Research Publications (Engineering and Built Environment)

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Applications of artificial intelligence to photovoltaic systems : a review
(MDPI AG, 2022) Mateo Romero, Héctor Felipe Mateo; González Rebollo, Miguel Ángel González; Cardeñoso-Payo, Valentín; Alonso Gómez, Victor Alonso; Redondo Plaza, Alberto Redondo; Moyo, Ranganai Tawanda; Hernández-Callejo, Luis
This article analyzes the relationship between artificial intelligence (AI) and photovoltaic (PV) systems. Solar energy is one of the most important renewable energies, and the investment of businesses and governments is increasing every year. AI is used to solve the most important problems found in PV systems, such as the tracking of the Max Power Point of the PV modules, the forecasting of the energy produced by the PV system, the estimation of the parameters of the equivalent model of PV modules or the detection of faults found in PV modules or cells. AI techniques perform better than classical approaches, even though they have some limitations such as the amount of data and the high computation times needed for performing the training . Research is still being conducted in order to solve these problems and find techniques with better performance. This article analyzes the most relevant scientific works that use artificial intelligence to deal with the key PV problems by searching terms related with artificial intelligence and photovoltaic systems in the most important academic research databases. The number of publications shows that this field is of great interest to researchers. The findings also show that these kinds of algorithms really have helped to solve these issues or to improve the previous solutions in terms of efficiency or accuracy.
Barrier and biodegradable properties of corn starch-derived biopolymer film filled with nanoclay fillers
(SAGE Publications, 2016-12-18) Mohan, T. P.; Devchand, Kay; Kanny, Krishnan
The objective of this work is to study the effect of nanoclay fillers on the biodegradation and barrier properties of corn starch polymer-based biofilm. Starch derived from corn plant source was used to prepare a biofilm by plasticization method. The barrier properties, namely, water absorption, moisture permeation, oxygen permeation and swelling of unfilled and nanoclay-filled corn starch biofilms were examined. The results indicate: ∼22% reduced water absorption, 40% reduced moisture uptake, 30% reduced oxygen permeation and 31% reduced swelling for 2–3 wt.% nanoclay-filled biofilm, when compared with unfilled biopolymer. The biodegradation result of unfilled and nanoclay-filled film series indicates that the nanoclay addition delays the biodegradation and is a function of nanoclay content in the film. The tensile, dynamic mechanical analysis and biodegradable studies were conducted on the biopolymers before and after water absorption, and the result shows that the nanoclay-filled biopolymer increased these properties when compared with unfilled biopolymer even after water absorption and is dependent on the nanocomposite structure and morphology as examined by X-ray diffraction and transmission electron microscopy analysis.
A controlled deflection routing and wavelength assignment based scheme in Optical Burst Switched (OBS) networks
(Walter de Gruyter GmbH, 2020-07-05) Nleya, Bakhe; Khumalo, Zephaniah Philani; Mutsvangwa, Andrew
Abstract - Heterogeneous IoT-enabled networks generally accommodate both jitter tolerant and intolerant traffic. Optical Burst Switched (OBS) backbone networks handle the resultant volumes of such traffic by transmitting it in huge size chunks called bursts. Because of the lack of or limited buffering capabilities within the core network, burst contentions may frequently occur and thus affect overall supportable quality of service (QoS). Burst contention(s) in the core network is generally characterized by frequent burst losses as well as differential delays especially when traffic levels surge. Burst contention can be resolved in the core network by way of partial buffering using fiber delay lines (FDLs), wavelength conversion using wavelength converters (WCs) or deflection routing. In this paper, we assume that burst contention is resolved by way of deflecting contending bursts to other less congested paths even though this may lead to differential delays incurred by bursts as they traverse the network. This will contribute to undesirable jitter that may ultimately compromise overall QoS. Noting that jitter is mostly caused by deflection routing which itself is a result of poor wavelength and routing assigning, the paper proposes a controlled deflection routing (CDR) and wavelength assignment based scheme that allows the deflection of bursts to alternate paths only after controller buffer preset thresholds are surpassed. In this way, bursts (or burst fragments) intended for a common destination are always most likely to be routed on the same or least cost path end-to-end. We describe the scheme as well as compare its performance to other existing approaches. Overall, both analytical and simulation results show that the proposed scheme does lower both congestion (on deflection routes) as well as jitter, thus also improving throughput as well as avoiding congestion on deflection paths.
