M.G.M. Khan

University of the South Pacific | USP · School of Information Technology Engineering Mathematics & Physics

Numerous optimization problems arise in survey designs. The problem of obtaining an optimal (or near optimal) sampling design can be formulated and solved as a mathematical programming problem. In multivariate stratified sample surveys usually it is not possible to use the individual optimum allocations for sample sizes to various strata for one re...

In a multivariate stratified sample survey with L strata and p > 1 characteristics, defined on each unit of the population, let the estimation of all the p-population means be of interest. As discussed by Cochran (1977), since the optimum allocation for one characteristic will not in general be optimum for other characteristics some compromise must...

In this paper, two problems of optimal resource allocation to modules during testing phase are studied: (1) maximization of the number of faults removed when the amount of testing-effort is fixed, and (2) maximization of the number of faults removed satisfying a certain percentage of initial faults to be removed with a fixed amount of testing-effor...

Recently, there has been a shift in the global energy landscape to move to reliable, clean, and eco-friendly renewable energy sources to address global issues such as climate change and greenhouse gas emissions. One such energy source is wave energy; researchers attempt to develop models that can accurately forecast the availability of wave energy...

Analysis of wind characteristics and assessment of wind energy resource is carried out at a location in Tonga with the help of twelve months of measurements carried out at 34 m and 20 m heights above ground level. The daily, monthly and annual averages are computed. The wind shear analysis and its diurnal variation were studied and compared with th...

Introduction The COVID-19 pandemic has had a significant impact on mental health globally. To understand the impact of the pandemic on mental health in Fiji, this study aimed to investigate the prevalence of anxiety disorder and depression among the young adults. Method An online survey was conducted to assess the prevalence of anxiety disorder an...

This study applies a popular data mining algorithm, as a branch of Artificial Intelligence (AI), to investigate the characteristics that influence the adoption of Enterprise Resource Planning (ERP) systems within SMEs in Fiji. A logistic regression classifier is utilised to identify the key determinants that contribute to the adoption of ERP system...

For maximum precision in population parameter estimation under the Stratified sampling design, the optimum strata boundaries (OSB) could be constructed based on a continuous study variable rather than a set of categorical variables. If constructed optimally, the OSB results in homogenous units within each stratum leading to optimal stratum sample s...

The two-parameter Weibull distribution has garnered much attention in the assessment of wind energy potential. The estimation of the shape and scale parameters of the distribution has brought forth a successful tool for the wind energy industry. However, it may be inappropriate to use the two-parameter Weibull distribution to assess energy at every...

Though natural resources are abundantly available for utilization of renewable energy sources, many Pacific Island countries continue to rely on fossil fuels. The use of fossil fuels is known to significantly contribute to climate change. Heavy reliance on fossil fuels also hinders the economic development of most of the Pacific Island Countries. T...

Generation of quality data to aid planning, assessing the education performance, monitoring programs implementation and learning outcomes are the basic functions of the Education Management Information System (EMIS). This study examines the existing EMIS in the Pacific Island Countries PICs and proffers solution. A SWOT analysis on the selected PIC...

The two-parameter Weibull distribution has garnered much attention in the assessment of wind energy potential. The estimation of the shape and scale parameters of the distribution has brought forth a successful tool for the wind energy industry. However, it may be inappropriate to use the two-parameter Weibull distribution to assess energy at every...

The emergence and advancement of Information Communication Technologies have transformed facilitation and content delivery in higher education worldwide, the Pacific region being no exception. The extensive use of mobile phones in the Pacific, especially with the student-aged populace, is gradually creating a niche for mobile learning in the educat...

Wind energy resource assessments at two islands in the Cook Islands are carried out in the present work. The wind data were collected for one year from sites on Mauke and Rarotonga Islands in the Cook Islands and the daily, monthly and seasonal average wind speeds, the diurnal variations of the wind shear coef cient, average temperature and turbule...

The development of cyber-attacks carried out with ransomware has become increasingly refined in practically all systems. Attacks with pioneering ransomware have the best complexities, which makes them considerably harder to identify. The radical ransomware can obfuscate much of these traces through mechanisms, such as metamorphic engines. Therefore...

Cluster analysis of real-life data often encounters the challenges of noisy data or may rely heavily on the uncertainty of the main clustering variable owing to its stochastic nature, which has a potential influence on its performance. In this study, we propose a novel clustering technique that is efficient in dealing with noise and uncertainty in...

