• East Asian mathematical journal
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• v.32 no.3
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• pp.387-397
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• 2016

This paper is concerned with the optimal control problem for some reaction diusion model. That is, we show the existence of the global weak solution for the Field-Noyes model. We also show the existence of the optimal control.

• Proceedings of the KSMRM Conference
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• 2006.11a
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• pp.33-33
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• 2006

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.3
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• pp.222-230
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• 2016

As the global game market has been more competitive, it has been important to analyze success factors of game products. In this paper, we applied a Bass Diffusion Model and Clustering Analysis to identify the success factors of games based on data from Steam, an international game platform. By using a diffusion model, we first categorize game products into two groups : successful and unsuccessful games. Then, each group has been analyzed by using clustering analysis based on product features such as genres, price, and minimum system requirements. As a result, success factors of a game have been identified. The result shows that customers in game industry appreciate sophisticated contents. Unlike many other industries, price is not considered as a key success factor in the game industry. Expecially, advanced independent video games (commonly referred to as indie games) with killer contents show competitiveness in the market.

• The Journal of Information Systems
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• v.9 no.1
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• pp.61-86
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• 2000

CALS(Commerce At Light Speed) which originated in the early 1980's in the military sector is now an integral component in our global strategy to further heighten competitiveness. Through integration and streamlining of production, distribution, technical information and management, CALS will certainly lead the world out of these economically challenging times and into new global prosperity. However, not much effort have been focused on the development and diffusion issues of component technologies such as ERP/SCM(Enterprise Resourses Planning/supply Chain Management), PDM(Product Data Management), and BPR(Business Process Reengineering) related with the CALS in electronic industry. Therefore, the purpose of this study is to analyze the advancing status and to present suggestions for the development of the CALS in electronic industry. In order to achieve the purpose, the case study has been conducted using the questionaries on the end-users and the interviews on the managers in the CALS area. The case study cover 57 users of the CALS for the three outstanding electronics(L, S, and D Electronics) in Korea. The questionaries include five success measures and eleven diffusion factors for the component technologies such as ERP/SCM, PDM, and BPR. In summary, the CALS will serve as the bases for exciting corporated innovations and the common business framework which facilitates the realization of Virtual Enterprise and Electronic Commerce in the 21st century.

• Membrane Journal
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• v.26 no.3
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• pp.187-196
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• 2016

Pressure-assisted forward osmosis (PAFO) process has recently been under spotlight for its potential to improve forward osmosis (FO) process performance by applying low hydraulic pressure on the feed side. Structure parameter, one of the governing factors in estimating water flux and solute flux across FO membranes in the solution-diffusion model (S-D model), determines solute resistivity in FO and PAFO processes. This study aims to estimate the trend of structure parameter change with respect to varying additional hydraulic pressure condition in PAFO.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.124-130
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• 2004

The structure of the nonpremixed methane-air counterflow flames in microgravity was investigated by axisymmetric simulation with Fire Dynamics Simulator (FDS) to evaluate the numerical method and to see the effects of strain rate and fuel concentration on the diffusion flame structure in microgravity. Results of FDS for the methane mole fractions, $X_m$=20, 50, and 80% in the fuel stream, and the global strain rates $a_g$=20, 50, and $90s^{-1}$ for each methane mole fraction were compared with those of OPPDIF, an one-dimensional flamelet code. There was good agreement in the temperature and axial velocity profiles between the axisymmetric and one-dimensional computations. It was shown that FDS is applicable to the counterflow flames in a wide range of strain rate and fuel concentration by predicting accurately the flame thickness, flame positions and stagnation points.

• Advances in concrete construction
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• v.7 no.1
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• pp.11-22
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• 2019

A comprehensive assessing approach for durability of reinforced concrete structures dealing with the corrosion process of rebar subjected to the attack of aggressive agent from environment was proposed in this paper. Corrosion of rebar was suggested in the form of combination of global corrosion and pitting. Firstly, for the purposed of considering the influence of rebar's radius, a type of Plane Corrosion Model (PCM) based on uniform corrosion of rebar was introduced. By means of FE simulation approach, global corrosion process of rebar regarding PCM and LCM (Linear Corrosion Model) was regressed and compared according to the data from Laboratoire $Mat{\acute{e}}riaux$ et $Durabilit{\acute{e}}$ des Constructions (LMDC). Secondly, pitting factor model of rebar in general descend law with corrosion degree was introduced in terms of existing experimental data. Finally, with the comprehensive numerical simulation, the durability of an existing arch bridge was studied in depth in deterministic way, including diffusion process and sectional strength of typical cross section of arch, crossbeam and deck slab. Evolution of structural capacity considering life-cycle rehabilitation strategy indicated the degradation law of durability of reinforced arch bridges.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.265-276
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• 2008

Transient global amnesia(TGA) is a clinical syndrome characterized by sudden, temporary dysfunction of anterograde and recent retrograde memory without other neurologic deficits. Different hypotheses have been considered for its etiology, but it still remains obscure. Recently the diffusion-weighted magnetic resonance imaging(DWI), has been considered as the sensitive tool to detect small punctate hyperintense lesions in the hippocampus in transient global amnesia(TGA). We report two TGA cases, all of them answers to TGA clinical criteria, and one of them showed two dot like high signal intense foci in Rt. hippocampus on DWI.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.47-58
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• 2000

The relationship among the flame radiation, NOx emissions, residence time, and global strain rate are examined for turbulent non-premixed jet flames with wide variations in coaxial air conditions. Measurements of NOx emission, flame geometry and flame radiation were made to explain the NOx emission scaling based on global parameters such as flame residence time, global strain rate, and radiant fraction. The overall 1/2-power scaling is observed in coaxial air flames, irrespective of coaxial air conditions, but the degree of deviation from the l/2-slope curve in each case differs from one another. From the comparison between the results of pure hydrogen flames and those of helium diluted hydrogen flames, it is observed that flame radiation plays a significant role in pure hydrogen flames with coaxial air and the deviation from 1/2-power scaling may be explained in two reasons: the difference in the flame radiation and the difference in jet similarity in coaxial air flames. From the radiation measurements, more detailed explanations on these deviations were suggested.

• Asian review of World Histories
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• v.3 no.2
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• pp.235-253
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• 2015

It has been about twenty years since world history in a new sense was introduced to Korean academia. At first, it was the educators who showed a lot of interest in world history. But, before long, world/global history came to exert an important influence on history research and teaching in Korea. Even though certain unfavorable conditions still exist, the need for world/global history is growing and a number of academic institutes and scholars are putting in a great deal of effort to advance it in Korea. Here, we examine the changing meanings of world history on the basis of the history of concepts and provide a general idea of its introduction and diffusion in historiography and history education in Korea.