Clinton Aigbavboa

Bio: Clinton Aigbavboa is an academic researcher from University of Johannesburg. The author has contributed to research in topics: Business & Sustainability. The author has an hindex of 18, co-authored 438 publications receiving 1528 citations. Previous affiliations of Clinton Aigbavboa include Oxford Brookes University.

A Comparative Analysis of Gradient Descent-Based Optimization Algorithms on Convolutional Neural Networks

Abstract: 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.

Barriers to successful implementation of sustainable construction in the Ghanaian construction industry

Abstract: 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.

Offsite Construction: Developing a BIM-Based Optimizer for Assembly

Abstract: © 2019 Elsevier Ltd The lack of adequate consideration of the underlying factors affecting the methods of building assembly often results in inefficiencies in the uses of building materials, equipment and manpower. These inefficiencies are further compounded by the nature of the construction industry, which traditionally involves complex processes that result in wastages during production. To address this problem, this study integrates the principles of Design for Manufacture and Assembly (DFMA) and Lean Construction to develop a design assessment and optimization system to assist designers in the selection of alternative building design elements and materials in a building information model. This assessment and optimization system rely on metrics derived from production data associated with the ease of assembling, ease of handling, the speed of assembling and the wastage during assembly or construction of a building element or material. This paper presents the development of BIM-OfA assessment logic and its application for assessment and optimal selection of building envelop through the extension of Building Information Modelling (BIM). The system demonstrates its adequacy as an indicator of construction and material efficiency, its integration with BIM further enhances the practicality of using production data such weight of components, number of on-site workers and number of parts, for buildability assessment to improve efficiency and reduce waste.

COVID-19 Recovery for the Nigerian Construction Sites: The Role of the Fourth Industrial Revolution Technologies

Abstract: Fourth industrial revolution (4IR) technologies have been proved as successful platforms to communicate and visualise construction projects within team meetings. These techniques possibly can enhance compliance with Covid-19 rules on sites. How far concerning Nigerian construction contractors in the use of 4IR technologies are yet to receive in-depth studies. Therefore, this paper offers a collective insight into the issues affecting construction firms from Covid-19 regarding lockdown rules and the role of 4IR technologies. Given the unexplored nature of the problem, a virtual face-to-face type of qualitative research method was employed. Twelve semi-structured interviews from selected construction firms and consultant experts were engaged and collated data analysed via a thematic approach. Findings group the 4IR technologies into smart construction site, simulation and modelling, and digitisation and virtualisation in Nigeria’s context, and majority of the 4IR technologies can be useful to enhance Covid-19 compliance. Reluctant to adopt, high implementation cost, inadequate knowledge management, resistance to change, among others emerged as the factors hindering 4IR technologies usage. Findings will strengthen and provide a rich insight into the impact of Covid-19 on construction sites and contribute towards informing key stakeholders to create an enabling environment for the implementation of 4IR technologies on site.

Barriers to the adoption of value management in developing countries

Abstract: The purpose of this paper is to determine the barriers to the adoption of value management (VM) in the construction industry of developing countries with a view to providing possible measures in avoiding these barriers and increasing the usage of the system within the construction industry.,The level of knowledge and adoption of VM practices, as well as the barriers to its adoption in the construction industry were assessed through a survey design. Construction professionals were sampled from the six geo-political zones in Nigeria through the use of a structured questionnaire. Factor analysis was conducted on data gathered on the barriers of VM.,The study revealed a moderate level of knowledge of VM among construction professionals. This implies that the problem of VM is not that of awareness, but readiness to adopt the system. The study also reveals that the barriers to the adoption of VM can be categorised under the general stakeholder’s barriers, training and education barriers, client barriers and government/top management barriers.,This study was conducted across the six geo-political zones of the country as against common practice of selecting a particular region or states to represent the entire country. The findings therefore show a true reflection of the barriers to VM adoption in the country and its recommendations can to a large extent promote the adoption of VM in the country and also other developing countries where construction projects are executed through similar method, style and approach.,This paper highlights the possible barriers to the adoption of VM in Nigeria construction industry and provides ways to avoiding these barriers in order to achieve better quality construction and value for money.

Research Design: Qualitative, Quantitative, and Mixed Method Approaches

Abstract: หนงสอเรอง การออกแบบการวจย: วธการวจยเชงคณภาพ วธการวจยเชงปรมาณ และวธการวจยแบบผสม (Research Design: Qualitative, Quantitative, and Mixed Method Approaches) เปนหนงสอทเรยบเรยงเพออธบายเกยวกบความแตกตางของกระบวนทศนการวจยทง 2 แบบ ไดแก การวจย เชงปรมาณ และการวจยเชงคณภาพ และความจำเปนของประเดนปญหาการวจยทตองนำกระบวนทศนทง 2 มารวมกนหาขอคนพบเพอนำไปสผลการวจยทสามารถนำผลการวจยไปใชประโยชนไดอยางจรงมากยงขน เรยกวา “การวจยแบบผสมผสาน” ซงเปนหนงสอทอธบายวธการวจยทง 2 ประเภทไดอยางชดเจน และการรวมกนของกระบวนทศนการวจยทง 2 แบบอยางลงตว

반도체 공정 overview

Abstract: With digital equipment becoming increasingly networked, either on wired or wireless networks, for personal and professional use alike, distributed software systems have become a crucial element in information and communications technologies. The study of these systems forms the core of the ARLES' work, which is specifically concerned with defining new system software architectures, based on the use of emerging networking technologies. In this context, we concentrate on the study of distributed systems which bring to life the vision of ubiquitous computing systems, also known as ambient intelligence.

[서평]「Applied Cryptography」

Abstract: The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.