Browsing by Author "Ibrahim R.I."
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Publication Analysis of mortality trends by specific ethnic groups and age groups in Malaysia(American Institute of Physics Inc., 2014) ;Ibrahim R.I. ;Siri Z. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)University of Malaya (UM)The number of people surviving until old age has been increasing worldwide. Reduction in fertility and mortality have resulted in increasing survival of populations to later life. This study examines the mortality trends among the three main ethnic groups in Malaysia, namely; the Malays, Chinese and Indians for four important age groups (adolescents, adults, middle age and elderly) for both gender. Since the data on mortality rates in Malaysia is only available in age groups such as 1-5, 5-9, 10-14, 15-19 and so on, hence some distribution or interpolation method was essential to expand it to the individual ages. In the study, the Heligman and Pollard model will be used to expand the mortality rates from the age groups to the individual ages. It was found that decreasing trend in all age groups and ethnic groups. Female mortality is significantly lower than male mortality, and the difference may be increasing. Also the mortality rates for females are different than that for males in all ethnic groups, and the difference is generally increasing until it reaches its peak at the oldest age category. Due to the decreasing trend of mortality rates, the government needs to plan for health program to support more elderly people in the coming years. � 2014 AIP Publishing LLC. - Some of the metrics are blocked by yourconsent settings
Publication Bachok-Hasham polynomials for solving a special class of singular integral equations(American Institute of Physics Inc., 2018) ;Eshkuvatov Z. ;Alhawamda H. ;Taib B.M. ;Ibrahim R.I. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)In this note, we propose a new class of orthogonal polynomials (named Bachok-Hasham polynomials of the first and second kind for order k, denote it as Z(i,n)k(x), i={ 1,2 }, which is extension of the Chebyshev polynomials of the first and second kind respectively. It is found that Bachok - Hasham polynomials of first and second kind Z(i,n)k(x) are orthogonal with respect to weights w(1,k)(x)=xk-11-x2k, w(2,k)(x)=xk-11-x2k on the interval [-1,1], where k is positive odd integers. Spectral properties Bachok - Hasham polynomials of the first and second kind Z(i,n)k(x),i={ 1,2 } are proved. These properties are used to solve a special class of singular integral equations. Finally, numerical examples and comparison results with other methods are provided to illustrate the effectiveness and accuracy of the proposed method. � 2018 Author(s). - Some of the metrics are blocked by yourconsent settings
Publication Butterfly effect in porous Bénard convection heated from below(American Institute of Physics Inc., 2014) ;Siri Z. ;Liew K.Y. ;Ibrahim R.I. ;Faculty of Science and Technology ;University of Malaya (UM)Universiti Sains Islam Malaysia (USIM)Transition from steady to chaos for the onset of Bénard convection in porous medium was analyzed. The governing equation is reduced to ordinary differential equation and solved using built in MATLAB ODE45. The transition from steady to chaos take over from a limit cycle followed by homoclinic explosion. - Some of the metrics are blocked by yourconsent settings
Publication A comparison among two composite models (without regression processing) and (with regression processing), applied on Malaysian imports(Hikari Ltd., 2015) ;Milad M.A.H. ;Ibrahim R.I. ;Marappan S. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)The current paper reports an empirical study on the use of a composite model for developing a statistical model to predict the value of imports of the crude material in Malaysia. It is a combination of both regression and autocorrelation integrated moving average (ARIMA) models to produce a better forecast. The study reported in this paper mainly aimed at comparing the two composite models: the first model (Without Regression Processing) and the second model (With Regression Processing). The initialization set of the data has 91 data points, starting from first quarter 1991 to third quarter 2013. The general steps followed in comparing the two models were test significance of parameters and the minimum value of the statistical measure of forecast error (Thiel Coefficient) of its forecasting power. The results showed the composite model (With Regression Processing) had better significant and a lower percentage of U-statistics. This implies that the model had a substantially better fit. � 2015 Mohamed A. H. Milad et al. - Some of the metrics are blocked by yourconsent settings
