• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.168-172
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• 2013

In 3D wafer-stacking technology, one of the major issues is wafer warpage. Especially, The important reason of warpage has been known due to CTE(Coefficient of Thermal Expansion) mismatch between materials. It was too hard to choose how to make the FE model for blanket structured wafer level 3D packaging, because the thickness of each layer in wafer level 3D packaging was too small (micro meter or nano meter scale) comparing with diameter of wafer (6 or 8 inches). In this study, the FE model using the shell element was selected and simulated by the ANSYS WorkBench to investigate effects of the CTE on the warpage. To verify the FE model, it was compared by experimental results.

• Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.88-95
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• 2015

Recently, fiber composite materials have been attracting attention from industry because of their remarkable material characteristics, including light weight and high stiffness. However, the costs of products composed of fiber materials remain high because of the lack of effective manufacturing and designing technologies. To improve the relevant design technology, this paper proposes a novel simulation method for deforming fiber materials. Specifically, given a 3D model with constant thickness and known fiber orientation, the proposed method simulates the deformation of a model made of thick fiber-material. The method separates a 3D sheet model into two surfaces and then flattens these surfaces into two dimensional planes by a parameterization method with involves cross vector fields. The cross vector fields are generated by propagating the given fiber orientations specified at several important points on the 3D model. Integration of the cross vector fields gives parameterization with low-stretch and low-distortion.

• Proceedings of the CALSEC Conference
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• 1999.07a
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• pp.215-231
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• 1999

CALS, Enterprise Integration, Virtual Enterprise 등을 구현하는데 있어서 BPR (business process re-engineering), ISP (Information Strategy Planning), Analysis/Design 등은 필수 적이다. 이러한 BPR, ISP, A/D 추진하는데 있어서 각 단계의 산출물은 유연하게 연계되지 못한다. 그 이유는 각 단계가 접근하는 초점이 다르고, 산출물의 성격이 다르며, 무엇보다도 각 단계의 전문가가 다르기 때문에 발생한다. 현재 기업이 각 단계를 추진할 때에는 반복적인 피드백을 통하여 정보를 공유하거나, 각 단계의 정보 연계가 제대로 이루어지지 않는다. 이러한 문제를 해결하기 위하여 BPR-ISP-A/D의 정보 연계를 유연하게 하기 위하여 PPO (Product-Process-Organization) 객체 진화에 의한 통합 방법론을 제안 하고자 한다. 그 과정은 1) Real world 정보를 PPO 객체로 정의하고, 2) PPO 객체를 기반으로 BPR을 수행하여 TO-BE model 을 만드는 동시에, 3) PPO TO-BE model과 함께 IT Architecture를 정의하며, 4) PPO 객체를 기반으로 Analysis and Design 과정을 통하여 Application system 객체 및 Data 객체를 정의한다. 이때 PPO 객체는 Real-world 객체에서 Application system 객체 및 Data 객체로 진화하게 되고 BPR-ISP-A/D의 seamless 통합이 이루어진다. 여기서, 단계 1) 과 2)는 System Engineering을 통하여 이루어진다. ARIS(Architecture of Integrated Information System, Dr. A-W. Scheer, 1998)개념을 도입하여 실세계를 정해진 규약에 따라 Model로 Mapping하고, 생성된 Model을 바탕으로 BPR을 수행하여 개선된 Model을 산출해 낸다. 단계 3)은, IE (Information Engineering, James Martine, 1990) 의 ISP가 도입되어, 설계업무를 지원하기위한 기본적인 시스템 구조를 구상하게 된다. 이와 함께 IT Model을 구성하게 되는데, 객체지향적 접근 방법으로 Model을 생성하고 UML(Unified Modeling Language)을 Tool로 사용한다. 단계 4)는 Software Engineering 관점으로 접근한다. 이는 최종산물이라고 볼 수 있는 설계업무 지원 시스템을 Design하는 과정으로, 시스템에 사용될 데이터를 Design하는 과정과, 데이터를 기반으로 한 기능을 Design하는 과정으로 나눈다. 이를 통해 생성된 Model에 따라 최종적으로 Coding을 통하여 실제 시스템을 구축하게 된다.

