ghanaopendata/ghanaian-research-english huggingface dataset:
Improved Weighted Information Criterion For Model Selection In Univariate Time Series Analysis

In this study, we propose a new information criterion for model selection in univariate time series analysis by weighting the penalty terms of the three most commonly used information criteria (i.e. Akaike Information Criterion (AIC), Schwarz Information Criterion (SIC) and Hannan Quinn Information Criterion (HQ)). The penalties of these three information criteria are considered as a linear function. Two di erent methods for calculating an optimal weight (a model performance based criterion and an eigenvector based criterion) were considered for the new information criterion. A simulation of a univariate time series models with ve di erent sample sizes was carried out to compare the performance of our proposed information criteria (Model Performance based weight information criterion (PWIC) and Eigenvectors based weight information criterion (EIC)) to three existing information criteria. Results obtained showed that the EIC along with HQ performed better than the SIC and AIC with respect to the overall performance in choosing the order of univariate time series model. Hence, the results indicate that the proposed information criterion based on the eigenvector weight work well in nite sample. Our approach showed outstanding performance with the HQ criterion in selecting the "best" model and this combination is recommended for model selection.

Source: KNUST
Improved teaching method for teaching ICT in schools in Ghana using a school management software (ITALC software) – a case study of Fiaseman Senior High School

ABSTRACT The objective of this study was to improve upon the existing teaching methods used in our schools and the effectiveness of the teaching methods on students’ academic performance. A sample of 60 students from Fiaseman Senior High School was used for the study. The two main teaching methods (teacher-centred and the student-centred methods) were considered. Both methods were used to teach the sampled students. Then the School Management Software was used to improve upon the methods used. Students’ performance was tested and the result analyzed. The results demonstrate that student-centred interactive method was the most effective teaching method, followed by the teacher-centred approach. In every nation across the world, education is now seen as an essential path of our daily lives, that is, whether economic, social or political. Education has now becomes necessary as it assists students in a more sociable and interactive environment progressively. To be effective and efficient as a teacher does not always mean being perfect all the time, instead, to bring the best out of your students. Teaching, as it is said, is an “Art.” An “Art” of exhibiting one’s skills in our quest to impart knowledge to the next generation It is assumed that there should not be any effective teaching when students are not engaged in the learning process. Therefore, teachers introduce teaching style that addresses the individualism in students, thereby dealing with the self-evaluation of his strengths and weaknesses. For teaching and learning process in our educational institutions to be active, specific recommended professional skills and knowledge are necessary. Teaching is one main component in educational planning which is a critical factor in conducting educational plans. Secondly, the right teaching method also motivates learners to participate fully in the learning process. In the past years, teachers have used several methods to impact knowledge to students. Which of the methods used is appropriate for teaching Information and Communication Technology in our Senior High Schools. Who qualifies to teach Information and Communication Technology at the Senior High School? The research revealed that a lot of Information and Communication

Source: KNUST
Improved Propagation Models for LTE Path Loss Prediction in Ghana

Long Term Evolution (LTE) Networks offer significant advancement compared with third generation (3G) Networks in the areas of capacity, latency, network complexity and quality of service. To maximize these benefits of LTE cellular networks, careful and proper planning is needed. This requires the use of accurate propagation models to quantify the path loss required for base station (BS) deployment. However deployed LTE networks in Ghana mostly do not offer the desired 100Mbps throughput leading to customer dissatisfaction. This stems from the fact that Network operators rely on transmission planning tools designed for generalized environments, having no detailed knowledge of the Ghanaian environment. These transmission planning tools come with already embedded propagation models for path loss prediction suited to other environments. A challenge therefore to Ghanaian Network operators at the planning stage will be choosing a propagation model that best suits the Ghanaian environment for accurate path loss prediction. Therefore an accurate and precise propagation model reflecting the Ghanaian environment is needed. In view of this, this study considers extensive LTE path loss measurements at 800MHz and 2600MHz taken in selected urban(Adum, Sunyani, Techiman) and suburban(Agogo, Afrancho, New Dorma, Berekum) environments in Ghana. The measured path loss is compared with the corresponding results obtained from six(6) commonly used propagation models: Stanford University Interim model (SUI), Electronic Communication Committee model (ECC-33), Hata model, COST 231 model, Free space path loss model , and the Ericson model. The commonly used industry standard propagation models that best fit measurement data in these Ghanaian environments were then selected. The measured results show that the Ericson model predicts best in urban areas at 800MHz, the SUI model predicts best rather in suburban areas at 800MHz and the ECC 33 model best predicts path loss in urban and suburban areas at 2.6GHz.These models were modified and developed to predict more accurately the path loss in these environments.

