A Knowledge-based Fuzzy Multi-criteria Evaluation Model of Construction Robotic Systems

Wi-Sung Yoo 대한건축학회 2010 Architectural research Vol.12 No.2

In recent years, construction projects have been forced to cope with lack of skilled labor and increasing hazard circumstance of human operations. A construction robotic system has been frequently accomplished as one alterative for overcoming these difficulties in increasing construction quality, enhancing productivity, and improving safety. However, while the complexity of such a system increases, there are few ways to carry out an assessment of the system. This paper introduces a knowledge-based multi-criteria decision-making process to assist decision makers in systematically evaluating an automated system for a given project and quantifying its system performance index. The model employs linguistic terms and fuzzy numbers in attempts to deal with the vagueness inherent in experts’ or decision makers’ subjective opinions, considering the contribution resulted from their knowledge on a decision problem. As an illustrative case, the system, called Robotic-based Construction Automation, for constructing steel erection of high-rise buildings was applied into this model. The results show the model’s capacities and imply the application to other extended types of construction robotic systems.

Development of Expertise-based Safety Performance Evaluation Model

Yoo, Wi Sung,Lee, Ung-Kyun The Korean Institute of Building Construction 2013 한국건축시공학회지 Vol.13 No.2

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.

A Progress-based Expert System for Quantitative Assessments of Project Delay

Wi Sung Yoo 대한건축학회 2008 Architectural research Vol.10 No.1

Construction projects have frequently exceeded their schedule despite reliable estimates at the start of a project. This problem was attributed to unpredictable causes at the beginning and to shortage of proper tools to accurately predict project completion date. To supplement this difficulty, project managers need a comprehensive system that can be employed to monitor the progress of an ongoing project and to evaluate potential delay for achieving the goal on time. This paper proposed a progressive-based expert system for quantitative assessments of project delay at the early stages of the execution. Furthermore, the system is used to inspect the change of the uncertainty on completion date and its magnitude. The proposed expert system is helpful for furnishing project managers a warning signal as a project is going behind schedule and for tracking the changed uncertainty at a desired confidence level. The main objectives of this paper are to offer a new system to overcome the difficulties of conventional forecasting tools and to apply a construction project into the system to illustrate its effectiveness. This paper focuses on construction phase of project development and is intended for the use by project managers.

A Knowledge-based Fuzzy Multi-criteria Evaluation Model of Construction Robotic Systems

Yoo, Wi-Sung Architectural Institute of Korea 2010 Architectural research Vol.12 No.2

In recent years, construction projects have been forced to cope with lack of skilled labor and increasing hazard circumstance of human operations. A construction robotic system has been frequently accomplished as one alterative for overcoming these difficulties in increasing construction quality, enhancing productivity, and improving safety. However, while the complexity of such a system increases, there are few ways to carry out an assessment of the system. This paper introduces a knowledge-based multi-criteria decision-making process to assist decision makers in systematically evaluating an automated system for a given project and quantifying its system performance index. The model employs linguistic terms and fuzzy numbers in attempts to deal with the vagueness inherent in experts' or decision makers' subjective opinions, considering the contribution resulted from their knowledge on a decision problem. As an illustrative case, the system, called Robotic-based Construction Automation, for constructing steel erection of high-rise buildings was applied into this model. The results show the model's capacities and imply the application to other extended types of construction robotic systems.

A Progress-based Expert System for Quantitative Assessments of Project Delay

Yoo, Wi Sung Architectural Institute of Korea 2008 Architectural research Vol.10 No.1

Construction projects have frequently exceeded their schedule despite reliable estimates at the start of a project. This problem was attributed to unpredictable causes at the beginning and to shortage of proper tools to accurately predict project completion date. To supplement this difficulty, project managers need a comprehensive system that can be employed to monitor the progress of an ongoing project and to evaluate potential delay for achieving the goal on time. This paper proposed a progressive-based expert system for quantitative assessments of project delay at the early stages of the execution. Furthermore, the system is used to inspect the change of the uncertainty on completion date and its magnitude. The proposed expert system is helpful for furnishing project managers a warning signal as a project is going behind schedule and for tracking the changed uncertainty at a desired confidence level. The main objectives of this paper are to offer a new system to overcome the difficulties of conventional forecasting tools and to apply a construction project into the system to illustrate its effectiveness. This paper focuses on construction phase of project development and is intended for the use by project managers.

