Sung-Hoon An

A Comparative Analysis of the Safety Awareness of Korean and Chinese Construction Workers

Accompanied by Chinese strong economic growth rates and development of demand for the construction industry, Chinese construction industry has already become one of the largest construction markets in the world. Unfortunately, the frequent occurrence of safety incidents on Chinese construction sites is a large obstacle for other countries construction companies seeking to enter the Chinese construction market. This study aims to analyze and compare the safety awareness of Chinese and Korean construction workers. Our research showed that the safety awareness of Korean construction workers is far higher than that of their Chinese counterparts, particularly in terms of the efficiency of safety education and the observance of safety rules. The development of a safety management plan based on these results will contribute to reducing the frequency of accidents on Chinese construction sites.

Performance assessment model for robot-based automated construction systems

An adjusted assessment model based on benefit-cost analysis (BCA) is proposed for evaluating the economic efficiency of automated construction technologies. In contrast to conventional BCA, the model does not compare monetary values, but the differences in benefits and costs between traditional and automated construction methods. To verify the usefulness of the model, it was applied to a real-scale building construction project that used a fully automated building construction system, and the face validity of the model was confirmed. The results indicate that the model can support decision makers in identifying valuable benefit factors and in assessing the cost effectiveness of the system.

A study on the economic analysis of high-rise residential-commercial building that is made by precast concrete

The increase of hish-rise residential-commercial buildings is required to cut down a term of works and the cost of construction. Reinforced concrete structures and steel framed reinforcement concrete that are commonly used have the difficulty in reducing them. Therefore, the purpose of this study is to propose a new precast concrete complex system and to analyze its economical feasibility. The economic analysis is performed through comparing the cost of a high-rise reinforced building that was already constructed with that of the new proposed precast concrete system, which is limited to structural frame work of typical floors. This study shows that the proposed precast concrete complex system is economical. Further research should be directed at including the influence of a term of works.

Influence of Organizational Culture on Performance of Building Construction Project

Construction companies want to improve the abilities of field organizations for improving the performance of construction projects. It is possible to improve the performance of construction projects by managing the field organizational culture, due to the field organizational culture is concerned with the abilities of construction field organizations. Therefore, the purpose of this study is to reveal the influence of the field organizational culture on the performance of building construction projects. The results of this study showed that field organizational cultural characteristics influence on the performance of construction projects. Best performed projects have the higher characteristics of a consensus culture and rational culture, and worst performed projects have the lower characteristics of a development culture and consensus culture. In addition, the characteristics of rational culture and hierarchy culture effect on the performance in worst performed projects. This study is expected to help to improve the performance management system in construction field organization.

A Study on the Key Factors Influencing the Reliability of Conceptual cost estimates in Building Construction Projects

Cost estimates are very important to their decision-making in the early stages of a construction project. So Clients have wanted not only to know the results of conceptual cost estimates but also to assess their quality Conceptual cost estimates process is very complex process, so the results of cost estimates are influenced by various factors. So the purpose of this study is to reveal the key factors which influence the reliability of conceptual cost estimates in building construction projects. The analytic hierarchy process is used to determine the relative important weights of elements influencing the conceptual cost estimates. And factor analysis is used to reveal the key factors from the elements that influence the conceptual cost estimates. The results showed that the key factors is an experience level, available data level, level of will for winning the bid, difficulty level of conceptual cost estimate, uncertainty level.

Factors Influencing the Work Ability of Building Construction Field Managers

The success of construction projects is heavily dependent on the work ability of the field managers who manage the execution of projects. The work ability of field managers is influenced by various elements such as job stress and individual characteristics. The purpose of this study is to reveal the factors influencing the work ability of construction field managers in Korea. Work ability is evaluated bases on the Work Ability Index(WAI) developed by the Finnish Institute of Occupational Health, while job stress is measured using the Korean Occupational Stress Questionnaire Short Form developed by the Korean Occupational Safety & Health Agency. The results showed that field managers under higher job stress have lower work abilities. In addition, it is revealed that exercise or religious practice have a positive influence on work ability. This study will help to increase the work ability and enable the efficient management of organization at building construction sites.

Experimental Study on Field Applicability of Tightened Coupler with Two-Way Threading

A tightened coupler with two way-threading is suggested to overcome the previous one-way threaded coupler. The experiment and a mock-up test were conducted to analyze the constructability of the suggested coupler. The aim of the mock-up test was to assemble the suggested coupler in horizontal rebar of mat footing and vertical rebar of semi-fabricated column bars. The method using the suggested coupler in semi-fabricated column bars is developed by analyzing the problem of fabricated column bars using the one-way threaded coupler. The result of the mock-up test showed that the time required to assemble the suggested coupler in the horizontal bars is shorter than it is for the one-way threaded coupler. In addition, the method using the suggested coupler in semi-fabricated column bars has advantages such as lower working loads, supporting safe work and strongly tightening the rebar. From these results, it is revealed that the suggested coupler is adequate to use in rebar work in terms of cost, quality and time.

A Study on the process for Managing the Reliability of Conceptual cost estimates in Building Projects

Conceptual cost is estimated with insufficient information at an early stage of a building construction project, resulting in an inevitable gap between conceptual estimated cost and real constructed cost. For a project to be successful, this gap must be managed to be lower than a reliable level. Therefore, the purpose of this study is to propose a structural process for managing the reliability of conceptual cost estimates at an early stage of a building construction project. In researching this study, conceptual cost estimate experts were interviewed,and a risk management process was studied. Reliability assessment and a review process for improving the quality of conceptual cost estimate and the planning strategy of reliability management based on previous similar projects were added to the present estimate process. The proposed reliability management process will improve the chances of a successful project, by helping to decrease the risk of conceptual estimated cost.

A Study on Optimization Model of Time-Cost Trade-off Analysisusing Particle Swarm Optimization

It is time-consuming and difficulty to solve the time-cost trade-off problems, as there are trade-offs between time and cost to complete the activities in construction projects and this problems do not have unique solutions. Typically, heuristic methods, mathematical models and GA models has been used to solve this problems. As heuristic methods and mathematical models are have weakness in solving the time-cost trade-off problems, GA based model has been studied widely in recent. This paper suggests the time-cost trade-off optimization algorithm using particle swarm optimization. The traditional particle swarm optimization model is modified to generate optimal tradeoffs among construction time and cost efficiently. An application example is analyzed to illustrate the use of the suggested algorithm and demonstrate its capabilities in generating optimal tradeoffs among construction time and cost. Future applications of the model are suggested in the conclusion.