Study Group Problems

Industry: Wildlife management

Industry Representative: Barend Erasmus, Director, Global Change Institute, University of the Witwatersrand, Johannesburg

Moderator:

Student Moderator:

Problem statement

The development of airborne thermal imaging systems for security applications opens up many possibilities for other applications. Even though commercial and industrial applications of thermal sensors in the 8 ¨C 12 ?m range is quite common, these sensors are not suitable for long range, high resolution detection application due to lower sensitivity, small swath width and low pixel count. With the advent of commercial unmanned aerial vehicles (UAVs) some of these challenges can be overcome. However, the extent to which any airborne thermal imaging system and associated data processing chain can be used to map and count large mammals in a repeatable manner, with an accuracy that exceeds conventional aerial counts and at a lower operating cost than conventional aerial counts, remains unknown. Here is a list of capabilities required for such a system. I suggest selecting one of these as a problem.

• Locate all warm-blooded animals above the minimum detectable size from an airborne platform

• Count all these warm-blooded animals

• Record the position of each warm-blooded animal

• Record an image of a representative animal in each group with enough pixels to allow for species identification, using shape (from thermal information) or colour (RGB information)

• Ability to track a chosen animal while circling

• Post processing: Produce a map in a GIS with the location and species of each animal observed.

Supporting Documents

http://www.owyheeair.com/wildlife

Adapting astronomical source detection software to help detect animals in therma

Industry: Wildlife management

Industry Representative: Terence van Zyl, University of the Witwatersrand, Johannesburg

Moderator:

Student Moderator:

Problem statement:

Visual animal is an emerging research discipline in computer vision, pattern recognition and cognitive science. Many animals may be recognized by individual biometric characteristics in just the same way as human fingerprints. Since human fingerprints are relatively small and hidden characteristics, they cannot be used by other persons for mutual visual identification. In contrast to human fingerprints, there are animal skin patterns which are large enough to be used for mutual recognition without technical aids - at least theoretically.

Here we wish to given a number of examples of say for instance gazelle be able to uniquely identify each of them. This is very useful for game/livestock tracking and counting in nature conservationist settings.

Supporting Documents:

Santosh Kumar, Sanjay Kumar Singh: Visual animal biometrics: survey

Presentation: Nyala Visual Biometrics using Machine Learning

Industry: Agriculture

Industry Representative: Norman H?ltz, aparate

Moderator: Montaz Ali, University of the Witwatersrand

Student Moderator:

Problem Statement:

Urban and roof-top farming is important for food security in South Africa. Entrepreneurial and employment opportunities in urban farming have significantly risen in the past few months in Soweto and South Johannesburg. In contrast to traditional farming, urban and roof-top farming yields small crop sizes and are spread out throughout the city. Roof-top farming can be done year round as it is farmed hydroponically under controlled conditions. Hydroponic farming requires no soil, instead the roots are suspended in mineral rich static or continuously moving water. Ultraviolet lamps provide continuous artificial sunlight. On roof-tops, plants are grown in greenhouses to protect them from extreme temperatures, wind and pests. Farms can now produce food throughout the year.

The produce of the farms has to be collected and transported to the market. With urban farming, there are a large number of smaller farms in contrast to the norm of one or two large farms. These smaller farms are also separated by some distance.

Since the farming can be done throughout the year, the study group is asked to optimise the plant and harvest times for a large number of farms producing a range of products. Prices at different times of the year in South Africa and growing times for the produce will be provided.

The study group is also asked to optimise the routes, by road, between the farms during the collection of produce. Some produce, for example strawberries, require refrigeration which not all vehicles have. The optimal routes for non-refrigerated vehicles will therefore differ from that for refrigerated vehicles. The locations of the farms will be provided. The study group has to determine how the routes are calculated, for example, with Google maps.

