Papers by Daniel Mireku-Gyimah
Mathematical Problems in Engineering, Sep 26, 2022
e discount rate input parameter of Net Present Value (NPV) in mineral project evaluation is a fun... more e discount rate input parameter of Net Present Value (NPV) in mineral project evaluation is a function of a risk-free rate and risk premium component. To obtain a reliable NPV, it is important to estimate each of these components. is study employs a hybrid approach to predict risk-free rate using Discrete Wavelet Transform and Arti cial Neural Network (DWT-ANN). e DWT-ANN model was tested using London Interbank O ered Rate (LIBOR) dataset from 1986 to 2020. e results showed that Discrete Wavelet Transform-Radial Basis Function Neural Network (DWT-RBFNN) of the three di erent hybrid algorithms developed and applied performed best in predicting the risk-free rate. is is because it achieved the lowest root mean square error of 0.0376 and the highest correlation coe cient of 0.9995. e DWT-RBFNN model can be a useful alternative tool for predicting risk-free rate, which is a key input parameter for the determination of discount rate.
Improving Land Rights: A Model for Determining Compensation Package (Compacal-G) for Compulsorily Acquired Land in Ghana
Ghana Mining Journal, 2018
This paper demonstrates the application of Surpac and Whittle in open pit optimisation and design... more This paper demonstrates the application of Surpac and Whittle in open pit optimisation and design. Exploration data on the Tabakoto deposit of AngloGold Ashanti Sadiola Mine (AASM) has established 13 652 661 t of gold resource with an average grade of 1.15 g/t that could be mined using open pit method. The aim of this paper is to optimise and design a pit to mine the deposit safely and profitably using Surpac and Whittle software. The work entailed: block modelling of the Tabakoto deposit using Surpac; importing the block model to Whittle for pit optimisation; and importation of the optimal pit back to Surpac for detailed pit design. In all, 55 nested pit outlines were generated but the one with the highest Net Present Value (NPV) of US$3 185 637 was selected as the optimal pit. The optimal pit contains 446 750 t of ore at an average grade of 1.709 g/t and 2 310 910 t of waste while the designed pit has 444 982 t of ore at an average grade of 1.683 g/t and 2 416 988 t of waste. It ...
Ghana Mining Journal, Jun 17, 2015
The vegetation in the Tarkwa Mining Area (TMA) has experienced changes as a result of population ... more The vegetation in the Tarkwa Mining Area (TMA) has experienced changes as a result of population growth, urbanization, mining activities and illegal chainsaw operations and this has led to an increase in temperature over the past years. Therefore, studying its forest biomass carbon (C) stock and its spatio-temporal change is important to the sustainability of forest resources and understanding of the forest C budget in the TMA. In this study, aboveground forest biomass/carbon stock and its changes in the TMA were estimated from three nested-circular plots of horizontal radii 12.62 m, 8 m and 4 m using stratified random sampling from sixty locations in five land use/cover types as well as GIS/Remote Sensing techniques over a 21 year period. An estimated total of 1 250.93 ± 7 Mg/km 2 carbon was recorded in the TMA. Carbon in different land-use/cover types ranges from 587.76 ± 4 Mg/km 2 carbon in closed canopy to 270.23 ± 2 Mg/km 2 carbon in shrubs/herbaceous. The TMA also experienced an average of 412.14 Gg of carbon (equivalent to 19.63 Gg carbon per year) lost between 1986 and 2007 due to the changes in the land use/cover types. The study area is however, considered a net source of carbon.
Ghana Mining Journal , 2020
The consequences of collapsed stopes can be dire in the mining industry. This can lead to the rev... more The consequences of collapsed stopes can be dire in the mining industry. This can lead to the revocation of a mining license in most jurisdictions, especially when the harm costs lives. Therefore, as a mine planning and technical services engineer, it is imperative to estimate the stability status of stopes. This study has attempted to produce a stope stability prediction model adopted from stability graph using ensemble learning techniques. This study was conducted using 472 case histories from 120 stopes of AngloGold Ashanti Ghana, Obuasi Mine. Random Forest, Gradient Boosting, Bootstrap Aggregating and Adaptive Boosting classification algorithms were used to produce the models. A comparative analysis was done using six classification performance metrics namely Accuracy, Precision, Sensitivity, F1-score, Specificity and Mathews Correlation Coefficient (MCC) to determine which ensemble learning technique performed best in predicting the stability of a stope. The Bootstrap Aggregating model obtained the highest MCC score of 96.84% while the Adaptive Boosting model obtained the lowest score. The Specificity scores in decreasing order of performance were 98.95%, 97.89%, 96.32% and 95.26% for Bootstrap Aggregating, Gradient Boosting, Random Forest and Adaptive Boosting respectively. The results showed equal Accuracy, Precision, F1-score and Sensitivity score of 97.89% for the Bootstrap Aggregating model while the same observation was made for Adaptive Boosting, Gradient Boosting and Random Forest with 90.53%, 92.63% and 95.79% scores respectively. At a 95% confidence interval using Wilson Score Interval, the results showed that the Bootstrap Aggregating model produced the minimal error and hence was selected as the alternative stope design tool for predicting the stability status of stopes.
