• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.70-74
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• 1999

Remote sensing (RS) data show the surfaces of the earth only but cannot provide the shape data of building sides. The proposed method recovers a 3D shape of building sides from stereo images. Its result shows a higher possibility for recovering a large shaped object by overcoming the difficulties of traditional stereo matching techniques. The urban area will be visualized more realistically than the current model based on graphic and vector data.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.206-207
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• 2020

Accurate estimation of concrete strength development at early ages is a critical factor to secure structural stability as well as to speed up the construction process. The temperature generated from the heat of hydration is considered as a key parameter in predicting the early age strength. Conventionally, concrete temperature has been measured by temperature sensors installed inside concrete. However, considering the measurement on building structures with multiple floors, this method requires reinstallation and repositioning of hardware such as sensors, data loggers and routers for data transfer. This makes the temperature monitoring work cumbersome and inefficient. Concrete temperature monitoring by using thermal remote sensing can be an effective alternative to supplement those shortcomings. In this study, image processing was carried out through K-means clustering technique, which is a unsupervised learning method, and the classification results were analyzed accordingly. In the future, research will be conducted on how to automatically recognize concrete among various objects by using deep learning techniques.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.621-626
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• 2006

Today's commercial high resolution satellite imagery such as IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Extraction of 3D building information from high resolution satellite imagery is one of the most active research topics. There have been many previous works to extract 3D information based on stereo analysis, including sensor modelling. Practically, it is not easy to obtain stereo high resolution satellite images. On single image performance, most studies applied the roof-bottom points or shadow length extracted manually to sensor models with DEM. It is not suitable to apply these algorithms for dense buildings. We aim to extract 3D building information from a single satellite image in a simple and practical way. To measure as many buildings as possible, in this paper, we suggested a new way to extract building height by triangular vector structure that consists of a building bottom point, its corresponding roof point and a shadow end point. The proposed method could increase the number of measurable building, and decrease the digitizing error and the computation efficiency.

• International Journal of High-Rise Buildings
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• v.10 no.3
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• pp.193-201
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• 2021

Cheongna City Tower is a 448-meter-high rise observatory tower with 8.7:1 aspect ratio located at central lake park in Incheon Cheongna international city. The tower is a crystal shaped image and it turns invisible when the façade is activated. The tower was planned to be hexagonal 30-story building with two basements which are composed of mega frame structure using mega column and mega brace. In order to minimize the wind effect, the blow-through area was installed so that the wind can pass through. This observatory tower is an unprecedented project since the whole building is covered by façade for invisibility effect.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.95-100
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• 2002

Detecting simple shaped buildings from 1m-resolution satellite imagery is presented. The proposed algorithm is that first, image features such as edges are detected and then segmentation process is performed with the detected features. It can be result in line primitives. These primitives are linked and grouped by building hypotheses. Proposed building hypotheses restrict a building to simple rectangular shape. And sub-region homogeneity test is performed for finding rooftops of buildings. The proposed algorithm has been tested on IKONOS satellite image with 1m-resolution.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.773-775
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• 2003

From the view point of data fusion, we integrate LIDAR data and digital aerial images to perform 3D building modeling in this study. The proposed scheme comprises two major parts: (1) building block extraction and (2) building model reconstruction. In the first step, height differences are analyzed to detect the above ground areas. Color analysis is then performed for the exclusion of tree areas. Potential building blocks are selected first followed by the refinement of building areas. In the second step, through edge detection and extracting the height information from LIDAR data, accurate 3D edges in object space is calculated. The accurate 3D edges are combined with the already developed SMS method for building modeling. LIDAR data acquired by Leica ALS 40 in Hsin-Chu Science-based Industrial Park of north Taiwan will be used in the test.

