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Wyszukujesz frazę "Purwani, Sri" wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
Multiple Linear Regression Using Cholesky Decomposition
Autorzy:
Sumiati, Ira
Handoyo, Fiyan
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1031897.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Cholesky decomposition
Multiple linear regression
covariance matrix
Opis:
Various real-world problem areas, such as engineering, physics, chemistry, biology, economics, social, and other problems can be modeled with mathematics to be more easily studied and done calculations. One mathematical model that is very well known and is often used to solve various problem areas in the real world is multiple linear regression. One of the stages of working on multiple linear regression models is the preparation of normal equations which is a system of linear equations using the least-squares method. If more independent variables are used, the more linear equations are obtained. So that other mathematical tools that can be used to simplify and help to solve the system of linear equations are matrices. Based on the properties and operations of the matrix, the linear equation system produces a symmetric covariance matrix. If the covariance matrix is also positive definite, then the Cholesky decomposition method can be used to solve the system of linear equations obtained through the least-squares method in multiple linear regression. Based on the background of the problem outlined, such that this paper aims to construct a multiple linear regression model using Cholesky decomposition. Then, the application is used in the numerical simulation and real case.
Źródło:
World Scientific News; 2020, 140; 12-25
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Interpolation and Extrapolation of Newton and Cubic Splines to Estimate and Predict the Gas Content of Hydrogen and Iodine in the Formation of Iodic Acid Reactions
Autorzy:
Maryati, Ati
Pandiangan, Naomi
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1193309.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Cubic Spline Interpolation
Extrapolation and Time series data
Newtom Interpolation
Opis:
The problem that is mostly related to the pattern of experimental time series data is the function that involves the data. Experimental data in the field of exact sciences is very important to conclude a problem. Existing data can form certain functions. In this research, we are looking for a function that represents the gas content of hydrogen and iodine in the reaction of acid iodide formation. This is achieved by using interpolation in which the function interpolates a given group of data points. Interpolation can also be used to evaluate the function at points different from the group. In addition to constructing and evaluating a functions by interpolation, we can also predict experimental data outside the given group of data points by using extrapolation. The results of data extrapolation can be used as an alternative to experimental data, thereby saving time and cost. This research will also compare interpolation and extrapolation of both Newton method and cubic splines, which one better interpolates and extrapolates data on hydrogen and iodine gas content in the reaction of acid iodide formation. The research results show that the cubic spline method is better than Newton method at approaching data, in terms of interpolation, as well as extrapolation.
Źródło:
World Scientific News; 2021, 153, 2; 124-141
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficiency and Convergence of Bisection, Secant, and Newton Raphson Methods in Estimating Implied Volatility
Autorzy:
Mahrudinda, Mahrudinda
Munandar, Devi
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1193324.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Black-Scholes model
Newton Raphson
bisection
secant
volatility
volatility implied
Opis:
This study aims to estimate volatility prices based on the black-Scholes model (BSM) function with research data taken during the COVID-19 pandemic. The estimates of the volatility values are obtained by using three numerical methods, namely the bisection, secant, and Newton Raphson methods. The numerical processes that produce some iteration results in the three methods are then analyzed and the best convergence is sought. As a result, Newton Raphson method produces the smallest number of iterations, which stops at the 3rd iteration and gets a volatility value of 0.500451 with an absolute error value of 0.000388. However, the method requires an initial approximation which lies only in two intervals on the axis σ which are close to the true root. Meanwhile, for the other two methods, namely Bisection and Secant, this limitation does not apply, as long as there is an interval that guarantees the existence of roots. In this case, bisection method requires11 iterations to converge with volatility value of 0.500342 and error value of 0.000878. Whereas secant method requires 4 iterations to converge with a volatility value of 0.500449 and error value of 1.68938E-05. This suggests, that in some cases the use of Newton method, should be initialized with the use of bisection or secant method, to ensure successful iteration and accelerate the rate of convergence.
Źródło:
World Scientific News; 2021, 153, 2; 157-168
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractional Integral Approximation and Caputo Derivatives with Modification of Trapezoidal Rule
Autorzy:
Pandiangan, Naomi
Johar, Dwindi
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1193326.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Caputo fractional derivative
Fractional integral
Modified trapezoidal rule
Rieman Liouville fractional integral
Opis:
In classical calculus, a function can be derived or integrated as many as natural numbers. Then a question arises regarding the fractional order of derivatives and integrals. There is a development of classical calculus called fractional calculus. Fractional calculus may be a department of science that amplifies the orders of derivatives and integrals into the order of rational numbers or even real numbers. The difficulty of finding solutions analytically for a complicated function of fractional integrals or fractional derivatives often occurs. In this paper, we will solve Rieman Liouville's fractional integral and Caputo's fractional derivative analytically using the trapezoidal rule modification method. Trapezoidal method is an approximation method that is resulted from the linear interpolation function. In this paper, we will find numerical simulations with modified trapezoidal method, to estimate some functions, and the results will be compared with previous research related to the Rieman Liouville fractional integral approximation and the Caputo fractional derivative. The result from simulation find that modified trapezoidal can approximate Caputo fractional derivative by replace α with -α and Quadratic schemes method is the best method to approximate Rieman Liouville fractional integral and Caputo fractional derivative.
