• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.115-118
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• 2007

A tall building construction is needed to reduce the construction duration for project profitability. Reducing the cycle time of typical floor in the structural frame work which have the largest duration in the whole construction, greatly affects construction duration. Nowadays, some projects are accomplished in the 3 day cycle. In order to accomplish efficiently 3 day cycle, productivity information of similar projects is supported. Therefore, this study proposed labor productivity and application by slab formwork to construct by the 3 day cycle. In order to perform an analysis, we selected 3 cases and analyzed the labor productivity on the basis of the amount of slab forms, labors, and durations. Then, we performed the questionnaire to analyze the application by formwork of tall building construction engineers. This study will contribute to establish a reasonable scheduling in structural frame work of a new similar project.

• International Journal of High-Rise Buildings
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• v.11 no.2
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• pp.115-124
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• 2022

Welding is a significant part of the construction industry. Since most high-rise building construction structures rely on a robust metal frame welded together, welding defect can damage welded structures and is critical to safety and quality. Despite its importance and heavy usage in construction, the labor shortage of welders has been a continuous challenge to the construction industry. To deal with the labor shortage, the ultimate goal of this study is to design and develop an automated robotic welding system composed of a welding machine, unmanned ground vehicle (UGV), robotic arm, and visual sensors. This paper proposes and focuses on automated weaving using the robotic arm. For automated welding operation, a microcontroller is used to control the switch and is added to a welding torch by physically modifying the hardware. Varying weave patterns are mathematically programmed. The automated weaving is tested using a brush pen and a ballpoint pen to clearly see the patterns and detect any changes in vertical forces by the arm during weaving. The results show that the weave patterns have sufficiently high consistency and precision to be used in the actual welding. Lastly, actual welding was performed, and the results are presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.969-974
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• 2006

Labor shortages are a serious problem for Korea's construction industry. The problem is both quantitative and qualitative. There is a shortage in supply as due to a decrease in the influx of new labor, and existing workers are less productive as they age. The problem will only get worse as more and more major public projects are being planned. Options for increasing the labor supply are somewhat limited, and thus efforts need to be made to adopt new technologies that can improve the productivity and efficiency of field work and their processes. This paper introduces seven innovation technologies that have the best potential to increase productivity and thus reduce the burden of labor shortage problems. These include 1) Substitution by use of robotics and automation, 2) development and applications of Innovative materials to reduce on site field work, 3) increase in productivity through the implementation of Information Technology, 4) improved productivity through the application of modules, and prefabrication, 5) prevention of rework and redesign, 6) diversification of labor by integrating labor skills, and 7) improved productivity by standardizing site processes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.117-120
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• 2005

The business market of architecture has got a system that controls a deposit according to the price function. This system is written on a law of contract about countries. So the main body of construction has to make a reasonable contract. This study is written about a rate of numerical index on controling a deposit. We tried to fine problems and solutions of labor expenses, instrument costs and material costs which is so big and changable on the construction market Labor expenses are expressed according to the rate of construction scale between direct and indirect cost that applies ability of works. Instrument costs are expressed according to an output method of a unit price annually and a weight allowance of local instrument conditions and use frequence. The last material costs expressed according to a local weight allowance make a decision of the material cost index. They applies locally relative index more than absolute one on what uses the price rate of producers and importations. This solutions are not enough to apply to the real market, so it needs to exam and to be on the market after a feasibility study.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.295-300
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• 2001

Additional costs as well as schedule delay are occurred due to change orders in today's construction projects. Additional costs, overhead calculation methods are of various types. In a foreign country cases, many claims related to the loss of labor productivity quote research statistics data. In domestic cases, the study of the reason why the loss of labor productivity occurs and its effect have not been performed. Therefore, this paper analyzes factors affecting lost productivity and a methodology is presented to estimate the lost productivity.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.324-327
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• 2015

