• Transactions of Materials Processing
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• v.17 no.7
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• pp.501-506
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• 2008

In this study, a forming magnesium alloy circular cup was simulated accounting for heat transfer at elevated temperatures. In order to predict the failure of magnesium alloy sheet during simulation, the forming limit diagram, which is used in sheet metal forming analysis to determine the criterion for failure, was investigated. For the failure prediction in the simulation accounting for heat transfer, the forming limit diagram for a temperature the same as the temperature of the blank element was used. The result of the simulation showed that the drawn depth increases with the increase of the die-holder temperature, and is in accord with the experimental results above the die-holder temperature of $150^{\circ}C$. The forming limit diagram provided a good guide for the failure prediction of warm forming simulation accounting for heat transfer. In addition, the effect of the tool shoulder radius on the drawn depth at various tool temperatures is verified using the simulation conditions which agreed with the experimental results.

• Structural Engineering and Mechanics
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• v.46 no.5
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• pp.629-644
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• 2013

This paper concerns about the raking damages on the ultimate residual hull girder strength of bulk carriers by applying the modified R-D diagram (advanced method). The limited raking damage scenarios, based on the IMO's probability density function of grounding accidents, were carried out by using sampling technique. Recently, innovative method for the evaluation of the structural condition assessment, which covers the residual strength and damage index diagram (R-D diagram), was proposed by Paik et al. (2012). This concept is applied in the present study and modified R-D diagram, which can be considered vessel size effect, is then proposed. Four different types of bulk carrier structures, i.e., Handysize (37K), Supramax (57K), Kamsarmax (82K) and Capesize (181K) by Common Structural Rule (CSR), were applied to draw the general tendency. The ALPS/HULL, intelligent supersize finite element method, was employed for the ultimate longitudinal strength analysis. The obtained empirical formulas will be useful for the condition assessment of bulk carrier structures. It can also cover different sizes of the bulk carriers in terms of ultimate longitudinal strength. Important insights and findings with useful guidelines developed in this study are summarized.

• Communications of the Korean Mathematical Society
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• v.27 no.4
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• pp.815-834
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• 2012

In this paper, we characterize surgery presentations for $\mathbb{Z}$-homology 3-spheres and $\mathbb{Z}/2\mathbb{Z}$-homology 3-spheres obtained from $S^3$ by Dehn surgery along a knot or link which admits an even net diagram and show that the Casson invariant for $\mathbb{Z}$-homology spheres and the ${\mu}$-invariant for $\mathbb{Z}/2\mathbb{Z}$-homology spheres can be directly read from the net diagram. We also construct oriented 4-manifolds bounding such homology spheres and find their some properties.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.48-52
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• 2002

The fault analysis of the CNC machine tool which is controlled sequentially by PLC is generally based on ladder diagram. When machine tool has faults, it takes a lot of operator's experiences and times to identify logical relationship because ladder diagram is a step structured language. Therefore the technologies of finding out fault reasons automatically is necessary. In this paper, the SFG(Switching Function Generator) system is developed to analysis fault reasons correctly. The SF(Switching Function) and SSF(Step Switching Function) generated from SFG based on ladder diagram are experimented to identify the performance of SFG.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.939-943
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• 2001

PLC(programmable Logic Controller)s essential components of modern automation systems encompassing almost every industry. Ladder Diagrams (LD) have been widely used in the design of such PLC since the LD is suitable for the modeling of the sequential control system. However, the synthesis of LD itself mainly depends on the experience of the industrial engineer, which may results in unstructured or inflexible design. Hence, in this paper, we propose a ladder diagram conversion algorithm which systematically produces LDs for PLCs based on discrete event models to enhance the structured and flexible design mechanism.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.112-114
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• 2003

In order to survive in today's competitive world, understanding the business process and how it works can be a key to success. Visualization improves understandability of business process for developers, and accompanies modeling. There are two modeling methods that are often used in the industry - standard BPMN (Business Process Modeling Notation) and UML activity diagram. This paper shows whether the activity graph of UML 2.0 draft can support business process modeling or not through comparing it with the BPMN features.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.179-184
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• 2006

many corporation introduce information system by method to maximize profit and to reduce expense within flood of information along with development of Information Technology. In this paper, construed AS-IS using UML that is an object intention methodology design tool via process of TO-BE process model design and so on to base Use Case diagram, sequence diagram, component diagram make out that do and this is Microsoft's .NET And wished to raise reusability of component and development productivity of software as that embody smaller enterprise type business administration system that .NET-based relationship extension is possible.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.102-107
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• 2005

All concrete structure in agricultural improvement project must satisfied durability, serviceability, safety. It is important for structure that satisfied these natures to good quality at design and construction step, and must continuous maintenance. Most of the concrete structures is construct at winter season, is contacted with water, has various type and sporadic in wide area. The objective of this study is to make the Concrete-Quality-Control diagram for agricultural infrastructure project using GIS. And, analyze the diagram with external factor(terrain, stream, economic etc.) to know the factor of concrete quality control.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.246-251
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• 1998

차세대원전을 위한 새로운 운전여유도 평가체제를 정립하였다. 본 연구에서 개발된 운전여유도 평가체제는 노심감시 및 보호체제는 그대로 유지하되 부하추종운전시 운전여유도를 만족하는 운전허용범위를 P-ASI Diagram으로 나타내는 것이다. 새로운 운전여유도 평가 방법을 사용하여 Mode K 기법에 의한 차세대원전의 일일 부하추종운전에 대한 운전여유도 평가를 수행하였으며, 운전여유도를 만족하는 범위를 P-ASI Diagram으로 나타내었다. 본 연구에서 도출한 운전여유도와 ASI의 관계를 쉽게 파악할 수 있는 P-ASI Diagram이 COLSS와 병행된다면 운전유연성 증진 뿐만아니라 운전원의 입장에서도 더욱 용이한 부하추종운전을 수행할 수 있을 것으로 판단된다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.172-175
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• 2009

The purpose of this study is to predict the forming limit diagram (FLD) of strain-rate sensitive materials on the basis of the Marciniak and Kuczynski (M-K) theory. The strain-rate effect is taken into consideration in such a way that the stress-strain curves for various strain-rates are inputted into the formulation as point data, not as curve-fitted models such as power function. To solve the nonlinear system of equations derived from the equilibrium and constraints in the groove region and the safe zone, the Newton-Raphson method is used. The theoretical FLDs using four different yield criteria, that are von Mises, Hill (1948), Hill (1979), Logan and Hosford, are compared with the experimental, numerical (FEA) and other theoretical results. A new trial is made where a modified M-K model having n-step grooves is introduced to describe a real localized neck.