Fiji needs to invest in renewable energy sources to meet its energy needs to reduce the country’s dependence on imported fossil fuels. For investing in wind energy projects, a detailed assessment of wind energy resource is required. In this work, wind speeds were measured at 34 m and 20 m above ground level at a site in Suva for three years and the...

The development of cyber-attacks carried out with ransomware has become increasingly refined in practically all systems. Attacks with pioneering ransomware have the best complexities, which makes them considerably harder to identify. The radical ransomware can obfuscate much of these traces through mechanisms, such as metamorphic engines. Therefore...

With the rapid advancements in information technology, data security has become an indispensable component. Cryptography performs a significant role in establishing information security. Computational problems have been utilized extensively by cryptographers to construct digital signature schemes. Digital signature schemes offer security services s...

As with other Pacific Island nations, the scientific efforts of the Kingdom of Tonga have been hampered through a lack of local scientists and science graduates. As observed globally, the region appears to face a steady decline in student interest and achievement in science, resulting in reduced uptake of science subjects in schools and universitie...

The two-parameter Weibull distribution has garnered much attention in the assessment of wind energy potential. The estimation of the shape and scale parameters of the distribution has brought forth a successful tool for the wind energy industry. However, it may be inappropriate to use the two-parameter Weibull distribution to accurately characteriz...

The two-parameter Weibull distribution has garnered much attention in the assessment of wind energy potential. The estimation of the shape and scale parameters of the distribution has brought forth a successful tool for the wind energy industry. However, it may be inappropriate to use the two-parameter Weibull distribution to assess energy at every...

The two-parameter Weibull distribution has garnered much attention in the assessment of wind energy potential. The estimation of the shape and scale parameters of the distribution has brought forth a successful tool for the wind energy industry. However, it may be inappropriate to use the two-parameter Weibull distribution to assess energy at every...

The two-parameter Weibull distribution has garnered much attention in the assessment of wind energy potential. The estimation of the shape and scale parameters of the distribution has brought forth a successful tool for the wind energy industry. However, it may be inappropriate to use the two-parameter Weibull distribution to assess energy at every...

The development of cyber-attacks carried out with ransomware has become increasingly refined in practically all systems. Attacks with pioneering ransomware have the best complexities, which makes them considerably harder to identify. The radical ransomware can obfuscate much of these traces through mechanisms, such as metamorphic engines. Therefore...

There has been an increase in the capitalization of renewable energy resources to provide greenhouse gas emission-free sources of electricity in order to lessen the effect on climate change. This increase is due to trepidations about climate change, an increase in the energy demand and unpredictability of the prices and supply of fossil fuels. Wind...

In order to investigate gender and ethnicity-based differences in scientific attitudes among Fijian students, the widely studied Test of Scientific Related Attitudes (TOSRA) was administered to 1401 senior secondary Fijian students (Years 11–13; approximately 15–18 years of age). Students generally had a positive attitude towards science overall in...

We propose a classification model with various machine learning algorithms to adequately recognise malware files and clean (not malware-affected) files with an objective to minimise the number of false positives. Malware anomaly detection systems are the system security component that monitors network and framework activities for malicious movement...

Wind resource assessments are carried out for two sites in Tuvalu: Funafuti and Nukufetau. The wind speeds at 34 and 20 m above ground level were recorded for approximately 12 months and analyzed. The averages of each site are computed as the overall, daily, monthly, annual, and seasonal averages. The overall average wind speeds for Funafuti and Nu...

This R package determines optimal stratification of univariate populations under stratified sampling designs using a parametric-based method. It determines the optimum strata boundaries (OSB), optimum sample sizes (OSS) and multiple other quantities for the study variable, y, using the best-fit probability density function of a study variable avail...

Overrecentyears,watersinandaroundFijihasincreasinglysuccumbedtoareasonablelevel of contamination. Water quality is defined with set of standards that clearly state the parameters of different properties in water. These standards are different at various geographic locations. The specific quantitative values of these parameters for the Fiji Islands are...

Wind energy resource assessment for two sites, Fakaofo and Atafu, in Tokelau is carried out with the help of a detailed statistical analysis of one year of measured wind data. The average wind speeds recorded for the sites were 3.81 m/s and 3.92 m/s for the Fakaofo and Atafu sites respectively at 34 m above ground level (AGL). The turbulence intens...

