• International conference on construction engineering and project management
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• 2022.06a
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• pp.728-735
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• 2022

Roofers get exposed to increased risk of knee musculoskeletal disorders (MSDs) at different phases of a sloped shingle installation task. As different phases are associated with different risk levels, this study explored the application of machine learning for automated classification of seven phases in a shingle installation task using knee kinematics and roof slope information. An optical motion capture system was used to collect knee kinematics data from nine subjects who mimicked shingle installation on a slope-adjustable wooden platform. Four features were used in building a phase classification model. They were three knee joint rotation angles (i.e., flexion, abduction-adduction, and internal-external rotation) of the subjects, and the roof slope at which they operated. Three ensemble machine learning algorithms (i.e., random forests, decision trees, and k-nearest neighbors) were used for training and prediction. The simulations indicate that the k-nearest neighbor classifier provided the best performance, with an overall accuracy of 92.62%, demonstrating the considerable potential of machine learning methods in detecting shingle installation phases from workers knee joint rotation and roof slope information. This knowledge, with further investigation, may facilitate knee MSD risk identification among roofers and intervention development.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.606-612
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• 2024

The modeling and simulation of built environments are crucial preliminary steps for their design, planning, and management. Among various simulation methods, agent-based modeling (ABM) has recently gained traction for simulating built environments due to its ability to effectively model and capture complex interactions between simulated entities. The increasing applications of ABM for the simulation of built environments necessitate a comprehensive review of past scientific endeavors with positive accomplishments and those that remain unsolved. This study seeks to address this gap by reviewing ABM and its applications in the simulation of built environments, with a specific focus on the planning and design phases. First, the research introduces ABM and its unique features concerning the simulation of built environments. Second, it conducts a systematic review of past studies in the planning (e.g., feasibility analysis, risk management, and scheduling under constraints) and design (e.g., automated design, collaborative design, improving operations, and facilitating evacuation) aspects of built environments. Finally, following the in-depth review and subsequent analysis, the study identifies the strengths and weaknesses of using ABM for simulating the built environments. The study concludes with a remark on potential future research directions to overcome the limitations of the existing studies.

• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.78-87
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• 2009

Because of a wide range of performance and diversity of project and uncertainty caused by complexity and a number of stakeholder, conflict occur necessarily in Urban generation including large-scale and many project which do the same time, for long time. so active conflict management which recognized risk before the fact and deal with conflict is necessarily needed. Therefore, This study is typing conflict cases and indicating critical conflict type through analysis on conflict case about process and stakeholder of urban generation to offer information which is referred to finding a solution when conflict occur by forecasting conflict that can occur before the fact.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.509-512
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• 2003

The Critical Path Method(CPM) is an effective tool used for planning and scheduling. One of strong point in the CPM is what can calculate float. Float is able to prolong without having an effect on overall schedule of project, however concept and scope about ownership is not definite, because it is a by-product of project. Thus participants have had many dispute in using float because of their interests. In recent years, a few theories have evolved in an attempt to solve this problem. But the prior research did not make a reasonable distribution of float because their criteria of distribution was based on ratio for total project time. Actually, an application of float is achieved by participant's delay risk. Therefore. this paper proposes criteria for float distribution using delay risks, and the framework for the assessment of the delay risks.

• Journal of the Korea Institute of Building Construction
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• v.19 no.5
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• pp.439-448
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• 2019

There are various factors affecting the success and failure of an apartment building project. However, after the unit sale price has been determined and the sale has started, the most important factor affecting on the project is the initial sales ratio for one month after the sale. Generally, developers predict an initial sales ratio by various data such as economic situation, the trend of the housing market, and the house price near the business place. However, it is very difficult for these factors to be calculated quantitatively in connection with the initial sales ratio. Therefore, the purpose of this study is to develop a regression model for forecasting the initial sales ratio of apartment building projects. For this study, pre-sales data collection, correlation analysis between influencing factors, and regression model development are performed sequentially. The results of this study are used as basic data for predicting the initial sales ratio in the feasibility analysis of apartment building projects and are used as key data for the development of the risk management model.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.3-15
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• 2022

