45 research outputs found
A decision support system for the selection of green roof for residential buildings
Green roofs have been installed as a sustainable approach for many years all around the world. There are myriad benefits for green roof installation in terms of private and public sectors such as energy saving, stormwater management, and carbon reduction. Furthermore, there are three types of green roofs with different levels of benefits and costs; however, there is lack of model, framework, or decision support system (DSS) to facilitate the process of decision making for selecting the optimum type of green roof. The aim of the research is to develop a DSS to determine the optimum type of green roof. The research was conducted on residential buildings due to the highest percentage of green roof installation among other building categories in Malaysia. Enhanced Fuzzy Delphi Method (EFDM) has been developed for this study as the approach for data collection, while Multi-Criteria Decision Making (MCDM) is adopted in order to develop the DSS. Moreover, Cybernetic Fuzzy Analytic Hierarchy Process (CFAHP) was also developed as the method used in MCDM. EFDM and CFAHP were developed due to the shortcomings of previous methods for the novelty in this research. A database was created for the DSS using EFDM, while CFAHP method was used for developing the DSS. Additionally, in terms of DSS evaluation, hypothetical examples were defined and after obtaining the results, multiple criteria approach was conducted to understand its level of effectiveness and efficiency. DSS evaluation has been conducted involving experts in the field of green roof. Finally, it was concluded that the DSS works well and can be utilized in construction industry in the design phase. The experts’ feedbacks showed that the developed DSS is effective and efficient, and were satisfied with the performance of the DSS
Investigating the environmental impacts of green roof installation
Green roof installation has been used as a sustainable approach for many years in order to reduce the adverse impacts of environmental issues all around the world. These environmental issues include: global warming, air pollution, flood, carbon footprint and so on. Green roofs are practical as a sustainable approach, especially in developed countries; however, there is an increasing trend of implementing green roofs in developing countries. This paper is reviewing the benefits of green roof installation and how green roof might contribute to reduce the negative environmental issues. The environmental problems that can be solved or reduced by these benefits are discussed separately in this paper. It is concluded that due to the environmental benefits of green roof installation, it leads to many economic benefits. Moreover, green roof implementation is beneficial in both urban areas and rural places
Economic comparison of industrialized building system and conventional construction system using building information modeling
The new construction method known as Industrialized Building System (IBS) offers several benefits compared to the Conventional Building System (CBS); however, IBS is perceived by most of the practitioners to be an expensive method for being utilized in construction industry. Whilst relatively numerous studies have been carried out on the subject of IBS and CBS methods, there has not been any exploiting building information modeling (BIM) as a useful tool to calculate quantities, time, and cost needed to construct building with each of the two aforementioned methods. The aim of this paper is to calculate cost of two similar buildings (one is constructed with IBS method and other one with CBS method) and compare them in terms of economy based on a chosen case study and same initial investment. To this end, the construction cost of buildings is calculated using BIM software, namely Revit Architecture and Navisworks Manage for modeling the chosen case study and estimating construction cost, respectively. The findings indicated that IBS was not economic in low investment of company; however, with investment on more than 100 units of IBS, this method was shown more economical compared to CBS method. In addition, the initial investment on IBS method could be returned when more than 200 units of IBS were implemented in the projects
Comparison of building existing partitions through building information modeling (BIM)
Partition walls are considered as one of the most crucial elements on interior space within the buildings. While a considerable amount of research has been carried out studying theses critical elements to be used on the interior space of the buildings, BIM has not been exploited so far in order to enhance the accuracy of work. Therefore, the main purpose of this study is to compare three types of commonly used partition walls in terms of materials, time and cost needed to install each of them using BIM. To achieve the specified goal, a case study was chosen. The framework used in this study consists of modeling the installation steps of each partition wall based on the chosen case study using Revit Architecture and Autodesk Inventor. In order to calculate the materials, time and cost required, Naviswork Manage was employed and it was found that drywall could be considered as the most useful one to be installed on the interior space of the buildings in comparison to the other two types of partitions
Review on pore-network modeling studies of gas-condensate flow: Pore structure, mechanisms, and implementations
Gas-condensate flow is a critical process in the near-well region where the well production efficiency is strongly affected by the production of condensate dropout. Pore-scale simulations have provided an understanding of the underlying processes such as snap-off and the effect of the interplay between viscous and capillary forces on gas-condensate flow and its induced blockage within the pore spaces. Among various modeling approaches used to explore these phenomena, pore-network modeling, due to its computational efficiency and the ability to simulate relatively large sample sizes, has appealed to researchers. This article presents a review of the development of pore-network models to simulate gas-condensate flow, particularly in the near wellbore regions. This contribution reviews pore-scale mechanisms that should be included in simulating the gas-condensate flow, together with the involved processes and the peculiarities pertinent to such modeling efforts. After a brief review of different pore scale studies and their differences, advantages, and disadvantages, the review focuses on pore-network modeling, and the application of pore-network modeling in gas-condensate flow in the recent studies. The employed methodologies, highlights, and limitations of each pore network study are examined and critically discussed. The review addresses pore-space evolution, flow mechanisms, and the involved flow and transport parameters. The formulations of capillary entry pressure in different pore geometries, the corresponding conductance terms, snap-off criteria, and conditions for the creation of condensate bridging in different pore structures are presented. Additionally, three major approaches used in pore-network modeling of gas condensation, namely quasi-static, dynamic methods and dynamic compositional pore-network modeling, are presented and their main governing equations are provided using various tables. Finally, the significance of gas-condensate flow modeling including its modeling challenges together with the main similarities and differences among pore-network studies are provided