Źródło:
World Scientific News; 2021, 153, 2; 169-180
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial-Temporal Analysis of Rainfall West Java Indonesia Using Empirical Orthogonal Function based on Singular Value Decomposition
Autorzy:
Pribadi, Diantiny Mariam
Sumiati, Ira
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1031922.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Empirical Orthogonal Function
Rainfall
Singular Value Decomposition
Spatial-Temporal
Opis:
Rainfall is one of the climate variables that have a significant influence, especially in supporting the activities of various sectors in tropical countries. Climate change is causing rainfall variability in Indonesia. However, the analysis of climate variable patterns is difficult because of the formation of a large matrix. Empirical Orthogonal Function (EOF) analysis can be used to reduce the dimensions of large data by maintaining as much variation as possible from the original data set. The method used in this study is through the Singular Value Decomposition (SVD) approach. The analysis shows that 98.50% of the total rainfall variance can be represented by four EOF modes. Analysis of the spatial pattern of EOF1 shows that rainfall is below average, while the other EOF modes show variations in rainfall.
Źródło:
World Scientific News; 2020, 140; 113-126
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter Estimation Using LU Decomposition in the Logistic Regression Model for Credit Scoring Analysis
Autorzy:
Rahmani, Ulfa
Pribadi, Diantiny Mariam
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1031893.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Credit Scoring
LU Decomposition
Logistic Regression
Problem Loans
Opis:
Banking is a financial institution that has a very important role in economic and trade activities which is useful for channeling funds in the form of loans to the public who need fresh funds for business in the hope of helping to improve the people's economy. In the loan process, banks are often exposed to risks known as credit risk or non-performing loans. Therefore, a credit analysis is performed by estimating the parameters using LU Decomposition in the Logistic Regression model. In this paper, the data used are data about cooperative financial services in Indonesia. Variables taken in the study are including the age of debtors (X1), family dependents (X2), the amount of savings (X3), the value of collateral (X4), the amount of income per month (X5), given the credit limit (X6), take home pay (X7), and the loan term (X8).
Źródło:
World Scientific News; 2020, 140; 1-11
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Susceptible-Infected-Removed Epidemiological Model for COVID-19 Spreading in Indonesia
Autorzy:
Achmad, Audi Luqmanul Hakim
Mahrudinda, Mahrudinda
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1193300.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
COVID-19
Indonesia
dynamical system
epidemiological model
Opis:
COVID-19 is a disease emerged from China in the late 2019 and still spreading to this date. Scientists worldwide are trying to give their contributions in many aspects, from searching for the vaccine to studying several policies in many aspects to deal with this disease. One of the important researches in COVID-19 is to study and predict the dynamic of the spreading by using epidemiological model. This research has been taken in many countries independently since the behavior of COVID-19 spreading might differ from one another. Each country has their own characteristics-e.g., the population density, geographic condition, health facilities and infrastructure, weather condition-which caused the different patterns of COVID-19 spreading. Therefore, each country probably has their own unique parameters which describe their own dynamicity of COVID-19 spreading even though the epidemiological models used in different countries are the same. Thus, in this paper, we estimate the parameters involved in our SIR epidemiological model for cases in Indonesia by using Least Square Method in Python. We use the daily cases released from Indonesian COVID-19 Response Acceleration Task Force. Several assumptions are made in this model, including the assumption that there is no vaccination to be released yet. The result shows that the COVID-19 will still exists in Indonesia for over 1.9 years from the first case emerged (until mid January 2022).
Źródło:
World Scientific News; 2021, 153, 2; 55-64
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bandung City Rainfall Data Interpolation Using Two Types of Cubic Spline Interpolation
Autorzy:
Haq, Al Fataa Waliyyul
Achmad, Audi Luqmanul Hakim
Purwani, Sri
Powiązania:
https://bibliotekanauki.pl/articles/1193368.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Interpolation
natural cubic spline
not-a-knot cubic spline
Opis:
This study discusses the application of two types of cubic spline, namely natural cubic spline and not-a-knotcubic spline. The applications of both types of splines are regarding rainfall data. The rainfall data studied were the monthly rainfall data for the year 2018 and 2019 in Bandung City which was obtained from the Bandung City Central Statistics Agency. Interpolation and analysis were carried out on all data using Maple software. As a result, interpolation using natural cubic spline and not-a-knotcubic spline shows a smoother and less oscillating graph than interpolation using Piecewise Linear and Polynomial Interpolation.
Źródło:
World Scientific News; 2021, 155; 36-46
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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