Open Pit Optimisation and Design of Tabakoto Pit at AngloGold Ashanti Sadiola Mine Using Surpac and Whittle Software
Ghana Mining Journal, Dec 28, 2018
This paper used the respective unit costs, over 15 years, of selected Housing Unit Major Componen... more This paper used the respective unit costs, over 15 years, of selected Housing Unit Major Components (HUMC): cement, iron rods, aluzinc roofing sheets, coral paint, wood and sand, to develop Principal Components Regression Model (PCRM) for determining Housing Unit Price (HUP) for one-bedroom and two-bedroom housing units. In developing the PCRM, the sample data (HUMC) was log transformed and bootstrapped; dimension reduction technique together with scree plots were used to determine the minimum number of principal components that explained the total variation in the sample data (HUP) for the PCRM. Principal Components Analysis method was used to derive the model coefficients. The resultant PCRM is: Ŷ iPCRM = β o +Ʃ p j=1 β j x i where β o is the population parameter not associated to any predictive variable, β j are the estimated population parameters associated to the predictive variables and x i is the ith row predictive variables for validating the PCRM. The specific model for one...
Ghana Mining Journal
Mine rescue practices have seen significant improvement over the century. There have been develop... more Mine rescue practices have seen significant improvement over the century. There have been developments in breathing apparatus, safe havens, rescue capsules, rescue simulators, underground communication technology, and training for rescue brigades. Most countries practice a mine-owned rescue system and the number of rescue brigades required in a mine is country-specific and determined by the mining regulations of the host country. A review of mining regulations globally shows that the number of brigades required in a mine depends solely on the number of people employed underground. For ages, this has been the only criterion used to determine the number of rescue brigades required in a mine. This criterion is not appropriate since there are other vital factors which must be taken into account. Considering the nature, complexity and innovations in mining operation currently, this paper considers eleven (11) factors that influence the number of rescue brigades in a mine. These eleven (1...
The Kofi Gold Mine (KGM) of Endeavour Mining Corporation in Mali needed to select one of two alte... more The Kofi Gold Mine (KGM) of Endeavour Mining Corporation in Mali needed to select one of two alternative blast designs, Blast Design 1 (BD1) and Blast Design 2 (BD2), for the fresh rocks of the deposit, both ore and waste, in their Kofi C Pit. BD1 has a burden of 3.2 m, a spacing of 3.5 m, a bench height of 5.0 m and a sub drill of 0.5 m. BD2 has a burden of 3.5 m, a spacing of 4.0 m, a bench height of 10.0 m and a sub drill of 0.8 m. Both designs have the same hole diameter of 115 mm and powder factor of 0.68 kg/m3. The Modified Kuz-Ram Fragmentation Model was used to estimate and compare the fragmentation of the two designs. The modelling results showed that the fragmentation of BD1 would be better than that of BD2 but cost analysis revealed that the drilling and blasting cost of BD2 would be lower than that of BD1. Consequently, BD2 was modified into Blast Design 3 (BD3) to improve the fragmentation without exceeding the drilling and blasting cost of BD1. The modification was d...
