In this paper, we perform a comparative evaluation of seven most commonly used first-order stochastic gradient-based optimization techniques in a simple Convolutional Neural Network (ConvNet) architectural setup. The investigated techniques are the Stochastic Gradient Descent (SGD), with vanilla (vSGD), with momentum (SGDm), with momentum and nesterov (SGDm+n)), Root Mean Square Propagation (RMSProp), Adaptive Moment Estimation (Adam), Adaptive Gradient (AdaGrad), Adaptive Delta (AdaDelta), Adaptive moment estimation Extension based on infinity norm (Adamax) and Nesterov-accelerated Adaptive Moment Estimation (Nadam). We trained the model and evaluated the optimization techniques in terms of convergence speed, accuracy and loss function using three randomly selected publicly available image classification datasets. The overall experimental results obtained show Nadam achieved better performance across the three datasets in comparison to the other optimization techniques, while AdaDelta performed the worst.

Sustainable construction efforts in some countries have been unsuccessful due to numerous barriers to its successful implementation. This study identifies and priorities likely barriers to successful implementation of sustainable construction in the Ghanaian construction industry and measures to overcome potential barriers. A multiple research approach involving semi-structured interviews and a questionnaire survey was adopted for the study. Interviews were carried out amongst purposively selected 18 contractors and 16 consultants whereas questionnaire survey was conducted among 100 randomly selected practitioners (58 Architects, 37 Quantity Surveyors and 5 Structural Engineers) to examine the relevance of the identified factors in the Ghanaian context. The factors identified as barriers to successful implementation of sustainable construction and measures to overcome potential barriers to sustainable construction were evaluated and ranked according to their mean scores. The five strongest barriers to the implementation of sustainable construction in Ghana are ranked as cultural change resistance, lack of government commitment, fear of higher investment costs, lack of professional knowledge, and lack of legislation respectively. Factor analysis using the SPSS Version 16 package enabled the barriers identified to be grouped under six components as 1) Financial barriers, 2) Political barriers, 3) Management/ Leadership barriers, 4) Technical barriers, 5) Socio-cultural barriers, 6) Knowledge/ Awareness barriers. The results of this study would enable the Ghanaian construction industry to be successful in its quest to implement sustainable construction. This will be possible through the implementation of the measures suggested to remove potential barriers to the implementation of sustainable construction. Identification of barriers and measures to overcome potential barriers are steps towards successful implementation of the sustainability concept in the Ghanaian construction industry

Purpose: The adoption of robotics and automation (R&A) within the construction industry has been adjudged as slow, despite the possibility of it reducing the high risk posed on health and safety of humans by the activities of the industry. The call for research and development in this area of technology to improve its adoption in the delivery of construction projects is evident in past studies. Thus, this paper aims to conduct a review of R&A in construction-related fields with a view to revealing the area of focus of past studies.Design/methodology/approach: A bibliometric approach was adopted for this study, and data used were gathered from the Scopus database. Keywords such as “robotics”, “automation” and “construction” were used to extract papers from the database. VOSviewer was used to prepare a co-authorship and co-occurrence map based on the bibliographic data gathered.Findings: The findings revealed that focus is placed on construction automation, industrial robots and application, robots’ systems and designs, robotics in earthworks, and robots’ control and information system. Furthermore, currently, research focus in this area is tending towards a more digitalised application of R&A especially in the areas of 3D manufacturing.Research limitations/implications: The findings of this study are limited due to the use of a single database.Practical implications: Despite its limitations, the findings open a knowledge gap that can be explored in developing countries particularly in Africa to improve construction delivery in the continent through R&A.Originality/value: The study adopted the bibliometric approach in mapping out research focus in R&A – an aspect of digital technology that has not been given considerable attention in recent bibliometric and scientometric studies.

Purpose: Construction 4.0 technology has the capabilities for improving the design, management, operations and decision making of construction projects. Therefore, this study aimed at examining the willingness of construction professionals towards adopting construction 4.0 technologies.Design/methodology/approach: The study adopts a survey design, and construction professionals in South Africa are assessed using a convenience sampling technique through a structured questionnaire. The questionnaire was analysed with SPSS while statistical test like; mean score, t-test and principal component analysis was used to present the data.Findings: The findings, from the analysis, revealed that the construction professionals are willing to adopt construction 4.0 technologies for construction project. However, the possibility of fully integrating the technologies into the construction industry is low. This is because the major technologies such as; Internet of things, robotics, human-computer interaction and cyber-physical systems that encourage smart construction site are rated as not important by the construction professionals.Practical implications: It is believed that the findings emanating from this study will serve as an indicator for investors that are interested in procuring construction 4.0 technologies for the construction industry.Originality/value: This paper presents a framework for the application of construction 4.0 technologies for the construction industry. It also contributes to the development of digitalising construction industry in South Africa.