• Journal of the HCI Society of Korea
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• v.6 no.1
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• pp.9-16
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• 2011

The previous researches of 3D object modeling have been performed in a limited environment where a target object only exists. However, in order to model an object in the real environment, we need to consider a dynamic environment, which has various objects and a frequently changing background. Therefore, this paper presents a segmentation and tracking method for a foreground which includes a target object in the dynamic environment. By using depth information than color information, the foreground region can be segmented and tracked more robustly. In addition, the foreground region can be tracked on the sequential images by referring depth distributions of the foreground region because both the position and the status in the consecutive images of the foreground region are almost unchanged. Experimental results show that our proposed method can robustly segment and track the foreground region in various conditions of the real environment. Moreover, as an application of the proposed method, it is presented a method for modeling an object extracting the object regions from the foreground region that is segmented and tracked.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.459-469
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• 2011

There are various factors for determining object shape, such as size, slope and its direction, curvature, length, surface, angles between lines or planes, distribution of the model key points, and so on. Most of the object description and recognition methods are for the 2D space not for the 3D object space where the objects actually exist. In this study, 3D chain code operator, which is basically extension of 2D chain code, was proposed for object description and analysis in 3D space. Results show that the sequence of the 3D chain codes could be basis of a top-down approach for object recognition and modeling. In addition, the proposed method could be applicable to segment point cloud data such as LiDAR data.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.75-79
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• 1999

Geo-features play a key role in object-oriented or feature-based geo-processing system. So the strategy for how-to-model and how-to-manage the geo-features builds the main architecture of the entire system and also supports the efficiency and functionality of the system. Unlike the conventional 2D geo-processing system, geo-features in 3B GIS have lots to be considered to model regarding the efficient manipulation and analysis and visualization. When the system is running on the Web, it should also be considered that how to leverage the level of detail and the level of automation of modeling in addition to the support for client side data interoperability. We built a set of 3D geo-features, and each geo-feature contains a set of aspatial data and 3D geo-primitives. The 3D geo-primitives contain the fundamental modeling data such as the height of building and the burial depth of gas pipeline. We separated the additional modeling data on the geometry and appearance of the model from the fundamental modeling data to make the table in database more concise and to allow the users more freedom to represent the geo-object. To get the users to build and exchange their own data, we devised a file format called VGFF 2.0 which stands for Virtual GIS File Format. It is to describe the three dimensional geo-information in XML(eXtensible Markup Language). The DTD(Document Type Definition) of VGFF 2.0 is parsed using the DOM(Document Object Model). We also developed the authoring tools for. users can make their own 3D geo-features and model and save the data to VGFF 2.0 format. We are now expecting the VGFF 2.0 evolve to the 3D version of SVG(Scalable Vector Graphics) especially for 3D GIS on the Web.

• Korean Journal of Computational Design and Engineering
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• v.10 no.4
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• pp.244-253
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• 2005

In the initial ship design stage of shipyards, the hull form design, the basic design (compartment modeling and ship calculation), and the hull structural design are being performed by different systems. Thus, the problem on interfaces between these systems occurs. To solve this, we developed the hull form design system 'EzHULL' and the compartment modeling and ship calculation system 'EzCOM-PART' for developing finally an integrated ship design system. And, in this study, we present an object-oriented hull structural design .system 'EzSTRUCT', which is developed recently. A structural design in an initial design stage can be frequently changed, because the design is not firmly determined yet. Therefore, designers perform the simplified structural modeling with bigger structural parts (or objects) such as deck, longitudinal bulkhead, etc. in the initial design stage, and the detailed structural modeling with smaller structural parts such as plate, seam, slot, etc. in the detailed design stage. However, the existing hull structural CAD system used in a shipyard is not efficient in generating a 3D CAD model in the initial design stage, because it has difficulty in handling frequent changes in design. Therefore, designers initially draw 2D drawings in the initial design stage, and generate the 3D CAD model from these 2D drawings in the detailed design and production design stages. In this study, the hull structural design system, which can efficiently generate a 3D CAD model through rapid modeling at an initial design stage, was developed in this study To evaluate the applicability of the developed system, we applied it to hull structural modeling of various ships such as a VLCC, a bulk carrier, etc. As a result, it could efficiently generate a 3D CAD model of a hull structure.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.409-410
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• 2006

We propose a surface modeling method using multi-laser lining. We can acquire 3D surface by analyzing projected laser lines on object. The laser lines reflect the surface curvature. In this paper, we show two novel approaches to reconstruct 3D shape of moving object. One is used for robust laser line extraction, and the other for registration between 3D shapes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.479-493
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• 2016

