• International conference on construction engineering and project management
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• 2015.10a
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• pp.310-312
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• 2015

Small Unmanned Aerial Systems (SUAS) have been gaining a special attention in the U.S. recently because it is capable of getting aerial footages conveniently and cost effectively, but also because of its potential threat to the safety of our society. Regarding the benefits, one can easily find successful cases. For example, remote controlled or pre-programmed unmanned aircraft help ranch owners monitor their livestocks or crop harvesting status cost-effectively without having to hire human pilots. The professionals in the construction industry also acknowledge the benefits they could gain from using SUAS. Some firms already use a small unmanned aircraft for monitoring their construction activities, which may help project managers figure out construction progress, resolve disputes in real time, and make proactive decisions for quality control. However, there are many technical challenges that my hinder the use of small unmanned aircraft in the construction industry. This paper explores opportunities and challenges in using unmanned aircraft to monitor concrete cracks on the surface of containment building in the nuclear power plant.

• Steel and Composite Structures
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• v.49 no.6
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• pp.701-711
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• 2023

In order to fully reflect variation characteristics of composite concrete dam health state, the monitoring data is applied to diagnose composite concrete dam health state. Composite concrete dam lesion development to wreckage is a precursor, and its health status can be judged. The monitoring data are generally non-linear and unsteady time series, which contain chaotic information that cannot be characterized. Thus, it could generate huge influence for the construction of monitoring models and the formulation of corresponding health diagnostic indicators. This multi-scale diagnosis process is from point to whole. Chaotic characteristics are often contained in the monitoring data. If chaotic characteristics could be extracted for reflecting concrete dam health state and the corresponding diagnostic indicators will be formulated, the theory and method of diagnosing concrete dam health state can be huge improved. Therefore, the chaotic characteristics of monitoring data are considered. And, the extracting method of the chaotic components is studied from monitoring data based on fuzzy dynamic cross-correlation factor method. Finally, a method is proposed for formulating composite concrete dam health state indicators. This method can effectively distinguish chaotic systems from deterministic systems and reflect the health state of concrete dam in service.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.517-520
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• 2013

In construction operation, the temporary structure is used to support designed facilities or to provide work spaces for construction activities. Since the structure is used only during the construction operation, the operation may be given insufficient attention. The contractor is likely to try to save cost on the material and labor cost. This contractor's behavior frequently leads to construction accidents. In order to prevent accidents from the failure, the operation should be carefully monitored for identifying the effect of dynamics in the surrounding site area. Otherwise, any unexpected adversary effect could result in a very costly construction failure. This study presents the feasibility of the ubiquitous sensor network (USN) technology in collecting construction data during the construction operation of earth retaining walls. The study is based on the result at the Construction System Integration Laboratory (CSIL) at the Pusan National University. A USN-based system has been developed for monitoring the behavior of the temporary structure of earth retaining walls. The data collected from the sensors were used to understand the behavior of the temporary structure. The result of this study will be used in increasing the safety during the construction operation of retaining walls.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.544-547
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• 2008

In 1990, Korea building contractors were indifferent maintenance management cause focus on completion of construction before construction collapsed. Currently, structures monitoring systems are restrictive on large structures. Structures monitoring systems are limited many old and small structures in the whole nation. Recently, we make efforts application Ubiquitous technology as like sensor, sensor network system, and wireless communication system in construction. This paper applies bridge management system using Ubiquitous skill which is real-time monitoring report offering system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.73-81
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• 2018

The purpose of this study is to research the regulation of durability standard of underground structures monitoring sensors. The durability criteria for construction monitoring sensors of domestic construction companies, the standard years of contents such as buildings on the income tax implementation regulations, and the standards of the Public Procurement Service for construction monitoring and construction machinery were analyzed. The durability criterion on products such as the inclination meter and the strain gauge, which are purchased from the Public Procurement Service prior to installation on the underground structure, is 8 to 10 years. It is considered that the monitoring sensor installed in the paperboard and the concrete structure at the time of construction will have considerably shortened service life rather than the useful life of the product itself due to various adverse factors such as groundwater influence and compaction.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.53-59
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• 2021

