• Journal of Cadastre & Land InformatiX
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• v.51 no.2
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• pp.73-82
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• 2021

According to the government's announcement of the safety management enhancement policy for small and medium-sized private construction sites, the subject of mandatory CCTV installation has been expanded from large construction sites to small and medium-sized construction sites. However, since the existing CCTV at construction sites has been used for simple control for safety management, so research is needed for monitoring of construction sites. Therefore, in this study, three vanishing points were calculated based on a single image taken with a monocular camera, and then a camera matrix containing interior orientation parameters information was determined. And the accuracy was verified by calculating the height of the target object from the height of the reference object. Through height determination experiments using vanishing points based on a monocular camera, it was possible to determine the height of target objects only with a single image without separately surveying of ground control points. As a result of the accuracy evaluation, the root mean square error was ±0.161m. Therefore, it is determined that the progress of construction work at the construction sites can be monitored through the single image taken using the single camera.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1250-1251
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• 2022

Measuring management is an important part of preventing the collapse of retaining walls in advance by evaluating their stability with a variety of measuring instruments. The current work of measuring management requires considerable human and material resources since measurement companies need to install measuring instruments at various places on the retaining wall and visit the construction site to collect measurement data and evaluate the stability of the retaining wall. It was investigated that the applicability of the current work of measuring management is poor at small and medium-sized urban construction sites(excavation depth<10m) where measuring management is not essential. Therefore, the purpose of this study is to develop a laser sensor-based hardware to support the wall displacement measurements and their control software applicable to small and medium-sized urban construction sites. The 2D lidar sensor, which is more economical than a 3D laser scanner, is applied as element technology. Additionally, the hardware is mounted on the corner strut of the retaining wall, and it collects point cloud data of the retaining wall by rotating the 2D lidar sensor 360° through a servo motor. Point cloud data collected from the hardware can be transmitted through Wi-Fi to a displacement analysis device (notebook). The hardware control software is designed to control the 2D lidar sensor and servo motor in the displacement analysis device by remote access. The process of analyzing the displacement of a retaining wall using the developed hardware and software is as follows: the construction site manager uses the displacement analysis device to 1)collect the initial point cloud data, and after a certain period 2)comparative point cloud data is collected, and 3)the distance between the initial point and comparison point cloud data is calculated in order. As a result of performing an indoor experiment, the analyses show that a displacement of approximately 15 mm can be identified. In the future, the integrated system of the hardware designed here, and the displacement analysis software to be developed can be applied to small and medium-sized urban construction sites through several field experiments. Therefore, effective management of the displacement of the retaining wall is possible in comparison with the current measuring management work in terms of ease of installation, dismantlement, displacement measurement, and economic feasibility.

• International Journal of Advanced Culture Technology
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• v.12 no.3
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• pp.396-405
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• 2024

This study analyzed the practical issues in the Serious Accident Punishment Act (SAPA) for construction sites and proposed measures to improve provisions that are detached from reality. The Act aims to prevent major accidents across various industries, with a particular emphasis on the construction sector. While the Act's intention is commendable, several significant legal flaws have emerged during its implementation. These issues were critically analyzed and strategic recommendations were proposed. Key issues include ambiguous legal definitions, the differential impact of the law on small and large businesses, and the increased administrative and managerial burdens. This study proposed specific measures to enhance the clarity of legal terminology and technology, balance the responsibilities between small and large businesses, and streamline administrative processes. Additionally, methods for effectively revising the regulations and reasonably complying with them on-site were proposed. By addressing these issues, we aim to improve the effectiveness of the law, ensure fair application, and ultimately create a safer working environment in the construction industry. The recommendations are expected to serve as valuable resources for future revisions and improvements to SAPA and contribute to the broader goal of sustainable industrial safety and development.

• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.15-22
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• 2020

Scaffolding works are demolished after this structure is completed, and safety accidents often occur because they are installed differently from legal standards or frequently change during work. Therefore, in order to strengthen the safety of scaffolding, the Ministry of Land, Infrastructure and Transport required a need for design standards for temporary facilities that can systematically prevent and solve large-scale safety accidents that are repeatedly increasing during temporary construction. It has been enacted, and some contents have been revised for the past three years. However, construction site personnel do not know or know the revised matters, but often install scaffolding by the installer's experience rather than complying with relevant laws and regulations. It is the situation that the ground strength test of the foundation ground for the load applied to the floor of the column is omitted in most sites. Therefore, this study grasped the actual situation on the degree of recognition of the revised laws and regulations of the construction site and the foundation-based treatment of the floor working load of the scaffolding column, and derived problems. In addition, we intend to provide reference materials for the endurance test according to the ground conditions to small-scale small sites where it is difficult to conduct the test by carrying out the endurance test of the scaffolding ground according to the revised standards.