Wind energy resource assessments for Pentecost Island and Epi Island in Vanuatu were carried out using one year of wind data. The wind data were used to calculate the daily average wind speed, diurnal variation of wind speed and monthly average wind speed. The diurnal variation of wind shear coefficient of the site was also studied and it correlate...

Wind resource assessment is carried out for a site in Kadavu, Fiji Islands. This included estimating the Weibull parameters and wind power density using ten different methods and carrying out an economic analysis. The wind speeds at 34 m and 20 m above ground level, wind direction, atmospheric pressure and temperature were measured for 18 months an...

Past climatological studies use only one or two local stations to describe the full climate of Solomon Islands. In this paper, we examined all available daily minimum and maximum surface air temperature data between 1951 and 2011 for all seven weather stations operated by the Solomon Islands Meteorological Service. Taro has the highest mean tempera...

Literature contains over fifty years of accumulated methods proposed by researchers for predicting the secondary structures of proteins in silico. A large part of this collection is comprised of artificial neural network-based approaches, a field of artificial intelligence and machine learning that is gaining increasing popularity in various applic...

The use of neural network models for currency exchange rate forecasting has received much attention in recent time. In this paper, we propose an exchange rate forecasting model based on artificial neural network. We tested our model on forecasting the exchange rate of Solomon Islands Dollar against some major trading currencies of the country such...

This article presents a problem of determining optimum cluster size and sampling units in multivariate surveys. When a cluster sampling design is to be used and more than one characteristic is under study, it is usually not advisable to use the individual optimum cluster size and sampling unit for one reason or the other. In such situations, some c...

Wind resource assessment is carried out for Suva, the capital of the Republic of Fiji Islands. The wind speeds at 34 m and 20 m above ground level (AGL), wind direction, atmospheric pressure and temperature were measured for more than five years and statistically analyzed. The daily, monthly, yearly and seasonal averages were estimated. For the sit...

Wind resource assessment is carried out for Suva, the capital of the Republic of Fiji Islands. The wind speeds at 34 m and 20 m above ground level, wind direction, atmospheric pressure, and temperature were measured for more than five years and were statistically analyzed. The daily, monthly, yearly, and seasonal averages were estimated. For the si...

Nuclear Magnetic Resonance Spectroscopy (most commonly known as NMR Spectroscopy) is used to generate approximate and partial distances between pairs of atoms of the native structure of a protein. To predict protein structure from these partial distances by solving the Euclidean distance geometry problem from the partial distances obtained from NMR...

Sampling has evolved into a universally accepted approach for gathering information and data mining as it is widely accepted that a reasonably modest-sized sample can sufficiently characterize a much larger population. In stratified sampling designs, the whole population is divided into homogeneous strata in order to achieve higher precision in the...

There is an increase in demand for renewable sources of energy due to apprehensions about climate change, increase in the energy demand and unpredictability of the prices and supply of fossil fuels. Wind energy is one of the world's fastest growing sources of energy. As a result of the stochastic behavior of wind, the demand for accurate wind forec...

Wind speeds during the tropical cyclones that affected Suva, Fiji, during the last six cyclone seasons are statistically analysed. Since 2012, there were at least 13 cyclones that affected Suva. The wind data were recorded for the six cyclones seasons from October 2012 to April 2018. NRG#40C cup anemometers with a data-logger were used to record th...

We consider a problem of allocation of a sample in two- and three-stage sampling. We seek allocation which is both multi-domain and population efficient. Choudhry et al. (Survey Methods 38(1):23–29, 2012) recently considered such problem for one-stage stratified simple random sampling without replacement in domains. Their approach was through minim...

Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves hi...

Wind energy resource assessments at two locations in Kiribati are carried out. The wind resource on the main atoll of Tarawa is analysed along with a nearby atoll Abaiang. Measurements of wind speed, direction, ambient temperature and pressure were performed and analysed. The Tarawa site has an average wind speed of 5.355 m/s at 34 m above ground l...

We have tested the purchase power parity hypothesis using the consumer price index of USA and UK against Solomon Islands for the sample monthly period from January 1993 to December 2013. This paper uses cointegration and the error correction as methodologies as the data are found to be non-stationary. The result shows that the changes in Solomon Do...

