• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.3
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• pp.305-323
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• 2010

This paper proposes an efficient and yet powerful local descriptor called phase-space partition based descriptor (PPD). This descriptor is designed for the mobile image matching and retrieval. PPD, which is inspired from SIFT, also encodes the salient aspects of the image gradient in the neighborhood around an interest point. However, without employing SIFT's smoothed gradient orientation histogram, we apply the region based gradient statistics in phase space to the construction of a feature representation, which allows to reduce much computation requirements. The feature matching experiments demonstrate that PPD achieves favorable performance close to that of SIFT and faster building and matching. We also present results showing that the use of PPD descriptors in a mobile image retrieval application results in a comparable performance to SIFT.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1417-1430
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• 2015

In this study we were to explore the seasonal variation of water temperature distributions before and after weir construction at Gumi, Chilgok, Gangjung(Goryung), Dalsung in the Nakdong River using Landsat satellite images. Relationship between in-situ water temperature and radiance values of Landsat-5, 7, 8 satellite images showed high correlation. Seasonal variation of water temperature in Nakdong River showed that the fluctuation ranges of water temperature before weir construction were larger than those after weir construction. This indicated that the variation of water temperature is due to the difference of heat storage volume by weir construction and dredging work. In particular, the water temperature after weirs construction in autumn was 4-8 times lower than that before weirs construction. Water temperature after weir construction decreased in spring and summer at the downstream of Gumi weir and Gangjung(Goryung) weir, and the upstream of Dalsung weir. In autumn and winter, the water temperature after weir construction increased in the upstream and downstream of the whole weirs except upstream of Gumi weir. Relationship between water temperature and meteorological elements (air temperature, wind speed, sunshine, radiation) showed high correlation of above 94% in air temperature, and then radiation was high correlation before and after 65%.

• Computers and Concrete
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• v.33 no.5
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• pp.535-544
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• 2024

In the rapidly advancing landscape of computer vision (CV) technology, there is a burgeoning interest in its integration with the construction industry. Camera calibration is the process of deriving intrinsic and extrinsic parameters that affect when the coordinates of the 3D real world are projected onto the 2D plane, where the intrinsic parameters are internal factors of the camera, and extrinsic parameters are external factors such as the position and rotation of the camera. Camera pose estimation or extrinsic calibration, which estimates extrinsic parameters, is essential information for CV application at construction since it can be used for indoor navigation of construction robots and field monitoring by restoring depth information. Traditionally, camera pose estimation methods for cameras relied on target objects such as markers or patterns. However, these methods, which are marker- or pattern-based, are often time-consuming due to the requirement of installing a target object for estimation. As a solution to this challenge, this study introduces a novel framework that facilitates camera pose estimation using standardized materials found commonly in construction sites, such as concrete forms. The proposed framework obtains 3D real-world coordinates by referring to construction materials with certain specifications, extracts the 2D coordinates of the corresponding image plane through keypoint detection, and derives the camera's coordinate through the perspective-n-point (PnP) method which derives the extrinsic parameters by matching 3D and 2D coordinate pairs. This framework presents a substantial advancement as it streamlines the extrinsic calibration process, thereby potentially enhancing the efficiency of CV technology application and data collection at construction sites. This approach holds promise for expediting and optimizing various construction-related tasks by automating and simplifying the calibration procedure.

• Korean journal of communication and information
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• v.34
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• pp.244-274
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• 2006

To explore the social construction of the concept of leadership, image of media mogul depicted in the popular business newspaper, the Wall Street Journal, was analyzed. Then, the reconstructed image of the CEO was compared with the firm's stock price change to see their relationship, if any. This paper focused on the case of Steve Case (previous chairman of AOL Time Warner), who was the leader of the world largest media company. The period for the analysis was three years and five months from his inauguration(January 2000) to the resignation(May 2003). In general, CEO of a firm represents the firm itself. Thus, the image of the CEO is highly transcends to the image of the firm as well. Consequently, the image of CEO might have an impact on the firm's performance. Since business newspaper works as one of the most important information intermediaries in the stock market, the image of CEO constructed in the newspaper might be a critical indicator for the investors. The results revealed that media coverage of Steve Case was commensurate with the financial performance, particularly stock price change of the AOL Time Warner.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.1
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• pp.8-17
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• 1998