Degree accreditation report auto-generation by logic encoding and processing
(2021-11-10) Chetty, Manimagalay; Rawatlal, Randhir
Maintaining the accreditation profile of an academic programme is a key activity in so-called professional degrees such engineering, commerce and law. The complexity of the accrediting criteria tends to rise over time as accrediting bodies require quantitative evidence of competence of increasingly specific graduate attributes. Evaluation of graduate attributes may therefore require complex logic processing which challenges the human capacity. This has the negative side effect of discouraging curriculum revision not for pedagogic reasons but simply due to the complexity of evaluating complex logic patterns against a data set whose structure is shifting. These challenges can be overcome through the application of logic encoding and processing. A computing system is better suited to such processing tasks since logic processing is fundamental and well-established to such systems. On the other hand, the efficient representation of a complex accreditation logic rule base then becomes the challenge. This paper describes the representation of the accreditation logic of eight engineering academic programmes at the Durban University of Technology through the AutoScholar Advisor System in preparation for evaluation by the Engineering Council of South Africa. It is shown that the system generates accurate reports even with deeply nested logic structures and with changes in curriculum over time.
Design optimization of anisotropic pressure vessels with manufacturing uncertainties accounted for
(Elsevier, 2013-04) Tabakov, Pavel Y.; Walker, Mark
Accurate optimal design solutions for most engineering structures present considerable difficulties due to the complexity and multi-modality of the functional design space. The situation is made even more complex when potential manufacturing tolerances must be accounted for in the optimizing process. The present study provides an original in-depth analysis of the problem and then a new technique for determining the optimal design of engineering structures, with manufacturing tolerances accounted for, is proposed and demonstrated. The numerical examples used to demonstrate the technique involve the design optimization of anisotropic fibre-reinforced laminated pressure vessels. It is assumed that the probability of any tolerance value occurring within the tolerance band, compared with any other, is equal, and thus it is a worst-case scenario approach. A genetic algorithm with fitness sharing, including a micro-genetic algorithm, has been found to be very suitable to use, and implemented in the technique.
Evaluating the performance of high-volume fly ash (HVFA) concrete, for South African fly ash
(IJRTEM, 2016-07) Zulu, Sabelo; Allopi, Dhiren
Due to the benefits provided by the usage of FA in concrete, the usage of HVFA concrete is increasing within the concrete industry. This study looked at the effects of increasing the content of FA in concrete, beyond the conventional 30% amount, to find an optimum amount suitable for use in concrete structures, without compromising the quality of concrete. Concrete mixes of 25MPa, 35MPa and 50MPa with FA partially substituting the cement at 30%, 40%, 50% and 60%, were produced and numerous concrete properties were evaluated in a laboratory environment, to determine an optimum amount of HVFA that can be used and still obtain better or comparable concrete to ordinary concrete. Concrete testing for compressive strength, durability, slump, setting time and drying shrinkage was performed at laboratories over a period of one year. Also a cost comparison between the ordinary concrete and FA concrete was done. Test results showed that HVFA concrete can perform well in structures with good compressive strength and durability result even if the amount of cement is less than of fly ash. It can also be economical to utilize HVFA concrete, especially in larger project.
Evaluation and effective management of non-technical losses in power networks
(2002-10) Davidson, Innocent Ewean
Market-driven economies and deregulated electricity industry environment have stimulated the minimization of technical and non-technical losses (NTL) even though they do not constitute major operational or quality of supply problems. Their impact is economic and utilities often passed down the costs to consumers. NTL need to be addressed to determine the overall performance of power networks, as these losses are expected to be more dominant at the sub-transmission (132kV-33kV) and reticulation (22kV and 11kV) levels of the electricity supply industry value chain. In some national grid operations, NTL are estimated to account for up to 30% in revenue losses to electric utilities, and overhead expenditure in added maintenance costs. This paper discusses a method for NTL evaluation and an effective management approach to loss minimization and revenue collection. Copyright © 2002 IEEE.