Publication Comparison of three methods for estimating complete life tables(2013) ;Ibrahim R.I. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)A question of interest in the demographic and actuarial fields is the estimation of the complete sets of qx values when the data are given in age groups. When the complete life tables are not available, estimating it from abridged life tables is necessary. Three methods such as King's Osculatory Interpolation, Six-point Lagrangian Interpolation and Heligman-Pollard Model are compared using data on abridged life tables for Malaysian population. Each of these methods considered was applied on the abridged data sets to estimate the complete sets of qx values. Then, the estimated complete sets of qx values were used to produce the estimated abridged ones by each of the three methods. The results were then compared with the actual values published in the abridged life tables. Among the three methods, the Six-point Lagrangian Interpolation method produces the best estimates of complete life tables from five-year abridged life tables. � 2013 AIP Publishing LLC. - Some of the metrics are blocked by yourconsent settings
Publication Composite model approach for forecasting malaysian imports of machinery and transport equipments: A comparative study(Pushpa Publishing House, 2017) ;Milad M.A.H. ;Ibrahim R.I.Marappan S.Imports are regarded as an important factor in contributing to the economic growth. Specifically, this study proposes a composite model for predicting the future imports of machinery and transport equipments in the Malaysian context. In this study, a proposed composite model (with regression processing of autocorrelation) was employed for extracting information that increases the accurate prediction of the size of future imports as well as enhances forecasting methods in Malaysia and compares with commonly used methods including regression method, ARIMA models, composite model (without regression processing), and simple seasonal exponential smoothing model. The forecasting results of this study reveal that the proposed composite model (with regression processing of autocorrelation) offers more probabilistic information that improves the forecasting of Malaysian imports of machinery and transport equipment than other models. The proposed model offers a good solution to the problem of autocorrelation in residuals. The emerging problem cannot be processed in the regression model; it can be processed only through the composite model (without regression processing). � 2017 Pushpa Publishing House, Allahabad, India. - Some of the metrics are blocked by yourconsent settings
Publication Empirical Study on Impact of Demographic and Economic Changes on Pension Cost(American Institute of Physics Inc., 2014) ;Yusof S. ;Ibrahim R.I. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)A continuation of the same financial standard of living after retirement as before is very importance to retired person. The pension provider has a responsibility to ensure their employees receive the sufficient benefit after retirement and regularly monitor the factors that cause insufficient funds to pay benefit to retirees. Insufficient funds may be due to increased in pension cost. Some of the factors that increase the cost of pensions are changes in mortality rates and interest rates. This study will used these two factors to determine their sensitivity to pension cost. Two methods which are Accrued Benefit Cost Method and Projected Benefit Cost Method will be used to estimate pension cost. Interest rates has a inversely related to pension cost while mortality rates has a directly related to pension cost. � 2014 AIP Publishing LLC. - Some of the metrics are blocked by yourconsent settings
Publication Extended Chebyshev polynomials for solving bounded and unbounded singular integral equations(Institute of Physics Publishing, 2019) ;Alhawamda H. ;Eshkuvatov Z.K. ;Taib B.M. ;Ibrahim R.I. ;Faculty of Science and Technology ;Ministry Deputy of Planning and DevelopmentUniversiti Sains Islam Malaysia (USIM)In this note, we have developed new classes of one dimensional orthogonal polynomials Zk(i,n)(x),i = {1,2},n = 0,1,2,..., namely extended Chebyshev polynomials (ECPs) of the first and second kinds, which are an extension of the Chebyshev polynomials of the first and second kinds respectively. For non-homogeneous SIEs (bounded and unbounded case) truncated series of the first and second kind of ECPs are used to find approximate solution. It is found that first and second kinds of ECPs Zk(in)(x),i = {1,2} are orthogonal with weights w(1,k)(x)= xk-1/1-x2k and w(2,k)(x) = xk-11-x2k, where k is positive odd integer. Spectral properties of first and second kind of ECPs are also proved. Finally, two examples are presented to show the validity and accuracy of the proposed method. - Some of the metrics are blocked by yourconsent settings