The Sugar Research Institute of Fiji breeds and produces new varieties of sugarcane for the Fiji sugar industry for commercial production. The development of sugar cane varieties that show superior performance in different environments is a major challenge for breeders due to the response of genotypes across environments. This study was to evaluate...

The emergence and advancement of Information Communication Technologies have transformed facilitation and content delivery in higher education worldwide. The Pacific region is no exception, the most commonly owned used tool amongst the people are the mobile phones. The extensive use of mobile phones in the Pacific is making a niche of its own in th...

In most surveys, the target variables (items of interest) commonly resemble right-skewed distributions where the Stratified Random Sampling technique is used as a method of sampling and estimation. The methodology of constructing strata is called stratification. Over a particular characteristic chosen as the stratification variable (such as gender,...

It is quite natural to produce reliable software systems since the breakdown of the computer systems, which is caused by software faults, results in a tremendous loss and damage for social life. Hence, software reliability is a key factor in software development process. Testing phase of software begins with module testing whereby, modules are test...

With continual changes made and reviews of the exchange rate regime of Solomon Islands it is imperative that a proper forecasting modelling tool is established. The use of neural network models in exchange rate forecasting has received much attention in recent research. In this paper we propose an artificial neural network (ANN) model for forecasti...

Because emigration plays a major role in the national demographic structure, it is vital that some model be identified to forecast population by identifying prevailing emigration trends, apart from other contributing factors. The choice of which model to use depends on which ones incur minimal errors in the forecasting process. This paper proposes...

The present investigation was conducted to identify the stable cultivars across different environmental condition. Seventeen genotypes of which fourteen were in the final stage of multi-location secondary adaptation trials of the plant breeding program and three commercial varieties were evaluated in five different locations. The stability paramete...

Calibration estimator uses calibrated weights that minimize a given distance measure to the design weights while satisfying a set of constraints based on the known auxiliary information such as population total (or mean). In this paper, we propose an improved multivariate calibration estimator of population mean in stratified sampling design. The p...

When a cluster sampling design is to be used and more than one characteristic are under study, usually it is not possible to use the individual optimum cluster size and sampling unit for one reason or the other. In such situations some criterion is needed to work out an acceptable cluster size and sampling unit which are optimum for all characteris...

Reliability is a major concern in the process of software development because unreliable software can cause failure in the computer system that can be hazardous. A way to enhance the reliability of software is to detect and remove the faults during the testing phase, which begins with module testing wherein modules are tested independently to remov...

In most economic and business surveys, the target variables (e.g. turnover of enterprises, income of households, etc.) commonly resemble skewed distributions with many small and few large units. In such surveys, if a stratified sampling technique is used as a method of sampling and estimation, the convenient way of stratification such as the use of...

Stratified Sampling is one of the most widely used sampling techniques as it increases the precision of the estimate of the survey variable. On the other hand, calibration estimation is a method of adjusting the original design weights to improve survey estimates by using auxiliary information such as the known population total (or mean) of the aux...

The paper compares Artificial Neural Network (ANN) model against traditional models in the modeling of population and external migration for Fiji population components during the years from 1986 to 2012. The performance of the various models used are based on the values of the various error functions such as the R-squared (R2), Root Square Mean Err...

In this paper we propose an Artificial Neural Network model for forecasting exchange rate of Kina against AUD. We use daily exchange rate data during the period of 2 January 2008 to 30 November 2012. The proposed model is compared with autoregressive time series model, exponential smoothing with trend; and Holt-Winter multiplicative and adaptive mo...

The aim of survey design is to obtain optimum precision at minimum cost. Stratification is one of the commonly used methods of survey design. When using stratification one of the main problems to consider is the determination of optimum strata boundaries. This paper will discuss how to determine the optimum strata boundaries when the measurement co...

IN most surveys, the target variables (items of interest) commonly resemble right-skewed distributions where the Stratified Random Sampling technique is used as a method of sampling and estimation. The methodology of constructing strata is called stratification. Over a particular characteristic chosen as the stratification variable (such as gender,...

The method of choosing the best boundaries that make strata internally homogenous as far as possible is known as optimum stratification. To achieve this, the strata should be constructed in such a way that the strata variances for the characteristic under study be as small as possible. If the frequency distribution of the study variable x is known,...