• Tunnel and Underground Space
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• v.34 no.3
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• pp.208-217
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• 2024

There is so much research effort for developing and implementing deep learning-based surveillance systems to manage health and safety issues in construction sites. Especially, the development of deep learning-based object detection in various environmental changes has been progressing because those affect decreasing searching performance of the model. Among the various environmental variables, the accuracy of the object detection model is significantly dropped under low illuminance, and consistent object detection accuracy cannot be secured even the model is trained using low-light images. Accordingly, there is a need of low-light enhancement to keep the performance under low illuminance. Therefore, this paper conducts a comparative study of various deep learning-based low-light image enhancement models (GLADNet, KinD, LLFlow, Zero-DCE) using the acquired construction site image data. The low-light enhanced image was visually verified, and it was quantitatively analyzed by adopting image quality evaluation metrics such as PSNR, SSIM, Delta-E. As a result of the experiment, the low-light image enhancement performance of GLADNet showed excellent results in quantitative and qualitative evaluation, and it was analyzed to be suitable as a low-light image enhancement model. If the low-light image enhancement technique is applied as an image preprocessing to the deep learning-based object detection model in the future, it is expected to secure consistent object detection performance in a low-light environment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.16-17
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• 2018

A few years ago, the rapid degradation of domestic air quality has led to the efforts of exhaust gas policy and fine dust mask, but it is not a fundamental measure. In Korea, photocatalyst will be applied to residential and multi-use facilites to purify indoor and outdoor air. Also, in this study, it is tried to produce exposed concrete that is aesthetically pleasing as well as air purification of indoor by combining with light transparent concrete according to the increasing interest in human indoor living environment. For this purpose, we have developed a block formwork for photocatalysis light transparent concrete and established a suitable manufacturing method for on-site construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.909-914
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• 2007

Today's dynamic nature of the construction environment requires management systems to be active enough to take real-time decisions. For real-time decision making, effective 3D spatial information acquisition is imperative. Various 3D data acquisition technologies are being developed and tested for 3D spatial information acquisition and its use for wide range of areas in the construction industry, however, there are shortcomings in these technologies. The major problems are long processing time and high cost which make current technologies impossible to be used for real-time applications. Laser-based Flash LADAR that illuminates the entire scene with diffuse laser light is comparatively fast and cost effective, therefore it is well suited for 3D spatial modeling of dynamic environment on a construction site. This paper presents experimental results to evaluate the performance of flash LADAR and discuss issues of applicability of Flash LADAR to 3D spatial modeling on a construction site.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.304-310
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• 2011

The populations of major cities in Australia are increasing rapidly and facing an acute housing shortage. Traditional apartment procurement techniques involve lengthy lead-times and factory-based, or offsite manufactured (OSM) multi-storey apartment buildings may offer the opportunity to help fulfill the need by significantly reducing build times. Other advantages of OSM may include superior quality, low weight ratios, economies of scale achieved through repetition of prefabricated units, use on infill sites, sustainable design standards and better occupational health and safety. There are also positive labour and training implications, which may help to alleviate an industry-wide shortage of skills through use of semi-skilled labour. Previous uncertainties about the adoption of offsite due to the high capital costs and perception issues were generally based on pre-cast concrete structures, which are quite a different building type in terms of flexibility, construction, delivery and finishes. Identification of drivers and constraints assists in the determination of current industry status, allows for a benchmark to be established and future opportunities and directions for OSM to be determined.

• The Journal of Korea Robotics Society
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• v.5 no.2
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• pp.143-151
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• 2010

Automation and robotization has been required in construction for several decades and construction industry has become one of the important research areas in the field of service robotics. Especially in the steel construction, automatic recognition of structural steel members in the stockyard is emphasized. However, since the pose of steel frame in the stockyard is site dependent and also the stockyard is usually in the outdoor environment, it is difficult to determine the pose automatically. This paper adopts the recognition method based on the augmented reality to cope with this problem. Particularly focusing on the light condition of the outdoor environment, we formulated the optimization problem with the constraint and suggested the methodology to evaluate the optimal camera arrangement. From simulation results, sub-optimal solution for the position of the camera can be obtained.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.5-9
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• 2007

The construction method for Foamed-Concrete has not been important due to following process of construction work. However, according to the code about enhance of energy saving design policy and impact noise, noised isolation has been used in construction site so that the resistance for cracking and capability for insulating of Foamed-Concrete has been required. Therefore, new alternatives are demanded. Optimum mixing design, which can get the improvement of insulation and resistance of crack for Foamed-Concrete adding EVA chip, was derived and also the device, applying to construction site, was invented to equalize quality. This device can measure quantity of all input and placement, and show up the sum of placement and mixing design on a touch screen. This valuable construction method is friendly environment and recycling method because of using EVA chip, by-product of an EVA insole scrap burned or embedded, as a light-weight aggregate.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.30-31
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• 2009