An evaluation of WIL training for Durban University of Technology Civil Engineering - employer and student experience : lessons for the new programme
(Stellenbosch University, 2021-11) Khuzwayo, B.P.; Vahed, S.
The Durban University of Technology (DUT) previously offered the now phased-out National Diploma in Civil Engineering, incorporating a two-year academic enrolment and a year-long work- integrated learning programme (WIL). The support offered by the University lecturers was essential in the WIL, to ensure that the engineering tasks assigned to students aligned with the DUT curriculum; any concerns or comments expressed were investigated further and addressed appropriately. In 2017 and 2018 interviews were conducted, generating 918 structured comments by employers. These included 304 general comments (with no academic value) and 593 comments specific to disciplines by students, of which 346 were general comments. This exploratory study aims to determine critical feedback that should be considered when enrolling for the new qualification: Bachelor of Engineering Technology Degree in Civil Engineering (B Eng Tech degree). The data received helped to discover and understand the experiences, perspectives and thoughts of the participants who responded to open-ended questions (i.e., comments about their experiences, without any limitations). The data collected were presented and evaluated using the thematic analysis method to discover patterns and to develop subjects for discussion. Findings show that employers were generally happy with the quality of the students from DUT, however, they found professionalism among the DUT students to be a major concern. They also requested that the institution communicates with employers regarding the curriculum so that employers might properly align the WIL with it. Most students were challenged by the new work environment they had entered. The most common factor that made the experience more challenging was the exposure to the state- of-the-art equipment used in the workplace.
Female graduation rate in STEM programs in tertiary education : the case of the Gulf Cooperation council Countries (GCCs)
(2022-11-01) Fomunyam, Kehdinga George
There is increased demand for professionals with science, technology, engineering and mathematical (STEM) skills globally and with the advent of the fourth industrial revolution, it is expected that there will be new jobs which requires new skills. It is therefore imperative that there are increased demands in enrolment and graduation rate in STEM programs so as to curtail the disproportionality between current skills and the skills that are vital for the future. The study focused on the percentage of graduates from STEM programmes in tertiary education in the GCCs who are women. Data from World Bank provided insight into the graduation rate in STEM programs. Findings from the study revealed that the higher education landscape in the Gulf Cooperation Council (GCC) has had significant development over the past two decades and one of the things that made this possible is the revenues from oil and gas exports and the diversification into the knowledge driven economy. It was also found out that females are important in STEM programs, and this was considered from a human, scientific and development perspective. The study recommended that that there should be intensification of effort on females transiting from the universities into employment to encourage sustainability and contribute to the sustainable development goals (SDGs).
Finding solid ground : law enforcement, key populations and their health and rights in South Africa
(International Aids Society, 2016) Scheibe, Andrew; Howell, Simon; Muller, Alexandra; Katumba, Munyaradzi; Langen, Bram; Artz, Lillian; Marks, Monique Michal
Introduction: Sex workers, people who use drugs, men who have sex with men, women who have sex with women and transgender people in South Africa frequently experience high levels of stigma, abuse and discrimination. Evidence suggests that such abuse is sometimes committed by police officers, meaning that those charged with protection are perpetrators. This reinforces cycles of violence, increases the risk of HIV infection, undermines HIV prevention and treatment interventions and violates the constitutional prescriptions that the police are mandated to protect. This paper explores how relationship building can create positive outcomes while taking into account the challenges associated with reforming police strategies in relation to key populations, and vice versa. Discussion: We argue that relationships between law enforcement agencies and key populations need to be re-examined and reconstituted to enable appropriate responses and services. The antagonistic positioning, ‘‘othering’’ and blame assignment frequently seen in interactions between law enforcement officials and key populations can negatively influence both, albeit for different reasons. In addressing these concerns, we argue that mediation based on consensual dialogue is required, and can be harnessed through a process that highlights points of familiarity that are often shared, but not understood, by both parties. Rather than laying blame, we argue that substantive changes need to be owned and executed by all role-players, informed by a common language that is cognisant of differing perspectives. Conclusions: Relational approaches can be used to identify programmes that align goals that are part of law enforcement, human rights and public health despite not always being seen as such. Law enforcement champions and representatives of key populations need to be identified and supported to promote interventions that are mutually reinforcing, and address perceived differences by highlighting commonality. Creating opportunities to share experiences in mediation can be beneficial to all role-players. While training is important, it is not a primary mechanism to change behaviour and attitudes.
