• Journal of Welding and Joining
• /
• v.9 no.3
• /
• pp.41-51
• /
• 1991

The thermomechanical coupling phenomena in the resistance welding process is complicated due to interactions of mechanical, thermal and electrical factors. Although experimental investigations of resistance spot welding have been carried out, but there are a few by computer simulation. so the purpose of this research is to decrease the time and cost much required in experimental investigation by carrying out the analysis of the resistance spot welding process through computer simulation based on the finite element method. The tool used in the computer simulation is the commercial ANSYS program package. A two dimensional axisymetric model is used to simulate the resistance spot welding for two stainless steel sheets of equal thickness and parametric study is carried out for variable welding current, workpieces of unequal thickness and dissimilar materials. The results from the computer simulation are in good agreement with the experimental one. Through these results, such items as stress distribution, temperature profiles, thermal expansion and weld nugget formation are predicted. Reliability and applicability of finite element models have been demonstrated to simulate and to analyze the resistance spot welding process.

• Journal of the Korean Ceramic Society
• /
• v.46 no.6
• /
• pp.700-707
• /
• 2009

This paper described finite element analysis (FEA) for fabrication processes of PZT perform using ceramic injection molding (CIM). The viscosity and the PVT characteristics of the manufactured PZT feedstock were measured. The filling patterns, pressure and temperature distributions of the preform were analyzed with TIMON 3D packages during CIM process. The geometrical variables such as gate type, location, and base thickness of the preform were considered. Also the fabrication conditions of the preform were optimized during the entire CIM process. Based on the simulated results, the various good perform was easily fabricated with the CIM process.

• Journal of the Korea Society for Simulation
• /
• v.24 no.3
• /
• pp.55-60
• /
• 2015

This paper presents an SBA (simulation-based acquisition) effectiveness analysis environment using the RUP (Relational Unified Process) model. The RUP model has 4 phases which cover the whole development steps such as requirement analysis, design, development and test. By applying the RUP model, SW development can be represented with the iterations of developments for each phase. Such a characteristics of the model would make the model suitable for defense acquisition. In this paper, we show the relation between the RUP model and V process model, which is the foundation for defense acquisition. In order to show how the model could be applied to SBA effectiveness analysis, graphical user interfaces for the analysis are presented at the end of the paper.

• Transactions of Materials Processing
• /
• v.27 no.3
• /
• pp.154-159
• /
• 2018

In the rectangular bar multi-stage drawing process, the cross-section dimensional accuracy of the rectangular bar varies depending on the aspect ratio and process conditions. It is very important to predict the dimensional error of the cross-section occurring in the multi-stage drawing process according to the aspect ratio of the rectangular bar and the half die angle of each pass. In this study, a process map for improving the dimensional accuracy according to the aspect ratio was derived in the drawing process of a rectangular bar. FE-simulation of the multi-stage shape drawing process was carried out with four types of rectangular bar. The results of the FE-simulation were trained to the nonlinear relationship between the shape parameters using an Artificial Neural Network (ANN), and the process maps were derived from them. The optimum half die angles were determined from the process maps on the dimensional accuracy. The validity of the suggested process map for aspect ratios 1.25~2:1 were verified through FE-simulation and experimentation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.53-56
• /
• 2007

Computer simulation of microstructure evolution during hot forging process is of great interest in recent years. Recrystallization model and grain growth model which use a phenomenological approach were summarized. For the waspaloy, upsetting process and cogging process were simulated using $DEFORM^{TM}$ and the change in grain size were investigated in each deformation procedure.

• Nuclear Engineering and Technology
• /
• v.52 no.2
• /
• pp.429-447
• /
• 2020

The considered simulation tasks are based on an electrometallurgical process development strategy and associated telemanipulator simulation systems are proposed with various scales of experimental facilities. Fundamentally, target facilities are assumed to be operated only by remote handling systems because the considered process is operated in hazardous environments. Futhermore, the feasibility at various scales should be experimentally verified with gradual increase in throughput. In this regard, bench, engineering, and pilot-scale simulation systems are important early-stage tools for assessing the practical operability of the target process with the material handling systems. Such simulation systems are highly customized for applications and are a precursor to larger pilot and demonstration-scale plants. This paper introduced and classified the developed simulator systems for this approach at various scales using remote handling systems which were assembled inside a virtual target facility, and the manmachine interface was included for a more realistic operation of the simulator. The results obtained for each simulator show the feasibility and requirement for improvement of the systems for the considered test issues with respect to the operation and maintenance of the process.

