Wi Sung Yoo

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.

Case study of a synchronous hydraulic jack-up system for constructing high-rise residential buildings

In recent years, contractors have frequently needed to apply innovative technologies to fulfil architects’ creative and intricate designs. They have often encountered abnormal construction conditio...

Benefit/cost analysis of a robot-based construction automation system

Many studies which try to integrate construction technologies with robotic technologies have been actively progressing. It is critical for an assessment model of the economical efficiency of new technologies to ensure the correct investment and the spread of these new technologies. However, an assessment model of economical efficiency of automated construction technology to evaluate properly various influencing factors in terms of technology and economy is relatively unsatisfied as there are no practical cases. Therefore, our research team has developed a new assessment process for automated construction technologies as a decision tool, inspired by benefit-cost analysis. This presented process was employed to evaluate the test-bed and the results show that the BI and CI are 1.24 and 5.22, respectively, and economic efficiency is 0.24. The results indicate that the applications of four new technologies present a significantly strong benefit and respectively large cost, compared to the traditional process. As establishing an assessment model of an automated construction system which has not previously been known, it is expected to understand the effect and potential power of the application of robot technology to the construction industry. For further study, it is necessary for the integration method to be developed because of the degree of difference between BI and CI.

Early Warning Model using Case-Based Reasoning for Construction Site Safety Accidents

In these days, the accidents on construction site are continuously increasing in spite of the managerial efforts and financial investments. This trend encourage safety managers or decision makers to enhance existing approaches and to develop innovative and proactive management aids. In this study, we propose an early warning model, called the Early Warning Model (hereafter EWM), for the potential types and causes of an accident as a project is progressive, using Case-Based Reasoning technique. The EWM was tested with illustrative cases, and the results showed a few possible cases with high likelihood for a specific situation randomly selected in the construction field. It is expected that the EWM is useful for furnishing safety managers and field supervisors with warning signals during the construction and helpful for assisting them in responding preactively and minimizing the ripple effect of construction site accidents.

Impact of Balance between Productivities on Repetitive Construction Projects

Fast delivery of construction projects provides more value to project owners. Batch production, which is production not in single pieces, but in batches, is a common approach in repetitive construction projects such as multi-unit residential building construction projects. In batch production, the use of a small batch size allows the early start of subsequent activities, and thus can lead to early completion of projects. In addition to batch size, balance between productivities on construction activities can affect project duration. However, the impact of the balance between productivities with regard to their order on project duration has not been studied. The main goal of this study is to test a hypothesis, which is that the order of construction activities’ unbalanced productivities affects the amount of time reduction that can be achieved by using a small batch size. A computer-based simulation model was developed, and five different cases were simulated to test the hypothesis. The conclusion of the simulation result is that the order of productivities does not affect the time reduction achieved by using a small batch size. It is expected that the findings of this study can help general contractors make decisions in terms of batch size.

Development of Expertise-based Safety Performance Evaluation Model

Construction projects have become increasingly complex in recent years, resulting in substantial safety hazards and frequent fall accidents. In an attempt to prevent fall accidents, various safety management systems have been developed. These systems have mainly been evaluated qualitatively and subjectively by practitioners or supervisors, and there are few tools that can be used to quantitatively evaluate the performance of safety management systems. We propose an expertise-based safety performance evaluation model (EXSPEM), which integrates a fuzzy approach-based analytic hierarchy process and a regression approach. The proposed model uses S-shaped curves to represent the degree of contribution by subjective expertise and is verified by a genetic algorithm. To illustrate its practical application, EXSPEM was applied to evaluate the safety performance of a newly developed real-time mobile detector monitoring system. It is expected that this model will be a helpful tool for systematically evaluating the application of a robust safety control and management system in a complex construction environment.