Browsing by Author "Arditi, David"

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Citation - WoS: 64
Citation - Scopus: 79
Assessing Coordination Performance Based on Centrality in an E-Mail Communication Network
(American Society of Civil Engineers (ASCE), 2015-05-01) Doğan, Sevgi Zeynep; Arditi, David; Günhan, Suat; Erbaşaranoğlu, Bengi
Building design and construction require the collective effort of diverse project participants. The coordination performance of these project participants is important for effective management and needs to be assessed periodically. However, there is no uncomplicated quantitative way to measure coordination. Measuring coordination is cumbersome and time-consuming particularly during the project execution phase. This study proposes an easy procedure for monitoring the coordinative performance of project participants. The degree, betweenness, and closeness centrality measures of the project participants in a wayfinding signage project at a major airport construction project are calculated using social network analysis on the e-mail communication network between the participants. A centrality index is defined for each firm based on the average of these three centrality measures. The firm's coordination score is also calculated based on content analysis of the sent and received e-mails between the participants. The coordination scores are found to be highly correlated with the centrality indices. To define the coordinative role of a firm, its centrality index could therefore be measured easily using a simple software and only the number and direction of e-mails exchanged between
Citation - WoS: 5
Citation - Scopus: 12
Critical Success Factors of Partnering in the Building Design Process
(Middle East Technical University, 2015) Doğan, Sevgi Zeynep; Kılıç Çalğıcı, Pınar; Arditi, David; Günaydın, Hüseyin Murat
The construction industry is vertically fragmented because of the inherent nature of construction projects, which require planning, design, letting, construction, and operation in distinct phases (Fellows and Liu, 2012; Fong and Lung, 2007). The construction industry is also horizontally fragmented because of the general tendency of participants to work independently in all phases of the project (Fellows and Liu, 2012; Saram and Ahmed, 2001). Given the increasing number of construction projects in the current global environment, geographical fragmentation is caused by project participants that are frequently geographically separated. The construction industry is also temporally fragmented, as the phases of construction projects diverge over an estimated time period (Luck, 1996). According to Evbuomwan and Anumba (1998), the fragmentation in the industry results in costly engineering changes and design iterations, time and cost increases, poor communication between project participants, neglect of the application of sustainability principles throughout the life cycle of the building, and inadequate coordination and integration of the various participants. The root cause of much of these problems encountered in the management of building projects can be traced back to the design phase.
Citation - WoS: 86
Citation - Scopus: 99
Determining Attribute Weights in a Cbr Model for Early Cost Prediction of Structural Systems
(American Society of Civil Engineers (ASCE), 2006) Doğan, Sevgi Zeynep; Arditi, David; Günaydın, Hüsnü Murat
This paper compares the performance of three optimization techniques, namely feature counting, gradient descent, and genetic algorithms (GA) in generating attribute weights that were used in a spreadsheet-based case based reasoning (CBR) prediction model. The generation of the attribute weights by using the three optimization techniques and the development of the procedure used in the CBR model are described in this paper in detail. The model was tested by using data pertaining to the early design parameters and unit cost of the structural system of 29 residential building projects. The results indicated that GA-augmented CBR performed better than CBR used in association with the other two optimization techniques. The study is of benefit primarily to researchers as it compares the impact attribute weights generated by three different optimization techniques on the performance of a CBR prediction tool.
Leed Certification: a Comparison of Contractors' Perspectives
(Research Publishing Services, 2013) Doğan, Sevgi Zeynep; Günhan, Suat; Gerçek, Bilge; Arditi, David
The Leadership in Energy and Environmental Design (LEED) certification system for green buildings has been used extensively in the US and has gained increased attention in developing countries as well. The related literature focuses extensively on the perspectives of owners and designers, whereas constructors' role receives less attention. One significant research is based on a survey administered to 22 contractors, who built LEED certified green building projects in the US. The survey inquired about earned LEED credits and best practices in LEED certification process regarding past experiences. The same survey was administered to seven Turkish contractors, who also built LEED certified green buildings in Turkey. The similarities and differences between US and Turkish constructors' perspectives were studied. Both groups stated that the LEED process was slightly difficult or was just straightforward. US contractors needed a lot of additional time for the LEED documentation; Turkish contractors required no extra time. LEED certification system incurred a little additional cost for US contractors; however Turkish contractors mentioned about up to 10% additional project costs. The achieved LEED credits from materials and resources, and indoor environmental quality by the two groups of contractors were highly correlated. Both groups emphasized the inclusion of LEED documentation and specifications in coordination meetings and in subcontracts to streamline the process; and emphasized the early collaboration of the entire project team for earning LEED credits. Copyright © 2013 by Research Publishing Services.
Citation - WoS: 35
Citation - Scopus: 46
Perceptions of Process Quality in Building Projects
(American Society of Civil Engineers (ASCE), 1999-03) Arditi, David; Günaydın, Hüsnü Murat
A Delphi process and a questionnaire survey are conducted to investigate the differences in the perceptions of entry-level professionals and long-time practitioners with regard to process quality in building projects. The factors that affect process quality in the three phases (design, construction, and operation) of a building project's life cycle are identified and ranked by the respondents' perceived degree of importance. The findings indicate that the perceptions of entry-level professionals and long-time practitioners are in agreement for most (74%) of the factors. Given the differences in the respondents' background, expectations, and experience, differences in perceptions are to be expected in the remaining 26% of the factors. Analyzing these differences helps in revising and improving existing training courses and academic programs. It is recommended that college programs include courses that treat the administrative aspects involved in the building project in great detail and that continuing education programs cover quality training and life cycle cost analysis.
Citation - WoS: 65
Citation - Scopus: 75
Using Decision Trees for Determining Attribute Weights in a Case-Based Model of Early Cost Prediction
(American Society of Civil Engineers (ASCE), 2008) Doğan, Sevgi Zeynep; Arditi, David; Günaydın, Hüsnü Murat
This paper compares the performance of three different decision-tree-based methods of assigning attribute weights to be used in a case-based reasoning (CBR) prediction model. The generation of the attribute weights is performed by considering the presence, absence, and the positions of the attributes in the decision tree. This process and the development of the CBR simulation model are described in the paper. The model was tested by using data pertaining to the early design parameters and unit cost of the structural system of residential building projects. The CBR results indicate that the attribute weights generated by taking into account the information gain of all the attributes performed better than the attribute weights generated by considering only the appearance of attributes in the tree. The study is of benefit primarily to researchers, as it compares the impact of attribute weights generated by three different methods and, hence, highlights the fact that the prediction rate of models such as CBR largely depends on the data associated with the parameters used in the model.