• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.8
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• pp.642-653
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• 2008

In this paper, we propose a 3-D finite element (FE) analysis model with combined physical behavior and kinematical impact factors for evaluation of residual stress in multi-impact shot peening. The FE model considers both physical behavior of material and characteristics of kinematical impact. The physical parameters include elastic-plastic FE modeling of shot ball, material damping coefficient, dynamic friction coefficient. The kinematical parameters include impact velocity and diameter of shot ball. Multi-impact FE model consists of 3-D symmetry-cell. We can describe a certain repeated area of peened specimen under equibiaxial residual stress by the cell. With the cell model, we investigate the FE peening coverage, dependency on the impact sequence, effect of repeated cycle. The proposed FE model provides converged and unique solution of surface stress, maximum compressive residual stress and deformation depth at four impact positions. Further, in contrast to the rigid and elastic shots, plastically deformable shot produces residual stresses closer to experimental solutions by X-ray diffraction. Consequently, it is confirmed that the FE model with peening factors and plastic shot is valid for multi-shot peening analyses.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.5
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• pp.625-638
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• 1999

Air quality modeling for coastal urban region has been composed of a complex system including meteorological, chemical and physical processes and emission characteristics in complex terrain. In this study, we studied about an effect prediction for deposition phenomenon affecting on air quality in Pusan metopolitan metropolitan city. In air quality modeling including ship sources, a situation considered deposition process habe better result than not considered when compared with observed value. Air pollutants emitted into urban air during the daytime nearly removed through urban atmosphere polluted. Also these phenomena correlated concentration variation connent with sea/land breezes and terrain effect. Therefore we conclude that the concentration was low at daytime when deposition flux is high, and deposition effect on industrial complex and Dongrae region is considerable in particular.

• Fashion & Textile Research Journal
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• v.26 no.1
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• pp.78-87
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• 2024

This study aimed to propose an innovative teaching pedagogy using a half-scale body form in apparel design education and evaluate its effectiveness in augmenting students' understanding of ergonomic patterns. Constructed in alignment with Phoenix's (2018) study, which used 3D body scanning and digital editing software, the half-scale body form was created through a five-step process, encompassing body measurement, 3D body modeling, fabrication of a physical half-scale body form, pattern making, and evaluation. Implemented in an undergraduate patternmaking course offered at a 4-year university in the metropolitan Seoul, this instructional approach's effectiveness was gauged through students' course projects and exit interviews. The results underscored the positive impact of the proposed teaching pedagogy on students' grasp of ergonomic pattern development, fostering a keen understanding of diverse body shapes and sizes and the relationship between the human body and garments. Furthermore, it played a role in cultivating positive body image and self-endorsement among students. The research contributes meaningfully by presenting a fresh perspective in apparel design education, seamlessly integrating advanced anthropometric and technological tools into a conventional patternmaking classroom. It offers a novel learning experience for students majoring in apparel, creating a fun and interactive teaching environment.

• Geophysics and Geophysical Exploration
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• v.22 no.3
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• pp.160-167
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• 2019

Resistivity inversion result may be distorted if the seepage line fluctuation within central core with the change of reservoir water level as well as the conductivity of the reservoir water is not taken into consideration because the reservoir dike is composed of three-dimensional (3D) resistivity structure. Consequently, to accurately analyze the resistivity changes inside the reservoir dike according to the change of reservoir water level, 3D electrical resistivity modeling for the 2D survey line considering topography and physical properties of dam components was carried out. In addition, 2D inversion was performed with the simulated 2D resistivity data for a given 3D model in order to compare it with the inversion result of real field data. For 283 reservoirs in Korea, 2D inversion results for the simulated 2D data and field 2D resistivity data were compared. Finally, the reservoirs with an inversion ratio of 50% or less were selected as reservoirs that require further precise investigation.