This paper presents a method of construction and re-use of a GCP database for precision geometric correction of high resolution satellite images. Accurate geometric correction can be achieved by using accurate GCPs. The GCP information which is extracted from maps or other sources is saved in a database in conjunction with the corresponding image chips. The usage of the GCPs from the database gives reusability and efficiency in marking new GCPs. An image matching algorithm was developed to determine the corresponding positions between an image chip and a new image. The proposed technique can save time in the regular operation of satellite image preprocessing by propagating the pre-determined GCPs to the new image correction.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.150-160
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• 2008

The present domestic underwater and ocean facilities management depends on analysis with the naked eye. This study performs quantitative analysis to improve conventional methods, analyze spatial situation of underwater facilities. This research is divided into two steps; underwater image distortion correction and image mosaic step. First, underwater image distortion correction step is for the production of underwater target, calculates the correction parameters, and then developed the method that convert the original image point to whose distortion is corrected. Second step is for the obtaining pipe images installed in the underwater, corrects the distortion, and then transforms a coordinates of the correction pipe image. After coordinate transformation, we make the mosaic image using the singularities. As a result, when we measure the distance between pipe and underwater ground and compare with calculation value on mosaic image, it is showed that RMSE is 0.3cm.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.293-300
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• 2013

Road signs are important infrastructures for safe and smooth traffic by providing useful information to drivers. It is necessary to establish road sign DB for managing road signs systematically. To provide such DB, manually detection and recognition from imagery can be done. However, it is time and cost consuming. In this study, we proposed algorithms for automatic recognition of direction information in road sign image. Also we developed algorithm code using OpenCV library, and applied it to road sign image. To automatically detect and recognize direction information, we developed program which is composed of various modules such as image enhancement, image binarization, arrow region extraction, interesting point extraction, and template image matching. As a result, we can confirm the possibility of automatic recognition of direction information in road sign image.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.30-31
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• 2021

The construction industry is an industry in which skilled construction workers should be secured and trained because of the quality and productivity of buildings, but the negative image makes it difficult to supply and demand skilled construction workers. In response, this study derived the factors influencing the intention of transferring construction workers to other occupations and investigated ways to improve the prevention of leaving other occupations by age of construction workers. The factors influencing the turnover of construction workers have also been derived, and work overload, salary, workplace stability, and employment competitiveness have a significant impact on the intention of new employees to change jobs. According to a survey on ways to improve the prevention of leaving other jobs, those in their 20s and 30s are "improving working conditions, such as providing holidays, paying overtime, compliance with working hours," and those in their 50s and 60s.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.203-208
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• 2004

Recently, digital image is increasing greatly practical use degree in several industry fields including construction. And interest about 3D digital image that can express practical object realistically is augmented greatly. In this study, developed 3D digital image generation system based on digital photogrammetry and created 3D digital image for object. And, wished to verify of 3D digital image through comparative analysis with processing result by digital photogrammetry system been using much the latest for acquisition of 3D information. Also, wished to apply to surface information acquisition about rock slope and execute investigation about discontinuity of joint etc. As the result, could created 3D digital image for object using the 3D digital image generation system developing in this study, and acquire surface information about rock slope efficiently.

• Korean Institute of Interior Design Journal
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• no.26
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• pp.88-94
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• 2001

This paper explores idea of the integration of text and image information in interior design. In this paper, we designed a structure of text and image information. Text information includes the information about materials and projects, and image information includes images of interior design. Material information consists of such as name and price of materials. Image information involves images of interior design that have been scanned and categorized into 15 groups according to the building regulation. Project information consists of construction brief and materials relevant to the image of interior design. The interior design information that is based on cases offers various information to designer and customers. In addition, the connection between text information and image information improves the quality of interior design by decreasing the trial and error in interior design processes. Finally, we discuss the method that integrates text and image information of interior design.