• Journal of the Korea Institute of Building Construction
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• v.23 no.1
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• pp.81-92
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• 2023

According to the 2020 industrial accident reports of the Ministry of Employment and Labor, the number of fatal accidents in the construction industry over the past 5 years has been higher than in other industries. Of these more than 50% of fatal accidents are initially caused by fall accidents. The central government is intensively managing falling/jamming protection device and the use of personal protective equipment to eradicate the inappropriate factors disrupting safety at construction sites. In addition, although efforts have been made to prevent safety accidents with the proposal of the Special Act on Construction Safety, fatalities on construction sites are constantly occurring. Therefore, this study developed a model that automatically detects the wearing state of the worker's safety helmet and belt using computer vision technology. In considerations of conditions occurring at construction sites, we suggest an optimization method, which has been verified in terms of the accuracy and operation speed of the proposed model. As a result, it is possible to improve the efficiency of inspection and patrol by construction site managers, which is expected to contribute to reinforcing competency of safety management.

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.101-112
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• 2005

Recently, a curtain wall construction is a exterior finishing components which is most used for shortening time in high-rise building as well as the class of key management factors in cost and schedule control. Also, it is recognized that an effective management for curtain wall process is a major subject to accomplish the project successfully. However, as the current management for curtain wall construction is focused on the construction stage, it makes problems such as errors in business performance, rework by mistakes and duplications, errors and omissions by ineffective information management and there has never been any efficient management from a view of the entire Curtain Wall Life-cycle process. Therefore, the aim of this study is to suggest a stage check point for process improvement in the curtain wall Life-cycle process through current curtain wall process analysis, and then to investigate the cause of waste factors using the Muda method from the Toyota Production System and extract the weighted effects of the waste factors using the analytical hierarchy process method. According to the result, Most of the inefficient factors happened in architectural design stage of the entire curtain wall Life-cycle process and my research identified that detail factors of them are a delay of decision making and an approval in changes, a deficit of engineering capacity and a delay of approval in architectural design drawings by owner, etc.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.249-257
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• 2018

The number of deaths for railway traffic accidents is mainly caused by working close to the track, or when unauthorized passage pass through the track. The safety fences are being used to ensure safety for workers close to the track, and to improve the efficiency of the work, without interfering with the passage of trains. However, a safety fence for railway tracks needs to be examined to see if it will interfere with the passage of trains. The purpose of this study is to analyze the safe distance between train and safety fence developed in Korea. In addition, the lateral load condition of wind pressure by trains is estimated and numerical analysis is carried out according to the installation intervals of railway safety fences. It has been confirmed that the proper spacing between the train and the railway safety fence should be at least 200 mm from the vehicle limit, and that the proper spacing of railway safety fence must be calculated in consideration of the wind pressure by trains.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.159-167
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• 2008

This study provides a effective approach to the construction management problem with the limited number or amount of available resources using the analytic hierarchy process. Construction management is a series of decision making processes for planning and controling of cost, time and quality as main objectives in construction works. When several activities need the limited same resource at the same time, it is very hard to decide the priority of the activities in the real situations. For that the scientific decision making method and procedure for resource allocation are required. This study solves the resource allocation problem by dealing with the decision making problem which the activities are distributed to multiple projects and under multiple criteria. The analytic hierarchy process is a method devised to solve complex multi-criteria decision problems. The result shows that this study can be effectively used to make decisions in situations involving multiple objectives by evaluating the prioritized ranking and degree of the activity alternatives based on the overall preferences.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.845-849
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• 2024

Currently, rail surface defects are increasing due to the aging of urban railway rails, but in the detailed guidelines for track performance evaluation established by the country, rail surface damage is inspected with the naked eye of an engineer and with simple measuring tools. It is very important to discover defects in the rail surface through periodic track tours and visual inspection. However, evaluating the severity of defects on the rail surface based on the subjective judgment of the inspector has significant limitations in predicting damage inside the rail. In this study, the characteristics of cracks inside the rail due to rail surface damage were studied. In field measurements, rail surface damage was selected, old rail samples were collected in the acceleration and braking sections, and a scanning electron microscope (SEM) was used to evaluate the rail surface damage was used to analyze the crack characteristics. As a result of the analysis, the crack mechanism caused by the running train and the crack characteristics of the acceleration section where cracks occur at an angle rising toward the rail surface were experimentally proven.

• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.84-91
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• 2021

In the 21st century, a number of storm and flood disasters caused by rapidly changing climate change is increasing, and the number of flood accidents at construction sites is also increasing. However, no specific reduction measures have been presented and thereby safety management to prevent flood accident need to be improved. Therefore, in this study, the inundation pattern by downpour at the excavation site was interpreted and the inundation risk quantification method was used to classify the risk magnitude. Finally, using the fish-bone diagram, we derived the major reasons of inundation accident at construction site systematically. The simulation results showed that the inundation depths of small-scale excavation sites and excavation sites exceeded 3 m due to the fluid flowing through the excavation surface. In addition, depending on the excavation site, a high velocity temporarily observed and decreased due to the storage effect, or high velocity surpassing 10 m/s continued. Since this type of flooding can pose a risk to most or all workers, if proper management measures are insufficient, fatal damage to life and property could occur. Consideration of the roots of these disasters is judged to be helpful in understanding the causes of inundation accidents that result in casualties and presenting accident reduction measures.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.539-547
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• 2012

Volume survey for earthwork is conducted periodically at every month at large scaled construction sites for request payment for the construction. Currently, the earthwork volume is calculated on the overlapped drawing for two cross sections which were created by new and previous surveying data observed by GPS and TS. However the survey is required lots of time and expenses as it is a pin-point surveying method thus surveyors intend to get data only for the heavy undulated topographic features chosen by himself to save time and expenses. Consequently, it causes poor results due to low dense measurement as well as it's not matched with the results by another surveyors. As a result, the conflicts related in earthwork volume calculation often arises among the owner, contractors and sub contractors. In this study, we developed a method to get surveying data for fast and accurate volume calculation using 3D Mobile Laser System and conducted an application test. Also we carried out experiments for topographic survey using MLS to judge for the application additionally. The results showed that we could reduce a time for cross section survey from 48 hours to 2 hours and collected high dense data which have 0.2m interval instead of 3m interval compare with existing method. Also we could make a map which has high accuracy within 10cm in horizontal through topographic survey using MLS.

• Korean Journal of Construction Engineering and Management
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• v.18 no.5
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• pp.59-67
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• 2017

At the completion of the construction, various finishing processes are concentrated. This imposes a burden on the on-site manager and imposes on experience based quality control, thereby causing deviations in the quality of construction depending on supervisor or worker's individual competence. In addition, the information related to quality control is frequently scattered in various types of documents such as specifications and drawings, and checkpoints are frequently omitted. It is necessary to provide a tool that can effectively provide the practitioner before or during the inspection work by systematically storing the information related to the defect prevention and linking them in a mutually referential state. This paper proposes an quality inspection support model that can systematically store necessary information on activity or room basis for the quality check of the apartment house finishing work. Establish a defect prevention information base and a information nexus by linking specifications, design standards, checklists, regulations, defect cases, and drawings to the finishing process and the rooms. Based on this, information registration and search interface are presented. It can contribute to securing a certain level of construction quality or more by suggesting a frame that can be utilized by linking various defects prevention information with the focus on closing activity and room.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.585-590
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• 2024

In this study, rail surface defects are increasing due to the aging of urban railway rails, but in the detailed guidelines for track performance evaluation established by the country, rail surface damage is inspected with the naked eye of engineers and simple measuring tools. With the recent enactment of the Track Diagnosis Act, a large budget has been invested and the volume of rail diagnosis is rapidly increasing, but it is difficult to secure the reliability of diagnosis results using labor-intensive visual inspection techniques. It is very important to discover defects in the rail surface through periodic track tours and visual inspection. However, evaluating the severity of defects on the rail surface based on the subjective judgment of the inspector has significant limitations in predicting damage inside the rail. In this study, the rail internal crack characteristics due to rail surface damage were studied. In field measurements, rail surface damage locations were selected, samples of various damage types were collected, and the rail surface damage status was evaluated. In indoor testing, we intend to analyze the correlation between rail surface defects and internal defects using a electron scanning microscope (SEM). To determine the crack growth rate of urban railway rails currently in use, the Gaussian probability density function was applied and analyzed.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.608-616
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• 2021

Purpose: Safety inspections by existing personnel have been limited in evaluation and data securing due to concerns about the safety of technicians or difficulty in accessing them, and are becoming a bigger problem as the number of maintenance targets increases due to the aging of facilities. As drone technology develops, it is possible to ensure the safety of personnel, secure visual data, and diagnose quickly, and use it is increasing as safety inspection of facilities by drones was introduced recently. In order to further enhance utilization, it is considered necessary to base a consideration standard for facility appearance investigation by drones, and in this paper, research was conducted on dams. Method: To calculate the quality, existing domestic safety inspection and drone-related consideration standards were investigated, and procedures related to safety inspection using drones were compared and analyzed to review work procedures and construction types. In addition, empirical data were collected through drone photography and elevation image production for the actual dam. Result: Work types for safety inspection of facilities using drones were derived, and empirical survey results were collected for two dams according to work types. The existing guidelines were applied for the adjustment ratios for each structural type and standard of the facility, and if a meteorological reference point survey was necessary, the unmanned aerial vehicle survey of the construction work standard was applied. Conclusion: The finer the GSD in appearance investigation using drones, the greater the number of photographs taken, and the concept of adjustment cost was applied as a correction to calculate the consideration standard. In addition, it was found that the problem of maximum GSD indicating limitations should be considered in order to maintain the safe distance.