• Korean Journal of Construction Engineering and Management
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• v.23 no.3
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• pp.45-55
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• 2022

BIM models allow building spaces to be instantiated and recognized as unique objects independently of model elements. These instantiated spaces provide the required semantics that can be leveraged for building code checking, energy analysis, and evacuation route analysis. However, theses spaces or rooms need to be designated manually, which in practice, lead to errors and omissions. Thus, most BIM models today does not guarantee the semantic integrity of space designations, limiting their potential applicability. Recent studies have explored ways to automate space allocation in BIM models using artificial intelligence algorithms, but they are limited in their scope and relatively low classification accuracy. This study explored the use of Graph Convolutional Networks, an algorithm exclusively tailored for graph data structures. The goal was to utilize not only geometry information but also the semantic relational data between spaces and elements in the BIM model. Results of the study confirmed that the accuracy was improved by about 8% compared to algorithms that only used geometric distinctions of the individual spaces.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.51-63
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• 2023

Riverine tree management is crucial in realizing a balance between flood control and ecological preservation, which requires an accurate assessment of the impact of trees on river water elevations. In this study, eight different formulas for evaluating vegetation roughness considering the drag force acting on trees, were reviewed, and the characteristics and applicability of these methods were evaluated from a practical engineering perspective. The study compared the characteristics of vegetation roughness measurement methods for calculated roughness coefficients at different water depths and analyzed factors such as effects of tree canopy width, tree density and diameter, and tree stiffness coefficient, and water level estimation results. A comparison of roughness coefficients at the same water depths revealed that the Kouwen and Fathi-Moghadam formulas and the Fischenich formula yield excessive drag coefficients compared to other formulas. Factors such as channel geometry, tree diameter, and tree density showed varying trends depending on the formula but did not exhibit excessive outliers. Formulas considering the tree stiffness coefficient, such as the Freeman et al.'s formula and the Whittaker et al.'s formula, showed significant variations in drag coefficients depending on the stiffness coefficient. When applied to small- and medium-sized virtual rivers in South Korea using the drag coefficient results from the eight formulas, the results indicated a maximum increase in water level of approximately 0.2 to 0.4 meters. Based on this review, it was concluded that the Baptist et al., Huthoff et al., Cheng, Luhar, and Nepf's formulas, which exhibit similar characteristics and low input data uncertainties, are suitable for practical engineering applications.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.33-43
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• 2001

Mario Botta is one of the modern architects who established his own architectural world on the basis of the architectural spirit of Modernism. His works have been a good theme not only for those who study architecture but also for those who study the relationship between architecture and the surrounding environment and there have been many published papers and reports on his works. However, most of them stressed on the importance of the external appearance of architecture or on the relationship between architecture and the surrounding environment. There have been relatively few studies that have dealt intensively with interior space. The aim of this study is to find the characteristics of interior space in public buildings that were designed by Botta and to analyze them from the view design principles and design elements. For this purpose, the five most important public buildings were selected and the public space of the building like the central hall, the lobby, and the foyer were analyzed. Through this study, the followings are realized. A) Spatial features: $\circled1$ Refined and graceful interiors where the principle of symmetry was applied, $\circled2$ Centripetal interiors surrounded by thick walls, $\circled3$ Interior design lit by skylights above the central area, B) Formative features: $\circled1$ The shapes of the external and internal spaces are identical, $\circled2$ Simple geometrical shapes were applied in defining the shapes of internal spaces, $\circled3$ Skylights and light wells were combined and were utilized as form elements, $\circled4$ Architectural vocabularies of Corbusier such as stairs, round pillars, and bridges were developed and utilized, $\circled5$ Utilized the geometry that resembled his architecture as a form element to the furniture, C) material pattern features: $\circled1$ Plainly expressed the patterns of bricks that appear in the course of construction, $\circled2$ Made and used horizontal stripe patterns using stones of different colors.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.65-71
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• 2016

In recent years, 3D printing has received increasing attention due to releases of low-cost 3D printers based on open-source platform. 3D printing is expected to reduce the barrier to entry in the traditional manufacturing processes by increasing flexibility and creating an advantage to manufacture customized products at low costs. In this study, a unique eyeglass frame was designed to have a snake shape, which has an asymmetric geometry unlike traditional frames. The eyeglass frame was designed in a customized manner by reflecting dimensional characteristics of a customer's face. Finite element analysis was performed to investigate the structural safety of the 3D printed frames during the assembly process. The analysis also considered the effect of anisotropic material properties as determined by tensile tests. The eyeglass frame was then printed using the customized sizes and the best building process. The eyeglass frame was successfully assembled with lenses and without structural failure during its assembly procedure.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.36-43
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• 2009

