• International conference on construction engineering and project management
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• 2009.05a
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• pp.224-229
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• 2009

Digital image recognition has been used for steel bridge surface assessment since late 1990s. However, the non-uniform illumination problems such as shades, shadows, and highlights are still challenges in image processing to date. Therefore, this paper develops a new approach to tackle the non-uniform illumination problem for rust image adjustment. The inhomogeneous illumination problem is divided into shades/shadows and highlights in this paper. The proposed BEMD-morphology approach (BMA) utilizes the bidimensional empirical mode decomposition to mitigate the shade/shadow effect, and the morphological processing to detect and replace the highlight area. Finally, the rust image processed with the BMA will be segmented by the K-Means algorithm, one of the most popular and effective methods, to show the effectiveness of illumination adjustment.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.5
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• pp.31-38
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• 2002

This study attempts to grasp the correlation between the image of bridges and bridge landscapes with their surroundings during day and nighttime viewing, and to understand the psychological influence of nighttime lighting through quantitative analysis. In addition, it presents a design to construct bridges in order to increase viewers enjoyment of bridge landscapes lit at night. To attain this objective and contrive generalization of the results, this paper selects 8 of 9 bridges with lightings in Seoul and excludes bridges constructed by 2004. The criteria for selection of the viewpoints is that each must be within easy reach of bridges, and must allow viewers to recognize surrounding landscape details both in daylight and at night. As well, the pictures of bridges are taken in the terraced land by the riverside. The study selects 16 pictures, judged to be of similar quality and angle, to establish the conditions of luminosity, color, definition and angle. The results are as follows. First, viewers preferences of night landscapes are higher than day landscapes due to the effect of lighting. By day, viewers preferred bridges with various structures such as cable-stayed bridges and arch bridges more than simple bridges like girder bridges. Viewers also indicated preferences for lightings which feature a unique color and which are harmonized with their surroundings. Second, components representing the images of bridge landscape are classified into three types, 'beauty', 'system' and 'agreeableness'. Third, the factors affecting preference are the shape of bridge by day and lighting at night. Esthetic appeal is the most important factor in visual preference so each bridges own esthetic appeal and surroundings must be considered. Thus, a complete plan must be created which considers safety, beauty and the local surroundings. In addition, when the lighting of a bridge is selected, the design of the bridge landscape must consider various lighting schemes to harmonize the upper and lower parts of the structure. At this point, the study reveals the basic elements of bridge planning in order to increase appreciation of the bridge landscape.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.513-516
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• 2007

We introduce a new copolymer alignment film made by bridge-building structure. It is a better film to decrease the image-sticking level in LCD displays. It is noted that the image-sticking was decreased by preventing ion mixing between inter-layers through high hardness. We have investigated the electrical characteristics such as pretilt angle, Residual DC, VHR by changing cure temperature and process delay time conditions of the new alignment film. In this paper, we have investigated the solution for the deep-rooted image defect and incidentally got a contrast ratio improvement by high anchoring force and hardness elevation through the new copolymer alignment film.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.12
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• pp.53-58
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• 1996

In this paper, a simple fabrication technique of an air-bridge for interconnection of isolated electrodes of microwave active and passive devices and MMIC's is proposed. The proposed air-bridge proceses are mainly combinations of thermal evaporation, positive photoresist and image reversal processes for easy lift-off of up to 2.0 .mu.m thick metal. According to the resutls of air-birdge processes, it is confirmed that air-gap and thickness of theair-bridge are about 3.5.mu.m, and 2.0.mu.m, respectively. And it is also possible to make the fine air-bridge with widths of 5~60.mu.m and post-intervals of 25~200.mu.m withot collapse. finally, GaAs power MESFET's and rectangular spiral inductors are fabricatd and measured in order to confirm of feasibility of the proposed air-bridge processes. The MAG of the fabricated power MESFET's is 10dB at 10GHz, and the inductance of the (200.mu. * 6 turns) rectangular spiral inductors 4.5 nH inX-band.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.117-126
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• 2008