Scaffold is the most commonly used equipment in various types of construction works. Since various types of construction works use the same scaffold equipment, it becomes more difficult to be controlled and managed, thus resulting hazard frequently. According to the information announced in July 2012 by Council of Labor Affairs Executive Yan, the site collapse or incomplete anti-falling protection has led the site to accident frequently, and this is the main reason that causes construction industry occupational disasters. The labor death occupational hazard ratio rises up to 13% in scaffold activity, and the Council of Labor Affairs Executive Yan has showed that the death ratio is higher when using the scaffold in construction site, the total number of death has reached to 139 from 2005 to 2010. In order to ensure the safety of scaffold user, this study tends to build a wireless sensor monitoring system to detect the reliability and safety of the scaffold. The wireless sensor technique applies in this study is different with the traditional monitoring technique which is limited with wired monitoring. Wireless sensor technique does not need wire, it just needs to consider the power supply for establishing the network and receiving stable information, and it can become a monitoring system. In addition, this study also integrates strain gauge technique in this scaffold monitoring system, to develop a real-time monitoring data transfer mechanism and replace the traditional wired single project monitoring equipment. This study hopes to build a scaffold collapse monitoring system to effectively monitor the safety of the scaffold as well as provide the timesaving installation, low-cost and portable features.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.12
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• pp.173-180
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• 2019

Construction work is a labor-intensive industry, which is required systematic production activities using materials, manpower, and equipment. Among them, manpower resources play a very important role in achieving efficiently production in the organization. Construction work is highly dependent on construction craft workers, and the level of proficiency can be directly related to the construction productivity and quality. However, a rapidly aging construction craft workers in Korea, is being replaced by a foreign construction craft workers because of advoidance of new laborers in the construction site. In the future, if the continuous development and management of construction manpower is not made properly, it may be lead to adverse effects such as setbacks in production, delayed completion, faulty construction, industrial disasters, and decreased productivity in construction site. In this study, it was proposed four important factors for work capacity management of construction craft workers. These were ensuring of physical strength through the health management of construction craft workers, securing of proficiency through career management, ensuring of productivity through work capacity and establing of informatization through work capacity management. By introducing a systematic system, it is possible to improve construction craft workers' professionalism, enhancing the level of welfare, reflecting the realities of labor costs, increasing the quantitative and qualitative levels of construction craft workers, Futhermore it was demanded the continued interest and policy support for the realization of effective management of construction craft workers.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.106-111
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• 2005

After many casualties of conventional bulk carriers in recent years, a double hull bulk carrier was proposed to enhance the structural safety of a side shell and a transverse bulkhead. In this paper, two alternative structural designs of a double hull bulk carrier were carried out based on the Lloyd's rule. One has the double sided hull with longitudinal stiffeners and the other has that with a girder. The final structural design was examined in comparison with an existing single hull bulk carrier from the viewpoints of cargo hold capacity and the increases of weight and construction cost. Generally, the construction cost of a ship consists of the costs of material, labor and overhead cost. But, in this study, the relative construction cost concept was introduced to compare the economical validity more precisely. In this concept, fixed overhead cost is excluded in the assessment of construction cost, and only the variable overhead cost is added up to labor cost. As the result of this study, a double hull bulk carrier can be constructed within 1% increase of weight and construction cost.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.107-113
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• 2015

Recently mechanization construction methods are developed rapidly in the field of construction processing. The construction industry is one of the sector that still requires a lot of manual labor of the entire industry. There are still various kinds of work done by human labors, especially in the disassembling and separation of materials for recycling. However, database of relevant statistics including estimating standards are difficult to analyze by actual human workload, and furthermore the disassembling processes are being analyzed by qualitative assessment. This study attempted to introduce the accelerometer for the quantitative evaluation of human workload in the construction field. Still, it is possible to calculate the amount of energy which is required for the assembling and disassembling of nail and screw through three-dimensional accelerometer.

• International journal of advanced smart convergence
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• v.12 no.2
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• pp.159-166
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• 2023

Due to the aging workforce in the construction industry in South Korea, the accident rate has been increasing. The cognitive abilities of older workers are closely related to both safety incidents and labor productivity. Therefore, there is a need to improve cognitive abilities through personalized training based on cognitive assessment results, using cognitive training content, in order to enable safe performance in labor-intensive environments. The provided cognitive training content includes concentration, memory, oreintation, attention, and executive functions. Difficulty levels were applied to each content to enhance user engagement and interest. To stimulate interest and encourage active participation of the participants, the difficulty level was automatically adjusted based on feedback from the MMSE-DS results and content measurement data. Based on the accumulated data, individual training scenarios have been set differently to intensively improve insufficient cognitive skills, and cognitive training programs will be developed to reduce safety accidents at construction sites through measured data and research. Through such simple cognitive training, it is expected that the reduction of accidents in the aging construction workforce can lead to a decrease in the social costs associated with prolonged construction periods caused by accidents.