• Geomechanics and Engineering
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• v.24 no.5
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• pp.457-470
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• 2021

In this study, the pull-out behavior of a tunnel-type anchorage for suspension bridges was investigated using experimental tests and image processing analyses. The study focused on evaluating the initial failure behavior and failure mode of the tunnel-type anchorage. In order to evaluate the failure mode of tunnel-type anchorage, a series of scaled model tests were conducted based on the prototype anchorage of the Ulsan Grand Bridge. In the model tests, the anchorage body and surrounding rocks were fabricated using a gypsum mixture. The pull-out behavior was investigated under plane strain conditions. The results of the model tests demonstrate that the tunnel-type anchorage underwent a wedge-shaped failure. In addition, the failure mode changed according to the differences in the physical properties of the surrounding rock and the anchorage body and the size of the anchor plate. The size of the anchor plate was found to be an important parameter that determines the failure mode. However, the difference in physical properties between the surrounding rock and the anchorage body did not affect its size. In addition, this study analyzed the initial failure behavior of the tunnel-type anchorage through image analysis and confirmed that the failure was sequentially transferred from the inside of the tunnel to the surrounding rock according to the image analysis. The reasonable failure mode for the design of the tunnel-type anchorage should be wedge-type rather than pull-out type.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.655-661
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• 2020

SGM (Semi Global Matching) can be used to find all the conjugate points between stereo images. Therefore, it enables high-density DSM (Digital Surface Model) production from high-resolution satellite images. However, water, shadows, and occlusion areas cause mismatching of the surrounding points in this method. Particularly, in buildings with large-parallax and elongated-shapes such as a Korean style apartment, it is difficult to reconstruct the 3D building even if the SGM method is applied to a high-resolution 50cm satellite image. This study proposed and performed the SGM technique with a classified image and an edge image from the IKONOS-2 satellite stereo-image with a 1m resolution to produce DSM. It was compared with the DSMs from the general SGM and the high-density ABM (Area Based Matching) matching of ERDAS software. The results of the apartment DSM by the proposed method were the best in the test area. As a result, despite the image having a resolution of 1m, the outline of the building DSM could be expressed more clearly than the existing method.

• Korean Institute of Interior Design Journal
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• v.23 no.1
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• pp.78-87
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• 2014

The purpose of this paper is to analyze the relationship between panoramic perception and space organization for restoration of urban environment and architecture. Panorama is a collective visual catalogue composed by series of perspective images. It is a product from continuous movements of viewer by defamilarizing real image and structuring order between city and building. Through understanding the panoramic image, the viewer is able to achieve the total image of the city. For example, achieving visual perception of the city by employing the panoramic view from different historical backgrounds and cultures, Berlin developed its urban characteristic by rebuilding panoramic view as an aesthetic device. First, this paper mention theory of panorama as an aesthetic device for shaping the city from the building. Second, this paper analyze the relationships between characteristics of panorama and historical contexts for why those panoramic views are valuable by mentioning the Altes Museum, the Berlin National Gallery, Museum of Modern Literature, and Folkwang Museum of panoramic view. In conclusion, this paper argues that visual perception such as panoramic view is the valuable device for organizing the image of the city's own identity. Constructing vision of each city influences not only shaping the city but also mapping the mental views of the building. Also, historical conditions and open spaces are one of the inherent elements combined with panoramic view for establishing urban identity. In search for good place making, it is important to understand the role of the historical context and fabric plan in shaping how a resident sees - literally, sees- their city with buildings. Berlin serve as excellent counter example in how the valuable place making panoramic mental views of urbanities take shape.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.159-161
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• 2003

Fitting the projected wire-frame model to the detected edge pixels on images by using least-squares approach, called Least-squares Model-image Fitting (LSMIF), is the key of the Model-based Building Extraction (MBBE). It is implemented by iteratively adjusting the model parameters to minimize the squares sum of distances from the extracted edge pixels to the projected wire-frame. This paper describes a series of experiments and studies on various factors affect the fitting results, including the edge detectors, the weighting rules, the initial value of parameters, and the number of overlapped images. The experimental result is not only helpful to clarify the influences of each factor, but is also able to enhance the robustness of the LSMIF algorithm.