MatematikaPub Date : 2023-04-15DOI: 10.11113/matematika.v39.n1.1447
A. A. Gwani, S. Sek
{"title":"Dynamic modelling of Renewable Energy Consumption and Production on African Economic Growth and the Environment Using Vector Error Correction Models","authors":"A. A. Gwani, S. Sek","doi":"10.11113/matematika.v39.n1.1447","DOIUrl":"https://doi.org/10.11113/matematika.v39.n1.1447","url":null,"abstract":"Prior research has explored the influence of renewable consumption on economic growth and carbon emissions (CO2), but few studies have examined the impact of both renewable energy consumption (REC) and renewable energy production (REP) on economic growth and CO2 emissions in Africa. The objective of this work is to dynamically estimate the effects of both REC and REP on economic growth and CO2 emissions in Africa, based on empirical evidence and using a data set from the years 1965 to 2020. This research aims to determine how REC and REP affect the economies and ecosystems of Africa. The Error Correction Models (ECMs) were utilized in the analysis, focusing on howREP and REC influence economic growth and environmental carbon dioxide emissions (CO2). Vector Error Correction Models (VECM) and Johansen cointegration methods were used on the data set. The results demonstrated that economic forces existed between the variables and that there was a long run equilibrium relationship between GDP and CO2 emissions in Africa, from REC to REP. Additionally, the outcomes showed that both REC and REP slowed down environmental deterioration while promoting economic growth. Africa can lower the negative impacts of environmental pollution caused by the consumption of nonrenewable energy sources by adopting and aggressively promoting renewable energy production and utilization.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46494534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2023-04-15DOI: 10.11113/matematika.v39.n1.1448
Nur Nadiah Mohd Rahan, Nur Nadiah Abd Hamid
{"title":"Besse Extended Cubic B-spline Collocation Method for Solving Benjamin-Bona-Mahony Equation","authors":"Nur Nadiah Mohd Rahan, Nur Nadiah Abd Hamid","doi":"10.11113/matematika.v39.n1.1448","DOIUrl":"https://doi.org/10.11113/matematika.v39.n1.1448","url":null,"abstract":"Extended cubic B-spline collocation method is formulated to solve the Benjamin-Bona-Mahony equation without linearization. The Besse relaxation scheme is applied on the nonlinear terms and therefore transforms the equation into a systemof two linear equations. The time derivative is discretized using Forward Difference Approximation whereas the spatial dimension is approximated using extended cubic B-spline function. Applying the von-Neumann stability analysis, the proposed technique are shown unconditionally stable. Two numerical examples are presented and the results are compared with the exact solutions and recent methods.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48450422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2021-03-27DOI: 10.11113/matematika.v39.n1.1437
M. A. Khan
{"title":"Block Toeplitz Matrices: Multiplicative Properties","authors":"M. A. Khan","doi":"10.11113/matematika.v39.n1.1437","DOIUrl":"https://doi.org/10.11113/matematika.v39.n1.1437","url":null,"abstract":"Given A, B, C, and D, block Toeplitz matrices, we will prove the necessary and sufficient condition for AB - CD = 0, and AB - CD to be a block Toeplitz matrix. In addition, with respect to change of basis, the characterization of normal block Toeplitz matrices with entries from the algebra of diagonal matrices is also obtained.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":"1 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44423167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2020-05-31DOI: 10.29313/jmtm.v19i1.6312
Andi Pujo Rahadi
{"title":"Kendali Mode Luncur Pada Sistem Suspensi Aktif Dengan Simulasi MATLAB","authors":"Andi Pujo Rahadi","doi":"10.29313/jmtm.v19i1.6312","DOIUrl":"https://doi.org/10.29313/jmtm.v19i1.6312","url":null,"abstract":"Sistem suspensi mobil yang terdiri hanya dari pegas dan redaman merupakan sistem pasif sebab tidak menyediakan energi aktif untuk melawan gangguan profil jalan. Untuk mendapatkan kenyamanan dan keamanan berkendara yang lebih baik, ditanamkan sistem suspensi aktif pada mobil. Sistem suspensi aktif dilengkapi sensor dan komponen aktuator gaya yang menyediakan energi aktif dengan skema kendali tertentu. Penelitian ini bertujuan membangun sistem suspensi aktif menggunakan kendali mode luncur ( sliding mode control / SMC ). Simulasi sistem kendali dilakukan menggunakan MATLAB 2014, membandingkan performa sistem pasif, sistem aktif Linear Kuadratik (LQR), dengan sistem aktif Kendali Mode Luncur (SMC). Berdasarkan hasil simulasi, sistem aktif SMC mencapai kondisi stabil lebih cepat dan menggunakan gaya aktif lebih rendah. Dengan demikian, sistem SMC memiliki performa terbaik dibandingkan dengan dua sistem yang lain. Penelitian ini dapat dilanjutkan dengan membangun prototype suspensi dengan sistem kendali SMC. Kata Kunci: Sistem Suspensi Aktif, Kendali Mode Luncur, Simulasi MATLAB .","PeriodicalId":43733,"journal":{"name":"Matematika","volume":"1 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44824867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2020-03-31DOI: 10.11113/matematika.v36.n1.1181
N. Harudin, K. R. Jamaludin, F. Ramlie, M. N. Muhtazaruddin, Che Munira Che Razali, W. Z. A. Wan Muhamad
