a different business style and economic behavior. It may, therefore, be dangerous to accept that the phenomenon of IRS is applied to all areas of Internet business. For this reason, the research for the close look into the IRS phenomenon should provide significant implications for the managers in the Internet business industry. This article divides the internet business into four sub-areas, and analyzes the IRS phenomenon using AHP/DEA-based full ordering technique. Interpretations are given, based upon the research results, for each sub-area of Internet business, as a guideline of setting business strategies for practical managers.

• Journal of the Korea Computer Industry Society
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• v.2 no.11
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• pp.1365-1372
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• 2001

We have suggested three learning rules and implemented an experimental system that automatically restructures hypertext networks according to their user browsing behavior. The system applies link weights to the hypertext networks and updates these weights according to the learning rules. The learning rules are based on how often a particular hyperlink is being traversed and operate on strictly local information of link traversals. Changes in network structure are fed back to users by dynamic link ordering according to descending link weight. This approach is used collaborative filtering and navigation support techniques. The system has been investigation to be able to structure random hypertext networks into valid representations of their user browsing preferences in experiments.