Improving project communications management practices in the construction sector during the COVID-19 pandemic: A Malaysian scenario
The construction industry remains an important economic sector that supports the growth of a nation. It is vital to maintain the industry’s momentum when facing the Coronavirus Disease 2019 (COVID-19) pandemic, or similar in the future, to ensure employability and decent jobs for every individual in the industry, especially foreign labourers who are always regarded as vulnerable. Improving existing project communications management practices is essential to suppressing infection among labourers, however, there are only a few efforts made to understand the current condition. This study explores the communications management barriers and the potential improvement measures amid the COVID-19 outbreak sweeping across the Malaysian construction industry. The findings disclose that out of eleven communication channels, only six communications management barrier variables with eight items, and three communications management improvement measure variables with seven items, are classified as highly critical, based on a systematic literature review (SLR), and a questionnaire survey on 100 foreign labourers and management team members, respectively, where the data gathered were analysed using the Rasch measurement model. The finding also suggests that site review meetings, team meeting discussions and project reports require immediate attention to ensure the construction industry remains robust without significant interruption during the course of the pandemic
Investigating the barriers to applying the internet-of-things-based technologies to construction site safety management
The utilization of Internet-of-Things (IoT)-based technologies in the construction industry has recently grabbed the attention of numerous researchers and practitioners. Despite the improve-ments made to automate this industry using IoT-based technologies, there are several barriers to the further utilization of these leading-edge technologies. A review of the literature revealed that it lacks research focusing on the obstacles to the application of these technologies in Construction Site Safety Management (CSSM). Accordingly, the aim of this research was to identify and analyze the barriers impeding the use of such technologies in the CSSM context. To this end, initially, the extant literature was reviewed extensively and nine experts were interviewed, which led to the identification of 18 barriers. Then, the fuzzy Delphi method (FDM) was used to calculate the importance weights of the identified barriers and prioritize them through the lenses of competent experts in Hong Kong. Following this, the findings were validated using semi-structured interviews. The findings showed that the barriers related to “productivity reduction due to wearable sensors”, “the need for technical training”, and “the need for continuous monitoring” were the most significant, while “limitations on hardware and software and lack of standardization in efforts,” “the need for proper light for smooth functionality”, and “safety hazards” were the least important barriers. The obtained findings not only give new insight to academics, but also provide practical guidelines for the stakeholders at the forefront by enabling them to focus on the key barriers to the implementation of IoT-based technologies in CSSM
Probabilistic cost-benefit analysis of installing extensive green roof in Malaysia
Green roofs have been known as an environmentally friendly application and a sustainable approach in the developed countries such as: Germany, United States and Canada. Although environmental cost-benefits related issues of green roofs are already proven by many researchers in developed countries, it is not used widely in developing countries like Malaysia. It is estimated that the market at first focuses on extensive green roof due to the lower initial and maintenance costs; as a result, a probabilistic cost-benefit analysis for extensive green roof is conducted in this study. Installation, maintenance, and disposal costs of extensive green roof system are compared with the related private and social benefits (increase of property value, savings for air conditioning, longevity, air quality improvement, carbon reduction, etc.), determining two indicators: the Net Present Value (NPV) and the Pay Back Period (PBP), using Monte Carlo simulation. The analysis demonstrated that green roofs are not long-term investments in terms of net returns. In general, installing extensive green roof is a low risk investment. Furthermore, the probability of profits out of this application is much higher than the potential financial losses
Towards the success of building information modelling implementation: a fuzzy-based MCDM risk assessment tool
The adoption of Building Information Modelling (BIM) brings numerous benefits to Industrialised Building System (IBS) construction projects. However, implementing new technologies in a complex environment involves several risks such as having insufficient information, an increase in short-term costs, and reluctance to share information. This research aims to develop a prototype risk assessment tool (PRAT) for identifying and evaluating the risk factors associated with implementing BIM in IBS construction projects. The “Fuzzy Delphi Method” was employed to identify the critical risk factors, while “DEMATEL” and the “Parsimonious-fuzzy analytic network process” were employed for data analyses. The novelty of this research is twofold: developing a risk assessment tool for BIM-based IBS projects and employing a hybrid, comprehensive, and efficient method for model development. PRAT consists of six main parts: instructions and opening window; modifiable database, pairwise comparison modules 1 and 2, calculation, and result window. After refining the risk factors, PRAT analyses the risk of BIM-based IBS projects considering thirty-two risk factors. The results of PRAT implementation show that it enables users to prioritise the risk factors, considering their importance and interdependencies, with an understandable procedure by the managers. Hence, it increases the possibility of successful BIM implementation for IBS construction companies
The Hindrances to Green Roof Adoption in a Semi-Arid Climate Condition
Green roofs (GRs) offer several environmental, social, and economic benefits while numerous barriers are limiting their adoption. This study covers two gaps in the literature: first, the lack of indicating separate hindrances to different types of GRs; second, the dearth of research related to the hindrances on GR adoption in any climate of Iran. This research aims to identify and analyze the importance of hindrances to GR adoption by considering the two major types of GRs using the Fuzzy Delphi Method (FDM) and Fuzzy Analytic Network Process (FANP), respectively. The results indicated that eight out of twenty-five identified hindrances to GR adoption were rejected using FDM. Moreover, it was found that although financial hindrances are significant for both types of GRs, public awareness is the most important hindrance to extensive GR adoption. As the first research of its kind in a semi-arid climate of Iran, the findings of this research provide an insight for the researchers and policymakers regarding the hindrances to GR adoption for further research and action