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All Journal Eksakta : Berkala Ilmiah Bidang MIPA Jurnal Ilmiah Matematika dan Pendidikan Matematika (JMP) Jurnal Matematika Integratif

Khafsah Joebaedi

Department Of Mathematics, Faculty Of Mathematics And Natural Science (FMIPA), Universitas Padjajaran, Bandung, Indonesia

Author-ID : 605268

Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Electrical & Electronics Engineering Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Transportation

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MODEL STAR(1;1) PADA DATA PRODUKTIVITAS TEH Khafsah Joebaedi
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 1 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Model STAR (1;1) atau model Space Time Auto Regresi(1;1) adalah salah satu bentuk model yang melibatkan lokasi dan waktu. Model STAR(1;1) stasioner dapat digunakan untuk prakiraan observasi di suatu lokasi pada waktu mendatang berdasarkan satu waktu sebelumnya dari lokasinya sendiri dan lokasi-lokasi lain disekitarnya. Penerapan model STAR(1;1) pada data stasioner produktivitas teh menunjukkan bahwa nilai Eigen dari matriks parameter model STAR(1;1) bernilai lebih kecil dari 1. Hal ini menunjukkan bahwa parameter model STAR(1;1) untuk data produktivitas teh tersebut memenuhi syarat stasioner.

Some Operations on Mixed Monotone Operator in Banach Spaces Badrulfalah Badrulfalah; I Irianingsih; Khafsah Joebaedi
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 2 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

This paper discusses some operations on mixed monotone operator in Banach space, especially addition an multiplication operations. We will prove the sum and product of two mixed monotone operators. The proof using some relevant definitions. The result is the sum o of them is a mixed monotone operator and the product is too if both satisfy some conditions

First Order Space Time Autoregressive Stationary Model on Petroleum Data Khafsah Joebaedi; K Parmikanti; Badrulfalah Badrulfalah
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 2 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

First order Space-Time Autoregressive model is one of the models which involves location and time. STAR(1;1) model stationary can be used to forecast future observation at a location based on one previous time of its own location and the spatial neighborhood. STAR(1;1) model on petroleum productivity data in Balongan, Indramayu, West Java with eigenvalue less than 1. It indicates that STAR (1;1) model on petroleum productivity data in Balongan, Indramayu, West Java meets the stationary requirement

Factors Affecting the Amount of Investment Loans in Commercial Banks with the Application of Linear Regression Analysis Methods Khafsah Joebaedi; D Susanti; N Warwah; K Parmikanti; Badrulfalah Badrulfalah
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 20 No. 1 (2019): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Several factors can affect the amount of investment credit issued by the bank. This study discusses the effect of interest rates, inflation rates, capita income, and the number of medium-large industries on the number of investment loans, using the method of linear regression analysis. The independent variables examined to determine the influence of each and all the independent variables on the number of investment loans in commercial banks, namely interest rates, inflation rates, capita income, and the number of medium-large industries using the parameter estimation method, OLS (Ordinary Least Square).

Parameter Estimation STAR (1;1) Model Using Binary Weight Khafsah Joebaedi; Iin Irianingsih; Badrulfalah Badrulfalah; Dwi Susanti; Kankan Parmikanti
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 20 No. 2 (2019): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Space Time Auto Regressive(1;1) Model or STAR(1;1) model is a form of model that involves location and time. The STAR(1;1) model is a stationary space time model in mean and variance. The STAR model can be used to forecast future observations at these locations by involving the effects of observations at other nearby locations in spatial lag 1 and lag time 1 [2]. The STAR model can be written as a linear model assuming that error is normally distributed with zero mean and constant variance. In this research, the parameter estimation procedure for STAR model using binary weight, MKT method and STAR model for the estimation of petroleum production in 3 wells is assumed to be in a homogeneous reservoir.

A Solution of Nonlinear Boundary Value Problem of System With Rectangular Coefficients Badrulfalah Badrulfalah; Iis Irianingsih; Khafsah Joebaedi
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 21 No. 1 (2020): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

This paper discusses a nonlinear boundary value problem of system with rectangular coefficients of the form with boundary conditions of the form A(t)x' + B(t)x = f(t,x) and which is is a real matrix with whose entries are continuous on the form B1x(to)=a and B2x(T)=b which is A(t) is a real m n matri with m > n matrix with m > n whose entries are continuous on J = [to,T] and f E C[J x Rn, Rn]. B1, B2 are nonsingular matrices such that and are constant vectors, especially about the proof of the uniqueness of its solution. To prove it, we use Moore-Penrose generalized inverse and method of variation of parameters to find its solution. Then we show the uniqueness of it by using fixed point theorem of contraction mapping. As the result, under a certain condition, the boundary value problem has a unique solution.