• Korean Journal of Cognitive Science
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• v.11 no.2
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• pp.1-10
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• 2000

Realistic facial animation research field which communicates with human and computer using face has increased recently. The human face is the part of the body we use to recognize individuals and the important communication channel that understand the inner states like emotion. To provide the intelligent interface. computer facial animation looks like human in talking and expressing himself. Facial modeling and animation research is focused on realistic facial animation recently. In this article, we suggest the method of facial modeling and animation for realistic facial synthesis. We can make a 3D facial model for arbitrary face by using generic facial model. For more correct and real face, we make the Korean Generic Facial Model. We can also manipulate facial synthesis based on the physical characteristics of real facial muscle and skin. Many application will be developed such as teleconferencing, education, movies etc.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.437-439
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• 2002

Tangible user interfaces have attracted strong attention in the HCI(Human and Computer Interface) community for their ability to take advantage of skills humans develop in the real world. We are developing "tangible media aided design system" which employs physical objects i.e., brick as interfacing media for 3D graphic modeling. This system is targeting for persons who are afraid of experiencing 3D graphic modeling and virtual space, or have a sense of reluctance in approaching to them. Our approach suggests the easiest way for people to experience computer system and virtual space carefree while developing and improving their space sense. This work is one of initial explorations of media aided design system using tangible user interfaces.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.82-87
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• 2002

RFM is the sensor model of IKONOS imagery for end-users. IKONOS imagery vendors provide RPC (Rational Polynomial Coefficients), Ration Function Model coefficients for IKONOS, for end-users with imagery. So it is possible that end-users obtain geospatial information in their IKONOS imagery without additional any effort. But there are requirements still fur rigorous 3D positions on RPC user. Provided RPC can not satisfy user and company to generate precision 3D terrain model. In IKONOS imagery, physical sensor modeling is difficult because IKONOS vendors do not provide satellite ephemeris data and abstract sensor modeling requires many GCP well distributed in the whole image as well as other satellite imagery. Therefore RPC modification is better choice. If a few GCP are available, RPC can be modified by method which is introduced in this paper. Study on evaluation modified RPC in IKONOS reports reasonable result. Pseudo GCP generated with vendor's RPC and additional GCP make it possible through sequential solution.

• IE interfaces
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• v.14 no.2
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• pp.127-133
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• 2001

Virtual Manufacturing is a technology facilitating effective development and agile production of products via computer models representing physical and logical schema and the behavior of the real manufacturing systems. For the successful application of this technology, a virtual plant as a well-designed and integrated environment is essential. We propose a series of systematic approaches and effective methods for construction and operation of a virtual plant in this paper, such as a 3-D CAD modeling, cell and line simulations and databases. We developed key technologies for measuring and 3-D CAD modeling of many equipments, facilities and structures of the buildings. In order to study the benefit of virtual manufacturing, we constructed a sophisticated virtual plant model of a Korean automotive company's body shop, and conducted precise simulations of unit cell, lines and the whole plant. We could obtain the benefit of savings in time and cost in many manufacturing preparation activities in the new car development processes.

• Geophysics and Geophysical Exploration
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• v.19 no.1
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• pp.20-28
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• 2016

Recently many sinkholes have appeared in urban areas of Korea, threatening public safety. To predict the occurrence of sinkholes, it is necessary to investigate the existence of cavity under urban roads. Ground-penetrating radar (GPR) has been recognized as an effective means for detecting underground cavity in urban areas. In order to improve the understanding of the governing physical processes associated with GPR wave propagation, and interpret underground cavity effectively, a theoretical approach using numerical modeling is required. We have developed an algorithm employing a three-dimensional (3D) staggered-grid finite-difference time-domain (FDTD) method. This approach allows us to model the full electromagnetic wavefield associated with GPR surveys. We examined the GPR response for a simple cavity model, and the modeling results showed that our 3D FDTD modeling algorithm is useful to assess the underground cavity under urban roads.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1143-1145
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• 2003

Some of satellites such as IKONOS don't provide the orbital elements so that we can’ utilize the physical sensor model. Therefore, Rational Function Model(RFM) which is one of mathematical models could be a feasible solution. In order to improve 3D geopositioning accuracy of IKONOS stereo imagery, Rational Polynomial Coefficients(RPCs) of the RFM need to be updated with Ground Control Points(GCPs). In this paper, a method to improve RPCs of RFM using GCPs and 3D cube is proposed. Firstly, the image coordinates of GCPs are observed. And then, using offset values and scale values of RPC provided, the image coordinates and ground coordinates of 3D cube are initially determined and updated RPCs are computed by the iterative least square method. The proposed method was implemented and analyzed in several cases: different numbers of 3D cube layers and GCPs. The experimental results showed that the proposed method improved the accuracy of RPCs in great amount.