Prediction Model of Final Project Cost using Multivariate Probabilistic Analysis (MPA) and Bayes' Theorem

Yoo, Wi Sung,Hadipriono, FAbian C. Korea Institute of Construction Engineering and Ma 2007 한국건설관리학회 논문집 Vol.8 No.5

This paper introduces a tool for predicting potential cost overrun during project execution and for quantifying the uncertainty on the expected project cost, which is occasionally changed by the unknown effects resulted from project's complications and unforeseen environments. The model proposed in this stuff is useful in diagnosing cost performance as a project progresses and in monitoring the changes of the uncertainty as indicators for a warning signal. This model is intended for the use by project managers who forecast the change of the uncertainty and its magnitude. The paper presents a mathematical approach for modifying the costs of incomplete work packages and project cost, and quantifying reduced uncertainties at a consistent confidence level as actual cost information of an ongoing project is obtained. Furthermore, this approach addresses the effects of actual informed data of completed work packages on the re-estimates of incomplete work packages and describes the impacts on the variation of the uncertainty for the expected project cost incorporating Multivariate Probabilistic Analysis (MPA) and Bayes' Theorem. For the illustration purpose, the Introduced model has employed an example construction project. The results are analyzed to demonstrate the use of the model and illustrate its capabilities.

An Information-based Forecasting Model for Project Progress and Completion Using Bayesian Inference

Yoo, Wi-Sung,Hadipriono, Fabian C. Korea Institute of Construction Engineering and Ma 2007 건설관리 : 한국건설관리학회 학회지 Vol.8 No.4

In the past, several construction projects have exceeded their schedule resulting in financial losses to the owners; at present there are very few methods available to accurately forecast the completion date of a project. These nay be because of unforeseen outcomes that cannot be accounted for earlier and because of deficiency of proper tools to forecast completion date of said project. To overcome these difficulties, project managers may need a tool to predict the completion date at the early stage of project development. Bayesian Inference introduced in this paper is one such tool that can be employed to forecast project progress at all construction stages. Using this inference, project managers can combine an initially planned project progress (growth curve) with reported information from ongoing projects during the development, and in addition, dynamically revise this initial plan and quantify the uncertainty of completion date. This study introduces a theoretical model and proposes a mathematically information-based framework to forecast a project completion date that corresponds with the actual progress data and to monitor the modified uncertainties using Bayesian Inference.

Multiple Regression Technique for Productivity Analysis of the Jointed Plane Concrete Pavement (JPCP)

Yoo, Wi-Sung Korea Institute of Construction Engineering and Ma 2008 건설관리 : 한국건설관리학회 학회지 Vol.9 No.6

In highway construction projects, concrete pavement productivity has been challenged with constructors and decision-makers; at present there are few methods available to accurately evaluate the factors impacting on it. Any inefficient method to analyze it leads to the excessive schedule, higher rehabilitation costs, shorter service life, and reduction of ride quality. To implement these negative outcomes, constructors or decision-makers need a systematic tool that can be used to categorize the factors related to construction productivity. This paper applies multiple regression technique for productivity analysis of the Jointed Plane Concrete Pavement (JPCP), identifies the significant factors, and provides a predictive model assisting in monitoring and managing the productivity of the JPCP construction process. The completed and progressive projects are employed to derive and assess the proposed model. The results are analyzed to illustrate its capabilities.

