Research Articles (Logistics)
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- ItemAllocating epidemic response teams and vaccine deliveries by drone in generic network structures, according to expected prevented exposures(Public Library of Science, 2021) Matter, Dean; Potgieter, LinkeThe tumultuous inception of an epidemic is usually accompanied by difficulty in determining how to respond best. In developing nations, this can be compounded by logistical challenges, such as vaccine shortages and poor road infrastructure. To provide guidance towards improved epidemic response, various resource allocation models, in conjunction with a network-based SEIRVD epidemic model, are proposed in this article. Further, the feasibility of using drones for vaccine delivery is evaluated, and assorted relevant parameters are discussed. For the sake of generality, these results are presented for multiple network structures, representing interconnected populations—upon which repeated epidemic simulations are performed. The resource allocation models formulated maximise expected prevented exposures on each day of a simulated epidemic, by allocating response teams and vaccine deliveries according to the solutions of two respective integer programming problems—thereby influencing the simulated epidemic through the SEIRVD model. These models, when compared with a range of alternative resource allocation strategies, were found to reduce both the number of cases per epidemic, and the number of vaccines required. Consequently, the recommendation is made that such models be used as decision support tools in epidemic response. In the absence thereof, prioritizing locations for vaccinations according to susceptible population, rather than total population or number of infections, is most effective for the majority of network types. In other results, fixed-wing drones are demonstrated to be a viable delivery method for vaccines in the context of an epidemic, if sufficient drones can be promptly procured; the detrimental effect of intervention delay was discovered to be significant. In addition, the importance of well-documented routine vaccination activities is highlighted, due to the benefits of increased pre-epidemic immunity rates, and targeted vaccination.
- ItemProvincial Dietary Intake Study (PDIS) : prevalence and sociodemographic determinants of the double burden of malnutrition in a representative sample of 1 to under 10-year-old children from two urbanized and economically active provinces in South Africa(MDPI, 2019) Senekal, Marjanne; Nel, Johanna H.; Malczyk, Sonia; Drummond, Linda; Harbron, Janetta; Steyn, Nelia P.The objective of this study was to determine the prevalence and socio-demographic predictors of malnutrition in two urbanized economically active provinces (Gauteng N = 733, Western Cape N = 593) in South Africa. A multistage stratified cluster random sampling design was applied. Fieldworkers visited homes, measured children aged 1-<10-years old (N = 1326) and administered a questionnaire (mother/primary caregiver). In under-five year old children (N = 674) 21.6% were stunted [height-for-age z-score < −2 SD], 5.6 % underweight [weight-for-age z-score < −2 SD], 10.3% overweight (body mass index-for-age z-score) (BAZ)> +2 SD ≤ +3 SD] and 7.0% obese (BAZ > +3 SD). In 5–<10-year olds (N = 626) 6.7% were stunted, 6.8% underweight, 13.4% overweight and 6.8% obese. Stunting and overweight in the same child was present in 5.7% under-five year olds and 1.7% in 5–<10-year olds. Multiple logistic regression analyses identified having a mother with a post-grade 12 qualification (OR = 0.34) and having an obese mother (OR 0.46) as protectors and being in the under-five age group (OR = 3.73) as a risk factor for stunting. Being in the under-five age group was also a risk factor for a BAZ > 1 (OR 2.39), while being in the third wealth quintile was protective (OR = 0.62). Results indicate that stunting and overweight/obesity are still present at concerning levels, especially in the under-five age group.
- ItemLogistics aspects of petroleum pipeline operations(AOSIS, 2010) Pienaar, W. J.The paper identifies, assesses and describes the logistics aspects of the commercial operation of petroleum pipelines. The nature of petroleum-product supply chains, in which pipelines play a role, is outlined and the types of petroleum pipeline systems are described. An outline is presented of the nature of the logistics activities of petroleum pipeline operations. The reasons for the cost efficiency of petroleum pipeline operations are given. The relative modal service effectiveness of petroleum pipeline transport, based on the most pertinent service performance measures, is offered. The segments in the petroleum-products supply chain where pipelines can play an efficient and effective role are identified.
- ItemRisk profile of weather and system-related port congestion for the Cape Town container terminal(Unisa Press, 2020) Potgieter, Lilian; Goedhals-Gerber, Leila L.; Havenga, JanThe South African maritime industry suffers from a number of risks, with the most prominent source of risk stemming from congestion within port terminals. The Port of Cape Town is one of South Africa’s main ports. Two of the risks faced by the Cape Town Container Terminal (CTCT) and associated with port congestion are adverse weather and system challenges. The study investigated the current frequency and scheduling impact of weather- and system-related congestion experienced by ocean carriers in the CTCT. This study was conducted in two phases, namely exploratory secondary research, followed by primary research. The secondary research provided background information and historical data on the Port of Cape Town, the CTCT, and congestion in South Africa’s ports as well as global port congestion. In addition, the primary data collected, which comprised personal interviews and email correspondence, were used to analyse current port congestion within the CTCT and to develop risk profiles. The major findings of this study indicate that both weather- and system-related port congestion are ranked as major risks occurring between 2011 and 2018 in the CTCT, suggesting that greater risk mitigation strategies should be implemented. This risk ranking will likely worsen in the future, if mitigation strategies are not improved. The study classifies weather- and system-related port congestion in the CTCT in terms of the level of risk and helps identify which areas management should focus on to mitigate greater levels of risk in the future.
- ItemInvestigating supply chain sustainability in South African organisations(AOSIS, 2018) Niehaus, Gabrielle; Freiboth, Heinrich W.; Goedhals-Gerber, Leila L.Background: The need for sustainable supply chain management has become a necessity given the growing impact of climate change and global warming. The South African (SA) government is planning to implement a carbon tax in the future, which will present financial challenges for organisations already facing social and environmental difficulties. Objectives: The main objective of this article was to investigate the current sustainability reporting practices in supply chains of SA organisations. The focus was specifically on the supply chain sustainability practices of organisations listed in selected sectors on the Johannesburg Stock Exchange (JSE). A secondary objective was to investigate preparation efforts by SA companies for the impending carbon tax. Method: Data collected from sustainability and integrated annual reports of organisations in the sample were analysed using non-parametric statistical tests to compare sectors on the JSE and to compare companies listed on the socially responsible investment (SRI) Index with those that are not. Results: The results showed that there is insufficient data for some of the sectors; however, there are differences in the supply chain and sustainability practices for the remaining sectors. There are also differences in these practices between SRI and non-SRI companies. The research also showed that companies are discussing important concepts relating to the implementation of the impending carbon tax. Research impact: SA organisations need to increase their focus on sustainable supply chain practices. Further investigation into the preparation efforts of companies to reduce their emissions and/or footprint and mitigate the impact of the impending carbon tax is necessary.