{"title":"Binary particle swarm optimization for variables selection optimization in Taguchi’s T-Method","authors":"N. Harudin, K. R. Jamaludin, F. Ramlie, M. N. Muhtazaruddin, Che Munira Che Razali, W. Z. A. Wan Muhamad","doi":"10.11113/matematika.v36.n1.1181","DOIUrl":"https://doi.org/10.11113/matematika.v36.n1.1181","url":null,"abstract":"Prediction analysis has drawn significant interest in numerous field. Taguchi’s T-Method is a prediction tool that developed practically but not limited to small sample analysis. It was developed explicitly for multidimensional system prediction by relying on historical data as the baseline model and adapting the signal to noise ratio (SNR) as well as zero proportional concepts in strengthening its robustness. Orthogonal array (OA) in T-Method is a variable selection optimization technique in improving the prediction accuracy as well as help in eliminating variables that may deteriorate the overall performance. However, the limitation of OA in dealing with higher multidimensionality restraint the optimization accuracy. Binary particle swarm optimization used in this study helps to cater to the limitation of OA as well as optimizing the variable selection process to better prediction accuracy. The results show that if the historical data consist of samples with higher correlation of determination (R2) value for the model creation, the optimization process in reducing the number of variables would be much reliable and accurate. Comparing between T-Method+OA and T-Method+BPSO in four different case study, it shows that T-Method+BPSO performing better with greater R2 and means relative error (MRE) value compared to T-Method+OA.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":"1 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63543628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2019-12-31DOI: 10.11113/matematika.v35.n4.1269
A. Abidemi, Rohanin Ahmad, N. Aziz
{"title":"Global Stability and Optimal Control of Dengue with Two Coexisting Virus Serotypes","authors":"A. Abidemi, Rohanin Ahmad, N. Aziz","doi":"10.11113/matematika.v35.n4.1269","DOIUrl":"https://doi.org/10.11113/matematika.v35.n4.1269","url":null,"abstract":"This study presents a two-strain deterministic model which incorporates Dengvaxia vaccine and insecticide (adulticide) control strategies to forecast the dynamics of transmission and control of dengue in Madeira Island if there is a new outbreak with a different virus serotypes after the first outbreak in 2012. We construct suitable Lyapunov functions to investigate the global stability of the disease-free and boundary equilibrium points. Qualitative analysis of the model which incorporates time-varying controls with the specific goal of minimizing dengue disease transmission and the costs related to the control implementation by employing the optimal control theory is carried out. Three strategies, namely the use of Dengvaxia vaccine only, application of adulticide only, and the combination of Dengvaxia vaccine and adulticide are considered for the controls implementation. The necessary conditions are derived for the optimal control of dengue. We examine the impacts of the control strategies on the dynamics of infected humans and mosquito population by simulating the optimality system. The disease-freeequilibrium is found to be globally asymptotically stable whenever the basic reproduction numbers associated with virus serotypes 1 and j (j 2 {2, 3, 4}), respectively, satisfy R01,R0j 1, and the boundary equilibrium is globally asymptotically stable when the related R0i (i = 1, j) is above one. It is shown that the strategy based on the combination of Dengvaxia vaccine and adulticide helps in an effective control of dengue spread in the Island.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44642929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2019-12-31DOI: 10.11113/matematika.v35.n4.1265
Khang Yi Sim, S. Sek
{"title":"Distinguishing the Effect of Oil Shocks on the Global Economy: A Threshold Regression Approach","authors":"Khang Yi Sim, S. Sek","doi":"10.11113/matematika.v35.n4.1265","DOIUrl":"https://doi.org/10.11113/matematika.v35.n4.1265","url":null,"abstract":"The effect of oil shock on the global economy is evident through many studies. However, the effect is heterogeneous over time. One of the reasons that lead to such different impacts is due to the oil source that is either the oil shock is demand or supply-driven. Applying the structural vector autoregressive (SVAR) model to generate the three oil shocks based on the three oil sources (oil supply, oil demand and oil specific-demand), we extended the examination on the effect of oil shock on the global economy using the threshold regression. Our results reveal the threshold effects of oil directly and indirectly on the global economy. The impacts of oil shocks differ across sectors, implying oil intensity, as well as oil sources, are the factors that determine the impact of oil shocks on the global economy. Overall, the oil specific-demand shock is more influential among the three oil shocks. Hence, the global economy is oil demand-driven. Besides that, the impact of oil is relatively large in the energy sector when compared to the non-energysector and precious metals industry. Despite that, the impact of oil shocks is small if compared to the non-oil shocks such as exchange rate changes and global consumer price inflation shock. Consequently, non-oil shocks are the main determinants of the global economic fluctuation. The study leads to a better understanding of the transmission of oil shock and its sources, the interaction between oil and economic indicators and the policy implication due to oil dependency/ intensity.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42391866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2019-12-01DOI: 10.11113/matematika.v35.n3.1105
