• Journal of KIBIM
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• v.7 no.1
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• pp.1-8
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• 2017

Aesthetic design guidelines of bridges were developed in many countries. As iconic structures, bridges need to be attractive and durable as they serve many generations. In this paper, a new design process of concrete structures considering 3D shapes and texture was proposed. The 3D design needs to consider function, economy, advanced technology, tradition and local culture. 3D printers enable the combination of artistic design and engineering design for concrete structures. Parametric modeling with iconic design was utilized to produce 3D formworks. As a pilot project, a railway bridge girder was designed and the proposed technologies were applied. Detail requirements to improve constructability and quality of concrete surfaces were derived. From the pilot applications, design guidelines were suggested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.35-46
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• 2013

A parametric modeling method, one of the core technology of BIM (Building Information Modeling), is proposed for efficient 3D assembly design among components of a superstructure module of modular steel bridge. Assembly system is classified into 3 levels as LoD (Level of Details) for 3D assembly design of the parts. Components forming 3D shape of the parts are identified and defined as parameters, variables depending on parameters, or constants independent of the parameters. Then, spatial assembly rules among the parts are defined according to the assembly system. Positional relations among the identified shape components are defined for mating spatial position and geometrical relations are defined for constraining degree of freedom on X, Y, and Z axis. Finally, a standardized template is designed by applying the rules to 3D based assembly design for the parts of the superstructure module. In addition, applicability of the parametric modeling method is demonstrated by testing the shape variation of the superstructure module according to changing the defined parameters.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.27-33
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• 2016

In this study we propose a method for 3D landform reconstruction and object modeling method by generating contour lines on the map using a depth sensor which abstracts characteristics of geological layers from the depth map. Unlike the common visual camera, the depth-sensor is not affected by the intensity of illumination, and therefore a more robust contour and object can be extracted. The algorithm suggested in this paper first abstracts the characteristics of each geological layer from the depth map image and rearranges it into the proper order, then creates contour lines using the Bezier curve. Using the created contour lines, 3D images are reconstructed through rendering by mapping RGB images of the visual camera. Experimental results show that the proposed method using depth sensor can reconstruct contour map and 3D modeling in real-time. The generation of the contours with depth data is more efficient and economical in terms of the quality and accuracy.

• Journal of Fashion Business
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• v.20 no.3
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• pp.30-42
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• 2016

The objective of this study was to perform 3D solid modeling from 3D scanned surface images of cotton and silk in order to calculate the thermal heat transfer responses using numerical simulations. Continuing from the previous methodology, which provided 3D surface data for a fabric through optical measurements of the fabric microstructure, a simplified 3D solid model, containing a defined unit cell, pattern unit and fabric structure, was prepared. The loft method was used for 3D solid-model generation, and heat transfer calculations, made for the fabric, were then carried out using the 3D solid model. As a result, comprehensive protocols for 3D solid-model generation were established based on the optical measurements of real fabric samples. This method provides an effective means of using 3D information for building 3D models of actual fabrics and applying the model in numerical simulations. The developed process can be used as the basis for other analogous research areas to investigate the physical characteristics of any fabrics.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.599-607
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• 2002

The octree model, a hierarchical volume description of 3D objects, nay be utilized to generate projected images from arbitrary viewing directions, thereby providing an efficient means of the data base for 3D object recognition and other applications. We present 2D projected image and made pseudo gray image of object using octree model and multi level boundary search algorithm. We present algorithm for finding feature points of 2D and 3D image and finding matched points using geometric transformation. The algorithm is made of data base, it will be widely applied to 3D object modeling and efficient feature points application for basic 3D object research.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.2
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• pp.35-47
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• 2018

The 4th industrial revolution, digital image technology has developed beyond the limit of multimedia industry to advanced IT fusion and composite industry. Particularly, application technology related to HCI element algorithm in 3D image object recognition field is actively developed. 3D image object recognition technology evolved into intelligent image sensing and recognition technology through 3D modeling. In particular, image recognition technology has been actively studied in image processing using object recognition recognition processing, face recognition, object recognition, and 3D object recognition. In this paper, we propose a research method of human factor 3D image recognition technology applying human factor algorithm for 3D object recognition. 1. Methods of 3D object recognition using 3D modeling, image system analysis, design and human cognitive technology analysis 2. We propose a 3D object recognition parameter estimation method using FACS algorithm and optimal object recognition measurement method. In this paper, we propose a method to effectively evaluate psychological research techniques using 3D image objects. We studied the 3D 3D recognition and applied the result to the object recognition element to extract and study the characteristic points of the recognition technology.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.1
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• pp.38-48
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• 2007

In this paper, we propose an image-based method for modeling 3D objects with curved surfaces based on the NURBS (Non-Uniform Rational B-Splines) representation. Starting from a few calibrated images, the user specifies the corresponding curves by means of an interactive user interface. Then, the 3D curves are reconstructed using stereo reconstruction. In order to fit the curves easily using the interactive user interface, NURBS curves and surfaces are employed. The proposed surface modeling techniques include surface building methods such as bilinear surfaces, ruled surfaces, generalized cylinders, and surfaces of revolution. In addition to these methods, we also propose various advanced surface modeling techniques, including skinned surfaces, swept surfaces, and boundary patches. Based on these surface modeling techniques, it is possible to build various types of 3D shape models with textured curved surfaces without much effort. Also, it is possible to reconstruct more realistic surfaces by using proposed view-dependent texture acquisition algorithm. Constructed 3D shape model with curves and curved surfaces can be exported in VRML format, making it possible to be used in different 3D graphics softwares.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.99-108
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• 2010

This paper presents the results of a study that aimed to develop a module for auto connection modeling that can be applied to the structural details design and modeling phase. It was established that the steel connection library database from the structural analysis resulted from the consideration of the input parameters of the 3D modeling program and the guidelines for Korean standard steel connections. The module for the auto connection modeling in steel structures was developed by linking it with the established library database through the use of the OpenAPI software to prove that the developed module carried out the modeling of the six story (steel structure) office building. The productivity and efficiency of the module introduction was verified by comparing the conventional process and the proposed process.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.91-101
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• 2011

This research aims to suggest web-based 3D face modeling system for hairline modification surgery. As public interests in beauty regarding face escalate with era of wide persoanl mobile smart iCT devices, need for medical information system is urgent and increasing demand. This research attempted to build 3D facing modeling library deploying conventional technology and proprietary software available. Implications from the our experiment found that problems and requirement for developing new web based standard. We suggest new system from our experiment and literature review regarding relevant technologies. Main features of our suggested systems is based on studies regarding hair loss treatment such as medical science, beauty studies and information technology. This system processes input images of 2D frontal and profile pictures of face into 3D face modeling with mesh-data. The mesh data is compatible with web standard technology including SVG and Canvas Tag supported natively by HTML5.

• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.318-325
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• 2008

Assigning an exact boundary condition is of great importance in three-dimensional (3D) magnetotelluric (MT) modeling, in which no source is considered in a computing domain. This paper presents a 3D MT modeling algorithm utilizing a Dirichlet condition for a 2D host. To compute boundary values for a model with a 2D host, we need to conduct additional 2D MT modeling. The 2D modeling consists of transverse magnetic and electric modes, which are determined from the relationship between the polarization of plane wave and the strike direction of the 2D structure. Since the 3D MT modeling algorithm solves Maxwell's equations for electric fields using the finite difference method with a staggered grid that defines electric fields along cell edges, electric fields are calculated at the same place in the 2D modeling. The algorithm developed in this study can produce reliable MT responses for a 3D model with a 2D host.