Report-back presentation:

MISG 2019 Report-back Presentation: Farming optimization

Industry: Shipping and Offshore Oil and Gas

Industry Representative: Thama Duba, Durban University of Technology

Moderator: 

Student Moderator:

Problem Statement:

Rogue waves are waves whose height and crest exceed the average wave in a given sea state. These abnormal waves have received significant attention both in media and in the scientific community, especially in the shipping and offshore industry. Rogue wave accidents involving large ships and offshore structures are on the rise as these waves are no longer rare. In 1995, a 23-meter high wall of water struck the Draupner platform and this caught the attention of oceanographers, and the oil and gas and other offshore industries. Abnormal waves no longer became a sailor¡¯s folklore but a problem to these industries.

Rogue waves have an impact on standard shipping and offshore rules. Rogue waves occur in different sea states, low, intermediate and high seas states. Rough sea states are no longer the only ones that we must take into account in the operation of ships, but all sea-states due to these monster waves. Therefore, it is imperative that we develop new warning criteria for the rogue-prone sea-states.

Furthermore, the engineering design of ships, offshore structures and platform deck will have to be different as rogue waves are no longer rare, probably due to climate change. In addition, it is not clear when they will appear, hence under such uncertainties, it is necessary to have new regulations for safety standards.

The study group is asked to investigate the initial conditions of the sea state from which rogue waves can form and grow.

References:

https://www.dnvgl.com/feature/rogue-waves.html

https://eos.org/model-predicts-heights-of-rogue-waves

http://www.nature.com/scientificreports

http://www.conocophillips.no/our-norway-operations/

Application of Zakharov equation in three dimensions to deep water gravity waves

2019 4 Rogue Wave Wikipedia

2019 4 Rethinking Rogue Waves DNV GL June 2017

2019 4 Journal P One 0054629 2013 Rogue Waves

2019 4 Application of Zakharov equation

2019 4 ROGUE WAVES Impact on ships and offshore structures

2019 4Annex D Extreme wave impact on offshore platforms and coastal structures

Presentation

Rogue Waves

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MISG 2019 Report-back Presentation: Rogue Waves

Industry: Sugar Cane Processing

Industrial Representative: Richard Loubser, Sugar Milling Research Institute, c/o University of KwaZulu-Natal, Durban.

Moderator:

Student Moderator:

Problem Statement

 Under ideal conditions, the sugar crystals produced in the sugar process need to be uniform size and have a regular shape. This simplifies the design of equipment such as centrifuge screens. In reality, however, a range of crystal sizes are produced and impurities cause crystals to elongate resulting in a poor crystal habit.

Photomicrographs are used to manually assess massecuites (mixture of crystals and mother liquor) samples in terms of mean size (length and width), median (length and width), size coefficient of variation (CV) and elongation ratio (length to width ratio). In addition to this, it is often necessary to estimate the number of crystals in a unit volume of syrup (in the order of 10⁵ crystals per mL).

In certain circumstances, the image may include air bubbles, agglomerated crystals, conglomerates and crystals which touch or overlap. These must be excluded from the analysis. However, the conglomerates percentage by number is of importance w.r.t sugar quality and will need to be counted.

We are looking for an algorithm that will identify single crystals, count them and give size, distribution and shape statistics.

Several photomicrographs will be made available for development and testing.

Sugar Crystal Image Analysis - C-massec.zip

Sugar Crystal Image Analysis - Photomic of seed and masc.zip

Presentation

Sugar Crystal Image Analysis

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MISG 2019 Report-back presentation: Sugar crystals

Industry: Energy

Industry Representative: Denis Ndanguza, University of Rwanda, Rwanda

Moderator:

Student Moderator:

Problem Statement:

Lake Kivu is known to be a dangerous lake in East Africa. A new type of hazard which may occur is now to be taken seriously under consideration in relationship with the existence of high concentration of dissolved gas in the water at depth in the lake. This new hazard is the water pollution and it seems that living around Lake Kivu means accepting a higher risk than living elsewhere in the region.

