• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.318-321
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• 2003

In order to generate the extrusion die surface of non-symmetric H- and U-shaped sections, an automatic surface construction method based on B-spline surface and scalar field theory is proposed in this study. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u- and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.197-200
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• 2003

An automatic surface construction method based on B-spline surface and scalar field theory is proposed to generate the extrusion die surface of complicated sections in this paper. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u- and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.195-202
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• 2002

The primary objective of Supply Chain Management (SCM) is to optimize the cash, material and information flow for satisfying customer demands through coordinating the relationship between Supply Chain components such as suppliers, manufacturers, and inventories, etc. By Supply Chain Planning (SCP), operation tasks or goals, should be done in specific due date, are ordered to each SC component for achieving such objective. However, the achievement for operation tasks or goals is affected by uncertainties in SC. In general, reliability theory Is explained as the probability that a product or system will perform its specified function under prescribed conditions without failure for a specified period of time. Therefore, the reliability of SC can be defined as the probability that SC will satisfy customer demands until the specific due date. In this paper, a basic framework to evaluate reliability is respectively proposed as supply chain components, and then a overall framework to estimate the reliability for SC is also proposed.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.31-34
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• 1991

This paper presents a voltage-reactive power control algorithm considering fuzziness. In this paper, a coordination technique based on fuzzy set theory is applied for system loss-voltage compromises. Here, we introduce membership functions to measure the adaptability of real power loss of transmission line and the deviation of load bus voltage from the constraints. Then the optimization of problem is solved by a linear programming technique considering the fuzzy set theory. The objective is a degree of satisfaction about the fuzzy decision-making function. The effectiveness of this algorithm has been verified by testing on sample systems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.619-622
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• 2005

Purpose of this study is to investigate the size-dependent mechanical properties in micron scale medium. Theories such as the couple stress theory and strain gradient theory explain that the deformation in the micron scale is dependent upon the size of the medium. Specimens of the cantilever type, bridge type and paddle type beam that have thickness of 900, 1000 and 1200 nm and width of 10, 20, 30 and $50{\mu}m$ were fabricated by the MEMS technique. We carried out the bending and torsion test to measure the mechanical properties such as the young's modulus, yield strength and torsional rigidity using the AFM(Atomic Force Microscopy).

• Computers and Concrete
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• v.18 no.1
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• pp.69-97
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• 2016

Performance-based remaining life assessment of reinforced concrete bridge girders, subject to chloride-induced corrosion of reinforcement, is addressed in this paper. Towards this, a methodology that takes into consideration the human judgmental aspects in expert decision making regarding condition state assessment is proposed. The condition of the bridge girder is specified by the assignment of a condition state from a set of predefined condition states, considering both serviceability- and ultimate- limit states, and, the performance of the bridge girder is described using performability measure. A non-homogeneous Markov chain is used for modelling the stochastic evolution of condition state of the bridge girder with time. The thinking process of the expert in condition state assessment is modelled within a probabilistic framework using Brunswikian theory and probabilistic mental models. The remaining life is determined as the time over which the performance of the girder is above the required performance level. The usefulness of the methodology is illustrated through the remaining life assessment of a reinforced concrete T-beam bridge girder.

• Knowledge Management Research
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• v.12 no.5
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• pp.41-57
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• 2011

Social commerce is simply a kind of e-commerce by adopting SNS(Social networking service). It has been spread as SNS is widely used all over the world. In this situation, companies attempt to make the best use of social commerce to understand its advertising effect and to sell more products and/or services they provide. Although social commerce is a recent trend in Korea, it is necessary for companies to find a way to effectively adopt and utilize the social commence. Therefore, the focus of this study is to identify critical success factors for social shopping. We generated 40 items to measure 8 constructs. Using data collected from 300 respondents who have experienced both SNS and social shopping, we analyzed our model and its hypotheses. The analysis result shows that social shopping customers don't use SNS to get information when they purchase products and/or services in social shopping web sites.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.51-58
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• 2011

Simulation plays a pivotal role in the analysis of complex systems. In this study, a job shop manufacturing system has been analyzed through DBR (Drum-buffer-rope) simulation. Specific attention has been put to examine the rate of due-date achievement. We first derived key factors affecting the system performance. We then developed ARENA simulation program based on DBR of TOC (Theory of Constraints) concepts. Based on the performance measure, factors, and experimental design, we obtained the results. We have drawn meaningful results through examination of the results. The results obtained from this study may provide a good base for practical applications.

• Korean Journal of Child Studies
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• v.22 no.4
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• pp.315-330
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• 2001

The purpose of this study is to research for the educational method developing morality of the preschool children. For this purpose, the embodiment method based on Confucianism was conceptualized and compared with the existing methods of instruction. The research was conducted by dividing into 3 groups such as embodiment group, discussion group and usual group with 161 subjects of 4~5 years old preschool children. Six week program was composed from "Yangjungpyon(養正篇)" and was compared to the curriculum of kindergarten and primary school as the educational content. To measure the effectiveness of the Confucian method, the Test of Basic Life Habituation and Autonomy Rating Scale were used. The result showed that the embodiment group which followed the present method was more effective than the other two groups of existing usual methods in both ages.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.573-578
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• 2001

This research proposes a generalized local feature structure named "LSG(Local Surface Group) for model-based 3D object recognition". An LSG consists of a surface and its immediately adjacent surface that are simultaneously visible for a given viewpoint. That is, LSG is not a simple feature but a viewpoint-dependent feature structure that contains several attributes such as surface type. color, area, radius, and simultaneously adjacent surface. In addition, we have developed a new method based on Bayesian theory that computes a measure of how distinct an LSG is compared to other LSGs for the purpose of object recognition. We have experimented the proposed methods on an object databaed composed of twenty 3d object. The experimental results show that LSG and the Bayesian computing method can be successfully employed to achieve rapid 3D object recognition.