Ghana Mining Journal, Jun 30, 2017
Atiwa Quarries Limited (AQL) is one of the large operating granite quarries in the Central Region... more Atiwa Quarries Limited (AQL) is one of the large operating granite quarries in the Central Region of Ghana. AQL's current production of 24 000 m 3 of aggregates per month cannot meet current demand let alone support a new contract to supply 25 000 m 3 of aggregates per month for a major road infrastructure project. Fortunately, AQL has another granite concession at Loye, about 3 km from the first concession, with estimated granite reserves of 6 286 208 m 3 , which can be developed as a new quarry to meet the demand of the new contract. This will require capital to build infrastructure, purchase equipment, recruit labour and provide working capital. The objective of this paper is to evaluate the economic viability of the new quarry, considering it as a stand-alone project. The yearly revenue was estimated based on projected production of 25 000 m 3 /month and average price of US$ 15.63/m 3. Capital and operating costs were estimated using detailed cost estimation method based on quotations from equipment suppliers and operational unit costs of AQL. It turns out that AQL can generate yearly gross revenue of US 4.69 million but requires total capital of US$ 3.67 million; the yearly operating cost is US$ 1.72 million. Cash flow and sensitivity analyses using Net Present Value (NPV) and Internal Rate of Return (IRR) as criteria, and risk analysis using Monte Carlo simulation method were carried out. The economic analysis indicates that based on AQL's preferred capital structure of 80% equity and 20% loan, the NPV is $ 5.17 million and the IRR is 53.01%, showing the new quarry is profitable; the sensitivity analysis indicates that the project can withstand up to 40% drop in revenue, or over 60% increase in capital or operating cost. The risk profile indicates a probability of success of 98.2%. The study therefore recommends that AQL invests in the new quarry as it is economically viable.
The challenge for everyone involved in preserving the ecosystem is to find creative ways to prote... more The challenge for everyone involved in preserving the ecosystem is to find creative ways to protect and restore the remaining ecosystems while accommodating and enhancing the country social and economic well-being. Frequent fires of anthropogenic origin have been affecting the ecosystems in many countries adversely. Hence adopting ways of decision making such as Multicriteria Decision Making (MCDM) is appropriate since it will enhance the evaluation and analysis of fire risk and hazard of the ecosystem. In this paper, fire risk and hazard data from the West Gonja area of Ghana were used in some of the methods (Analytical Hierarchy Process, Compromise Programming, and Grey Relational Analysis (GRA) for MCDM evaluation and analysis to determine the optimal weight method for fire risk and hazard. Ranking of the land cover types was carried out using; Fire Hazard, Fire Fighting Capacity and Response Risk Criteria. Pairwise comparison under Analytic Hierarchy Process (AHP) was used to de...
Ghana Mining Journal, 2015
Malaria is the leading cause of morbidity and mortality in Ghana, accounting for over three milli... more Malaria is the leading cause of morbidity and mortality in Ghana, accounting for over three million cases and thousands of deaths annually. The risks of morbidity and mortality associated with malaria are characterized by spatial and temporal variation across the country. This research sought to use GIS and multi-criteria decision analysis to produce a predictive model of malaria using eight risk factors ranging from environmental to anthropogenic. Each of the risk factors was classified into three classes of malaria risk according to how it impacts malaria prevalence. The classified risk factors were finally overlaid through the use of weighted overlay after weights were determined from them using the Analytical Hierarchy Process (AHP). Results indicate that high risk areas are concentrated at the central as well as the west-southern parts of the country consisting mainly of the Ashanti, Brong Ahafo, Eastern, Central and the Western Regions. No area was classified as low risk while...
The University of Mines and Technology (UMaT) has a Local Area Network (LAN) with a download and ... more The University of Mines and Technology (UMaT) has a Local Area Network (LAN) with a download and upload bandwidth capacity of 60 MB, which is connected to a Network Operating Center (NOC) by fiber optic cable and distributed to about 3000 users in the UMaT community via Cat 6 Ethernet cables and wireless access connections. The primary purpose of the internet facility is to support teaching and learning, research and sharing of information. Unfortunately, even though the capacity of the bandwidth is considered sufficient, the LAN had two main challenges: the network appeared to be slow; and sometimes it gave signals of insecurity from virus attacks. This paper sought to study the behaviour patterns and bandwidth utilisation trends of the network users using Squid Analysis Report Generator (SARG); identify the causes of the challenges and deploy effective bandwidth management control policies using squidGuard. The results of the study revealed that the challenges of the LAN are attri...
African Journal of Environmental Science and Technology, 2015
Forest fires (wildfires) have become a major concern for several environmental experts. Assessmen... more Forest fires (wildfires) have become a major concern for several environmental experts. Assessment of fire effects at local scale is increasingly considered a critical aspect of ecosystem functioning, since fire plays a crucial role in vegetation composition, biodiversity, soil erosion and the hydrological cycle. At global scale, fire is the most generalized means of transforming tropical forest in agricultural areas, and it has severe impacts on global atmospheric chemistry. Fire is a natural factor in many climates with high levels of vegetation stress. However, changes in traditional land use such as hunting, charcoal production, inefficient logging practices and rural abandonment patterns, which have been identified as major causes of wild fires, have recently modified the incidence of fire. Several assessment techniques and methods have been developed to help model and evaluate forest fire risk and hazard. There is the need to identify a method or combination of methods to help...