The most obvious type of water pollution affects surface water. Most water pollution does not begin in the water itself. The literature argues that there is a quantity of gas vented in the atmosphere during the harvest and there are other toxic substances entering the Lake; all those substances get dissolved or lie suspended in water Chemicals released by smokestacks (chimneys) can enter the atmosphere and then fall back to earth as rain, entering the Lake and causing water pollution. This results in the pollution of water. The pollution may cause the quality of the water to deteriorate and further affects the aquatic ecosystems. These pollutants can also seep down and affect the groundwater deposits or disturb density-stratified lake waters.

In general, water pollution has many different causes and this is one of the reasons why it is such an interesting problem to solve. There is a clear danger lying ahead, and something needs to be done in advance to alert decision makers from all points of view (environmentally, economically and risk monitoring). To do nothing would be completely unacceptable.

In the course of the methane extraction by venting a certain percentage of gas in the atmosphere, it would increase the risk of water pollution, which is why the continuous monitoring and regulation is mandatory. Therefore, the extraction projects have to be regulated and well monitored.

The Study Group is asked to model the surface water pollution in Lake Kivu.

Supporting Documents

Anthropogenic Pollution Impact on Physico-Chemical Characteristics of Lake Kivu

Anthropogenic Pollution Impact on Microbial Contamination of Lake Kivu, Rwanda

Industry: Energy

Industry Representative: Denis Ndanguza, University of Rwanda, Rwanda

Moderator:

Student Moderator:

Problem Statement:

Lake Kivu is a stratified lake with several gradient layers (density variation of the water with depth) which serve as ``flexible lids¡¯¡¯ ensuring both a resistance to mixing (which could cause a gas release), and a barrier which allows for the accumulation of methane gas (and carbon dioxide) in the lake. All four layers have different characteristics and composition, Notably there are two gradient layers at about 80 and 260 m depth, respectively, where the upper layer protects the overlying biozone and the lower layer confines and protects the major part of the gas deposit. The gas is kept dissolved at the lake bottom by the weight of water containing nutrients above it, and mixing toward the surface is prevented by strong density gradients which act like stability layers at certain depths in the lake. This may result in double diffusive convection where two different density gradients have different rates of diffusion.

Convection in fluids is driven by density variations within them under the influence of gravity. These density variations may be caused by gradients in the composition of the fluid, or by differences in temperature (through thermal expansion). Thermal and compositional gradients can often diffuse with time, reducing their ability to drive the convection and requiring that gradients in other regions of the flow exist in order for convection to continue. A common example of double diffusive convection is in Lake Kivu, where temperature and salinity or CO2 and CH4 diffuse at differing rates. Double diffusion convection plays a significant role in upwelling of nutrients and vertical transport of heat and salt in the lake.

This is opposing the thermal diffusion which is an effect wherein a temperature gradient in a gaseous or liquid mixture tends to cause a separation: the concentration of components in the regions of increased and decreased temperatures, respectively, becomes different. Since the establishment of a concentration gradient causes, in turn, ordinary diffusion, in a stationary non-uniform temperature field a steady state inhomogeneous state is possible in which the separation effect of thermal diffusion is balanced by the counteraction of concentration diffusion.

The magnitude of vertical mixing with double diffusive convection depends upon the density ratio. This ratio requires knowledge of the expansion coefficients of temperature, salinity, CO2 and CH4 as well as the change in these constituents with depth. Any change in the horizontal distribution of temperature, salinity or the dissolved gases will set the stage for an increase in intrusions formed by double diffusive convection. These will increase both lateral and horizontal mixing rates. The extraction of water at depth will create horizontal heterogeneity of properties and therefore, the following points are crucial to understanding the concept of double diffusion and some quantities have to be calculated.

