• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.781-789
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• 2016

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1214-1219
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• 2018

A variety of VR contents are being introduced as of 2017. VR contents are concentrated in the genre of games and interactive because of the difficulty of $360^{\circ}$ shooting production environment. Live action $360^{\circ}$ VR content has many problems due to the difficulty of the production environment. In this paper, a three - dimensional information value is generated in binocular disparity of a real image by using a re-light technique based on real image data. The generated 3D information values are combined with a technique of converting the depth information into a depth map and a re-light technique by installing virtual lighting on the surface formed in the 3D space. In order to solve the problem of lighting exposure, we apply the technique of re-lighting to the VR production pipeline by comparing and analyzing the result image of actual image and virtual image data.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.209-220
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• 2008

This paper presents the differences in the analysis results according to the underlying layer modeling methods when analyzing the curling behaviors of the concrete slabs on grade under environmental loads. The models of the slab on grade system considered in this study included a three-dimensional(3D) model, a model composed of 3D slab and springs for underlying layers, and a model composed of 2D slab and springs for underlying layers. First, when the underlying layer consisted of one layer, the curling behaviors according to the different models were compared. Then, the underlying layers that consisted of two different materials and thicknesses were considered. The results of this study showed that the tensionless spring model for the underlying layer gave very accurate results when the underlying layer consisted of one layer. However, when the underlying layers consisted of two layers, the spring model for the underlying layers could overestimate the displacements and underestimate the maximum stress with a large elastic modulus of upper underlying layer, a small elastic modulus of under underlying layer, and thick underlying layers.

• Journal of Radiation Protection and Research
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• v.36 no.4
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• pp.183-189
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• 2011

To quantitatively evaluate how setup errors in conjunction with dose gradients contribute to the error in IMRT dose quality assurance (DQA) measurements. The control group consisted of 5 DQA plans of which all individual field dose differences were less than ${\pm}5%$. On the contrary, the examination group was composed of 16 DQA plans where any individual field dose difference was larger than ${\pm}10%$ even though their total dose differences were less than ${\pm}5%$. The difference in 3D dose gradients between the two groups was estimated in a cube of $6{\times}6{\times}6\;mm^3$ centered at the verification point. Under the assumption that setup errors existed during the DQA measurements of the examination group, a three dimensional offset point inside the cube was sought out, where the individual field dose difference was minimized. The average dose gradients of the control group along the x, y, and z axes were 0.21, 0.20, and 0.15 $cGy{\cdot}mm^{-1}$, respectively, while those of the examination group were 0.64, 0.48, and 0.28 $cGy{\cdot}mm^{-1}$, respectively. All 16 plans of the examination group had their own 3D offset points in the cube. The individual field dose differences recalculated at the offset points were mostly diminished and thus the average values of total and individual field dose differences were reduced from 3.1% to 2.2% and 15.4% to 2.2%, respectively. The offset distribution turned out to be random in the 3D coordinate. This study provided the quantitative data that support the large individual field dose difference mainly stems from possible geometric errors (e.g., random setup errors) under the influence of steep dose gradients of IMRT field.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.49-56
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• 2019

In this study, a blasting nozzle was designed based on incompressible flow analysis to clean wide surface of parts used in power plant. The outlet side section of the designed nozzle has a wide bore with a linear shape. After the design, the nozzle prototype was made by three dimensional printing, and the cleaning performance test was performed after mounting it on the blasting machine. The wide bore size obtained after the analysis was almost the same as the wide bore size obtained from the surface of the plate specimen after the experiment. Ultimately, it was confirmed that the design of blasting nozzle for wide surface treatment is effective.