Profit-oriented Impact Analysis of Demand Management Strategy on Design-Build Firms Using System Dynamics

Yoo, Wi-Sung The Korean Institute of Building Construction 2012 한국건축시공학회지 Vol.12 No.2

In the past, a strategic management of work demands has been increasingly challenged to design-build (DB) firms. Such a management is capable of providing sufficient profitable impact of a project on them. Total project profit is mainly related to actual resources, work completion time, amount of rework, and costs. The degree of recycling work packages in the DB project delivery system is used as a measure of the quality of the performed work. However, there are few models available to evaluate the impact of a demand management strategy on the DB firms and to predict its behavior. We propose a decision-making support model as an aid for assessing the amount of rework and for predicting project profit resulting in a convincible demand management strategy. This model is constructed by using a dynamic feedback approach that can analyze the problems arising in complex managerial systems. For the purpose of illustration, widely acceptable strategies were applied into the model to explore their impacts on the DB firms. The results indicate that the model is helpful for the managers in selecting the most appropriate demand management strategy for successfully achieving their objectives.

해외사업 잠재 리스크 모니터링 체계 구축에 관한 연구

유위성 ( Wi Sung Yoo ) 한국건설경제산업학회 2015 건설경제산업연구 Vol.6 No.1

200년대 중후반 이후로 국내 건설시장의 성장은 지속적으로 정체되면서, 대형 건설기업들은 해외로 시장을 확대하고 있다. 하지만, 최근 몇 년간 해외 사업에서 상당한 재무적 손실을 경험하면서 산업 차원의 해외사업 잠재 리스크 선제적으로 모니터링하여 대응할 수 있는 조기경보체계에 대한 요구가 크게 부각되고 있는 실정이다. 본 연구는 국내 건설산업이 보유하고 있는 해외사업 잠재 리스크를 탐색하고 입체적인 의사 결정을 지원 할 수 있는 리스크 조기경보체계(Pisk-EWS)를 소개하여 산업의 사전적 대응 수립을 지원하는데 목적이 있다. Rise-EWS는 리스크 지수, 불안정 지수, 민감도 지수, 현황ㆍ경보ㆍ예측 맵으로 구성되어 있다. 1998년 12월 부터 2015년 6월까지 금융감독원에 신고된 해외 산업 실적 데이터를 기반으로 구축되어 향후 활용 방안과 기대 효과를 제공한다. 과거 15년간의 잠재 리스크 추이를 분석할 결과, 중동 및 아프리카 권역에 1조원 이상의 산업설비 사업의 잠재 리스크 규모가 가파르게 증가하고 있는데, 이는 발주처의 재정 악화, 지속적 유가 하락, 공사 대금 지연 등의 요인들이 동시적으로 발생한 것에 크게 기이한 것으로 분석된다. Risk-EWS는 기업이 향후 자체적으로 구축하여 운영할 수있고, 정부의 금융 정책 수립에 활용하여 선제적이고 효율적인 해외건설 진출을 지원할 것으로 기대된다. 또한 산업 차원의 모니터링 기능과 기업의 경영전략을 수립하는데 기초 자료로 활용될 것이다. Since the rnid-2000s, Korean large-sized construction companies have pursued in earnest to expand their business to global construction market in surroundings that domestic market have a continuous and long-term stagnation. However, during last a few years, they have experienced the serious financial loss from international projects. In the meantime, for the sound improvement of Korean construction industry, many stakeholders pursue to an alternative for providing efficient early warning signals, so to monitor and track the potential risks on international projects in industry level. In this study, we introduce a potential risk early warning system(Risk-EWS) of international projects, which is derived from massive data provided by large-sized companies. This system is composed of risk index, unstability index, sensitivity index, and watchingㆍwarningㆍforecasting map. Also, it is intended to assist in making a decision in the diverse angles. Risk-EWS is applied with the data derived from Financial Supervisory Service during last 15 years. Based on the results from the Risk-EWS, it is expected that the progress of industrial plant projects more than 1 billion USD in middle east and africa is getting worse. For the future, the system can be used as a fundamental guideline if domestic companies try to customize this system and when government institute establishes a financial policy for supporting to expand their business. Also, we expect to provide the practitioners and decision makers as an aid to proactively cope with the change of the potential risks and to prepare a timely management strategy.