• Due to the inferred double diffusive mixing above and below the main stability layer at 260 m and its drawdown and subsequent exposure to potentially different rates of geothermal heating which could lead to instabilities, it is imperative that this ratio be frequently calculated.
• Furthermore, given the vital role of mixing in control of lake heat storage, climate, carbon dioxide absorption and pollutant dispersal, it is increasingly important that we achieve a more complete understanding of the lake double diffusion.
• Evaluate the impacts of the heterogeneity along-side the horizontal diffusivities.
• Show how opposing stratifications of two component species could drive convection if their diffusivities differ.
• To compute the rates of mixing.
• To compute the Rayleigh number in the layers.
• To initiate the theoretical study of double-diffusive phenomena in Lake Kivu.
• To check if the lake is strongly unstable to double-diffusive processes and seems to be profoundly affected by their presence.
• To investigate the nature of double-diffusive mixing in the large, under-explored fuid which covers most of the lake
• Investigate the double diffusion effect due to the opposing effects of thermal diffusion and mass diffusion.

Supporting Documents

• Hupert, Double-diffusive convection
• Nonlinear double-diffusive convection
• Lake Kivu Gas Extraction Report (Problem 7 2019)
• Double Diffusion in Oceanography

Industry: Conservation

Industry Representative: Tim Myers, Centre de Recerc Matematica, Barcelona, Spain

Moderator:

Student Moderator:

Problem statement

It is generally accepted that global warming and climate change are real. The main cause of warming is the greenhouse effect, whereby the atmosphere traps heat that would otherwise radiate back into space. In reality what is really happening is that energy is being added to the system (the planet), which leads to more energetic events including global warming, but also increased likelihood of extreme events: more powerful storms; heat waves; flooding etc.

One of the worst culprits for climate change is the burning of fossil fuels, such as coal and oil. This has greatly increased the amount of CO2 (a greenhouse gas) in the atmosphere.

Obviously one way to reduce CO2 production is to stop the use of fossil fuels, however it seems unlikely that this will occur in the near future. Further, it is now becoming increasingly clear that it will be necessary to reduce the CO2 already in the atmosphere if current goals on global temperature increases are to be met.

A controversial technology is Carbon Capture (CC). The most obvious form is CC technology applied close to a source, such as a power plant. Direct Air Capture (DAC) processes atmospheric air to remove CO2. Controversy over these techniques include the cost, the fact that some countries may use this as a way to keep using ¡®dirty fuels¡¯, and what to do with the carbon or carbon dioxide afterwards.

The aim of this project is to investigate these technologies, to verify whether they are indeed viable and identify areas where mathematical modelling can help.

References

1. S. Li et al. Mathematical modeling and numerical investigation of carbon capture by adsorption: Literature review and case study. Applied Energy 221 (2018) 437¨C449. Mathematical modeling and numerical investigation of carbon capture by adsorptio
2. M.S. Shafeeyan et al. A review of mathematical modeling of fixed-bed columns for carbon dioxide adsorption. Chemical Engineering Research and Design 92 ( 2 0 1 4 ) 961¨C988. A review of mathematical modeling of fixed-bed columns for carbon dioxide adsorp
3. R. Ben-Mansour et al. Carbon capture by physical adsorption: Materials, experimental investigations and numerical modeling and simulations ¨C A review. Applied Energy 161 (2016) 225¨C255. Carbon capture by physical adsorption: Materials, experimental investigations an
4. Numerical investigations and mathematical models of carbon capture by adsorption

Presentation

Mathematical modelling of carbon capture

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MISG 2019 Report-back presentation: Carbon capture

Industry:  Fishing

Industry Representative: Philip Broadbridge, La Trobe University, Melbourne, Australia

Moderator: Ashleigh Hutchinson, University of the Witwatersrand

Student Moderator:

Problem statement

Recently an exact solution was produced of the Verhulst nonlinear reaction-diffusion equation for a fish population with logistic Fisher-type source term. It was assumed that the population is contained within a circular protection zone, with severe culling at the boundary. In order for there not to be a solution that approaches extinction, there is a minimum diameter of the exclusion zone. For example, for a species randomally spreading over 100 square km per year, with a population renewal time of 5 years, the minimum diameter is 103 km. How does this estimate change if we soften the boundary conditions, change to a heterogeneous habitat so that population growth is stronger in the centre, or have a 2-species ecosystem with two different mobility levels?

Presentation

Geometric design of effective fishing exclusion zones

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MISG 2019 Report-back presentation: Fishing