In this study, the impact of the covariance between the baselines on the network-based GPS positioning is analyzed. For the analysis, the multi-baseline solutions with properly modeled covariance between the baselines and the combined solutions from the single-baseline solutions are obtained, respectively. Then, the accuracies of both solutions are evaluated in terms of coordinate residuals, i.e., the differences between the positioning solutions and the published stations' coordinates. The results indicate that the positioning accuracy in static mode depends much on the geometry of GPS satellites rather than the proper modeling of covariance between the baselines. Also, slight but negligible improvement in positioning accuracy is observed in static solutions. Therefore, one may use combined solutions as an alternative to multi-baseline solutions for the network-based GPS positioning. However, multi-baseline solution with properly modeled covariance between the baselines is recommended to use especially for the applications to detect very small displacement, i.e., deformation of the building or bridge.

• Composites Research
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• v.18 no.4
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• pp.44-51
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• 2005

In this paper, we developed the direct numerical simulation(DNS) model considering the geometry of yams which consist of 3D orthogonal woven composite materials, and using this model, the dynamic behavior of under transverse low-velocity impact has been studied. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is presented and used in building structural plate model based on DNS. For comparison, DNS results are compared with those of the micromechanical approach which is based on the global equivalent material properties obtained by DNS static numerical tests. The effects with yarn geometrical irregularities which are difficult to consider in a macroscopic approach are also investigated by the DNS model. Finally, the multiscale model based on the DNS concepts is developed to enhance efficiency of analysis with real sized numerical specimen and macro/micro characteristics are presented.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.99-108
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• 2010

Due to the recent emergence of global warming concerns, the UN has made the issue of climate change its top priority. Accordingly, Korea has announced a new national master plan titled, 'Participation in global efforts in climate change through -Low Carbon, Green Growth-'. As part of the plan, the constructions of bicycle path networks are being pushed forward. Although the building of bicycle paths and infrastructure is being implemented, little consideration has been given for bicycle path signage. This essay is the study of methodology in the installation of signs on bicycle paths. The research includes a theoretical study of the standard and installation position of signs with consideration of the geometry of bicycles as well issues such as the distance required for the bicyclist to recognize and understand the road sign and to take actions like stopping, In addition, experimental verification of the test results has been carried out. Also, the test on height of signs by changing the installation heights according to a bicyclist's forward vision angle has been conducted.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.1-7
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• 2015

A gutter is generally a fixed beneath the edge of a roof to carry off rainwater, or a narrow trough that collects rainwater from the roof of a building to diverts it from the structure, typically into a drain. Reasonable designs reduce the mass of the gutters (~ 16.9%), make it faster and easier to assemble, and gives it consistent strength and integrity (about 10%). New gutter systems are presented according to the results of structural analyses performed by ANSYS and ADAMS/Durability Hot Spots. In addition, the CATIA program can improve the precision of the 3D system simulations. The design of a gutter system installations also needs to comply with the specific rainfall intensities and adequate overflow provisions needs to be provided to prevent water from sides of the roofs during heavy rainfall periods. The principle outcome of this work is a computational design tool that can be used to improve the gutter performance considering a variety of factors (gutter geometry, drainage and rainfall intensity). A good gutter design must satisfy many criteria, including durability, low cost, and ease of repair and cleaning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6922-6931
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• 2014

The development of modern science and technology and computer engineering breakthroughs in the field of information and communication have brought about many changes in lifestyle. The government announced the goal of educational policy in 2030 to educate people in future society on a future-oriented perspective. Changes in the curriculum along with changes in educational facilities are essential. Therefore, the operation of a classroom should be associated with classroom spatial information. The BIM design based on 3D geometry information was designed. The BIM design can link the design information and non-geometric information of spatial information. This study examined the operation of school facilities based on classroom spatial information with BIM. This study suggests standardization of classroom spatial information based on BIM. The scenarios of BIM ordering and design for departmentalized classrooms management is proposed.