• Korean Journal of Adult Nursing
• /
• v.26 no.1
• /
• pp.107-116
• /
• 2014

Purpose: The purpose of this study was to identify the effects of multi-mode simulation learning on critical thinking disposition, on the problem solving process and on clinical competence of nursing students. Methods: A non-equivalent control group with pre-posttest was designed. The participants in this study were 65 students who were enrolled in an emergency and critical nursing course at N university. The treatment group consisted of 33 juniors in 2010 and the control group 32 juniors in 2011. Collected data were analyzed using chi-square, independent t-test, and ANCOVA with the SPSS/WIN 18.0 for Window Program. Results: There were significant increases in problem solving process and clinical competence in the treatment group who participated in the multi-mode simulation learning compared to the control group who did not (t=-2.39, p=.020; F=12.76, p=.001). However, there were no significant differences in critical thinking disposition between the treatment and control group (t=0.40, p=.692). Conclusion: Multi-mode simulation is an effective teaching and learning method to enhance the problem solving process and clinical competence of nursing students. Further exploration is needed to develop and utilize multi-mode simulation for diverse scenarios, depending on emergency nursing educational goals and environments and to develop a universal method to measure outcomes.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2001.10a
• /
• pp.170-202
• /
• 2001

Simulation is used to reduce a risk involved in the new project and decision-making in an organization and to save cost and time by forecasting different situations. The objectives of this research are to acknowledge the need of simulation through the real life sample and to encourage the use of the simulation method in the future consulting project by continuously making the necessary improvements. This research analyzed the effectiveness of the simulation based on the sample use of simulation method in 1994 and 1997 for the BPR project of certification issuance process at the Supreme Court. In order to evaluate the value of the proposed simulation model, we examined the gap, which existed between the simulation result and the operational data collected by visiting the actual sites where AROS (Automated Registry Office System: automation system developed by LG-EDS Systems) is being utilized. We also identified the causes for the existing gap. According to the analysis result, (1) the gap came from the status change of thinking that the concentration of certification issuance request has eased after the computerization, (2) the gap existed in the operational process because they failed to consider the situational factors of each registry office in the simulation model, and (3) lastly the gap came from the difficulty of formulating the mathematical model for predicting the complex and diverse behavior pattern of individuals requesting the certification issuance. In order to narrow the existing gaps, we made a proposal to improve the certification issuance process where software of certification issuance vending machine was upgraded in order to help the people to use the service conveniently, more part time workers were hared when there was a overload of certification issuance request, and the quality of the certification Issuance vending machine is improved, In this research, we examined an efficient way of resource allocation based on the simulation conducted in 1994 and 1997. By reflecting changes since the simulation of 1994 and allocating the clerk and machine based on the predicted results of the simulation, we maximized the efficiency of the certification issuance process. In conclusion, this research examined the future usability of simulation method based on the analysis result and identified the key issues to consider when using the simulation method in the future consulting project.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.638-642
• /
• 1994

The objectives of this work are to present the dynamic simulation strategy based on cluster-modular approach and to develop a prototype simulator. In addition, methods for the improvement of computational efficiency and applicability are studied. A process can be decomposed into several clusters which consist of strongly coupled units depending upon the process dynamics or topology. The combined approach of simultaneous and sequential simulation based on the cluster structure is implemented within the developed dynamic process simulator, MOSA(Multi Objective Simulation Architecture). Dynamic simulation for a utility plant is presented as a case study in order to prove the efficiency and flexibility of MOSA.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.3
• /
• pp.1-6
• /
• 2012

This study is focused on simulation technology in injection molding process for plastic optic lenses. The CAE program, $3D-TIMON^{TM}$ is used for the injection molding simulation with O-PET resin material. The design for different gate shape and runner layout has been under review by CAE simulation results. Moreover, the prediction of birefringence and polarized light in injection molded optic lenses has been tested by the CAE Program. The simulation results have been expected to effectively use in the design of injection molding mould.