In this paper, it is presented a digital image processing method and the program (Visual C++) to determine the shape of the suspension bridge. To investigate the precision of this method, a suspension bridge is divided into 5, 13 and 19 images, respectively, by using the 6.3M pixels digital camera with 300mm zoom lens. Obtained results of the Kwang-Ahn Grand Bridge by using this method are fairly close to the real precision surveyed data. The accuracy is more improved by increasing the number of divided images of the structure. The total cost, man power and time of field survey by this method presented in this study could be much more reduced and the developed program could be applied with little modification for other structures like cable-stayed bridges, if lens compensation algorithms and program access capabilities are improved.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.618-625
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• 2003

The recent development of PSC girder bridges are mostly dedicated for optimization of self-weight, simplification of girder section for easy construction and minimization of maintenance efforts. Moreover some of those bridges are required as a landmark facility which raises the image of locality and harmony with surroundings. An extradosed bridge is one of the best alternates which not only covers the longer span than PSC box girder and also performs the role of landmark facility with much cheaper cost than cable stayed bridge. Hyundai is carrying out the construction of unique style extradosed bridge which have central suspension system and uniform girder depth named Keong-An grand bridge on the Sungnam-Janghowon Express highway. In this paper, major process of design and construction features of Keong-An bridge is presented.

• Computers and Concrete
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• v.23 no.6
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• pp.445-457
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• 2019

Cracks are an important distress of concrete bridges, and may reduce the life and safety of bridges. However, the traditional manual crack detection means highly depend on the experience of inspectors. Furthermore, it is time-consuming, expensive, and often unsafe when inaccessible position of bridge is to be assessed, such as viaduct pier. To solve this question, the real-time automatic crack detecting system with unmanned aerial vehicle (UAV) become a choice. This paper designs a new automatic detection system based on real-time comprehensive image processing for bridge crack. It has small size, light weight, low power consumption and can be carried on a small UAV for real-time data acquisition and processing. The real-time comprehensive image processing algorithm used in this detection system combines the advantage of connected domain area, shape extremum, morphology and support vector data description (SVDD). The performance and validity of the proposed algorithm and system are verified. Compared with other detection method, the proposed system can effectively detect cracks with high detection accuracy and high speed. The designed system in this paper is suitable for practical engineering applications.

• Journal of Environmental Science International
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• v.14 no.10
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• pp.905-910
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• 2005

The purpose of this study is the comparative analysis of Susan citizens' images of Eulsook-do as a coastal tourism destination before and after the construction of a road bridge across the Nakdong estuary in order to analyze local people's changes in leisure patterns. Analysis of the images of a pre-construction Eulsook-do that people aged both 40 and less and 50 and more had on five dimensions showed values higher than zero(0) that suggests neutral image, while their images of a post-construction Eulsook-do showed the shrinking size of pentagon on all five dimensions: ET(Entertainment), CA(Culture & Art), EE(Environment & Ecology), RC(Recreation) and LP(Leports) dimensions. Its pre- and post- construction image analysis conducted 20 years after it came to be built finds that the road bridge construction has led to the ecological, environmental disruption of the coast and the lower Nakdong river, having negative influence on the images of Eulsook-so.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.1-10
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• 2002

As the preliminary stage for the countermeasure of thermal loading in miller cycle engine, coolant flows in the cylinder head of base engine including exhaust valve bridge were visualized and analyzed by using PIV technique. It was found that low coolant velocity regions were around exhaust valve bridge, around which stagnation of the coolant flow was observed due to the complex geometry configuration of water jacket. And velocity variation between each cylinder was remarkable. For the countermeasure of these, it is necessary to enhance coolant flow around exhaust valve bridge and to improve the deviation of coolant flow between each cylinder.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.117-126
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• 2022

Currently, the number of bridge structures in Korea is continuously increasing and enlarged, and the number of old bridges that have been in service for more than 30 years is also steadily increasing. Bridge aging is being treated as a serious social problem not only in Korea but also around the world, and the existing manpower-centered inspection method is revealing its limitations. Recently, various bridge damage detection studies using deep learning-based image processing algorithms have been conducted, but due to the limitations of the bridge damage data set, most of the bridge damage detection studies are mainly limited to one type of crack, which is also based on a close set classification model. As a detection method, when applied to an actual bridge image, a serious misrecognition problem may occur due to input images of an unknown class such as a background or other objects. In this study, five types of bridge damage including crack were defined and a data set was built, trained as a deep learning model, and an open set recognition-based bridge multiple damage recognition model applied with OpenMax algorithm was constructed. And after performing classification and recognition performance evaluation on the open set including untrained images, the results were analyzed.