Gold in the Offin placer deposit at Dunkwa-on-Offin, Ghana, occurs freely. Cravity concentration ... more Gold in the Offin placer deposit at Dunkwa-on-Offin, Ghana, occurs freely. Cravity concentration methods such as jigging and sluicing are employed to recover the gold. These methods are most efficient within specific size ranges of the gold grains. This paper conducts mineralogical, sieve and rnicroscopic analyses to establish the gold grain size and its distribution along the Offin River. The results of the size analyses are used as a basis to evaluate the effectiveness of the dredge treatment plants at Dunkwa Goldfields Lt.in gold recovery. The analyses take into consideration three operational zones: Upper, Middle and Lower Offin. In each operational zone, size analyses are carried out on the gold grains in the deposit, gold grains reeovered by the treatment plant, and those lost by the treatment plant. The particle sizes are grouped into three main classes: (i) 'Upper range: + 440 pm (ii) Middle range: 440 pm to + 120 pm (iii) Lower range: 120 pm The analyses show that withi...
The Tarkwa Mining Area (TMA) falls in the rainfall belt of Ghana with evergreen Equatorial forest... more The Tarkwa Mining Area (TMA) falls in the rainfall belt of Ghana with evergreen Equatorial forest vegetation. TMA has witnessed clearance of large tracts of vegetation to make room for mining and settlements. Destruction of vegetation has exacerbated since surface mining was introduced in the area in the 1980s. However, the actual extent of vegetation change since 1980 to date has not been assessed and quantified. This study uses Remote Sensing (RS) and Geographic Information Systems (GIS) techniques to estimate the changes in vegetation in the area. Temporal satellite images for four different years and 250 ground reference points were classified using maximum likelihood algorithm. The impact of mining on vegetation composition was also estimated using distant gradient. Phytosociological analysis was also carried out to determine the species density, dominance index and diversity index. The results revealed five dominant land use/cover types. Vegetated areas in the TMA lost 932.92 ...
Mining and the Environment in Ghana - An Economic Controversy
The aim of this paper is to compare the following developed models: Multiple Linear Regression Mo... more The aim of this paper is to compare the following developed models: Multiple Linear Regression Model (MLRM), Principal Components Regression Model (PCRM) and Time Series Analysis Model (TSAM) that could be used to determine realistic Housing Unit Price (HUP) for one-bedroom and two-bedroom housing units. The motive is to select the best model for HUP determination. The MLRM and PCRM were developed using yearly monetary costs over 15 years of Housing Unit Major Components (HUMC) that is, cement, iron rods, aluzinc roofing sheets, coral paint, wood and sand. Multicollinearity analysis was performed to show inputs that are redundant and hence can be removed from the MLRM and PCRM development without necessarily having an effect on the modelling accuracy. With regards to TSAM, observed yearly housing unit prices over 15 years were used to determine HUP for one-bedroom and two-bedroom housing units. To overcome the nonstationarity issues, the yearly nominal housing unit prices were trans...
Testing the efficiency of the financial market is of much importance to investors who wish to hol... more Testing the efficiency of the financial market is of much importance to investors who wish to hold diversifiable assets. This paper analysed the weak form market efficiency hypothesis for five sectors of the Ghana stock exchange using monthly returns of their respective stock market capitalisation as the information generating event. The paper investigated the weak form market efficiency in the framework of random walk hypothesis for the sectors of Ghana stock exchange by using the Run and the Lo-MacKinlay Variance Ratio tests. The results revealed that the sectors - consumer staples, financials and pharmaceuticals do not follow random walk and thus imply these sectors are not weak form efficient. The results also revealed contradictory results on the mining and the petroleum sectors, hence the issue of whether or not the random walk hypothesis holds for the two sectors is inconclusive.
Governments all over the world especially in developing countries continue to emphasise poverty a... more Governments all over the world especially in developing countries continue to emphasise poverty alleviation and eradication as their overarching goals. A number of international organisations also recognise the need for the reduction of poverty incidence within the next decade, making poverty reduction one of the greatest concerns worldwide. During the past three decades, the government of Ghana has developed and subsequently implemented several development policy frameworks as part of its poverty reduction programmes. One of the parameters that play a key role in reduction and alleviation of poverty is statistics on poverty. However, in many developing countries such as Ghana such statistics do not exist, making poverty alleviation intervention a bit scattered and untargeted. Due to this, there exists a major problem of reaching the poor to address their specific needs. In response to this challenge, there is the need to produce poverty map to assist policy makers. This research th...
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Papers by Daniel Mireku-Gyimah