Interest Rate in Pension Plan Premium Calculation Khafsah Joebaedi; Kankan Parmikanti; Agus Supriatna; Fauzi Akhmad; Badrulfalah Badrulfalah; Nendi Suhendi Syafei
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 21 No. 1 (2020): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

This research aims to analyze the relationship between the interest rate relationship is inversely proportional to the amount of the premium on the pension plan. The method used is to measure several variables, among others FSL (Future Service Liability), PVFSAL (Present Value Future Salary), PR (Pension Rate) and Premiums. Calculation, life annuity uses actuarial assumptions, one of which is the interest rate assumption, if the assumptions used are not in accordance with the actual conditions, then what happens is excessive payments or deficient payments. The interest rate has an influence in the process of calculating the defined benefit pension plan premium. Using the assumption of different interest rates (11%, 12 % and 13%), it is found that the interest rate relationship is inversely proportional to the amount of the premium. The results of this study are FSL, PVFSAL, PR and Premiums for the interest of 11%, 12% and 13% (participants aged 25 years) as follows 720,187.97; 554,000,24; 430,570.07 (FSL in Rupiah); 27,155,187.70; 24,922,770,59; 23,002,699.40 (PVFSAL in Rupiah); 2.6521; 2.2229; 1.8718 (PR in%) and 55,535.38; 46,546.85; 39,196.00 (Premiums in Rupiah)The higher the interest rate, the smaller the pension premium and vice versa.

Reliability Study of Oil and Gas Pipelines Using the Normal Distribution Method Nendi Suhendi Syafei; Darmawan Hidayat; Nanang Rohadi; Khafsah Joebaedi; Eddy Supriyana
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 22 No. 1 (2021): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Gas and oil pipelines have decreased function and damaged due to corrosion. This research aims to analyze and predict the life of gas and oil pipelines within a certain time span. The method used is a reliability study using a normal distribution. The analysis results show it is predicted that the pipe reliability probability in 2030 will decrease and the probability of failure will increase. The probability of reliability is 0.843572786617270 and the probability of failure is 0.156427213382730 in 2030. With the long distance pipeline, maximum depth as shown in the attachment the average thick remain is 0.2200 inches, the average corrotion rate is 0.0317 mm/year, with prediction thick remain from 2000 to 2030 in inches.

MODEL STAR DENGAN BOBOT SERAGAM SEBAGAI PENDETEKSI DEBIT AIR SUNGAI CITARUM Kankan Kankan Parmikanti; Khafsah Joebaedi; Iin Irianingsih
Jurnal Ilmiah Matematika dan Pendidikan Matematika Vol 8 No 2 (2016): Jurnal Ilmiah Matematika dan Pendidikan Matematika
Publisher : Jurusan Matematika FMIPA Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jmp.2016.8.2.2891

Lately when rainfall in West Java is quite high, the problem of flooding caused by overflowing of the river has always been a trending topic of regional leaders. Whatever the causes of flooding, be it because a lot of waste dumped in rivers or due to illegal logging of trees in the forest, the river water discharge increased rapidly, and overflowed into public housing. Based on the above, it should be made a model that can predict the water discharge of the river from time to time in various locations in West Java. In this paper will be presented studies Space Time Auto Regression models STAR (1,1) to model the problem of water discharge some rivers in West Java, which can be useful for predicting the discharge of river water in the future. By using Least Squares Method as predictors for the parameters, as well as assuming a uniform weighting matrix, the result that the water discharge of a river in addition affected by the river water flow at an earlier time, it is also influenced by the discharge of river water around.

Kajian Matriks Bobot Lokasi Model Space Time Autoregresi (STAR) Emah Suryamah; Budi Nurani Ruchjana; Khafsah Joebaedi
Jurnal Matematika Integratif Vol 9, No 2: Oktober, 2013
Publisher : Department of Matematics, Universitas Padjadjaran

Model STAR (Space Time Autoregresi) merupakan pengembangan dari model deret waktu univariat AR (Autoregresi), menjadi model kombinasi lokasi dan waktu. Keterkaitan antar lokasi penelitian pada model STAR dinyatakan dengan matriks bobot W yang merupakan matriks bujur sangkar dengan entri-entri berupa bobot antara dua lokasi yang bersesuaian. Dalam makalah ini dibahas tiga macam matriksbobot untuk model STAR(1;1), yaitu: matriks bobot seragam, matriks bobot seperjarak kuadrat dan matriks bobot spasial, menentukan dan menggunakan matriks bobot tersebut pada data simulasi, membandingkan serta memilih mana yang lebih baik diantara ketiganya dengan kriteria jumlah kuadrat galat yang paling minimum. Taksiran model STAR(1;1) dengan tiga macam bobot menghasilkan jumlah kuadrat galat yang minimum untuk model dengan matriks bobot spasial. Hal ini berarti bahwa bobot spasial memberikan taksiran parameter model STAR(1,1) yang lebih baik dibandingkan penggunaan matriks bobot seragam dan seperjarak kuadrat.Kata kunci: Matriks bobot, model STAR, autoregresi

Co-Authors Agus Supriatna Badrulfalah Badrulfalah Budi Nurani Ruchjana D Susanti Darmawan Hidayat Dwi Susanti Eddy Supriyana Emah Suryamah Emah Suryamah, Emah Fauzi Akhmad I Irianingsih Iin Irianingsih Iis Irianingsih K Parmikanti K Parmikanti Kankan Parmikanti N Warwah Nanang Rohadi Nendi Suhendi Syafei

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