Publication Forecasting the mortality rates of Malaysian population using Heligman-Pollard model(American Institute of Physics Inc., 2017) ;Ibrahim R.I. ;Mohd R. ;Ngataman N. ;Abrisam W.N.A.W.M. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)Actuaries, demographers and other professionals have always been aware of the critical importance of mortality forecasting due to declining trend of mortality and continuous increases in life expectancy. Heligman-Pollard model was introduced in 1980 and has been widely used by researchers in modelling and forecasting future mortality. This paper aims to estimate an eight-parameter model based on Heligman and Pollard's law of mortality. Since the model involves nonlinear equations that are explicitly difficult to solve, the Matrix Laboratory Version 7.0 (MATLAB 7.0) software will be used in order to estimate the parameters. Statistical Package for the Social Sciences (SPSS) will be applied to forecast all the parameters according to Autoregressive Integrated Moving Average (ARIMA). The empirical data sets of Malaysian population for period of 1981 to 2015 for both genders will be considered, which the period of 1981 to 2010 will be used as "training set" and the period of 2011 to 2015 as "testing set". In order to investigate the accuracy of the estimation, the forecast results will be compared against actual data of mortality rates. The result shows that Heligman-Pollard model fit well for male population at all ages while the model seems to underestimate the mortality rates for female population at the older ages. � 2017 Author(s). - Some of the metrics are blocked by yourconsent settings
Publication Forecasting the mortality rates using Lee-Carter model and Heligman-Pollard model(Institute of Physics Publishing, 2017) ;Ibrahim R.I. ;Ngataman N. ;Wan Mohd Abrisam W.N.A. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)Improvement in life expectancies has driven further declines in mortality. The sustained reduction in mortality rates and its systematic underestimation has been attracting the significant interest of researchers in recent years because of its potential impact on population size and structure, social security systems, and (from an actuarial perspective) the life insurance and pensions industry worldwide. Among all forecasting methods, the Lee-Carter model has been widely accepted by the actuarial community and Heligman-Pollard model has been widely used by researchers in modelling and forecasting future mortality. Therefore, this paper only focuses on Lee-Carter model and Heligman-Pollard model. The main objective of this paper is to investigate how accurately these two models will perform using Malaysian data. Since these models involves nonlinear equations that are explicitly difficult to solve, the Matrix Laboratory Version 8.0 (MATLAB 8.0) software will be used to estimate the parameters of the models. Autoregressive Integrated Moving Average (ARIMA) procedure is applied to acquire the forecasted parameters for both models as the forecasted mortality rates are obtained by using all the values of forecasted parameters. To investigate the accuracy of the estimation, the forecasted results will be compared against actual data of mortality rates. The results indicate that both models provide better results for male population. However, for the elderly female population, Heligman-Pollard model seems to underestimate to the mortality rates while Lee-Carter model seems to overestimate to the mortality rates. � Published under licence by IOP Publishing Ltd. - Some of the metrics are blocked by yourconsent settings
Publication Generalized fuzzy soft expert set(2012) ;Hazaymeh A.A. ;Abdullah I.B. ;Balkhi Z.T. ;Ibrahim R.I. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)In 2011 Alkhazaleh and Salleh defined the concept of soft expert sets where the user can know the opinion of all the experts in one model and give an application of this concept in decision-making problems. Also, they introduced the concept of the fuzzy soft expert set as a combination between the soft expert set and the fuzzy set. In 2010 Majumdar and Samanta presented the concept of a generalized fuzzy soft sets. The purpose of this paper is to combine the work of Alkhazaleh and Salleh (2011) and Majumdar and Samanta (2010), from which we can obtain a new concept: generalized fuzzy soft expert sets (GFSESs). We also introduce its operations, namely, complement, union intersection, "AND" and "OR", and study their properties. The generalized fuzzy soft expert sets are used to analyze a decision-making problem. Also in our model the user can know the opinion of all experts in one model. In this work we also introduce the concept of a generalized fuzzy soft expert sets with multiopinions (four opinions), which will be more effective and useful. Finally, we give an application of this concept in decision-making problem. Copyright � 2012 Ayman A. Hazaymeh et al. - Some of the metrics are blocked by yourconsent settings
