• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.205-212
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• 2003

This paper may provide a basic design data for the safer car seat mechanism and the quality of the material used by finding out the passenger's dynamic behavior when protected by seat belt during collision. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the seat is constructed using CAD program. The formation of a finite element from a geometric data of the seat is carried out using Hyper-Mesh that is the commercial software for mesh generation and post processing. In addition to seat modeling, the finite element model of seat belt and dummy is formed using the same software. Rear impact analysis is accomplished using Pam-Crash with crash pulse. The part of the recliner and right frame is under big stress in rear crash analysis because the acceleration force is exerted on the back of the seat by dummy. The stress condition of the part of the bracket is checked as well because it is considered as an important variable on the seat design. Front impact model which including dummy and seal belt is analyzed. A Part of anchor buckle of seat frame has high stress distribution because of retraction force due to forward motion of dummy at the moment of collision. On the basis of the analysis result, remodeling and reanalysis works had been repeatedly done until a satisfactory result is obtained.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.42-50
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• 2017

A cerebral aneurysm is a ballooning arising from a weakened area in the wall of a blood vessel in the brain. In this study, the flow analysis of the blood vessel, including the cerebral aneurysm and the stent, was conducted to investigate the effect of the stent shape on reduction of blood flowing into the cerebral aneurysm. We used the Carreau model to describe Non-Newtonian behaviors of blood flow. Two kinds of stents, which had different cross angles were modelled by the commercial CAD program and the geometries of those stents were reflected in the analysis domain of the blood vessel. From the results of the flow analysis, we found that the blood flowing into the cerebral aneurysm was decreased as the cross angle of the stent was decreased.

• Korean Journal of Computational Design and Engineering
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• v.4 no.4
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• pp.381-390
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• 1999

In this study, a pseudo ship structure data model for the :.hip cargo hold structure based on STEP is proposed. The proposed data model is based on Application Reference Model of AP218 Ship Structure which is the model that specifies conceptual structures and constraints used to describe the information requirements of an application. And the proposeddata model refers the Ship Common Model framework for the model architecture which is the basis for ongoing ship AP development within the ISO ship-building group and the ship product definition information model of CSDP research project for analyzing the relationship between ship structure model entities. The proposed data model includes Space, Compartment. Ship Structural System, Structural Part and Structural Feature of cargo hold. To generate this data model schema in EXPRESS format, ‘GX-Converter’was used which enables user to edit a model in EXPRESS format and convert schema file in EXPRESS format. Using this model schema, STEP physical file containing design data for ship cargo hold data structure was generated through SDAI programming. The another STEP physical file was also generated containing geometry data of ship cargo hold which was extracted and calculated by SDAI and external surface/surface intersection program. The geometry information of ship cargo hold can be then transferred to commercial CAD system, for example, Pro/Engineer. Examples of the modification of the design information are also Presented.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.126-132
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• 2005

In this paper, an auto-design system is introduced for a stamping tool based on commercial computer aided design system with its drafting language. The auto-design system consists of tool oriented product design subsystem which modifies and configures the product drawing, tool concept design subsystem which make a design of the punches and their punching progression and parts design subsystem that makes automatic dimension. The system is applied to the mechanical design of the stamping tool. The main logic of the system is based on half-edge theory, a kernel for the 3 dimensional CAD system, which is applied to 2 dimensional drafting auto-design system. The auto-design system enables to conspicuously reducing the designing time of the tool. In addition, there is little drafting error that had been about 3% without auto design program. It is effective to reduce the development time for new products because of rapid designing time of the tools, standardization of the stamping tool and the drafting rule for the auto-design system. The auto-design system yields high efficiency of the tool manufacturing system.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.149-156
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• 2006

The demands for the development of large scale software systems are being increased. Various software development methods have been introduced to meet these demands. The unit size of the codes that are reused is increasing in the development methods. These units reflect the concept of software reusability and can be identified as the object, component, and module. Recent trend in the development or a large scale software systems treats a commercial program as a unit to be reused. This approach lies along the same line as the identification of above three types of units. This paper shows how the above four types of units for enhancing the software reusability can be applied to the development of automatic graphic drawing System for a metal production.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.8-14
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• 2011

The clogging of the flow area at the tube support plates(TSPs), especially at the upper TSPs results in the water level oscillation of a steam generator during normal operation. A reduction of the TSP flow area causes to increase in pressure drop within the two-phase flow zone, which destabilizes the boiling flow through the tube bundle. This phenomenon was occasionally observed at a few domestic and foreign nuclear power plants. One of the methods for defining the flow area clogging is visual inspection, which is the most effective inspection method. The results of the visual inspection for TSPs' flow area are clogging images on TSPs' quartrefoil lobes. These images are complexly distorted due to lens aberration and external factors like the distance to a subject and angle etc. In this work, we developed the analysis algorithm for clogging image of the TSP flow area of steam generators. For this purpose, we designed an image verification device applicable to the camera employed in the field for visual inspection and then, we demonstrated the validity of image analysis algorithm by using this device and commercial autoCAD program.