• Water for future
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• v.24 no.1
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• pp.63-71
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• 1991

This study represents the methodology for feasibility analysis of small hydro power plants. Cumulative density function of Weibull distribution and Thi-essen method were adopted to beside flow duration curve at candidate sites. The performance prediction model and construction cost estimation model for tunnel-type small hydro power plants were developed. Eight candidate sites existing on Han river selected and surveyed for actual sites reconnaissance. The performance characteristics and economical feasibility for these sites were analyzed by using developed models. As a result, it was found that the optimum design flowrates with the lowest unit generation cost for tunnel-type small hydro power plants were the flowrate concerning with between 20 % and 30 % of time ratio on the flow duration curve. Additionally, primary design specifications such as design flowrate, effective head, capacity, annual average load factor, annual electricity production were estimated and discussed for surveyed sites.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.81-91
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• 2010

Daily workers in construction sites rarely receive the benefit of systematic safety and health training as they are required to move from one construction site to another in response to the start, completion, and repetition of construction works. Also, small- to medium-sized construction sites often lack the capacity to train their workers. Therefore, as in the advanced countries, basic safety training system for construction workers should be conducted in the industrial-level, rather than in individual workplace-level, to make the training more effective. By doing so, only workers with the basic safety training will be able to engage in construction works. Consequently, accidents in the construction industry will decrease, as workers themselves who are at the forefront of the construction worksites are empowered to play the central role in accident prevention activities.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.207-214
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• 1998

In the past several years, accident frequency rate was decreased but severity rate was increased at construction sites with less than two-hundred workers. Accidents caused by failure of education in respect with the management occupied about 40 % in 1997. In this research, a questionnaire survey to know the effects of safety education was committed for small & medium construction sites. Survey results showed that workers wanted to improve work environments and safety facilities than safety education, however they also were not satisfied to educational facilities, contents and methods. Whereas, they agreed that they improved safety consciousness after safety education. As a result, four appropriate methods to promote effective safety education were proposed.

• Journal of the Korean housing association
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• v.11 no.4
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• pp.53-63
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• 2000

The study focuses on the problems of store space supply in apartment sites and suggests policy directions for the problem. Based on the results of field survey and site reconnaissance, this study identifies following problems and policy directions. First, the stores do not meet consumers various demand due to item limitations with small size. Consequently, there are many closed and/or unsold stores with high vacancy rates, Second, there is a tendency that the closed store rate becomes higher as apartment size becomes smaller. We suggest some law and regulation amendment that make store supply optional rather than mandatory in the case of small apartment site construction.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.27-38
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• 2019

Sensors collect information for Internet of Things (IoT)-based services. However, indoor construction sites have a poor communication environment and many interfering elements that make it difficult to collect sensor information. In this study, a network was constructed between a Bluetooth Low Energy (BLE)-based IoT device based on a serverless IoT framework and a router. This experimental environment was applied to large- and small-scale indoor construction sites. Experiments were performed to test the communication performance of BLE-based IoT devices and routers at indoor construction sites. An analysis of the received signal strength indication (RSSI) graph patterns collected from the communication between the BLE-based IoT devices and routers for different testbed site situation revealed areas with good communication performance and poor communication performance due to interfering factors. The results confirmed that structural components of the building as well as the materials, equipment, and temporary facilities used in indoor construction interfere with the communication performance. Construction project managers will require improved technical knowledge of IoT, such as optimizing the router placement and matching communication between the router and workers, to improve the communication performance for large-scale indoor construction.

• Journal of the Korean Geotechnical Society
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• v.40 no.5
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• pp.103-111
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• 2024

Small-scale excavation sites in construction-defined as those involving excavation projects less than 10 meters deep-often lack dedicated safety managers, creating challenges in safety management. This study aims to develop an accident case-based checklist that enables workers to manage safety independently at these sites. Accident data from the past five years were obtained from the Construction Safety Management Integrated Information system, and the causes, types, and contributing factors of accidents were analyzed based on this data. These analyzed causes were linked to specific checklist items, resulting in a new checklist comprising 14 items divided into pre-construction and during-construction phases. To ensure the logical structuring of these 14 items, a group of experts conducted a survey employing pairwise comparisons. The results indicated that all items are essential for safety management at small-scale excavation sites. Furthermore, the reliability of the developed checklist was validated using newly occurring accident cases, confirming that each accident was associated with the checklist items. The checklist proposed in this study is expected to contribute to practical and effective accident prevention in small-scale excavation sites.