Gender and gender mainstreaming In engineering education in Africa
(Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP, 2020) Fomunyam, Kehdinga George; Matola, Noluthando; Moyo, Sibusiso
In Africa, a lot of debates on the issues of gender gap and gender inequality has raised concerns in engineering education (EE) and engineering workforce. Thus, gender inequality and equity are significant in realizing Sustainable Development Goals (SDGs), and in recent years much has been done to address gender gaps, yet women are still excluded, underrepresented, segregated and relegated inengineering profession and academia. With much sensitization on gender equality, Africa is still far from addressing gender gaps in EE; hence the crux of this paper. This paper was guided by Liberal Feminism theory, focusing on women’s freedom as an autonomy to be free from coercive interference, due to‘gender system’ or patriarchal nature of inherited traditions and institutions. This paper takes a broad look at the concepts of gender and gender mainstreaming in EE in Africa. Specifically, it explores gender and inequality in EE and how gender mainstreaming canbe enacted to address gender gaps in EE, as well as its implications in Africa. Thus, to address these gaps, recommendations such as developing gendersensitive curriculum for EE, adopting policies in facilitating women’s access to training and employment opportunities as well as creating gender-sensitive career counselling were advocated
Geo-polymerization of mining tailing for use as a pavement construction material : a review
(Cement & Concrete SA, 2023-07-14) Ikotun, Jacob Olumuyiwa; Aderinto, Gbenga; Katte, Valentine; Babafemi, Adewumi; Combrinck, R.; de Villiers, W.
Abstract Pavement construction usually involves using large quantities of natural aggregate materials majorly extracted from quarries and, in many cases, with the use of conventional stabilizers such as Portland cement, lime, and bitumen. In many developing countries, the exploitation of quarries has been so massive that there exists a shortage of these aggregates. Hence, the use of convenFonal stabilizers is a common pracFce. However, the use of conventional stabilizers is a major source of environmental contaminant for the environment. Therefore, alternaFve aggregate materials and stabilizaFon techniques in pavement construcFon are highly sought aNer. Recently, some researchers have proposed a new approach as an alternaFve to using convenFonal binders via alkali acFvaFon called geo-polymerizaFon to produce geopolymers. Some studies have shown that mine tailings (MT) can be used as a road base material through geopolymerizaFon. Even though there are different types of tailings, specific interest is on copper, iron, and gold tailings, this is due to their dominance in mining areas of South Africa. This paper presents a review of the mechanical properFes of geopolymerized tailings to enhance understanding of their potenFal applicaFon in sustainable infrastructures, such as pavements.
Inclusivity of ICT based solutions to public transportation problems : challenges and opportunities for Bloemfontein
(The Road Association of Serbia Via-vita, 2023-09-22) Bashingi, Ndakhona; Adedeji, Jacob Adedayo; Kumar Das, Dillip; Mostafa Hassan Mostafa, Mohammed
Promoting information and communication technologies as mobility and transportation accessibility solutions in efforts to achieve sustainable transportation excludes socioeconomic vulnerability. ICT-related efforts do not meet the mobility and accessibility needs of every single group in society, resulting in socioeconomic exclusion for specific groups of people. Social exclusion disadvantages vulnerable social groups in society's mobility, while limited mobility reduces access to activities for disadvantaged groups; travel for job hunting, education, work, and health facilities further increases these groups' physical isolation. The need to travel for activities, services, and basic goods for human consumption such as food, water, and medication must be addressed by developing inclusive transportation systems. Through tele-activities, e-payments, security and surveillance, among other components adaptable to travel and mobility, technological solutions have been at the forefront of prescriptions to transportation problems. However, they remain inaccessible to some of society. The study investigates whether inclusive, sustainable public transportation can be fully realized in developing countries by utilizing technology-based travel behavior solutions. It also investigates the effectiveness of ICT solutions to travel, mobility, and accessibility issues in a South African city with a relatively traditional public transportation system. The study considers socioeconomic travel processes as well as travel behavior constructs to inclusivity in order to weigh the prospects of equitable provision of ICT-enabled public transportation services in the developing world. This study discovered that travelers have smartphone access; however, the purposes of smartphones are not directly related to travel and transportation. Furthermore, public transportation service providers do not have an online presence. Overall, for ICT-enabled public transportation to thrive in developing countries, accessible technologies such as calls and SMS that do not require internet access must be considered.