Source: KNUST
Improved median filtering algorithm for the reduction of impulse noise in corrupted 2d greyscale images

Digital images are often corrupted by Impulse noise due to errors generated in noisy sensor, errors that occur in the process of converting signals from analog-to-digital and also errors that are generated in the communication channels. This error that occurs inevitably alters some of the pixels intensity while some of the pixels remain unchanged. In order to remove impulse noise and enhance the affected image quality, the median filter has been studied and a method based on an improved median filtering algorithm has been proposed. This method removes or effectively suppresses the impulse noise in the image whiles preserving the image edges information and enhancing the image quality. The proposed method is a spatial domain approach and uses the overlapping window to filter the signal based on the selection of an effective median per window. The approach chosen in this work is based on a functional level 2n +1 window that makes the selection of the normal median easier, since the number of elements in the window is odd. The median so chosen is confirmed as the effective median or, where the median is an impulse a more representative value is sought and used as the effective median. The improved median filtering algorithms uses the median switching technique to compute an effective median when the active median of the window is an impulse. The performance of the proposed effective median filter has been evaluated in MATLAB using a 3 × 3 fixed window for simulations on an image that has been subjected to various degrees of corruption with impulse noise. The results demonstrate the effectiveness of the proposed algorithm vis-à-vis the standard and adaptive median filtering algorithms, and others. The peak signal-to-noise ratios of the filtered image using the various filtering techniques are computed quantitatively, to show the effectiveness and efficiency of the method of this thesis. The peak signal-to-noise ratio has been used to compare the performance of the proposed median filtering algorithm with other digital median filtering algorithms. For example, the improved median filtering algorithm, when applied to the cameraman image after adding 20% impulse noise resulted in a filtered image with a peak signal to noise ratio of 38.0638. Applied to the same corrupted image, the adaptive median filter, the standard median filter, the maximum filter and the minimum filter yielded a filtered image with a peak signal to noise ratio of 33.9901dB, 32.1349dB, 25.9170dB and 30.3778dB, respectively.

Source: KNUST
Improved yam-baobab-tamarind flour blends and its potential use in extrusion cooking

This project was aimed at determining the physicochemical properties of water yam- baobab-tamarind flour composites and its potential use in extrusion cooking. Proximate and mineral composition of Baobab (B), Yam (Y), and Tamarind (T) were determined. Six blends of composite flours in the proportions of 0:0:100, 0:40:60, 40:0:60, 30:10:60, 10:30:60 and 20:20:60 (B: T: Y) were formulated and colour, physicochemical, pasting properties were determined. Two of the flour blends were used as trial samples and extruded at 300 rpm feed speed, temperature of 200°C and screw speed of 1200rpm. Sensory evaluation, physicochemical properties, colour, pasting properties and expansion ratio of the extruded products were assessed. Proximate composition of B, Y and T were comparable to literature, however, the mineral compositions were low. Moisture content, pH, water binding capacity, swelling power and bulk density values obtained were in the range of 3.01-5.61%, 3.90-5.39, 87.50-132.50%, 201.43-237.95% and 0.74-0.93g/ml, respectively for flour blends. Peak, minimum, cooling end, final, breakdown and setback viscosities were in the range of 2.50-291.00bu, 2.20-289.50bu, 11.00- 455.00bu, 10-440bu, 0.00-20.50bu and 69.50-148.00bu respectively. The addition of tamarind and baobab flours improved upon the physicochemical and pasting properties. The flours could be used for drinks, puddings, sauces, ice-creams, pastries and yoghurts depending on the desirable characterictsic of the flour blends. The L*valuesof composite flours was in the range of 84.67-85.49 as compared to water yam flour (100Y) which was 85.73. Generally the l, a, b values for extrudates were lower than the flour composites which resulted in a lower value of hue for extrudates. The bulk density and expansion ratio of extruded snacks were low: the values were 0.24g/cm3 and 0.19g/cm3; 3.45 and 4.15 for E5 (10B:30T: 100Y) and E6 (20B:20T: 60Y) respectively. Sensory evaluation results revealed that panellists preferred extrudates with higher tamarind kernel powder substitution (E5). Generally pasting analysis showed that the extruded composite flours (E6) had low viscosity values. The values were 14.67bu, 5.33bu, 14.33bu, 7.67bu and 8.33bu for peak, minimum, final, breakdown and setback viscoties respectively. This study has revealed that as tamarind and baobab flours were added to yam flour there was improvement in the physicochemical and pasting properties of flour blends as compared to yam flour only. These composite flours can be used in various food applications. It was demonstrated that incorporation of tamarind and baobab into water yam flour for development of low temperature extruded snacks has great potential as a ready to eat snack.