Purpose & Method: The purpose of this study is the theoretical study on the durability standard of ground structures monitoring sensors. A survey on the durability criteria for construction monitoring sensors of domestic construction companies and the income tax implementation regulations, the standard years of contents such as buildings and the standards of the Public Procurement Service for construction monitoring and construction machinery were analyzed. Result: The durability criterion such as the inclination meter and the strain gauge, which are purchased from the Public Procurement Service prior to installation on the ground structure, is 8 to 10 years. Conclusion: The actual durability analysis by comparing the reliability of various monitoring sensors installed in dams at home and abroad, As a result of comprehensive study on the loss and damage rate of the maintenance monitoring sensor installed in the tunnel, the proper durability period of the built-in type monitoring sensor such as domestic pore pressure meter and earth pressure meter installed in the structure or the ground is 5 to 8 years it seems reasonable.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.255-256
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• 2021

The performance measurement of construction projects has traditionally been evaluated as a prerequisite for successful project completion. Considering this importance, the UK and the US are operating quantitative performance measurement systems for construction projects. However, in the case of Korea, there is a limit to the use of existing methods due to the limitation of data collection. Recently, in consideration of the domestic situation, research is being conducted to measure the quantitative performance of a project by using big data including progress and project attribute information. Therefore, this study aims to present the design direction of a performance monitoring system using Quality Function Deployment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.165-166
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• 2023

Construction inspection and monitoring are key activities in construction projects. Automation of inspection tasks improves the limitations and inefficiencies of manual construction inspections, enabling systematic and consistent construction inspections. In this paper, an RTSP (Real-Time Streaming Protocol) system is used to remotely manage and supervise the construction site without having to visit the construction site by deploying a robot on site on behalf of four construction stakeholders (owner, supervisor, constructor, and designer). I would like to propose. The proposed system can contribute to identifying and monitoring the process process and work results at the construction site in real time.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1243-1244
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• 2022

In recent years, the growing interest in off-site construction has led to factories scaling up their manufacturing and production processes in the construction sector. Consequently, continuous large-scale site monitoring in low-variability environments, such as prefabricated components production plants (precast concrete production), has gained increasing importance. Although many studies on computer vision-based site monitoring have been conducted, challenges for deploying this technology for large-scale field applications still remain. One of the issues is collecting and transmitting vast amounts of video data. Continuous site monitoring systems are based on real-time video data collection and analysis, which requires excessive computational resources and network traffic. In addition, it is difficult to integrate various object information with different sizes and scales into a single scene. Various sizes and types of objects (e.g., workers, heavy equipment, and materials) exist in a plant production environment, and these objects should be detected simultaneously for effective site monitoring. However, with the existing object detection algorithms, it is difficult to simultaneously detect objects with significant differences in size because collecting and training massive amounts of object image data with various scales is necessary. This study thus developed a large-scale site monitoring system using edge computing and a small-object detection system to solve these problems. Edge computing is a distributed information technology architecture wherein the image or video data is processed near the originating source, not on a centralized server or cloud. By inferring information from the AI computing module equipped with CCTVs and communicating only the processed information with the server, it is possible to reduce excessive network traffic. Small-object detection is an innovative method to detect different-sized objects by cropping the raw image and setting the appropriate number of rows and columns for image splitting based on the target object size. This enables the detection of small objects from cropped and magnified images. The detected small objects can then be expressed in the original image. In the inference process, this study used the YOLO-v5 algorithm, known for its fast processing speed and widely used for real-time object detection. This method could effectively detect large and even small objects that were difficult to detect with the existing object detection algorithms. When the large-scale site monitoring system was tested, it performed well in detecting small objects, such as workers in a large-scale view of construction sites, which were inaccurately detected by the existing algorithms. Our next goal is to incorporate various safety monitoring and risk analysis algorithms into this system, such as collision risk estimation, based on the time-to-collision concept, enabling the optimization of safety routes by accumulating workers' paths and inferring the risky areas based on workers' trajectory patterns. Through such developments, this continuous large-scale site monitoring system can guide a construction plant's safety management system more effectively.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.8
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• pp.553-558
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• 2015

This paper aims at making a dedicated vibration monitoring and diagnosis framework for 3MW WTG(wind turbine generator). Within the scope of the research, vibration data of WTG drive train are used and WTG operating conditions are involved for dividing the vibration data class which included transient and steady state vibration signals. We separate two health detections which are CHD(continuous health detection) and EHD(event health detection). CHD has function of early detection and continuous monitoring. EHD makes the use of finding vibration values of fault components effectively by spectrum matrix subsystem. We proposed framework and showed application for 3MW WTG in a practical point of view.