• Land and Housing Review
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• v.8 no.1
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• pp.23-29
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• 2017

The BIM design is expected to expand to the domestic and overseas construction industries, depending on the effect of construction productivity and quality improvement. However, with the obligation of Public Procurement Service to design the BIM design, it includes a design error and the problem of utilization of 3D design by choosing a simple 2D to 3D remodelling method that can not be modelled in 3D modeling or use of the construction and maintenance phases. The results reviewed by BIM design results were largely underutilized and were not even performed with the verification of the error. In order to resolve this, one must develop the check system that secures the quality of BIM design and ensure that the reliability of BIM results are available. In this study, it is designed to develop a program that can automatically verify the design of the BIM design results such as violation of the rules of the BIM design, design flaws, and improve the usability of the BIM design. In particular, this programs were developed not only to identify programmes that were not commercially available, but also to validate drawings in low-light computer environments. The developed program(LH-BIM) store the information of attribute extracted from the Revit file(ArchiCAD, IFC file included) in the integrated DB. This provides the ability to freely lookup the features and properties of drawings delivered exclusively by the LH-BIM Program without using the Revit tools. By doing so, it was possible to resolve the difficulties of using traditional commercial programs and to ensure that they operate only with traditional PC performance. Further, the results of the various BIM software can be readily validated, which can be solved the conversion process error of IFC in the case of SMC. Additionally, the developed program has the ability to automatically check the error and design criteria of the drawings, as well as the ability to calculate the area estimation. These functions allow businesses to apply simple and easy tasks to operate tasks of BIM modelling. The developed system(LH-BIM) carried out a verification test by reviewing the review of the BIM Design model of the Korea Land & Housing Corporation. It is hoped that the verification system will not only be able to achieve the Quality of BIM design, but also contribute to the expansion of BIM and future construction BIM.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.348-357
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• 2024

Maneuvering performance is crucial for fishing vessels, especially under operational conditions that involve frequent course changes and weight variations due to catch. Small vessel accidents account for approximately 60% of maritime incidents as of 2022, mainly attributed to collisions and stranding accidents due to insufficient maneuvering performance. Especially, accidents that occur on small vessels less than 10 tons account for about 65% of all accidents. The absence of international standards presents challenges in accurately evaluating the maneuvering performance of small vessels. In this study, a 4.99-ton small fishing vessel was selected as the target, and a 3d-cad model was created. The commercial numerical analysis program STAR-CCM+ was employed to establish a simulation environment for the vessel's maneuvring motion. Based on this standard loading conditions and weight distribution were considered, 10° / 10°, 20° / 20° zigzag tests and 35° turning test were conducted. The results revealed a tendency for decreased yaw and course-keeping performance and improved turning performance as the hull weight increased. However, in partial arrival and full load departure condition, the manoeuvering performance were relatively poor. Based on this, the need for evaluation of maneuvering and standardized criteria of maneuvering performance for safe navigation of small vessels is presented. Furthermore, it is expected that the evaluation results of maneuvering performance in this study can serve as fundamental data for establishing criteria for evaluating the maneuvering performance of small vessels.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.62-67
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• 2007

The research team for the virtual construction development was established with the support of Korea Ministry of Construction and Transportation, and KICTEP (Korea Institute of Construction and Transportation Technology Evaluation and Planning). Its aims are to develop system that is to improve productivity & quality, to create a higher value-added business, and to cultivate international competitiveness in the construction industry. The virtual construction system is a design, engineering, and construction management information system that allows the project participants to effectively share the information throughout the construction life cycle with the support of 3D and design information. To achieve this, the research team focuses on developing several systems. First, the team focuses on developing for the pre-planning, the structural engineering, MEP, and the 3D based estimation system. Second, they focus on developing a simulation system for the construction process planning and feasibility study with help of the virtual reality technologies. Third, they focus on developing the CPLM (Construction Project Life-cycle Management) system for managing construction project data, and the decision support system that makes the collaboration among the project participants based on 3D technologies and information. We also focus on developing the SDAI (Standard Data Access Interface), the localized guideline for 3D design, and a training program. In addition, we focus on developing the undeveloped area of the commercial system and building an environment that can support the communication and collaboration in the construction life-cycle rather than developing the existing and commercialized system.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.82-108
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• 2024

With the transition of archaeological recording method's transition from analog to digital, the 3D scanning technology has been actively adopted within the field. Research on the digital archaeological digital data gathered from 3D scanning and photogrammetry is continuously being conducted. However, due to cost and manpower issues, most buried cultural heritage organizations are hesitating to adopt such digital technology. This paper aims to present a digital recording method of relics utilizing open-source software and photogrammetry technology, which is believed to be the most efficient method among 3D scanning methods. The digital recording process of relics consists of three stages: acquiring a 3D model, creating a joining map with the edited 3D model, and creating an digital drawing. In order to enhance the accessibility, this method only utilizes open-source software throughout the entire process. The results of this study confirms that in terms of quantitative evaluation, the deviation of numerical measurement between the actual artifact and the 3D model was minimal. In addition, the results of quantitative quality analysis from the open-source software and the commercial software showed high similarity. However, the data processing time was overwhelmingly fast for commercial software, which is believed to be a result of high computational speed from the improved algorithm. In qualitative evaluation, some differences in mesh and texture quality occurred. In the 3D model generated by opensource software, following problems occurred: noise on the mesh surface, harsh surface of the mesh, and difficulty in confirming the production marks of relics and the expression of patterns. However, some of the open source software did generate the quality comparable to that of commercial software in quantitative and qualitative evaluations. Open-source software for editing 3D models was able to not only post-process, match, and merge the 3D model, but also scale adjustment, join surface production, and render image necessary for the actual measurement of relics. The final completed drawing was tracked by the CAD program, which is also an open-source software. In archaeological research, photogrammetry is very applicable to various processes, including excavation, writing reports, and research on numerical data from 3D models. With the breakthrough development of computer vision, the types of open-source software have been diversified and the performance has significantly improved. With the high accessibility to such digital technology, the acquisition of 3D model data in archaeology will be used as basic data for preservation and active research of cultural heritage.