• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.177-189
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• 2013

3D modeling and rendering technologies are getting more attention from landscape planners and architects because the virtual reality based on 3D graphic technology could give more realistic experience to landscape simulation users and boost promotional effects. The 3D landscape simulation, however, not only requires a lot of cost and time in production, but also demands efforts to distribute to consumers due to various computing environment of them. The purpose of this study is to suggest a process for developing an interactive 3D landscape simulator with low-cost, which can support multi-platform functionality in high quality through reviewing related current software and web services. We select GIMP for 2D image texturing, SketchUpfor 3D modeling, Unity for real-time rendering, and Google Earth for terrain modeling considering price and workability and apply the developed process for Windows, Web, and Android versions to test the applicability for Sangji-ri, Gosam-myeon, Gyeonggi-do, Korea.

• Science of Emotion and Sensibility
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• v.17 no.4
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• pp.3-18
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• 2014

In this study, drivers' longitudinal car control, subjective fatigue, and perceived fidelity were compared between 2D and 3D display driving simulation. The results can be summarized as followings. First, in all target speed conditions, the drivers tended to drove faster in 2D display condition than 3D display condition. Second, speed deviation from target speed increased as target speed decreased. Third, distances between the lead vehicle and the driver's vehicle were significantly reduced in the 3D display condition when the speeds of the lead vehicle were relatively fast(i. e., over 80km/h). Fourth, although the perceived fidelity was not significantly different between the two display conditions, subjective fatigue was higher in the 3D display condition than in the 2D display condition.

• Journal of Navigation and Port Research
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• v.32 no.4
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• pp.271-277
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• 2008

When performing steering by an autopilot (automatic steering gear), a sensitivity adjustment is mainly determined by P value and D value. These values differ in the optimal combination by model of ship and external forces. This research was carried out simulation case studies and examined movement of Pure Car Carrier, which easily received ship by wind pressure influence in low speed We investigated the relation of horizontal migration(transfer) of ship's body and P-D value. Based on it, four parameters of P-D at approaching berth could be suggested Hence there were suggestions of parameters; Distance to maximum lee point, Time to maximum lee point, Time to return to original course and Time to 300th second. The correlation of these parameters and P-D value were also considered. As a result, we think that this index, like formulated P-D, leads to an easy and safe navigation by utilizing these indices.

• Journal of IKEEE
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• v.25 no.4
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• pp.735-740
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• 2021

In this paper, we propose a new ESD protection device with high holding voltage with low current gain of parasitic NPN BJT by improving the structure of the existing LTDDSCR. The electrical characteristics of the proposed protection device were analyzed by HBM simulation using Synopsys' TCAD simulation, and the operation of the added BJT was confirmed by current flow, impact ionization and recombination simulation. In addition, the holding voltage characteristics were optimized with the design variables D1 and D2. As a result of the simulation, it was verified that the new ESD protection device has a higher holding voltage compared to the existing LTDDSCR and has a symmetrical bidirectional characteristic. Therefore, the proposed ESD protection device has high area efficiency when applied to an IC and is expected to improve the reliability of the IC.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.1027-1037
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• 2021

This study aims to evaluate the performance of an electric multi-purpose cultivator through a simulation analysis. The simulation model was developed using commercial software, Simulation X, by applying the specifications of certain parts, such as an electric motor, a battery, and so on. The input parameter of the simulation was the engine load data according to the rotary tillage level using a conventional multi-purpose cultivator. The data were collected by configuring a load measurement system, and the load cycle was developed by repeating the data collection process under the most severe conditions. The average output engine torque values of conventional multi-purpose cultivator were 10.7, 13.0, 9.4, and 11.2 Nm in the D1P1, D1P2, D2P1, and D2P2 conditions, respectively. As a result of the simulation, the maximum values of the motor torque, rotational speed, and power of the electric multi-purpose cultivator were 16.8 Nm, 2,033.3 rpm, and 3.3 kW, respectively, and the motor was driven in sections within 70, 68, and 45% of the maximum output range. The rate of decrease of the battery state of charge (SOC) level per minute was approximately 0.6%, and it was possible to supply electric power to the motor for 9,550 sec. In the future study, research to verify and improve simulation models of electric multi-purpose cultivators should be conducted.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.304-311
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• 2003

In this paper, we present the 2.4 ㎓ and 5 ㎓ dual band antenna fur access point of WLAN(Wireless Local Area Network). The proposed antenna must have equal gains in both frequency bands to accept two services. We proposed using collinear array to compensate gain difference for two different frequency bands. Simulation results using 3D simulation program, CST MWS(Microwave Studio), for dual band antenna with collinear away show that the maximum gain is about 4.7 dBi at 2.4 ㎓, 5.2 dBi at 5.7 ㎓. We got additional gain of about 2.1 ㏈ with collinear array for 2.4 ㎓ in measurement. Measured results for the dual band antenna with collinear array show applicable performances for access point of wireless LAN.

• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.75-84
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• 2019

The purpose of this study was to present a good pants pattern for boys aged 13-18 by comparing and analyzing the pants pattern according to lower body shape. And through it, this study was to provide basic data for pants production considering male student body shape. The pattern of this study used the industrial type Lee Hee-chun pattern and DC Suite Program for 3D virtual simulation. As a result of the appearance evaluation, there was a significant difference between the patterns in most items. Type 2 was rated highly, followed by Type 4, Type 3, and Type 1. Type 1 required correction of the length of the pants and the amount of crotch part, while type 3 required adjustment of the pants in the knee area. Type 4 required correction of pattern drawing method of crotch width, thigh circumference, and knee circumference. This pattern method was evaluated as suitable for slender body shape. This study suggests a pants pattern system suitable for adolescent boys by reflecting the body shape characteristics of adolescent boy with a change of body shape. It is expected that this will meet the increasing demand for fitting. In this study, we have examined 3D virtual simulation, not actual wear experiment, so it will be necessary to investigate the difference through actual clothing experiment for adolescent boys.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.4
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• pp.409-417
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• 2014

To prevent the occurrence of fractures in metal structures, it is very important to evaluate the 3D crack growth process in those structures and any related parts. In this study, tension tests and two simulations, namely, Simulation-I and Simulation-II, were performed using XFEM to evaluate crack growth in three dimensions. In the tension test, Mode I crack growth was observed for a notched metal specimen. In Simulation-I, a 3D reconstructed model of the specimen was created using CT images of the specimen. Using this model, an FE model was constructed, and crack growth was simulated using XFEM. In Simulation-II, an ideal notch FE model of the same geometric size as the actual specimen was created and then used for simulation. Obtained crack growth simulation results were then compared. Crack growth in the metal specimen was evaluated in three dimensions. It was shown that modeling the real shape of a structure with a crack may be essential for accurately evaluating 3D crack growth.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.199-209
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• 2022

As the uncertainty of technology development and market needs increases due to changes in the global business environment, the interest and demand for R&D activities of individual companies are increasing. To respond to these environmental changes, technology commercialization players are paying great attention to enhancing the qualitative competitiveness of R&D. In particular, R&D companies in the marine and fishery sector face many difficulties compared to other industries. For example, the R&D environment is barren, it is challenging to secure R&D human resources, and it is facing a somewhat more difficult environment compared to other sectors, such as the difficulty in maintaining R&D continuity due to the turnover rate of researchers. In this study, based on the empirical data and patent status of private companies closely related to the R&D technology status, big data analysis, and simulation analysis methods were used to identify the relative position of individual companies' R&D capabilities and industrial perspectives. In this study, based on industrial evidence and patent applications closely related to the R&D technology status, the R&D capabilities of individual companies were evaluated using extensive data analysis and simulation analysis methods, and a statistical test was performed to analyze if there were differences in capabilities from an industrial point of view. At this time, the industries to be analyzed were based on all sectors, the maritime industry, the fisheries industry, and the maritime industry integration sector. In conclusion, it was analyzed that there was a certain level of difference in the R&D capabilities of individual companies in each industry sector, Therefore when developing a future R&D capability system, it was confirmed that it was necessary to separate the population for each industry and establish a strategy.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.56-63
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• 2015

Gas explosion accidents could cause a catastrophe. we need specialized and systematic accident investigation techniques to shed light on the cause and prevent similar accidents. In this study, we had performed LNG explosion simulation using AUTODYN which is the commercial explosion program and predicted the damage characteristics of the structures by LNG explosive power. In the first step, we could get LNG's physical and chemical explosion properties by calculation using TNT equivalency method. And then, by applying TNT equivalency value about the explosion limit concentration of LNG on the 2D-AUTODYN simulation, we could get the explosion pressure wave profiles (explosion pressure, explosion velocity, etc.). In the last step, we performed LNG explosion simulation by applying to the explosion pressure wave profiles as the input data on the 3D-AUTODYN simulation. As a result, we had performed analyzing of the explosion characteristics of LNG in accordance with concentration through the 3D-AUTODYN simulation in terms of the explosion pressure behavior and structure's destruction and damage behavior.