• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.137-138
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• 2012

The two-equation soot model based on the transient laminar flamelet model is implemented for soot formation of laminar non-premixed $CH_4/Air$ flame with detailed chemical reaction mechanism and complex thermodynamic properties. The soot model represents nucleation, growth and oxidation with gas-phase chemistry. This represented unsteady flamelet soot model has been tested and compared using well verified reference calculation result obtained solving the Full Transport Equations method.

• Journal of the Korea Society for Simulation
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• v.4 no.1
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• pp.59-73
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• 1995

Local area networks(LANs) recently become so large that they exceed their architected limits and users on different LANs may need to talk each other. This trend has led to a growth in the practice of interconnecting many heterogeneous LANs. In this paper, we proposed a method to interconnect Ethernets and token rings, which are widely used today, through a fast FDDI network. We also developed a simulation tool to evaluate the performances of the interconnected networks. We used a simulation language SLAM II for modeling and OSF/MOTIF X-window for user interface. The developed tool can be used to make a decision which interconnecting method is suitable for a given environment before interconnecting many heterogeneous LANs.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1073-1078
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• 2009

A kinetic model for the oxidation of a $UO_2$ pellet to $U_3O_8$ powder has been suggested by considering the mass transfer and the diffusion of oxygen molecules. The kinetic parameters were estimated by a fitting of the experimental data. The activation energies for the chemical reaction and the product layer diffusion were calculated from the kinetic model. The oxidation conversion of a $UO_2$ pellet was simulated at various operating conditions. The suggested model explains the oxidation behavior of $UO_2$ well.

• Water Engineering Research
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• v.5 no.2
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• pp.81-99
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• 2004

Long term streamflow regime under virtual climate change scenario was examined. Rainfall forecast simulation of the Canadian Global Coupled Model (CGCM2) of the Canadian Climate Center for modeling and analysis for the IPCC SRES B2 scenario was used for analysis. The B2 scenario envisions slower population growth (10.4 billion by 2010) with a more rapidly evolving economy and more emphasis on environmental protection. The relatively large scale of GCM hinders the accurate computation of the important streamflow characteristics such as the peak flow rate and lag time, etc. The GCM rainfall with more than 100km scale was downscaled to 2km-scale using the space-time stochastic random cascade model. The HEC-HMS was used for distributed hydrologic model which can take the grid rainfall as input data. The result illustrates that the annual variation of the total runoff and the peak flow can be much greater than rainfall variation, which means actual impact of rainfall variation for the available water resources can be much greater than the extent of the rainfall variation.

• Applied Science and Convergence Technology
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• v.27 no.1
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• pp.14-18
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• 2018

In order to understand the mechanism of the synthesis of particles using a plasma torch, it is necessary to understand the reaction mechanisms using a computer simulation. In this study, we have developed a simulation method to combine the Lagrangian scheme to follow microparticles and a nodal method to treat nanoparticles categorized with different particle sizes. The Lagrangian scheme includes the Coulomb force which affects the dynamics of larger particles. In contrast, the nodal method is adequate for the nanoparticles because the charge effect is negligible for nanoparticles but the number of nanoparticles is much larger than that of microparticles. This method is helpful to understand the dynamics and growth mechanism of micro- and nano-powder mixture observed in the experiment.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.39-42
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• 2004

In the present paper, a novel systematic method using the 2-D hybrid special finite elements containing an edge crack is employed to study the fracture behaviors of laser beam spot-welds in automotive structures. 2-D hybrid special finite elements each containing an edge crack can assure the high precision especially in the vicinity of crack tips and give a better description of its singularity with only one hybrid element surrounding one crack. Therefore, the numerical modeling of the laser beam spot-welds can be greatly simplified. Some numerical examples are provided to demonstrate the validity and versatility of the proposed method. All the lap-shear, lap-tension and angle clip specimens are analyzed and some useful fracture parameters (such as stress intensity factors, the initial direction of crack growth) are obtained simultaneously.

• International Journal of Reliability and Applications
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• v.7 no.1
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• pp.71-77
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• 2006

The market for second hand products has been growing for a variety of reasons (e.g., new products appearing at a faster rate and the expected life of products increasing due to rapid advances in technology). The demand for warranties for second-hand products has been growing along with the growth of the market for second-hand products. Warranty for new products (consumer durables, industrial and commercial, and specialized defense products) has received a lot of attention. In contrast, warranties for second-hand product have received very little attention. Often, dealers of second-hand product such as cars offer 2D-warranties (Year and Kilometers). The expected warranty cost associated with a second-hand product for 2D-Policies is a function of the age of the item and its usage (as it affects failures over the warranty period), the warranty terms and the servicing strategy used by the dealer. This paper deals with development of models for warranty cost analysis along with the decision on sale price and warranty cover for 2D-Warranty policies associated with sale of second-hand products.

• The Journal of Information Systems
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• v.18 no.3
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• pp.327-349
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• 2009

Traditional keyword-based searching methods suffer from low accuracy and high complexity due to the rapid growth in the amount of information. Accordingly, many researchers attempt to implement a so-called semantic search which is based on the semantics of the user's query. Semantic information can be described using a semantic modeling language, such as Topic Map. In this paper, we propose a new method to map a topic map to a traditional Relational Database (RDB) without any information loss. Although there have been a few attempts to map topic maps to RDB, they have paid scant attention to handling multi-role topics. In this paper, we propose a new storage structure to map multi-role topics to traditional RDB. The proposed structure consists of a mapping table, role tables, and content tables. Additionally, we devise a query translator to convert a user's query to one appropriate to the proposed structure.

• Journal of Information Technology Applications and Management
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• v.17 no.3
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• pp.71-82
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• 2010

This study is to present effective ways of IT adoption as a new growth engine for vitalizing service industry. The paper identifies key success factors of IT adoption and analyzes empirically its' impact on user satisfaction. Additional analysis of control effect by company sizes is conducted. For data sampling, among 1590 companies in IT systems, equipment, and software, 1570 companies participated and total 2,000 questionnaires were collected. In order to analyze main effect analysis and control effect, Structural Equation Modeling method was applied. The result show that there are significant effect between key success factors and user satisfaction. Based on the result, the paper suggests effective way of IT adoption according to company sizes.

• Journal of Environmental Science International
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• v.21 no.4
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• pp.391-399
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• 2012

This study proposes lighting simulation approach to assess lighting quality on motor ways and walk ways considering each type of form and growth of roadside trees. Simulation approach to assess quality of lighting is frequently used for lighting design which guarantees secure of drivers and pedestrians during the night time. But, road side trees which have diverse benefits for citizens acts on obstacles during night time needs lighting. The results of this study shows a possible way for tuning the aims of both lighting and road side tree. It will be possible to develop harmonic design standards for road way lighting if further study achieved based on the result of this study.