• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.146-153
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• 2007

The detailed chemistry with reaction mechanism of GRI 2.11, which consists of 49 species and 279 elementary reactions, have been numerically conducted to investigate the flame structure and NO emission characteristics in a non-premixed counterflow flame of blended fuel of $H_2/CO_2/Ar$. The combination of $H_2,\;CO_2$, and Ar as fuel is selected to clearly display the contribution of hydrocarbon products to flame structure and NO emission characteristics due to the breakdown of $CO_2$. Radiative heat loss term is involved to correctly describe the flame dynamics especially at low strain rates. All mechanisms including thermal, $NO_2,\;N_2O$, and Fenimore are also taken into account to separately evaluate the effects of $CO_2$ addition on NO emission characteristics. The increase of added $CO_2$ quantity causes flame temperature to fall since at high strain rates diluent effect is prevailing and at low strain rates the breakdown of $CO_2$ produces relatively populous hydrocarbon products and thus the existence of hydrocarbon products inhibits chain branching. It is also found that the ratio of the contribution by Fenimore mechanism to that by thermal mechanism in the total mole production rate becomes much larger with increase in the $CO_2$ quantity and strain rate, even though the absolute quantity of NO production is deceased. Consequently, as strain rate and $CO_2$ quantity increase, NO production by Fenimore mechanism is remarkably augmented.

• Fashion & Textile Research Journal
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• v.13 no.2
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• pp.279-284
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• 2011

In this study, the process of preparation nonwoven with coated carbon nano fibers (CNFs) /poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite solution is described. The various contents of CNFs/PVDF-HFP composite coated nonwoven were prepared and characterized by morphological, mechanical, and electrical methods. Nonwovens are coated with CNFs/PVDF-HFP composite solution and decreased the pick up ratio with increasing CNFs contents in range from 0% to 16%. In the results of SEM images, it was clear that the CNFs were evenly distributed in coated nonwoven by SEM images, the existence of CNFs in coated nonwoven was confirmed regularly. The mechanical properties of various contents of CNFs/PVDF-HFP coated nonwoven were examined. The tensile linearity and compression linearity increased with increasing CNFs contents. The electrical properties of the CNFs/PVDF-HFP coated nonwoven increased with increasing CNFs contents.

• Environmental and Resource Economics Review
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• v.9 no.5
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• pp.973-997
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• 2000

The carbon tax is one of several measures to reduce the green-house gases emitted from burning the fossil fuels, which has been much discussed internationally. The analyses of the effects of a carbon tax on individual countries have been carried out by applying the computable general equilibrium(CGE) models, especially models with the assumption of non-existence of scale economies. However, the introduction of scale economies to CGE models changes the simulation results drastically. In this paper, two CGE models are used to compute and compare the economic and $CO_2$ reduction effects of a carbon tax, one of with is the model with scale economies and the other is without scale economies. One of main results is that the analysis using the CGE model without scale economies may underestimate the effects of a carbon tax on GDP and reducing the emission of $CO_2$.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.319-321
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• 2012

The flammability limit and the flame instability of nitrogen-diluted LPG fuel was experimentally studied on a co-flow flame configuration. The combustion reaction of nitrogen-diluted hydrocarbon with air could be interpreted as the equivalent reaction of pure fuel with nitrogen-diluted air. Nitrogen-diluted LPG with nitrogen up to 90 % of nitrogen mole fraction in fuel, which is close to the flammability limit, could form a co-flow flame. Various parameters such as laminar or turbulent flame, the existence of diffusion flame with pure fuel, air temperature could affect the limit of flame formation.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1759-1761
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• 2001

In this paper, a co-axial cylinder type ozonizer using silent discharge known as an ozone generation was designed and fabricated. A cooling system was installed to investigate the characteristics of ozone generation in accordance with temperature change of the supplied gas known as an important factor. The characteristics of ozone generation were investigated in accordance with the existence of cooling system and the change of cooling temperature.

• Journal of The Korean Astronomical Society
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• v.40 no.4
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• pp.83-89
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• 2007

A new type of object called "Very Low Luminosity Objects (VeLLOs)" has been discovered by the Spitzer Space Telescope. VeLLOs might be substellar objects forming by accretion. However, some VeLLOs are associated with strong outflows, indicating the previous existence of massive accretion. The thermal history, which significantly affects the chemistry, between substellar objects with a continuous low accretion rate and objects in a quiescent phase after massive accretion (outburst) must be greatly different. In this study, the chemical evolution has been calculated in an episodic accretion model to show that CO and $N_2H^+$ have a relation different from starless cores or Class 0/I objects. Furthermore, the $CO_2$ ice feature at $15.2{\mu}m$ will be a good tracer of the thermal process in VeLLOs.

• Journal of Magnetics
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• v.5 no.4
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• pp.135-138
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• 2000

In order to study the effect of the magnetic anisotropy on the giant magnetoresistance in a Co/Cu multilayered system, the angle dependent magnetoresistance (MR) was measured. The experimental results showed that the maximum MR ratio depends on the angle between the direction of the applied field and the easy axis. The angular modulation of the MR ratio can be explained by the alignments of the two 'effective' magnetization vectors that are bound to their own easy axes. Two maxima observed in MR loops at the second antiferromagnetic maximum are discussed in relation to the magnetic anisotropy, The simulated results under the assumption of the existence of two in-plane easy axes in the sample are compared with the experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11A
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• pp.1013-1020
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• 2008

Cognitive radio(CR) techniques have been considered as a strong solution of frequency scarcity due to the limitation of frequency resource, In this paper, an orthogonal beamforming method is proposed that enables cognitive radio systems to coexist with a primary users' system in the same spectrum and region without causing interference to primary systems. The orthogonal multiple beams for multi-users of CR systems are obtained through the generation of orthogonal subspaces from primary users' channel state information. To increase the sum-rate of the CR systems, the proposed scheme adopts opportunistic radio resource allocation techniques. Simulation results provides that the proposed scheme achieves 2.72bps/Hz, the sum-rate capacity at 20 cognitive users in an area with two antennas at the cognitive radio basestation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.1
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• pp.111-122
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• 2021

With the spread of technology in the 4th Industrial Revolution, the defense industry in South Korea is getting developed into an industrial structure in which high-tech technologies are concentrated. As the importance of defense technology has gradually increased, the government has enacted the Defense Technology Security Act and required to build a protection system for institutions that possess or manage defense technology. In order for the target institution to introduce a protection system, it is necessary to identify the defense technologies that are protected and to ensure systematic data management. In order to cope with this, we derived master data items for data management and analyzed the implementation types of defense technology master data system suitable for the defense industry environments. The derived method identified the defense technology master data, such as primary and secondary master data, and through AHP analysis, Co-existence type was suitable as the target model for the master data management system. We expect that stronger defense technology security policy will be implemented through the defense technology MDM system.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.20-29
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• 2021

With the creation of a multi-platform media environment, contents production flows through convergence are being detected in the broadcasting contents sector, breaking the boundary between each other and breaking away from the rigid atmosphere of the past, when broadcasters were strictly divided or careful to comment on other programs. It is also quite encouraging that the method of collaboration has been done horizontally as a win-win strategy of co-existence and co-existence, not vertically based on one side's recognition or program popularity. Thus, this study noted the establishment of a world view to capture transmedia phenomena that transcend boundaries between each other to adapt and survive the rapidly reshaping media ecosystem at the base of this trend and to maintain the type of convergence and unrivaled value that emerges in various forms in the process. The research targets were selected for 'Usanseul' and 'Pengsoo', which are prominent in these movements and produce significant results at this point, and analyzed and compared to the results.