A technique for optimally designing engineering structures with manufacturing tolerances accounted for
(Taylor & Francis, 2007) Tabakov, Pavel Y.; Walker, Mark
Accurate optimal design solutions for most engineering structures present considerable difficulties due to the complexity and multi-modality of the functional design space. The situation is made even more complex when potential manufacturing tolerances must be accounted for in the optimizing process. The present study provides an in-depth analysis of the problem, and then a technique for determining the optimal design of engineering structures, with manufacturing tolerances in the design variables accounted for, is proposed and demonstrated. The examples used to demonstrate the technique involve the design optimization of simple fibre-reinforced laminated composite structures. The technique is simple, easy to implement and, at the same time, very efficient. It is assumed that the probability of any tolerance value occurring within the tolerance band, compared with any other, is equal, and thus it is a worst-case scenario approach. In addition, the technique is non-probabilistic. A genetic algorithm with fitness sharing, including a micro-genetic algorithm, has been found to be very suitable to use, and implemented in the technique. The numerical examples presented in the article deal with buckling load design optimization of an laminated angle ply plate, and evaluation of the maximum burst pressure in a thick laminated anisotropic pressure vessel. Both examples clearly demonstrate the impact of manufacturing tolerances on the overall performance of a structure and emphasize the importance of accounting for such tolerances in the design optimization phase. This is particularly true of the pressure vessel. The results show that when the example tolerances are accounted for, the maximum design pressure is reduced by 60.2% (in the case of a single layer vessel), and when five layers are specified, if the nominal fibre orientations are implemented and the example tolerances are incurred during fabrication, the actual design pressure could be 64% less than predicted.
Use of DMAIC methodology to enhance online delivery and assessment during and beyond the COVID-19 pandemic
(University of Johannesburg, 2022) Dewa, Mendon
COVID-19 prompted a radical shift in many universities globally, from contact lectures to adoption of online learning and assessment. A university of technology in South Africa has similarly undergone this transition of adopting an online learning and assessment platform. However, there have been many challenges faced in ensuring integrity of online assessments and ensuring that learning outcomes are addressed. This study aims to investigate the factors that inhibit reliability and effectiveness of online assessment during and beyond the COVID-19 pandemic in a department of industrial engineering at a university of technology in South Africa. The study sample consisted of 80 third-year students enrolled in a Production Engineering course. A five-stage Define-Measure-Analyze-Improve-Control (DMAIC) methodology was used to identify the factors that influenced the reliability and effectiveness of online assessment and, thereafter, to improve the online assessment process. The results demonstrate that there was room for improvement in the online learning environment, which in turn led to more authentic assessment and better academic performance by the students. Recommendations are made regarding strategies that could enhance the integrity of online assessments and minimise cheating while ensuring that learning outcomes are addressed.
Women as canons in engineering theorizing their experiences and exploits
(Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP, 2020) Kehdinga, George Fomunyam
Globally theorizing women’s experiences and exploits in engineering has attracted a lot of debates. Thus, efforts put in place to address under-representation among women in engineering, have been thwarted to accomplish Sustainable Development Goal (SDG) 5 on gender equality, in areas of preconception of engineering male-dominated profession, gender gaps in recruitment of women engineers, lack of gender-sensitive curriculum and low female involvement in Science, Engineering and Technology (SET) subjects are still lacking in Africa. With much sensitization on equality, yet women engineers are still plagued with gender disparity in Africa; hence the crux of this paper. This paper was guided by Liberal Feminist Theory focusing on gender inequality, exists as a consequence ofstereotypingdivision of labour and sexparity can be realized if vital institutions are re-patterned. This paper takes a broad look at women as canons in engineering alongside theorizing their experiences and exploits in Africa. Specifically, it explores how women engineers have made huge contributions; and to showcase their experiences and exploits, as well as its implications for Africa. Thus, to address these gaps, implementing of gender policies in eliminating all forms of under-representation of women in engineering was advocated.