Publication Impact of increasing retirement age on longevity factor: An empirical study for government pensioners in Malaysia(Penerbit Universiti Kebangsaan Malaysia, 2012) ;Ibrahim R.I. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)Most contemporary research indicates that life expectancy in most countries is increasing. Since average life expectancy tends to increase over time for males and females, mortality risks tends to be smaller over time. Therefore, it is expected that pensioners will tend to live longer and cause an increase in pension liabilities to the government in the future. The government is looking for solutions to decrease the effects of increased longevity on pension costs. The most common changes recommended are to equalize the retirement age for males and females; and to increase the age of retirement. Since pensions are paid for the rest of pensioner's life; and to the spouse and child of the pensioner (if any) in the form of a derivative pension in the event of the death of the pensioner, the longevity factor can be considered as an important element when constructing an effective Government Pension Scheme. This paper estimates the longevity factor for case of government pensioners who survives and also dies at the particular age of retiement; and examines the impact of increasing retirement age on longevity factor. Based upon the findings, the overall longevity factors for a government pensioner who survives and dies are observed to decreases as retirement age increases. - Some of the metrics are blocked by yourconsent settings
Publication Natural Convection in a Triangular Enclosure Filled with Porous Media(AIP Publishing LLC., 2014) ;Siri Z. ;Ibrahim R.I. ;Faculty of Science and Technology ;University of Malaya (UM)Universiti Sains Islam Malaysia (USIM)A numerical analysis has been performed to investigate the natural convection in a triangular enclosure filled with porous media. The finite difference method is applied to solve the governing equations based on the Darcy model. Solutions of algebraic equations are made by Successive Under Relaxation technique. The effective parameters on flow and temperature fields are: Rayleigh number and Nusselts number. It was found that the fluid flow was depend on Rayleigh Number. 2014 AIP Publishing LLC. - Some of the metrics are blocked by yourconsent settings
Publication A new class of orthogonal polynomials for solving logarithmic singular integral equations(Ain Shams University, 2020) ;Alhawamda H. ;Taib B.M. ;Eshkuvatov Z.K.Ibrahim R.I.In this note, we propose a new class of orthogonal polynomials (named Bachok–Hasham polynomials H1nk(x)), which is an extension of the Chebyshev polynomials. Eigenfunctions and corresponding eigenvalues are found for the homogeneous second kind of Logarithmic Singular Integral Equations (LogSIEs). For non-homogeneous LogSIEs truncated series of the first kind Bachok–Hasham polynomials are used to find approximate solution. It is found that first kind of Bachok–Hasham polynomials (H1nk(x)) are orthogonal with weight [Formula presented], where k is positive odd integer. Properties of first kind of Bachok–Hasham polynomials are also proved. Finally, two examples are presented to show the validity and accuracy of the proposed method. © 2019 THE AUTHORS - Some of the metrics are blocked by yourconsent settings
Publication A study on longevity factors for the new and old government pension policies in Malaysia(Persatuan Ekonomi Malaysia, 2012) ;Ibrahim R.I. ;Siri Z. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)University of Malaya (UM)The objectives of this study are to compare and analyse the new and old government pension policies in Malaysia in terms of the longevity factor. Pensions are paid for the rest of the pensioner's life and in the form of derivative pensions to the spouse and child (if any) in the event of death. Hence, the longevity factor for a pensioner who survives and a pensioner who dies are formulated and estimated separately for both pension policies. In order to formulate these longevity factors, it is important to develop a family model for these two categories of pensioners separately. To formulate and estimate these factors, the theory of annuities and the Pension Law of Malaysia need to be studied. A comparison was conducted using empirical data sets of male pensioners in Malaysia from 1991 to 2000. It was found that the new government pension policy will result in more favourable financial implications for government employees or pensioners in the future. - Some of the metrics are blocked by yourconsent settings
Publication The impact on pension liabilities of Malaysian government pension scheme from remarriage due to removal of pension clause(American Institute of Physics Inc., 2014) ;Ibrahim R.I. ;Siri Z. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)University of Malaya (UM)In the event of death of any government employee, their monthly pension will be given to their widow and their child. The government will stop paying that pension when the widow died and when the widow chooses to remarry. However, in 1st January 2002, the remarriage clause has been removed from the regulations. This would allow all widows who remarried to receive pension as usual. In view of this, there are possibilities that those widows who are still young might remarried. If many of the widows choose to remarry, it will be a burden to the government as it would increase the pension liabilities. However, we do not know how many of the widow will remarry. In view of this, the purpose of the study is to assess the impact to pension liabilities of government pension schemes on individual life due to removal clause of the remarriage by determining the pension factor and to assess to what extent the pension liabilities of government pension schemes would be affected. � 2014 AIP Publishing LLC.