• Land and Housing Review
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• v.13 no.3
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• pp.115-123
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• 2022

Recently, the adoption of BIM technology in domestic civil engineering projects has continually increased both in its numbers and scope. However, the BIM model was developed and used after the 2D design was developed instead of creating the BIM model from the conceptual design phase. BIM must be used throughout every phase of design and construction to use BIM for its original purpose. However, if BIM application is applied in heavy civil projects without a step-by-step guideline, it can confuse the market and face industry resistance to using BIM. Therefore, BIM is currently being used step by step in the civil engineering field by using BIM as a conversion design. However, the BIM conversion design method, currently being performed in the Preliminary design stage, has many difficulties due to low work efficiency. This paper analyzes the existing process of converting a 2D design into a 3D BIM model while addressing the issues related to its low work efficiency. To this end, a novel approach to 2D to BIM conversion for the design development stage is proposed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.611-619
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• 2008

2.5D Mapping system that embody in this paper can make new design by doing draping to live various texture and model picture image of fashion clothes by pattern, and can confirm clothes work to simulation without producing direction sample or product directly. Also, the system can support function that can forecast fabric design and state of end article exactly, and the system can bring competitive power elevation of fashion industry and cost-cutting effect by doing draping using database of fabric and model picture image. 2.5D Mapping system composed and embodied by mesh warp algorithm module, light and shade extraction and application module, mapping path extraction module, mesh creation and transformation module, and 2.5D mapping module for more natural draping. Future work plans to study 3D fashion design system that graft together 3D clothes technology and 3D human body embodiment technology to do based on embodiment technology of 2.5D mapping system and overcomes expression limit of 2.5D mapping technology.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.155-159
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• 2020

In this study, the structural analyses were performed on the number of leaf springs in large truck. The deformations were small for all four models. The maximum stress of model A was found to be the largest, and that of model D was the smallest. Model A was seen about 1.87 times larger than model D and about 1.52 times larger than model B. The maximum stresses of models C and D were seen to be less. In terms of the effect to reinforce one more overlapping spring, The effect of the enhancement of the strength of model D was shown to be small by comparing with model C. Therefore, model C with three overlapping springs is thought to be efficient in design and good in strength. The structural strength of leaf spring can be evaluated by applying this study result to the leaf spring at large truck. And it is seen that the result can be the design of the leaf spring with durability at large truck and the aesthetic convergence.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1299-1307
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• 2014

In this work, an appropriate analysis model of a precise foot sensor with low detection pressure capability under a low range of variation in the dimensional variables was proposed. With a simple two-dimensional model, it was found that a remarkably high error level sometimes occurred between the analysis and experimental results. In order to overcome the error and improve the performance, a three-dimensional model was introduced, and the detection pressure and sensor characteristics were compared with those of the experimental results, which showed its enhanced performance with less error and higher precision.

• Journal of KIBIM
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• v.7 no.2
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• pp.8-15
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• 2017

Building Information modeling is playing an important role in transforming the construction industry. It helped the industry with better visualization, minimum design errors, and excellent planning of the construction activities. Time and cost saving can be effectively achieved by using BIM for any construction project. It improves information exchange between all the project stakeholders. However, the development of earthwork 3D BIM is still underway and has not been fully implemented yet. This paper presents the study of a complete process for Earthwork BIM design using Autodesk Civil 3D. A real site road construction project is used as a case study to explain the process of earthwork modeling, starting from laser scanning to 3D model. Quantity take off calculation is very important part of any road construction project so during this study earthwork volume from two 3D earthwork model is calculated. The results obtained through this study will be the basis for future work which has been concluded in this paper.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.67-76
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• 2012

In this paper, collision analysis of the full rake for the Next Generation High-speed EMU is conducted using a 3D/1D hybrid model, which combines 3-dimensional (3D) front-end structure of finite element model and 1-dimensional (1D) multi-body dynamics model in order to analyze train collision with a standard 3D deformable obstacle. The crush forces, passengers' accelerations and energy absorptions of a full rake train can be easily obtained through a simulation of a 1D dynamics model composed of nonlinear springs, dampers and masses. Also the obtained simulation results are very similar to those of a 3D model if an overriding behavior does not occur during collision. The standard obstacle in TSI regulation has been changed from a rigid body to a deformable body, and therefore 3D collision simulations should be conducted because their simulation results depends on the front-end structure of a train. According to the obstacle collision analysis of this study, the obstacle collides with the driver's upper structure after overriding over the front-end module. The 3D/1D hybrid model is effective to evaluate a main energy-absorbing module that is frequently changed during design process and reduce the need time of the modeling and analysis when compared to a 3D full car body.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.335-343
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• 2006

Design changes for an original surface model are frequently required in a manufacturing area: for example, when the physical parts are modified or when the parts are partially manufactured from analogous shapes. In this case, an efficient 3D model updating method by locally adding scan data for the modified area is highly desirable. For this purpose, this paper presents a new procedure to update an initial model that is composed of combinatorial triangular facets based on a set of locally added point data. The initial surface model is first created from the initial point set by Tight Cocone, which is a water-tight surface reconstructor; and then the point cloud data for the updates is locally added onto the initial model maintaining the same coordinate system. In order to update the initial model, the special region on the initial surface that needs to be updated is recognized through the detection of the overlapping area between the initial model and the boundary of the newly added point cloud. After that, the initial surface model is eventually updated to the final output by replacing the recognized region with the newly added point cloud. The proposed method has been implemented and tested with several examples. This algorithm will be practically useful to modify the surface model with physical part changes and free-form surface design.