LiDAR(Light Detection and Ranging) data acquired from ALS(Airborne Laser Scanner) has been intensively utilized to reconstruct object models. Especially, researches for 3D modeling from LiDAR data have been performed to establish high quality spatial information such as precise 3D city models and true orthoimages efficiently. To reconstruct object models from irregularly distributed LiDAR point clouds, sensor calibration, noise removal, filtering to separate objects from ground surfaces are required as pre-processing. Classification and segmentation based on geometric homogeneity of the features, grouping and representation of the segmented surfaces, topological analysis of the surface patches for modeling, and accuracy assessment are accompanied by modeling procedure. While many modeling methods are based on the segmentation process, this paper proposed to extract key points directly for building modeling without segmentation. The method was applied to simulated and real data sets with various roof shapes. The results demonstrate feasibility of the proposed method through the accuracy analysis.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.977-982
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• 2007

There have been many efforts in automatic object recognition using computing technologies. Especially in the development of automated construction equipment, automatic object recognition is very important issue for the proper equipment maneuvering. 3D laser scanning, which uses (time-of-flight) method to construct the 3-dimensional information, is applied to the civil earth work environment for its high accuracy, quick data collection, and object recognition capability that will be developed by the authors in the future. The 3D earth model is also used as a fundamental information for intelligent earth work task planning. This paper presents the analysis of the 3D laser scanner market and selection of the most optimum 3D scanner for the intelligent earth work planning. As well as the hardware configuration for the automated 3D earth modeling is developed but also the software structure and detailed user interface are designed in this research. In addition, it is presented in this paper that the accuracy comparison test between TotalStation(R) which is a traditional survey tool and ScanStation(R). The accuracy test is done by relative distance measurement using known targets.

• Journal of Multimedia Information System
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• v.4 no.1
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• pp.1-8
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• 2017

In recent years, the quixotic nature and concentration of rainfall due to global climate change has intensified. To monitor localized heavy rainfalls, a reliable disaster monitoring and warning system with advanced remote observation technology and high-precision display is important. In this paper, we propose a GIS-based intuitive and realistic 3D radar data display technique for accurate and detailed weather analysis. The proposed technique performs 3D object modeling of various radar variables along with ray profiles and then displays stereoscopic radar data on detailed geographical locations. Simulation outcomes show that 3D object modeling of weather radar data can be processed in real time and that changes at each moment of rainfall events can be observed three-dimensionally on GIS.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.177-180
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• 2006

In this paper we proposed a method of automatic point segmentation acquired by 2D laser scanner to recognize moving objects. Recently, Laser scanner is noticed as a new method in the field of close range 3D modeling. But the majority of the researches are pointed on precise 3D modeling of static objects using expensive 3D laser scanner. 2D laser scanner is relatively cheap and can obtain 2D coordinate information of moving object's surface or can be utilized as 3D laser scanner by rotating the system body. In these reasons, some researches are in progress, which are adopting 2D laser scanner to robot control systems or detection of objects moving along linear trajectory. In our study, we automatically segmented point data of 2D laser scanner thus we could recognize each of the object passing through a section.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1999.12a
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• pp.47-51
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• 1999

Geo-features play a key role in object-oriented or feature-based geo-processing system. So the strategy for how-to-model and how-to-manage the geo-features builds the main architecture of the entire system and also supports the efficiency and functionality of the system. Unlike the conventional 2D geo-processing system, geo-features in 3D GIS have lots to be considered to model regarding the efficient manipulation and analysis and visualization. When the system is running on the Web, it should also be considered that how to leverage the level of detail and the level of automation of modeling in addition to the support for client side data interoperability. We built a set of 3D geo-features, and each geo-feature contains a set of aspatial data and 3D geo-primitives. The 3D geo-primitives contain the fundamental modeling data such as the height of building and the burial depth of gas pipeline. We separated the additional modeling data on the geometry and appearance of the model from the fundamental modeling data to make the table in database more concise and to allow the users more freedom to represent the geo-object. To get the users to build and exchange their own data, we devised a fie format called VGFF 2.0 which stands for Virtual GIS File Format. It is to describe the three dimensional geo-information in XML(extensible Markup Language). The DTD(Document Type Definition) of VGFF 2.0 is parsed using the DOM(Document Object Model). We also developed the authoring tools for users can make their own 3D geo-features and model and save the data to VGFF 2.0 format. We are now expecting the VGFF 2.0 evolve to the 3D version of SVG(Scalable Vector Graphics) especially for 3D GIS on the Web.