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All Journal Jurnal Sains Matematika dan Statistika AKSIOMA JURNAL EKSAKTA PENDIDIKAN (JEP) AXIOM : Jurnal Pendidikan dan Matematika Eksakta : Berkala Ilmiah Bidang MIPA Pelita Eksakta Jurnal Lebesgue : Jurnal Ilmiah Pendidikan Matematika, Matematika dan Statistika Jurnal Kajian Matematika dan Aplikasinya Journal of Mathematics UNP Rangkiang Mathematics Journal Jurnal Edukasi dan Penelitian Matematika

Defri Ahmad

Universitas Negeri Padang

Author-ID : 2591774

Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Decision Sciences, Operations Research & Management Education Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Other

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Model Matematika Efek Perpindahan Polutan Pada Kolam Pertama Ke Kolam Kedua Dipengaruhi Adveksi Dan Dispersi Alya Anzira; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 1 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract —Pollution in the aquaculture environment can come from inedible food and not eaten by fish. In a variety of fish culture business basin become the choice for entrepreneurs, fish entrepreneurs have many basins for fish farming.Concentration of pollutans in the basin will decrease when the first basin is entering clean water, so pollutants will come out of the basin. Based on the results of research into the mathematical model of water pollution in the form of a partial differential equation system.Keywords — Mathematical Model, Water Pollution, n Basin.

Kondisi Optimum Pengaturan Lampu Lalu Lintas Simpang DPRD dan Simpang Presiden Di Kota Padang Kefiano Fangelis; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 4 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract — The high traffic density on roads in Padang has resulted in the accumulation of vehicles at intersections, especially the DPRD and the president intersection. Optimal traffic light settings are needed to reduce vehicle buildup at these intersections. Optimization is done by applying a graph coloring application. This optimization is seen from increasing the duration of green lights and decreasing the duration of red lights based on traffic density and road width. This study aims to determine the optimal traffic light settings at the DPRD intersection and the President's intersection of the city of Padang by using Graph Coloring.. This research is applied research,and data used are primary data obtained from direct observation. The completion of traffic light settings using graph coloring provides an alternative solution for the duration of the lights that is more effective than the data obtained from the observations. The results obtained are more optimal based on the level of effectiveness where the duration of the red light for the DPRD intersection and the president's intersection decreased by 9,27% and 39,02%, while the duration of the green light increased by 30,8% and 239,6%.Keywords — Coloring Graph, Weighted graph, Welch-Powell, Traffic Light.

Penentuan Nilai Opsi Saham Karyawan (OSK) dengan Memperhitungkan Efek Dilusi Menggunakan Metode Lattice Trinomial Neneng Gusnela; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 1 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract—Aim of this paper is to determine the value of Employee Stocks Options (ESO), in which the calculation is different with another options. This paper is based on literature study and example of the case is simulated by using computer software. Dilution effect that will causes a decrease in the stock value was also considered in this paper. Lattice trinomial method is used to modelling the stocks price movement. Based of the results of this paper, we obtain the value of ESO and observe the parameter effects. The influences of strike price, employee exit rate, and vesting time are inversely proportional to the value of ESO, while the interest rate and volatilitas are directly proportional to the value of ESO.Keywords—employee stocks options, dillution effect, lattice trinomial.

Optimasi Rute Pengiriman Barang dengan Meminimumkan Biaya Transportasi Menggunakan Metode Saving Matrix di PT. Amanah Insanillahia Rida arifi; Defri Ahmad
Journal of Mathematics UNP Vol 4, No 4 (2019): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract– The main problem in the distribution of stuff to consumers is the optimization of costs and shipping routes. PT. Amanah Insanillahia is a bottled mineral water company that distributes its products to every sub-district in Tanah Datar district. However, this company has not yet optimized its distribution cost. To do this optimization requires a transportation method to minimize costs and routes, namely the Saving Matrix method. The Saving Matrix method aims to determine the product distribution route to the marketing area by determining the distribution route that must be traversed and the number of vehicles based on the capacity of the vehicle in order to obtain the shortest route and minimum transportation costs. The results of the transportation costs of distributing stuff at PT. Amanah Insanillahia by using this method can reduce costs by 35.11% with the optimum distribution route of stuff, namely the first route delivers of stuff carried out, namely Pariangan and Batipuh Districts. The second route is the Sungayang and Rambatan Districts. The third route is Limo Kaum and Lintau Districts. The fourth route is Salimpaung and Sungai Tarab District. Finally the fifth route is Tanjung Emas District. Keywords– Saving Matrix, distribution of stuff