Source: KNUST
Improved Yam-Baobab-Tamarind flour blends: Its potential use in extrusion cooking

This project was aimed at determining the physicochemical properties of water yambaobab-tamarind flour composites and its potential use in extrusion cooking. Proximate and mineral composition of Baobab (B), Yam (Y), and Tamarind (T) were determined. Six blends of composite flours were formulated and colour and physicochemical properties were determined. Two of the flour blends were used as trial samples and extruded. Proximate composition of B, Y and T were comparable to similar literature reports, however, the mineral compositions were low. Moisture content, pH, water binding capacity, swelling power and bulk density values ranged from 3.01-5.61%, 3.90–5.39, 87.50–132.50%, 201.43–237.95% and 0.74–0.93 g/mL, respectively, for the flour blends. Peak, minimum, cooling end, final, breakdown and setback viscosities were in the range of 2.50–291.00bu, 2.20–289.50bu, 11.00- 455.00bu, 10–440bu, 0.00–20.50bu and 69.50–148.00bu, respectively, for flour blends. The addition of tamarind and baobab flours improved the swelling power, water binding capacity and peak viscosity of flour extrudates. Generally the L, a, and b values for extrudates were lower than the flour composites. However, the panelist preferred the appearance. The bulk density and expansion ratio of extruded snacks were low. Generally, panellists preferred extrudates with higher (40%) tamarind kernel powder substitution (E5). The extruded composite flour (E6) had low viscosity values. Incorporation of tamarind and baobab into water yam flour has great potential for development of extruded snacks.

Source: KNUST
Improvement in physical quality of a Sahelian Arenosol and implications on millet yield

Poor soil fertility remains a threat to crop production and livelihoods in the Sahel. Understanding the impacts of proposed soil fertility manage ment technologies on soil fertility status and millet yield is essential. We conducted a 2-year experiment to assess changes in selected physical properties of an Arenosol and their impacts on millet yields at Karabedji, Niger. Treatments consisted of four fertilizer rates applied on top and bottom farm types selected from a long-term experiment. Mixed-model analyses indicated considerable effects (P = 0.055) of fertilizer rates and farm types on soil structural stability being higher in the top farm than in the bottom farm type. Dexter’s soil physical quality index (S) varied significantly with soil depth. A significant correlation (R2 = 0.24) was found between the aggregate stability index and S. Plant available water recorded in fertilizer-treated soil was higher than the control and higher on the top farm than in the bottom farm. Fertilizer rates and farm types influenced millet yields. Moreover, we obtained positive relation ships between millet yield and soil aggregate stability, and plant avail able water, thereby elucidating the significant role played by soil physical properties in influencing crop yields. S can be a simple way for assessing the physical quality of Sahelian sandy soil.

Source: KNUST
Improvement of computer-aided book layout design in book publication in Ghana

Books are the basic sources of knowledge and a storehouse of the world’s knowledge. Owing to this, they remain a vital part in the development of any country. They act as one of the vital tools for the transfer of knowledge. A well laid-out book encourages reading while the opposite may lead to poor reading habit. The development of book layout design has seen growth from hand- composition to computer-aided. The technological age has improved book layout design globally. However, the use of the computer as an aid in book layout design in Ghana is faced with some problems. It is for this reason that this research set out to find some of the flaws that are associated with computer-aided book layout designs produced in the country. The researcher reviewed related literature, identified and discussed some of the flaws existing in Ghanaian Computer-aided book layout design and came out with a User-Guide that could serve as a teaching and learning material. The User-Guide is based on two layout software application packages namely Adobe PageMaker 7 and QuarkXPress 5. This guide is contains relevant basic book layout design principles and conventions and provides step-by-step information for using the software packages for book layout design. Qualitative method was used for this research. The whole study was descriptive using observation and interviewing as instruments for eliciting data. Some of the flaws identified in the study include: rivers of white space, exaggerated tabs and indentation, and use of too many typefaces. It was also observed that many of the flaws identified have come about as a result of the fact that many book designers in Ghana are not professionally trained or lacked the basic understanding of book layout principles and conventions or an understanding of the various software applications. Out of the study, it is recommended that Book Design and Typography (the hallmark of quality book publication), be given serious attention in the various institutions where they are studied to help bring up professionalism in book layout designs in the country.