Early detection of schedule delay in field construction activities is vital to project management. It provides the opportunity to initiate remedial actions and increases the chance of controlling such overruns or minimizing their impacts. This entails project managers to design, implement, and maintain a systematic approach for progress monitoring to promptly identify, process and communicate discrepancies between actual and as-planned performances as early as possible. Despite importance, systematic implementation of progress monitoring is challenging: (1) Current progress monitoring is time-consuming as it needs extensive as-planned and as-built data collection; (2) The excessive amount of work required to be performed may cause human-errors and reduce the quality of manually collected data and since only an approximate visual inspection is usually performed, makes the collected data subjective; (3) Existing methods of progress monitoring are also non-systematic and may also create a time-lag between the time progress is reported and the time progress is actually accomplished; (4) Progress reports are visually complex, and do not reflect spatial aspects of construction; and (5) Current reporting methods increase the time required to describe and explain progress in coordination meetings and in turn could delay the decision making process. In summary, with current methods, it may be not be easy to understand the progress situation clearly and quickly. To overcome such inefficiencies, this research focuses on exploring application of unsorted daily progress photograph logs - available on any construction site - as well as IFC-based 4D models for progress monitoring. Our approach is based on computing, from the images themselves, the photographer's locations and orientations, along with a sparse 3D geometric representation of the as-built scene using daily progress photographs and superimposition of the reconstructed scene over the as-planned 4D model. Within such an environment, progress photographs are registered in the virtual as-planned environment, allowing a large unstructured collection of daily construction images to be interactively explored. In addition, sparse reconstructed scenes superimposed over 4D models allow site images to be geo-registered with the as-planned components and consequently, a location-based image processing technique to be implemented and progress data to be extracted automatically. The result of progress comparison study between as-planned and as-built performances can subsequently be visualized in the D4AR - 4D Augmented Reality - environment using a traffic light metaphor. In such an environment, project participants would be able to: 1) use the 4D as-planned model as a baseline for progress monitoring, compare it to daily construction photographs and study workspace logistics; 2) interactively and remotely explore registered construction photographs in a 3D environment; 3) analyze registered images and quantify as-built progress; 4) measure discrepancies between as-planned and as-built performances; and 5) visually represent progress discrepancies through superimposition of 4D as-planned models over progress photographs, make control decisions and effectively communicate those with project participants. We present our preliminary results on two ongoing construction projects and discuss implementation, perceived benefits and future potential enhancement of this new technology in construction, in all fronts of automatic data collection, processing and communication.

• Journal of the Korea Institute of Construction Safety
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• v.1 no.1
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• pp.22-30
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• 2018

Construction accidents in Korea are continuously increasing. Safety signs with high visibility color can diminish such accidents in dangerous places. In order for safety color to be more effective as a global communication means in construction sites, it needs to be checked out whether safety color standard reflect the characteristics of construction industry such as worker or work environment. This paper compared safety color standards among Korea, the US, the UK, and Australia. First, blue color was included in all, which should be corrected considering aged workers increasing in construction industry. Because with age, the ability to distinguish between blue, purple, and gray colors decreases. Second, Korea, which has only single code designated to safety colors, should find alternatives like tolerance to be applicable to a variety of light environments on construction sites, as the contrast which affect the visibility may decrease in dark conditions.

• Journal of the Korea Institute of Building Construction
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• v.2 no.2
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• pp.121-127
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• 2002

The functions and uses of existing buildings are not properly changing as modern life needs. As a result, the frequent reconstruction(construction after removal) of existing buildings have been done but it became more and more difficult because of strengthening of regulations and systems concerning construction. And also it has several disadvantages like lower plot ratio and site coverage than existed buildings, enormous construction cost, production of waste-construction materials and thoughtless consumption of natural resources, which gives rise to environmental pollution. Therefore renovation is brought to the fore. In Korea, many business buildings were constructed in 1960s-1970s, during the period of high growth. Such buildings needs to be repaired in whole. It is caused by the change of social, economic, and cultural conditions and deterioration of equipments. Therefore renovation meets some necessary conditions; recovery of building functions and extension of building life span. In case study, the present state of renovation in business buildings is 1) Basic safety, for example, fire prevention and crime prevention, is great important. 2) Advanced technology, INS(international news service), IBS(Intelligent Building System), and internationalization, is pursued for adapting to multimedia ages. 3) It tries to promote proficiency, and to save the energy using spatial environment and natural energy(light and sound). Also, improving comfortable level of users and installing equipments for physically handicapped person needs to be considered.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.97-108
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• 2024

This research delves into the escalating concerns of accidents and fatalities in the construction industry over the recent five-year period, focusing on the development of a Safety Perception Model to augment safety measures. Given the rising percentage of elderly workers and the concurrent drop in productivity within the sector, there is a pronounced need for leveraging Fourth Industrial Revolution technologies to bolster safety protocols. The study comprises an in-depth analysis of statistical data regarding construction-related fatalities, aiming to shed light on prevailing safety challenges. Central to this investigation is the formulation of a Safety Perception Model tailored for small-scale construction projects. This model facilitates the quantification of safety risks by evaluating safety grades across construction sites. Utilizing the DWM1000 module, among an array of wireless communication technologies, the model enables the real-time tracking of worker locations and the assessment of safety levels on-site. Furthermore, the deployment of a safety management system allows for the evaluation of risk levels associated with individual workers. Aggregating these data points, the Safety Climate Index(SCLI) is calculated to depict the daily, weekly, and monthly safety climate of the site, thereby offering insights into the effectiveness of implemented safety measures and identifying areas for continuous improvement. This study is anticipated to significantly contribute to the systematic enhancement of safety and the prevention of accidents on construction sites, fostering an environment of improved productivity and strengthened safety culture through the application of the Safety Perception Model.