• The Journal of Korean Institute of Next Generation Computing
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• v.14 no.6
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• pp.66-74
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• 2018

Recently, there has been active studies on hand gesture recognition to increase immersion and provide user-friendly interaction in a virtual reality environment. However, most studies require specialized sensors or equipment, or show low recognition rates. This paper proposes a hand gesture recognition method using Deep Learning technology without separate sensors or equipment other than camera to recognize static and dynamic hand gestures. First, a series of hand gesture input images are converted into high-frequency images, then each of the hand gestures RGB images and their high-frequency images is learned through the DenseNet three-dimensional Convolutional Neural Network. Experimental results on 6 static hand gestures and 9 dynamic hand gestures showed an average of 92.6% recognition rate and increased 4.6% compared to previous DenseNet. The 3D defense game was implemented to verify the results of our study, and an average speed of 30 ms of gesture recognition was found to be available as a real-time user interface for virtual reality applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.62-65
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• 2022

NCS(Naval Combat System) is a system that maximizes the combat effectiveness for the naval ships by providing track detection, tracking, thereat analysis, engagement, hit assessment and many other capabilities using ship integrated heterogeneous sensor and weapon systems. In order to achieve the purpose of the NCS, every crew is require to be proficient in the operation of NCS. In accordance with the goal, NCS provides a onboard training function, and the crew conducts system operation proficiency and teamwork training on the ship. Training instructors for control training should have a high standard of training environment control and monitoring capabilities, which need to be studied. This paper studies a 3D display method for visualizing the training situation of training instructors.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.3
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• pp.138-151
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• 2023

Korea's port infrastructure is rapidly aging, with old port facilities with more than 30 years of public life expected to surge from about 23% in 2019 to 47% in 2029. Traditional, aging ports lose competitiveness in logistics processing, reducing development around the port and increasing human casualties due to the human resource-based maintenance of the facilities. Therefore, it is necessary to solve this problem by establishing systematic management technology based on a digital twin. This research aimed to present the specific implementation steps of a digital twin reflecting smart port technology through cases of port infrastructure disasters, aging status, and smart ports. The study analyzed the port infrastructure linkage system and created and mapped scenarios essential for digital twin implementation. Three-dimensional (3D) modeling and simulation data for disaster and aging management among existing port infrastructure systems were collected. A digital twin port was implemented with 3D modeling. It implements a port digital twin simulation that links data such as sensing data and image data acquired from the port infrastructure in real time. Implementing a digital twin port for port infrastructure disasters and aging management can secure predictive port infrastructure management and disaster safety

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.459-465
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• 2015

There exist different kinds of aircrafts, such as conventional airplane, rotorcraft, fighter, and unmanned aerial vehicle. Their shape and feature are dependent upon their own assigned mission. One of the fundamental analyses performed during the aircraft design is the structural analysis. It becomes more complicated and requires severe computations because of the recent complex trends in aircraft structure. In order for efficiency in the structural analysis, a simplified approach, such as equivalent beam or plate model, is preferred. However, it is not clear which analysis will be appropriate to analyze the realistic configuration, such as an aircraft wing, i.e., between an equivalent beam and plate analysis. It is necessary to assess the limitation for both the one-dimensional beam analysis and the two-dimensional plate theory. Thus, in this paper, the static structural analysis results obtained by EDISON solvers were compared with the three-dimensional results obtained from MSC NASTRAN. Before that, EDISON program was verified by comparing the results with those from MSC NASTRAN program and other analytic solutions.

• Geomechanics and Engineering
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• v.5 no.2
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• pp.165-185
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• 2013

In the present study, the numerical and experimental investigations were performed on the backfill- exterior wall-fluid interaction systems in case of empty and full tanks. For this, firstly, the non-linear three dimensional (3D) finite element models were developed considering both backfill-wall and fluid-wall interactions, and modal analyses for these systems were carried out in order to acquire modal frequencies and mode shapes by means of ANSYS finite element structural analysis program. Secondly, a series of field tests were fulfilled to define their modal characteristics and to compare the results from proposed approximation in the selected structures. Finally, comparing the theoretical predictions from the finite element models to results from experimental measurements, a close agreement was found between theory and experiment. Thus, it can be easily stated that experimental verifications provide strong support for the finite element models and the proposed procedures themselves are the meritorious approximations to the real problem, and this makes the models appealing for use in further investigations.