Daycare center is an important space for children's mental, physical and social development. Each space of daycare center should be designed and constructed considering interests of end-users such as children and teachers. However, insufficient related guidelines and standardized design and construction of daycare center to moderate potential risks of each space. This arises from the difference in perception of each space between end-users (head and sub teachers) and construction experts (designers and contractors). Therefore, research framework was developed for analyzing the factors of perception differences of each space in daycare center between these groups applied traditional and modified Importance-Performance Analysis (IPA). By comparing risk perception between end-users and experts in two methods, it can be support as construction guide for daycare center in the future and will help minimize conflicts in construction among stakeholders. Moreover, it was found that traditional IPA is comfortable to catch prior project perception of participants, and revised IPA is considered to judge outputs by identifying participant's importance based on the satisfaction of the project performance. Therefore, if IPAs are applied according to the characteristics of the circumstances, it is possible to analyze the perception difference between end-users and construction experts based on the context before and after the construction of the daycare center.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.1
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• pp.1-12
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• 2016

When utilizing a Tunnel Boring Machine (TBM) for tunnelling work, unexpected ground conditions can be encountered that are not predicted in the design stage. These include fractured zones or mixed ground conditions that are likely to reduce the stability of TBM excavation, and result in considerable economic losses such as construction delays or increases in costs. Minimizing these potential risks during tunnel construction is therefore a crucial issue in any mechanized tunneling project. This paper proposed the potential risk events that may occur due to risky ground conditions. A resistivity survey is utilized to predict the risky ground conditions ahead of the tunnel face during construction. The potential risk events are then evaluated based on their occurrence probability and impact. A TBM risk management system that can suggest proper solution methods (measures) for potential risk events is also developed. Multi-Criterion Decision Making (MCDM) is utilized to determine the optimal solution method (optimal measure) to handle risk events. Lastly, an actual construction site, at which there was a risk event during Earth Pressure-Balance (EPB) Shield TBM construction, is analyzed to verify the efficacy of the proposed system.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.278-288
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• 2020

Modular Integrated Construction (MiC) has gained quite momentum as it provides solutions for several problems in the construction sector, particularly in Hong Kong. MiC is converting the building into modules and erecting them easily on site providing various benefits, such as cost and time savings, better quality, lower risk, higher sustainability, less injuries and accidents, etc. The MiC is considered the best alternative to traditional construction approaches in solving the huge housing demand problem in many cities all over the world due to the time-saving privilege. The utilization of MiC is facing a lot of challenges, which are considered obstacles to the wide acceptance of this technique in the construction industry in Hong Kong. This, in turn, has led the interests of the research community to investigate its benefits and challenges aiming at addressing several solutions to harness the benefits of this technique and to tackle these challenges. The present research aims to review the main concept of MiC and to determine the benefits and the challenges of implementing MiC in construction industry. The findings of this research highlight the advantages and limitations of incorporating MiC technique in Hong Kong, which will help the stakeholders to effectively utilize this technique in the construction industry.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.306-310
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• 2002

Agreements such as the Uruguay Round and the New Round have dramatically changed international construction markets. The globalization of the construction industry provides tremendous opportunities for construction industry, while it generates the complex skeins of risks to contractors wllo would like to expand into new foreign markets. According to ENR, recently about $13.9\%$ of contractors that entered international construction markets have experienced loss in projects and furthermore, their average profits have also declined continuously. Accordingly, contractors need a strategic risk management system for assessing various risks and improving Profitability for overseas construction projects. This paper discusses the long-term trend of profitability performed by Korean contractors in international construction markets during the last 35 years. Then, it identifies the key factors that affect the profitability significantly through the structured surveys from 59 actual overseas projects. These factors can be used for developing a risk management system for international construction project.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.85-93
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• 2006

This study is started from a situation of korean construction which has been undergoing diversity. And risk of construction project has been increased recently. The purpose of this study is to propose the model which is able to estimate the proper manpower by eliciting the variable which is offered in the pre-design and construction phase. The existing method of estimate has a problem with calculating exact costs. For this model, it was analyzed the existing manpower estimating model and used historical data of 38 apartment houses, constructed from 2000 to now. Based on these, the regression model of the construction manpower was built. And then the regression model was verified. The result of verification was relatively adequate in the statistics exept for some cases. This regression model will help make it possible for constructor to estimate the deduction of retirement more accurate than existing method.