• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2255-2259
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• 2012

Aggregation of titania nanotubes (TNTs) fabricated by hydrothermal method were calcined in air and dry nitrogen; Changes in morphology and crystallinity of the nanotubes were studied by means of TEM, EDX, and XPS. EDX patterns and XPS spectra proved that there were a certain densities of oxygen vacancies in TNTs annealed in $N_2$. The photocatalysis experiments revealed TNTs/$N_2$ possesses significantly higher photocatalytic efficiency than TNTs annealed in dry air to degrade methylene blue. The correlation between oxygen vacancies and photocatalytic property may be attributed to: 1) oxygen vacancies might have affected results on water molecules adsorption and increase of the hydroxyl concentration; and 2) oxygen vacancies resulted in some changes in electronic structure of TNTs/$N_2$ aggregation and Fermi level extends into the conducting band.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.685-692
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• 2019

Smart grid enables efficient power management by allowing real-time awareness of electricity flows through two-way communication. Despite its various advantages, threats to user privacy caused by frequent meter reading hinder prosperous deployment of smart grid. In this paper, we propose a privacy-preserving aggregation method exploiting fully homomorphic encryption (FHE). Specifically, it achieves privacy-preserving fine-grained aggregation of electricity usage for smart grid customers in multiple electrical source environments, while further enhancing efficiency through SIMD-style operations simultaneously. Analysis of our scheme demonstrates the suitability in next-generation smart grid environment where the customers select and use a variety of power sources and systematic metering and control are enabled.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1487-1491
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• 2008

Detailed knowledge on the motion of blood cells flowing in micro-channels under simple shear flow and the influence of blood flow is essential to provide a better understanding on the blood rheological properties and blood cell aggregation. The microscopic behavior of red blood cell (RBCs) is numerically investigated using a fluid-structure interaction (FSI) method based on the Arbitrary-Lagrangian-Eulerian (ALE) approach and the dynamic mesh method (smoothing and remeshing) in FLUENT (ANSYS Inc., USA). The employed FSI method could be applied to the motions and deformations of a single blood cell and multiple blood cells, and the primary thrombogenesis caused by platelet aggregation. It is expected that, combined with a sophisticated large-scale computational technique, the simulation method will be useful for understanding the overall properties of blood flow from blood cellular level (microscopic) to the resulting rheological properties of blood as a mass (macroscopic).

• Asian Journal of Atmospheric Environment
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• v.9 no.2
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• pp.101-113
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• 2015

Air quality index (AQI) or air pollution index (API) is commonly used to report the level of severity of air pollution to public. A number of methods were developed in the past by various researchers/environmental agencies for determination of AQI or API but there is no universally accepted method exists, which is appropriate for all situations. Different method uses different aggregation function in calculating AQI or API and also considers different types and numbers of pollutants. The intended uses of AQI or API are to identify the poor air quality zones and public reporting for severity of exposure of poor air quality. Most of the AQI or API indices can be broadly classify as single pollutant index or multi-pollutant index with different aggregation method. Every indexing method has its own characteristic strengths and weaknesses that affect its suitability for particular applications. This paper attempt to present a review of all the major air quality indices developed worldwide.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.209-215
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• 2010

In an asymmetrical speed channel environment like asymmetric digital subscriber line, the up-link bandwidth is normally smaller than the down-link bandwidth, which will lead to extremely low utilization of down-link bandwidth when current P2P video transmission is applied. To overcome this, a new fast P2P video transmission method applied in an asymmetrical speed channel environment is proposed in this paper. On the basis of the many-to-one concept, the proposed method uses a new multipeer aggregation technique to enhance the utilization of down-link bandwidth. In addition, an adaptive peer assignment algorithm is also introduced in order to minimize the overall transmission time. Experimental results show that by using our proposed method, the utilization of down-link bandwidth is significantly improved, and the overall transmission time is greatly reduced.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.75-80
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• 1996

Fuzzy approaches used to solve MONLP(Multiobjective Nonlinear Programming Problem) are based on the max-min method of fuzzy sets theory However, since the min operator noncompensatory, these approaches can not guarentee an efficient solution to the problem. In this paper, we presents an algorithm for finding the aggregation operator to find efficient solution. In particular, our presented algorithm is guarentee an efficient solution. On the basis of proposed algorithm, an illustrative numerical example is presented.

• Korean Journal of Mathematics
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• v.28 no.2
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• pp.343-359
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• 2020

The paper aim is to resolve the issue of ranking to the fuzzy numbers in decision analysis, artificial intelligence and optimization. In the literature lot of ideologies have been established for ranking to the fuzzy numbers, that ideologies have some restrictions and limitations. In this paper, we proposed a method based on cubic picture fuzzy information's, for ranking to defeat the existing restrictions. Further introduced some cubic picture fuzzy algebraic and cubic picture fuzzy algebraic^* aggregated operators for aggregated the information. Finally, a multi-attribute decision making problem is assumed as a practical application to establish the appropriateness and suitability of the proposed ranking approach.

• Structural Engineering and Mechanics
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• v.57 no.3
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• pp.441-456
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• 2016

This work reports wave propagation in the nanocomposite cylinders that reinforced by straight single-walled carbon nanotubes based on a mesh-free method. Moving least square shape functions have been used for approximation of displacement field in weak form of motion equation. The straight carbon nanotubes (CNTs) are assumed to be oriented in specific or random directions or locally aggregated into some clusters. In this simulation, an axisymmetric model is used and also the volume fractions of the CNTs and clusters are assumed to be functionally graded along the thickness. So, material properties of the carbon nanotube reinforced composite cylinders are variable and estimated based on the Eshelby-Mori-Tanaka approach. The effects of orientation, aggregation and volume fractions of the functionally graded clusters and CNTs on dynamic behavior of nanocomposite cylinders are studied. This study results show that orientation and aggregation of CNTs have significant effects on the effective stiffness and dynamic behaviors.

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.116-120
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• 2000

Aspirin has been widely used as analgesic and anti-inflammatory drug. Recently, it was elucidated that aspirin have anti-coaggregatory effect in low dose. This study was carried out to investigate the synthesis of aspirin derivatives from aspirin and aromatic compound of antioxidant and its biological activities. Synthesis of aspirin derivatives was prepared by esterification in the presence of 1, 1-carbonyldiimidazole. Biological activities was examined using effect of anti-coagulant on bleeding time, effect of antioxidant and effect of anti-platelet aggregation. As a result, SJ-101 showed strong antioxidative activity and anti-coagulant activity among four compounds. Anti-platelet aggregation of SJ-101 was examined by collagen, ADP, PAF method. SJ-101 exhibited more stronger activity to aspirin at collagen aggregation reaction. These finding demonstrates that SJ-101 is usefull as care drug of aging and old-disease because of its has antioxidant activity, anti-coagulant activity and anti-platelet activity.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.1
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• pp.6-12
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• 2001

This paper deals with the development of dynamic equivalents of the Korea Electric Corporation (KEPCO) systems. The weak coupling method is chosen for the most suitable coherency identification to represent the characteristics of the KEPCO system by the dynamic characteristic comparison of several coherency identification methods. Also, this paper shows the detail aggregation of generator groups makes a better representation of the dynamic and static characteristics of the original system than the classical aggregation. The simulation results of the developed KEPCO equivalent system are presented in comparison with the original system to illustrate the validity of the equivalent system are presented in comparison with the original system to illustrate the validity of the equivalent system.