• Journal of the Korea Society for Simulation
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• v.4 no.1
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• pp.113-119
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• 1995

In 3D computer graphics, fractal techniques have been applied to terrain models. Even though fractal models have become popular for recreating a wide variety of the shapes found in nature, a specific 3D terrain model such as Uleung Island could not be formulated by statistical fractals easily owing to the random effects. However, by locating the midpoints on the edges and the surface of a specific terrain such as Uleung Island, a similar shape of the terrain model can be simulated. This paper shows the way of simulating 3D Uleung Island terrain model by the statistical fractals wherein the subdivision algorithm is used.

• Journal of the Korea Fashion and Costume Design Association
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• v.8 no.2
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• pp.27-35
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• 2006

We studied the 3D simulating shapes of the flared skirt using NARCIS-Drape Simulation software made in Korea D&M FT. The experimental conditions were made of three types of cuttings (lengthwise, crosswise, 45 bias) and polyester fabrics for flared skirt (light, medium, heavy) and different simulating repetitions (1, 2, ${\cdots}$, 9, 10 times). We accomplished some experimental data on the 3D simulating shapes of the flared skirt made by different conditions. The 3D simulation shapes of the flared skirts were gradually getting stabilized from 5 repetitions. And the length of skirts and the width and depth of hems diminished lower by degrees as the simulating repetitions. It is considered that the simulating repetition for the flared skirt was appropriate in the range of 8 to 10 times. But it was not reasonably showed that the difference in the drape of the flared skirt was made by different cuttings and fabrics.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.99-102
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• 2014

The skull defect can be made after the trauma, oncologic problems or neurosurgery. The skull reconstruction has been the challenging issue in craniofacial fields for a long time. So far the skull reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for skull reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile various types of allogenic and alloplastic materials have been also used. However, skull reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original skull anatomy as possible using the 3D printed titanium implant, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we fabricated Titanium implant to reconstruct three-dimensional orbital structure in advance, using the 3D printer. This prefabricated Titanium-implant was then inserted onto the defected skull and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.65-73
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• 2008

The purpose of this study is development of universal engine model for integrated Hybrid Electric Vehicle (HEV) simulator and a optimization of engine model. The engine model of this study is based on the MATLAB Simulink for universal and include engine fuel economy technologies for HEV. Various engine fuel economy technologies for HEV is estimated by commercial engine 1-D simulation program - WAVE. And, the 1-D simulation model of base version is compared with engine experiment result. The analyzed engine technologies with 1-D simulation are Dual-CVVT, Atkinson-Cycle and Cylinder-Deactivation System. There are improvement of fuel economy and power performance with Dual-CVVT model at part load and full load, pumping loss reduction with Cylinder-Deactivation System at idle and regeneration. Each estimated technologies are analyzed by 1-D simulation on all operation region for base data to converse simulink. The simulink based engine model maintains a signal with ECU for determination of engine operation point.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.92-94
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• 2003

In superconductive digital logic circuits, D2 cells can be used to compose a decoder an important component of an Arithmetic Logic Unit (ALU). In this wor, we simulated D2 cell by using WRspice. D2 cell has one input, one switch input, and two outputs (output1 and output2). D2 cell functions in such way that output1 follows the input and output2 is the complement of the input data, when the switch input is "0, ". However, when there is a switch input "1, " the opposite output signals are generated. In this paper, we optimized a D2 cell by using WRspice, and obtained the minimum margin of 26%. Our optimized D2 cell will play a key role in the ALU fabrication.the ALU fabrication.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.1-8
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• 2010

With recent development of computer hardware and 3D graphic technique, a lot of people have concern for something to express as the 3D graphic that look the real environment. Because the request of users have increased, the 3D simulation is developed and popularized in the many field. In this paper, we design and implement the simulation system that humans evacuate a building fires using the 3D graphic techniques. In this paper, we use the A* algorithm to humans have the artificial intelligence at evacuating a building fires, calculate the evacuation speed of each human considering temperature damage and smoke damage. In this paper, we applied the real building to demonstrate the effect of proposed evacuation simulation. Experimental results showed that the evacuation speed is affected by the temperature condition and the smoke density.

• Journal of Korea Water Resources Association
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• v.57 no.7
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• pp.451-460
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• 2024

It is necessary to apply a rational urban flood simulation method to analyze the causes of frequent urban flooding and to develop appropriate countermeasures. Previous studies in Korea have performed flood simulations by inputting the results of manhole overflow from sewer systems and river overflow into two-dimensional flood flow simulation models. It, however, is reasonable to simulate flooding from river and manhole overflows in a complex manner. In this study, we used the 1D-2D coupling functionality of the TUFLOW module, which is a part of XP-SWMM, to simulate the compound flooding of rivers and urban areas. That method was applied to the lower basin of the Naengcheon River in Pohang City, Gyeongsangbuk-do, where both inland flooding and river overflow coincided due to Typhoon Hinnamnor on September 5 and 6, 2022, to verify its applicability.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3567-3579
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• 2022

This paper provides an assessment of fluid transport and mixing processes inside the primary circuit of the test facility ROCOM through the numerical simulation of Test 2.1 with the system code ATHLET. The experiment represents an asymmetric injection of cold and non-borated water into the reactor coolant system (RCS) of a pressurized water reactor (PWR) to restore core cooling, an emergency procedure which may subsequently trigger a core re-criticality. The injection takes place at low velocity under single-phase subcooled conditions and presents a major challenge for the simulation in lumped parameter codes, due to multidimensional effects in horizontal piping and vessel arising from density gradients and gravity forces. Aiming at further validating ATHLET 3-D capabilities against horizontal geometries, the experiment conditions are applied to a ROCOM model, which includes a newly developed horizontal pipe object to enhance code prediction inside coolant loops. The obtained results show code strong simulation capabilities to represent multidimensional flows. Enhanced prediction is observed at the vessel inlet compared to traditional 1-D approach, whereas mixing overprediction from the descending denser plume is observed at the upper-half downcomer region, which leads to eventual deviations at the core inlet.

• Structural Engineering and Mechanics
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• v.32 no.1
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• pp.55-69
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• 2009

A quasi ideal importance sampling simulation method combined in the conditional expectation is proposed for the structural reliability estimation. The quasi ideal importance sampling joint probability density function (p.d.f.) is so composed on the basis of the ideal importance sampling concept as to be proportional to the conditional failure probability multiplied by the p.d.f. of the sampling variables. The respective marginal p.d.f.s of the ideal importance sampling joint p.d.f. are determined numerically by the simulations and partly by the piecewise integrations. The quasi ideal importance sampling simulations combined in the conditional expectation are executed to estimate the failure probabilities of structures with multiple failure surfaces and it is shown that the proposed method gives accurate estimations efficiently.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.67-70
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• 2014

3-D medical image reconstruction technique using computer simulation technology has been used in the knowledge of the anatomical features and the biomechanical characteristics with the advancement of computer hardware and software. Especially, the use of 3-D image reconstruction technique in orthopaedics demonstrates that this technique is useful to improve surgical technique as well as to help inform the knowledge of shoulder joint anatomy. The purpose of this article is to introduce the utilization of 3-D image technology in shoulder surgeries.