• Proceedings of the KSME Conference
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• 2001.06a
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• pp.523-528
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• 2001

In this study we tried to determine the work-hardening exponent using continuous indentation test. Work-hardening exponent, which was determined by Hollomon equation, in tensile test, is an important parameter to determine plastic deformation and brittle/ductile property of materials. For using Hollomon equation, true stress and true strain were defined by indentation depth and indentation load. Using them the new equation, which is constituted by indentation depth, indentation load and work-hardening exponent, was induced. Indentation depth was calibrated because of elastic deflection and pile-up/sink-in phenomena. Work-hardening exponents of various steels derived by it showed good agreement to the results of tensile tests. In addition to experiments, FEM simulation was accomplished to investigate changes of real contact depth with materials properties changes. Through this simulation it is concluded that the real contact depth is changed by Y/E value which affect the early stage of indentation, and work-hardening exponent which the latter stage.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.6-6
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• 1992

This work deals with nonlinear least squares method for estimating unknown universial constants C in a computer simulation code real experimental data(or database) and computer simulation data. The best linear unbiased predictor based on a spatial statistical model is fitted from the computer simulation data. Then nonlinear least squares estimation method is applied to the real data using the fitted prediction model(or simulation predictor) as if it were the true simulation model. An application to the computational nuclear fusion device is presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.203-208
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• 2004

The objective of this study is to analyze the efficiency of marshalling work using ATC(automated transfer crane) for ACT(automated container terminal). It is important fact to assignment of containers, because the character of ACT which block layout is vertical for berth and there are four other works which are inbound, oubound, loading and unloading in one block. And then there is need which assignment of containers with remarshaling work using ATCs in one block. Therefore, we analyze the efficiency of remarshaling work using simulation and suggest the assignment methodology of containers in yard

• Transactions on Electrical and Electronic Materials
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• v.16 no.3
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• pp.156-161
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• 2015

In this paper, we present simulation results obtained using SILVACO TCAD tools for a 3-D silicon on insulator (SOI) n-FinFET structure with a gate length of 8 nm at 300K. The effects of variations of the device’s key electrical parameters, such as threshold voltage, subthreshold slope, transconductance, drain induced barrier lowering, oncurrent, leakage current and on/off current ratio are presented and analyzed. We will also describe some simulation results related to the influence of the gate work function variations on the considered structure. These variations have a direct impact on the electrical device characteristics. The results show that the threshold voltage decreases when we reduce the gate metal work function Φ_m. As a consequence, the behavior of the leakage current improves with increased Φ_m. Therefore, the short channel effects in real 3-D FinFET structures can reasonably be controlled and improved by proper adjustment of the gate metal work function.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.443-449
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• 2004

In this paper, we established a simulation model for transport vehicle that carries the container transportation between apron and yard block on automated container terminal with a perpendicular yard layout. Usually, the efficiency of container terminal is evaluated by productivity of container cranes at apron, and though there are enough support of transport vehicles and yard cranes, can improve the productivity of container cranes. Especially, transport vehicle is very important factor in productivity of container cranes and has variable work productivity according to loading and unloading situation of container cranes. Therefore, a method that can estimate work productivity of transport vehicle efficiently is required. We analyzed work productivity of transport vehicle using simulation model that has state transition of transport vehicle. We performed various simulation experiment and analyzed work productivity of transport vehicle and calculated the required number of transport vehicle by container crane additionally.

• KIEAE Journal
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• v.13 no.1
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• pp.109-123
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• 2013

The study is to probe a technical alternative to enhance the reliability and accuracy of the results of various landscape simulations. This study to present technical criteria that are necessary in each stage of target site analysis, picture taking, and computer synthesis and, through these to present supplementary plans to enhance the reliability and accuracy of landscape simulations. In order to derive more practical and empirical results in terms of the reliability of the results of landscape simulations, examples that actually passed landscape review were selected. With regard to study process, an analysis was made first to analyze the landscape report data of designs that passed the review to analyze their characteristics, to be followed by an integrated analysis of problems that were revealed in various landscape simulations. Important factors that affect directly the work of landscape simulations such as the specification of camera lenses that were used in picture taking, distance, and angle. Design the work was carried out using Auto CAD, 3DS Max, and Photoshop program in the same way as in actual design. For verification of their accuracy and reliability, the results were entrusted to experts who have implemented similar jobs. To seduce differences from those too landscape simulations that conduct trial experiment of the virtual space that are to be created in the future with accurate numerical values.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.81-88
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• 2007

The objective of this study was to investigate the validity of the digital ergonomic simulation (DES) method as a prospective alternative to the ergonomic analyses conducted by experts. The DES method utilizes commercial digital manufacturing software, and can compute the RULA scores continuously throughout the simulated work cycle. It was shown in a case study that the accuracy and objectivity of the DES method are superior to those obtained by experts. Also, it was demonstrated that the DES method has a distinct capability to simulate and validate a proposed work plan. Major limitations of the current DES method lie in the extensive time and efforts required for accurate digital simulation, which may be overcome through an automatic module for RULA data acquisition and a motion capture system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.83-91
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• 2008

This study establishes the model to estimate a work time and a machine equipment combination in a NATM tunnel. Also it includes the increasing rate of haulage distance in the model for to make near to reality model. A simulation model focuses on the mucking process which affects the work effectiveness very highly to plan of machine use in tunneling operation. With the analysis of work effectiveness through tunnel simulation model, it is defined the problem of planning phase. Also it shows the optimal working time and efficiency of machine used through change the number of dump truck and haulage distance.

• IE interfaces
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• v.6 no.1
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• pp.99-112
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• 1993

This study deals with analysis of material from in Tube manufacturing line. This line is a multi product flow ship type production line, which consists of 5 steps of work station. Some work stations involve in unnecessary moving activities of workers and much work in-process storage due to the non-systematic material flow with respect to the different lot size production of multi-items. To improve productivity for this line, one alternative is considered such as grouping two work stations by using GT and JIT concepts. Also, feasibility analysis for this alternative is performed using and simulation model built by SIMAN IV simulation language.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.31-35
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• 2001

Simulation --- The ideal tool for BPR. Work now and CASE tools are static modeling tools. Based on our own customers surveys, we have discovered that the use of process modeling tools thus far has focused on modeling the current(What-Is) state of a business. We have found that 90 percent of reengineering projects, the modeling tools of choice have been flowcharting tools. Static models offer help in understanding the overall nature of an existing process. However, static models can not really help you see the step by step motions towards completion of your goals. In static modeling, you see two pictures in time, usually taken at the current state and final state models of your reengineering project. Static models are usually not object oriented, therefore can not show facility or office layout and movement of entities and objects throughout the facility. However, this does not mean that static modeling does not have its application nor add value to the user as in a few success stories. Simulation helps the team analyze the complex aspects of the project. Many times a plan that looks good on paper might turn out entirely different when put into action. Therefore, simulation helps you look at how situations might work before actual implementation. In particular, computer simulation models help you view a reengineered condition before they are rolled-out. Items such as a lead time and resource allocation.