Source: KNUST
Improvement of quality of cocoa beans (Theobroma cacao) through controlled fermentation

The purpose for which cocoa beans are fermented is to produce beans with good flavour, aroma and taste for making such cocoa products as chocolate, beverages etc. This study was designed to (i) isolate and identify lactic acid bacteria (LABS) from fermenting cocoa which are one of the microorganisms responsible for the fermentation of the beans, (ii) to attempt to modify the fermentation factors using the LABS exclusively in singles and in combination to enhance the efficiency of fermentation so as to improve bean quality. To achieve the above objectives, field and laboratory experiments were carried out. The field experiments sought to monitor the temperature profile, microfloral population of the fermenting cocoa heaps and isolate and identify the lactic acid bacteria present in the three experimental areas. The laboratory experiments were mainly to ferment sterile cocoa using the four different bacterial isolates in singles or in combination at 2.6 x 108 cells of bacterial suspension per kilogram of sterile fresh cocoa beans. In the field, the results indicated that generally there was a significant difference between the mean temperatures of the top and middle of the, heaps, the top having the highest and the bottom having the lowest temperatures. The mean temperatures, of the heap were also seen to increase with time of fermentation. On MRS agar, it was observed that the bacteria increased within 48 hours and then decreased on turning the heap before the organisms increased slightly until the end, of fermentation. On malt extract agar, however, there was a gradual decrease in their numbers until none were observed as the end of the fermentation period. Lactic acid bacteria isolated were of the genera Lactobacillus, Streptococcus, Leuconostoc and Pediococcus. The laboratory experiments produced generally cocoa beans of good quality in terms of pH, moisture content, anthocyanin content and “cut” test results of the fermented and dried cotyledons of the beans. The results suggest that lactic acid bacteria used exclusively in fermentation of cocoa may improve the already good flavour of cocoa and probably come out with new flavours in cocoa depending on the different combinations or single bacteria isolates used. Other microorganisms like yeasts which are also some of the microflora in cocoa fermentation can act with these bacteria metabolites and may bring about changes in the quality of fermented beans. The yeast study is to be verified in a subsequent research.

Source: KNUST
Improvement of naturally-occurring materials for road construction in the Kumasi Metropolis, Ghana

In some parts of Ghana road construction costs could be very high because of the limited opportunity of locating suitable base material within economic haul distances. This study was undertaken to improve sub- standard but abundant naturally - occurring materials within the Kumasi metropolis for use in road construction. Five soils typical of the soils within the Kumasi metropolis (e.g. sandy clayey quartzitic or lateritic gravel, clayey sandy quartzitic or lateritic gravel, micaceous silty sandy gravel, silty sandy gravel, silty gravelly sand) were studied. These were designated MP-l, MP-2, MP-3, MP-4 and MP-5. In their untreated form these soils do not satisfy the specification requirements for use as road base material. Changes in engineering properties due to the stabilisation of these soils with varying proportions of Rock Aggregates, River Gravel, Quarry Dust, lime and the blending of the other soils with MP-3 were investigated. Economic analysis of the use of these stabilisers was also made. The results of these improvement studies indicated the River Gravel to be the most effective in improving the particle size distribution of the soils. The improvement in plasticity of the soils varied with the type and content of stabiliser used. Lime had the most pronounced effect with respect to reducing plasticity; with only 2% lime the plasticity indices were reduced by 48 - 60%. The improvement in strength also varied with the soil type and stabiliser. The proportion of Quarry Dust needed to improve the strengths of the clayey sandy quartzitic gravel (MP-l) and the sandy clayey lateritic gravel (MP-3) to base material quality ranged from 10% to 15% and 20% to 30% respectively. The studies have also shown that the 96 - hour soaked California Bearing Ratio (CBR) value of at least 80% which is required for base material could be achieved for most of the stabilised soils. Rock Aggregates, Quarry Dust and, to a lesser extent, River Gravel were more efficient for strength improvements of all the soils than for the reduction of plasticity. However, lime was more efficient for strength improvements as well as the reduction of plasticity and swell characteristics of all the soils. The amount of lime required to ensure the optimum modification of any of the soils to enhance its workability, lime modification optima, was either higher than or equal to that for strength optimisation. Quarry Dust was the cheapest effective stabiliser while lime was the most expensive. The cost of incorporating 2% lime was generally equivalent to the cost of hauling suitable material from a borrow pit located at almost 10km from the project site. The results of the economic analysis have also shown that, beyond 16km, it would be uneconomical to haul gravel for road construction in the metropolis. Rather, Quarry Dust, River Gravel and Rock Aggregates, should in the decreasing order of preference, be used to stabilise abundant naturally - occurring materials for an economic and durable base course construction.

Source: KNUST