• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.58-68
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• 2003

Despite the availability of 3D CAD systems, the designers in shipyards still use 2D CAD systems because of the need to produce drawings rapidly and a shortage of labor. The design information of ship structure contained in 2D drawings is represented by symbols that are well known among designers in shipyard. The shapes of symbols are recognized by analysis of experienced and knowledgeable designers. We propose a method for automatic recognition of 2D symbols and extraction of design information from the midship drawings. The shape and rationale of 20 symbols used in ship design have been analyzed, and symbols have been classified according to the analysis. Based on the classified symbols, the developed system recognizes the symbols expressed in 2D drawings. The meaningless geometric shape is translated into the design information including designer's intents. The extracted design data can be applied to the downstream design process in shipyards, and the 3D ship model can be automatically created.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1596-1606
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• 2006

There has been more increased the development of 3D technique since many 3D contents of 3D graphic model, 3D mobile/computer game, and 3D CAD have been serviced in Web or industry fields. Therefore, the watermarking system is more required to protect the copyright for 3D contents. Currently there has been researched about the watermarking for 3D graphic model of mesh or NURBS. However, watermarking technique based on CAD design drawing leaves something to be desired yet. This paper proposed the watermarking technique for 3D CAD design drawing using Line and Arc components. After drawing out Line and Arc components from designed drawing, we embed the watermark into both the length of Line component and the radius of Arc component. Experimental results verified that the proposed algorithm satisfies the transparency about watermarked drawing and also has the robustness against several attacks by using public CAD tool.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.247-252
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• 2008

Recently, the virtual construction system in which project participants efficiently share and control the information throughout the life-cycle of construction project using 3D object models is being developed all over the world. In this paper, a design of interface between 3D object model of structures and structural analysis system that is essential for the analysis and design of civil structures in the virtual space is treated. The relation parametric modeling technique that is needed to make the 3D object models and the construction method of product breakdown structure(PBS) that considers the several parameters for the structural analysis are presented. PBS is built so that it is possible to extract needed attribute information from 3D object model and to apply it to the structural analysis. Design methodology for interface program is proposed that several numerical values determined by the cooperative work same as structural analysis are delivered to 3D object models without additional work. An interface program between 3D object models and structural analysis system developed based on the proposed method would be effectively used to develop virtual construction system.

• Korean Journal of Computational Design and Engineering
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• v.14 no.6
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• pp.364-373
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• 2009

In this paper, we suggest the method for constructing parameterized human body model which has any required body sizes from 3D scan data. Because of well developed 3D scan technology, we can get more detailed human body model data which allow to generate precise human model. In this field, there are a lot of research is performed with 3D scan data. But previous researches have some limitations to make human body model. They need too much time to perform hole-filling process or calculate parameterization of model. Even more they missed out verification process. To solve these problems, we used several methods. We first choose proper 125 3D scan data from 5th Korean body size survey of Size Korea according to age, height and weight. We also did post process, feature point setting, RBF interpolation and align, to parameterize human model. Then principal component analysis is adapted to the result of post processed data to obtain dominant shape parameters. These steps allow to reduce process time without loss of accuracy. Finally, we compare these results and statistical data of Size Korea to verify our parameterized human model.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.4
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• pp.24-29
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• 2015

Bridge construction cost estimates have generally been conducted by using historial unit-price(per meter or square meter). The traditional estimating method based on unit-price references can never completely reflect the specialty of cable supported bridge. In this paper, we have developed the system for supporting the approximate construction cost and the quantity estimation based on 3D model information in the pre-project planning phase of 3-span continuous suspension bridge with 2-pylons. First of all, we'd analyzed the design information (such as structural design report, blueprint and quantity) and the real cost data from the existing suspension bridges and derived the design variables of the bridges. We developed the BIM wizard that generates a suspension bridge model parametrically based on derived design variables. The principle material quantities of suspension bridge are calculated directly from 3-dimensional bridge model built by using the BIM wizard. We have established the system that the construction cost can be estimated more specific than the traditional estimating method.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.415-420
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• 1998

