Samsul Ariffin Abdul Karim

Shape Preserving Interpolation Using Rational Cubic Spline

This paper discusses the construction of new rational cubic spline interpolant with cubic numerator and quadratic denominator. The idea has been extended to shape preserving interpolation for positive data using the constructed rational cubic spline interpolation. The rational cubic spline has three parameters , , and . The sufficient conditions for the positivity are derived on one parameter while the other two parameters and are free parameters that can be used to change the final shape of the resulting interpolating curves. This will enable the user to produce many varieties of the positive interpolating curves. Cubic spline interpolation with continuity is not able to preserve the shape of the positive data. Notably our scheme is easy to use and does not require knots insertion and continuity can be achieved by solving tridiagonal systems of linear equations for the unknown first derivatives , . Comparisons with existing schemes also have been done in detail. From all presented numerical results the new rational cubic spline gives very smooth interpolating curves compared to some established rational cubic schemes. An error analysis when the function to be interpolated is is also investigated in detail.

Local Control of the Curves Using Rational Cubic Spline

This paper discussed the local control of interpolating function by using rational cubic spline (cubic/quadratic) with three parameters originally proposed by the authors. The rational spline has continuity. The bounded properties of the rational cubic interpolants and shape controls of the rational interpolants are discussed in detail. The value control, inflection point control, and convexity control at a point by using the proposed rational cubic spline are constructed. Several numerical results are presented to show the capability of the method. Numerical comparisons with the existing scheme are also further elaborated. From the results, it was indicated that the scheme works well and it is comparable with the established existing scheme.

Positivity Preserving Interpolation Using Rational Bicubic Spline

This paper discusses the positivity preserving interpolation for positive surfaces data by extending the C1 rational cubic spline interpolant of Karim and Kong to the bivariate cases. The partially blended rational bicubic spline has 12 parameters in the descriptions where 8 of them are free parameters. The sufficient conditions for the positivity are derived on every four boundary curves network on the rectangular patch. Numerical comparison with existing schemes also has been done in detail. Based on Root Mean Square Error (RMSE), our partially blended rational bicubic spline is on a par with the established methods.

Global solar radiation modeling using polynomial fitting

This paper studies the use of polynomial fitting to model the global solar radiation that was measured by using solarimeter at Universiti Teknologi PETRONAS (UTP), located in Perak, Malaysia. The measured solar radiation data was filtered by using fitting and smoothing methods. The polynomial data fitting method was used for data smoothing and was tested by using different degrees of polynomial curve fittings. The error measurement was calculated by using the root mean square error (RMSE) and by determining the 2 R value. The polynomial fittings were carried out by using MATLAB.

Numerical performance of AOR methods in solving first order composite closed Newton-Cotes quadrature algebraic equations

In this paper, the application of the Accelerated Over-Relaxation (AOR) iterative method is extended to solve first order composite closed Newton-Cotes quadrature (1-CCNC) algebraic equations arising from second kind linear Fredholm integral equations. The formulation and implementation of the method are also discussed. In addition, numerical results by solving several test problems are included and compared with the conventional iterative methods.

Denoising solar radiation data using coiflet wavelets

Signal denoising and smoothing plays an important role in processing the given signal either from experiment or data collection through observations. Data collection usually was mixed between true data and some error or noise. This noise might be coming from the apparatus to measure or collect the data or human error in handling the data. Normally before the data is use for further processing purposes, the unwanted noise need to be filtered out. One of the efficient methods that can be used to filter the data is wavelet transform. Due to the fact that the received solar radiation data fluctuates according to time, there exist few unwanted oscillation namely noise and it must be filtered out before the data is used for developing mathematical model. In order to apply denoising using wavelet transform (WT), the thresholding values need to be calculated. In this paper the new thresholding approach is proposed. The coiflet2 wavelet with variation diminishing 4 is utilized for our purpose. From numerical results it can be seen clearly that, the new thresholding approach give better results as compare with existing approach namely global thresholding value.

Shape Preserving Interpolation Using Rational Cubic Ball Function and Its Application in Image Interpolation

New rational cubic Ball interpolation with one parameter is proposed for shape preserving interpolation such as positivity, monotonicity, and convexity preservations and constrained data lie on the same side of the given straight line. To produce shape preserving interpolant, the data dependent sufficient condition is derived on the parameter. The rational bicubic Ball function is constructed by using tensor product approach and it will be used for application in image upscaling. Numerical and graphical results are presented by using Mathematica and MATLAB including comparison with some existing scheme.

Quantification of asphaltene precipitation by scaling equation

Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir conditions. Two conditions were followed in the conduct of the experiment. Firstly, a 45cc light crude oil was mixed with 18cc (40%) of CO2 and secondly, the same amount of crude oil sample was mixed with 27cc (60%) of CO2. Results showed that for a 45cc crude oil sample combined with 18cc (40%) of CO2 gas indicated a saturation pressure of 1498.37psi and asphaltene onset point was 1620psi. Then for the same amount of crude oil combined with 27cc (60%) of CO2, the saturation pressure was 2046.502psi and asphaltene onset point was 2230psi. The derivation of the scaling equation considered reservoir temperature, pressure, bubble point pressure, mole percent of the precipitant the injected gas CO2, and the gas molecular weight. The scaled equation resulted to a third order polynomial that can be used to quantify the amount of asphaltene in crude oil.Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir...

Construction of cubic Ball surface based on biharmonic partial differentiation equation

This paper proposes a method for generating DP surface from prescribed boundaries based on partial differential operator. The focus is on the use of biharmonic partial differentiation equation to construct a bicubic DP surface. Result shows that using biharmonic DP surface enables the overall surface to be generated and controlled based on the boundary curves rather than a set of control points. Graphical examples are used to illustrate the proposed method.

Implementation of optimum solar electricity generating system

Under the 10th Malaysian Plan, the government is expecting the renewable energy to contribute approximately 5.5% to the total electricity generation by the year 2015, which amounts to 98MW. One of the initiatives to ensure that the target is achievable was to establish the Sustainable Energy Development Authority of Malaysia. SEDA is given the authority to administer and manage the implementation of the feed-in tariff (FiT) mechanism which is mandated under the Renewable Energy Act 2011. The move to establish SEDA is commendable and the FiT seems to be attractive but there is a need to create awareness on the implementation of the solar electricity generating system (SEGS). In Malaysia, harnessing technologies related to solar energy resources have great potential for implementation. However, the main issue that plagues the implementation of SEGS is the intermittent nature of this source of energy. The availability of sunlight is during the day time, and there is a need for electrical energy storage syste...