• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.804-808
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• 2005

A pneumatic tire is made up of many flexible filaments of high modulus cord of natural textile, synthetic polymer, glass fiber, or fine hard drawn steel embedded in and bonded to a matrix of low modulus polymetric material. Adhesion property of these materials is very important in tire durability safety because belt-leaving-belt tread separation reduces the ability of a driver to control a vehicle, whether or not the separation is accompanied by a loss of air. In this study adhesion test of carcass-belt-tread is conducted on material properties of 5 PCR tire model, which are on sale in domestic market and analyzed adhesion properties. For those tire models FMVSS 109 indoor high speed durability test is conducted to analyze the correlation between adhesion force and high speed performance of tires and found the correlation between the two test results.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.171-182
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• 2000

For the last five years, data mining has drawn much attention by researchers and practitioners because of its many applicable domains. This article presents an adaptive decision tree algorithm for dynamically reasoning machine failure cause out of real-time, large-scale machine status database. Among many data mining methods, intelligent decision tree building algorithm is especially of interest in the sense that it enables the automatic generation of decision rules from the tree, facilitating the construction of expert system. On the basis of experiment using semiconductor etching machine, it has been verified that our model outperforms previously proposed decision tree models.

• Journal of Information Technology Services
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• v.9 no.1
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• pp.1-25
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• 2010

Many organizations are facing larger and more frequent changes in the current economic and managerial environment. And what is more, change is supposed to be a business as usual. Considering the importance of change management process and the organizational competency to rapidly and successfully change, in this study the components of change management maturity(CMM) was selected such as the leadership, communication, resistance, people culture factor, methodology, functional group, and change review. And information system performance affected by CMM is confined to the efficiency and effectiveness of information systems. Some results from the verification of research hypotheses and the analysis of the most appropriate model was drawn out. The result of this study can be applied to all organizations which plan to manage more successful change and implement more effective information systems.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.291-294
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• 2005

Recently, the usage of aluminum alloy is rapidly increasing in automobile industry to achieve weight reduction for fuel efficiency. However, design of forming process of aluminum is more difficult than steel because of poor formability and severe springback. Since applications of finite element analysis for the design of sheet metal forming process are actively performed, it is required to conduct proper consideration of aluminum material behavior. In this study, a plane stress yield function Yld2000(Yoon et al., 2000), proven to describe well the anisotropic behavior of aluminum alloy, is implemented for FE analysis. One element test is considered to verify the validity of implementation of Yld2000 model. In addition, cylindrical cup drawing test is performed to verify earing shape of a drawn cup.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.4
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• pp.2063-2077
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• 1970

The Purpose of this study is to give the hydrologically basic data for the development of water resources in Korea and a quantity of daily average precipitation and its frequency in a year are investigated to study the presumption which is affected to river flow. Characteristics of precipitation is poor as source of water resources compared with its efficiency. So, because of such characteristics of precipitation, river flow also is in harmony and distribution of river flow comes to the result of irregularity, that is, range of river coefficiet between the quantity of maximum river flow and others river flow is big, and it is insufficient as source of water resources. Yearly river flow being expressed by daily unit indicates the ratio(%) of distribution to total yearly river flow, and the model of hydrograph is drawn up. The gives the basis to make yearly water balance sheet. This study is not completed, yet but in forth-coming days, the water will try continuously to give more correct basis for the development of water resources according to a great deal of data.

• Proceedings of the Korean System Dynamics Society
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• 2000.02a
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• pp.29-37
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• 2000

In this paper an attempt is made to understand contribution factors in the field of electronic commerce(EC). To do that, we adopt and modify an existing commerce model. The following two major conclusions are drawn from our simulation. Most of all, the diminution of information delay introduce monotonous growth rather than fluctuation of EC market. The stable increase of revenue or market scale makes us decide the employment or capacity scale quickly. Second, for favorable and continuous evolution of EC, utilization system of electronic money should be established steadily. The following findings strongly support our claim: We found full oscillation of EC market when electronic money system didn't established well. On the contrary, if electronic money system could provide fast cash flow and fully trustful function, decisions of company or consumer would be executed promptly.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.113-121
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• 2010

Granular Compaction Pile are commonly used to improve bearing capacity and reduce settlements of soft soil in coastal and lowland areas. In this paper, through the field load test results of straight granular compaction piles and taper granular compaction piles, material properties of ground and GCP for numerical analysis were drawn and numerical model was established. In the numerical analysis of taper granular compaction piles with 3 different sections, a optimum dimension of taper granular compaction pile was considered at the side of settlement.

• International Journal of Human Ecology
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• v.9 no.2
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• pp.77-92
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• 2008

This study investigates the characteristics of young debtors at risk of repayment problems. A cumulative logistic model is used in order to examine the effects of explanatory variables on the probability for young adults to pay off debt obligations. The following conclusions can be drawn from the results. First, the high indebtedness of young debtors increases the probability of payment delinquency whereas high income by young debtors decreases the probability. Second, financial emergencies that young debtors experienced and payment delinquency are positively related. Finally, financial resources for emergency needs reduced the probability of being delinquency on payment of household debt.

• International Journal of Reliability and Applications
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• v.11 no.2
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• pp.123-138
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• 2010

This paper investigates a mathematical model of a system composed of two non-identical unit parallel system with common-cause failure, critical human error, non-critical human error, preventive maintenance and two type of repair, i.e. cheaper and costlier. This system goes for preventive maintenance at random epochs. We assume that the failure, repair and maintenance times are independent random variables. The failure rates, repair rates and preventive maintenance rate are constant for each unit. The system is analyzed by using the graphical evaluation and review technique (GERT) to obtain various related measures and we study the effect of the preventive maintenance preventive maintenance on the system performance. Certain important results have been derived as special cases. The plots for the mean time to system failure and the steady-state availability A(${\infty}$) of the system are drawn for different parametric values.

• Structural Engineering and Mechanics
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• v.38 no.6
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• pp.767-802
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• 2011

Developers of new finite elements or nonlinear solution techniques rely on discriminative benchmark tests drawn from the literature to assess the advantages and drawbacks of new formulations. Buckling benchmark tests provide a rigorous evaluation of finite elements applied to thin structures, and a complete and detailed set of reference results would therefore prove very useful in carrying out such evaluations. Results are usually presented in the form of load-deflection curves that developers must reconstruct by extracting the points, a procedure which is often tedious and inaccurate. Moreover the curves are usually given without accompanying information such as the calculation time or number of iterations it took for the model to converge, even though this type of data is equally important in practice. This paper presents ten different limit-point buckling benchmark tests, and provides for each one the reference load-deflection curve, all the points necessary to recreate the curve in tabulated form, analysis data such as calculation time, number of iterations and increments, and all of the inputs used to obtain these results.