In this paper, 2D SUB-3D STM approach for analysis and design of 3D structural concrete is presented. In the approach several 2D sub strut-tie models which are representations of compressive and tensile stress flows of each projected plane of 3D structural concrete are utilized in the sketch of a 3D strut-tie model, in the evaluation of effective strengths of compressive concrete struts, and in the verification of geometric compatibility and bearing capacity of critical nodal zones of 3D strut-tie model. To prove the validity and rationality of the suggested approach, the behavior and strength of a prestressed box girder diaphragm tested to failure are evaluated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.58-65
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• 2020

3D Models of offshore plant piping materials designed by 3D CAD systems are provided to the production processes in the form of 2D piping drawings and 2D piping installation drawings. In addition to the standard engineering information, the purchasing, procurement, manufacturing, installation, and inspection of raw materials are managed systematically in an integrated process control system. The existing integrated process management system can help reduce the processing time by managing the flow and progress of resources systematically, but it does not include 3D design model information. Hence, it is difficult to understand complicated pipe structures before installing the pipe. In addition, when design changes or immediate design modifications are required, it is difficult to find related data or exchange information quickly with each other. To solve this problem, an offshore plant-piping process-monitoring system was developed based on a 3D model. The 3D model-based piping monitoring system is based on Visual Studio 2017 C# and UNITY3D so that the piping-process work information can be linked to the 3D CAD model in real time. In addition, the 3D model could check the progress of the pipe installation process, such as block, size, and material, and the progress of functional inspection items, such as cleaning, hydraulic inspection, and pneumatic inspection.

• Journal of KIBIM
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• v.4 no.3
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• pp.1-9
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• 2014

As BIM application continues to increase in civil engineering, in this study, 3D information model for RC(Reinforced Concrete) bridge pylon was developed and verified its effectiveness at the structural-design stage. To define 3D information model of RC A-Type pylon, characteristics of pylon were analyzed and 3D model structure was constructed. The 3D information model, one of the core product of BIM, manages all information generated during all life-cycle of a structure and consequently maximizes the efficiency of utilizing information. Also, this study proposes interface module between input data in structural analysis and 3D model of RC pylon. The module can create the input data for non-linear structural analysis. It is essential to study on method of developing 3D information model and propose a structural analysis model by utilizing 3D model for the effective use of BIM techniques in construction industry. The results of this study can be used as the base data for developing the 3D information model of RC pylon in the structural analysis field.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.1
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• pp.66-74
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• 2019

In the field of shipbuilding design, the use of 3D CAD is becoming commonplace, and most of the large shipyards are conducting 3D design. However at the production site, workers are still working on 2D drawings rather than 3D models. This tendency is even worse in small-scale shipyards and block manufacturing shops. Particularly, in a manufacturing shop that is engaged in the outsourcing of blocks, it may not be possible to provide 3D model. However, the demand for 3D models in the production field is steadily increasing. Therefore, it would be helpful if 3D model could be generated from a 2D drawing. In this paper, we propose a method to extract template and unfolded surface shape information from shell template offset drawing using computer vision technology. Also a 3D surface model was reconstructed and visualized from the extracted information. The result of this study is thought to be helpful in the work environment where 3D model information can not be obtained.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.241-246
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• 2008

Design of a high-speed railway line requires collaboration of heterogeneous application systems and of engineers with different background. Object-based 3D models with metadata can be a shared information model for the effective collaborative design. In this paper, railway infrastructure information model is proposed to enable integrated and inter-operable works throughout the life-cycle of the railway infrastructures, from planning to maintenance. In order to develop the model, object-based 3-D models were built for a 10km railway among Korea high-speed railway lines. The model has basically three information layers for designers, contractors and an owner, respectively. Prestressed concrete box-girders are the most common superstructure of bridges. The design information layer has metadata on requirements, design codes, geometry, analysis and so on. The construction layer has data on drawings, real data for material and products, schedules and so on. The maintenance layer for the owner has the final geometry, material data, products and their suppliers and so on. These information has its own data architecture which is derived from similar concept of product breakdown structure(PBS) and work breakdown structure(WBS). The constructed RIIM for the infrastructures of the high-speed railway was successfully applied to various areas such as design check, structural analysis, automated estimation, construction simulation, virtual viewing, and digital mock-up. The integrated information model can realize virtual construction system for railway lines and dramatically increase the productivity of the whole engineering process.