Muhammad Fadhil Marsani, A. Shabri
{"title":"Random Walk Behaviour of Malaysia Share Return in Different Economic Circumstance","authors":"Muhammad Fadhil Marsani, A. Shabri","doi":"10.11113/matematika.v35.n3.1105","DOIUrl":"https://doi.org/10.11113/matematika.v35.n3.1105","url":null,"abstract":"This journal renders the random walk behaviour of the Malaysian daily share return, through tests of efficient market hypothesis (EMH) based on three different financial periods, namely growth, financial crisis, and recovery period. This review also covers the behaviour of extreme return for weekly and monthly series generated from Block maxima-minima method. Autocorrelation Function test (ACF) and Ljung-Box test had been employed to measure average correlation between observations, while Augmented Dickey-Fuller (ADF), Phillips-Perron (PP), Kwiatkowski Phillips Schmidt Shin (KPSS) test had been used to scan the unit root and the stationarity. Multiple variance ratio tests had also been conducted to examine the random walk behaviour. Serial correlation test indicated that the movement of daily return during the financial crisis period was weak-form efficiency. The unit root and stationary tests suggested that each daily series was stationary, but trend stationary for extreme cases. Variance ratio tests indicated that the return during the recovery period was weak-form inefficiency due to the short lag autocorrelation in series.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41581410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2019-11-30DOI: 10.29313/jmtm.v18i2.5138
R. F. Suwarman
{"title":"Real Option Valuation with Stochastic Interest Rate and Stochastic Volatility","authors":"R. F. Suwarman","doi":"10.29313/jmtm.v18i2.5138","DOIUrl":"https://doi.org/10.29313/jmtm.v18i2.5138","url":null,"abstract":"Abstract. Real options are one of the most interesting research topics in Finance since 1977 Stewart C. Myers from MIT Sloan School of Management published his pioneering article on this subject in the Journal of Financial Economics. Real options are techniques for supporting capital budgeting decisions that adapt techniques developed for financial securities options. The purpose of using this real option is to capture the options contained in projects that cannot be captured by the discounted cash flow model which operates as a basic framework for almost all financial analyzes. The process of valuing real options will be complemented by the stochastic interest rate and stochastic volatility to better capture the flexibility and volatility of the existing economic and financial situation. The valuation will use a Monte Carlo simulation with the MATLAB programming language on crude oil data from the North Sea oil field. Data were obtained from the thesis of Charlie Grafström and Leo Lundquist with the title \"Real Option Valuation vs. DCF Evaluation – An Application to a North Sea oilfield\".Keyword: real options, stochastic interest rate model, stochastic volatility model, simulation","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43357937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MatematikaPub Date : 2019-07-31DOI: 10.11113/MATEMATIKA.V35.N2.1108
Nurul Izzaty Ismail, Fong Wan Heng, N. Sarmin
{"title":"DNA Splicing Systems with at Most Two Cutting Sites of a Non-Palindromic Restriction Enzyme","authors":"Nurul Izzaty Ismail, Fong Wan Heng, N. Sarmin","doi":"10.11113/MATEMATIKA.V35.N2.1108","DOIUrl":"https://doi.org/10.11113/MATEMATIKA.V35.N2.1108","url":null,"abstract":"The modelling of splicing systems is simulated by the process of cleaving and recombining DNA molecules with the presence of a ligase and restriction enzymes which are biologically called as endodeoxyribonucleases. The molecules resulting from DNA splicing systems are known as splicing languages. Palindrome is a sequence of strings that reads the same forward and backward. Research on generalisations of splicing languages in DNA splicing system involving palindromic sequences for restriction enzymes has been done previously. In this research, the splicing languages resulting from DNA splicing systems with one non-palindromic restriction enzyme are determined using the notation from Head splicing system. The generalisations of splicing languages for DNA splicing systems involving one and two non-overlapping cutting sites of one non-palindromic restriction enzyme are presented in the first and second theorems, respectively, which are proved using direct and induction methods. The result from the first theorem shows a trivial string which is the initial DNA molecule; while the second theorem determines a splicing language consisting of a set of resulting DNA molecules from the respective DNA splicing system.","PeriodicalId":43733,"journal":{"name":"Matematika","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43236392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}