• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.25-36
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• 2021

This paper presents a topology based on packet tracer and a five-step scenario model to make it easier for students to understand the network on which VLANs are applied. Virtual LAN (VLAN), developed as an alternative solution to the Routers that distribute broadcast traffic, is a virtual local area network that logically configured regardless of the physical network. The VLAN prevents the network performance degradation resulting from the broadcast traffic by dividing the broadcast domain so that the bandwidth can be used more efficiently. In addition, it enhances the security because on communication between the devices belonging to different VLANs is impossible. The five-step scenarios in this paper presented an efficient implementation case for students to understand and validate the various functions of VLANs through ping/telnet/tracert test and simulation, after setting up each step of programming switches and routers in the virtual network.

• Journal of the Korea Computer Graphics Society
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• v.26 no.5
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• pp.15-24
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• 2020

We present a supervised learning method that estimates the simulation parameters required to simulate the fabric from the static drape shape of a given fabric sample. The static drape shape was inspired by Cusick's drape, which is used in the apparel industry to classify fabrics according to their mechanical properties. The input vector of the training model consists of the feature vector extracted from the static drape and the density value of a fabric specimen. The output vector consists of six simulation parameters that have a significant influence on deriving the corresponding drape result. To generate a plausible and unbiased training data set, we first collect simulation parameters for 400 knit fabrics and generate a Gaussian Mixed Model (GMM) generation model from them. Next, a large number of simulation parameters are randomly sampled from the GMM model, and cloth simulation is performed for each sampled simulation parameter to create a virtual static drape. The generated training data is fitted with a log-linear regression model. To evaluate our method, we check the accuracy of the training results with a test data set and compare the visual similarity of the simulated drapes.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.114-122
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• 2021

In this paper, an automated vehicle intersection collision accident was analyzed through simulation. Recently, the more automated vehicles are distributed, the more accidents related to automated vehicles occur. Accidents may show different trends depending on the sensor characteristics of the automated vehicle and the performance of the accident prevention system. Based on NASS-CDS (National Automotive Sampling System-Crashworthiness Data System) and TAAS (Traffic Accident Analysis System), four scenarios are derived and simulations are performed. Automated vehicles are applied with a virtual system consisting of an autonomous emergency braking system and algorithms that predict the route and avoid collisions. The simulations are conducted by changing the sensor angle, vehicle speed, the range of the sensor and vehicle speed range. A range of variables considered vehicle collision were derived from the simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.405-413
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• 2011

Defense Systems Test Center in ADD supports increasingly various missile test requirements such as higher altitude event, multi target operation and low-altitude, high velocity target tracking. In this paper, we have proposed the development of instrumentation radar tracking status simulator based on virtual reality. This simulator can predict the tracking status and risk of failure using several modeling algorithms. It consists of target model, radar model, environment model and several algorithms includes the multipath interference effects. Simulation results show that the predict tracking status and signal are similar to the test results of the live flight test. This simulator predicts and analyze all of the status and critical parameters such as the optimal site location, servo response, optimal flight trajectory, LOS(Line of Sight). This simulator provides the mission plan with a powerful M&S tool to rehearse and analyze instrumentation tracking radar measurement plan for live flight test at DSTC(Defense Systems Test Center).

• International Journal of Aerospace System Engineering
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• v.1 no.1
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• pp.10-15
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• 2014

This study presents technical description of the operating program development that operates the test bench for functional test of EECU. The test bench is capable of testing, simulation and adjustment of the EECU software using the operating program. The test bench is for the Development Project of the EECU platform for FADEC system. The operating program is consists of 3 modules which are the test bench operating module, cockpit simulator module and SILS module. The operating module mainly carries out the EECU test with manual operation and operating scenarios. Also that record and process the test data. The cockpit simulator module is capable of implementation of virtual cockpit control input and engine status display. The SILS module can simulate engine and EECU operation in software environment.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.1-8
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• 2013

Focused on the fact that sound is one of the important sensory cues delivering situations such as impact, this paper proposes an auditory interaction design approach for virtual environment. Based on a few sampling of basic material sound for various materials such as steel, rubber, and glass, the proposed method enables design transformations of the basic sound by allowing modification of mode gains that characterize natural sound for the material. In real-time virtual environment, it also provides simulation of modified sound according to the change of impact situation's perceptual properties such as colliding objects' size, hardness, contacting area, and speed. The test results on cognition experiment for discriminating objects' materials and impact situation by sound showed the feasibility of proposed auditory interaction design method.

• Journal of Powder Materials
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• v.26 no.4
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• pp.275-281
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• 2019

An artificial neural network (ANN) model is developed for the analysis and simulation of correlation between flake powder metallurgy parameters and properties of AA2024-SiC nanocomposites. The input parameters of the model are AA 2024 matrix size, ball milling time, and weight percentage of SiC nanoparticles and the output parameters are density and hardness. The model can predict the density and hardness of the unseen test data with a correlation of 0.986 beyond the experimental data. A user interface is designed to predict properties at new instances. We have used the model to simulate the individual as well as the combined influence of parameters on the properties. Moreover, we have analyzed the calculated results from the powder metallurgical point of view. The developed model can be used as a guide for further composite development.

• Journal of the Korea Society for Simulation
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• v.25 no.1
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• pp.35-43
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• 2016

Increasing the proportion of an embedded system in automotive industry, test methods for evaluation and fault detection of the embedded system have been researched. HILS is a test method that is used in the development and test of complex real-time embedded systems. In this study, we defined the HILS method of the ECU, one of the embedded systems used in automobiles. Our method is to create a test model that can provide a virtual vehicle environment to the ECU on the basis of the actual vehicle data. The test model has reference information that can transmit the sensor signal and CAN Message into the ECU from HILS tester. In this study, the HILS can detect faults of the target ECU.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.937-946
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• 2021

The floating crane is used to lift the heavyweight on the ocean. The floating crane has a winch system for lifting the heavyweight and the system is controlled by the winch control system. The heavyweight is lifted safely by control of the winch control system. Before the make the control system and controller, there are many restricted conditions to test and validate at design and development steps. In order to solve the problems, commonly use the HILS (Hardware-In-the-Loop-Simulation). HILS is the method of test and validation for the hardware control system. It can be composed of the control system in hardware with surrounding environments which is a virtual model. In this study, we developed the winch system model for HILS of the 150t winch control system in a floating crane. Through this simulation and winch model, it can be applied to HILS for the winch control system.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.553-561
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• 2020

The purpose of this study was to identify the effects of an immersive virtual reality-based simulation learning program(IVR-SLP) on the communication competence and learning attitude of students with intellectual disabilities. To do this, 23 participants with intellectual disabilities were selected from 2 special schools. 11 students were placed in an experimental group and 12 students in a control group. An IVR-SLP, focusing on possible situations in a convenience store, was implemented within the experimental group and a traditional intervention program was implemented within the control group. The programs were conducted 5 times per week for 4 weeks and each session lasted approximately 40 minutes. Evaluations were carried out by using a pre- and post- test, and the results of the evaluation were analyzed using the independent t-test. The results of this study indicated that the communication competence of the experimental group showed greater improvement than that of the control group. In addition, the learning attitude of the experimental group became more positive than that of the control group. This implies that the immersive virtual reality-based simulation learning program can be a very effective tool for teaching language and communication skills to students with intellectual disabilities.