Algoritma Genetika Untuk Menentukan Jalur Terpendek Wisata Kota Bukittinggi Indra Saputra; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 1 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract — Bukittinggi is a city with many tourist destination, thats close each other. Because of many tourist destination in Bukittinggi makes difficult for the tourist to visit all the places there at the limited time. To solve this problem, we did time and distance data processing between the tourist site around Bukittinggi using a genetic algorithm to find the shortest way for the tourists to reach the destination and be able to visit every place there. The steps for the genetic algorithm are; obtaining data from various sources, completing the Travelling Salesman Problem, calculating the time and distance between each tourist destination, creating the design system from input to output used, analyzing and evaluating the result that has been made by the system to make the most effective route to visit Bukittinggi. Keywords — Tour, Time, Distance, Travelling Salesman Problem, Genetic Algorithm

Analisis Curah Hujan di Kota Padang dengan Menggunakan Rantai Markov Ultari Femi Arshinta; Defri Ahmad
Journal of Mathematics UNP Vol 4, No 4 (2019): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract– Rainfall is one of the natural phenomena that always changes from one condition to another. If rainfall occurs with high intensity, it can result in natural disasters. One area in West Sumatra that receives high-intensity rainfall is Padang. In this research the Markov chain method is used to determine the results of rainfall analysis for the future. This study is an applied research using secondary data, namely dasarian rainfall data obtained from BMKG Padang Pariaman. For the future it is predicted that areas that have rainfall tend to be high (Water Plan Semen Padang), areas that have rainfall tend to be medium (Bandar Buat, Limau Manih-UNAND, Lubuk Minturun, Muara Palam-Parak Karakah, Nanggalo, Tambang Semen Padang, dan Teluk Bayur) and the probability for rainfall that falls for Padang tends to be medium. Keywords– Markov Chain, Matrix Transition Probability, Rainfall.

Model Matematika Penyebaran Penyakit Scabies pada Populasi Hewan dan Manusia Yani Sriyanti; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 3 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract — Scabies is a contagious skin disease caused by an infestation of the Sarcoptes Scabie mite which can spread quickly. This disease is spread in tropical areas where the level of hygiene, sanitation, and socio-economy is low and attacks all groups regardless of sex and age. The purpose of this research is to form a mathematical model, then the model is analyzed and interpreted. Based on the asumi and parameter values, a mathematical model of the spread of scabies in animal and human populations can be formed. The model that has been formed will then be analyzed using simulation. From the analysis obtained two points of equilibrium, which disease free and disease endemic. The simulation results show that scabies disease will continue to exist in the population because the equilibrium point at the endemic disease is unstable. Keywords— endemic, mathematical model, scabies, basic reproduction number.

Penerapan Teori Antrian pada Pelayanan Teller Bank BNI Kantor Cabang Pembantu Air Tawar Windy Septia Putri; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 1 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract– Queuing is one of the problems that is often faced by public services, as happened at the BNI Sub-Branch Office Air Tawar. It is due to the large number of customers who come to get services. This paper discusses the resolution of the problem faced by obtaining a queuing model that is applied to bank tellers. Data collection is carried out for 5 days (Monday to Friday, at 09.00 - 12.00 Western Indonesian Time) and is done through interviews and direct observations at the teller section of the BNI Sub-Branch Office Air Tawar. Based on the results of the analysis by measuring the performance of the queuing system, it is found that the model applied is .The arrival time of the customer is Poisson distribution and the time of service to the costumer is exponential distribution. The general discipline used is first in first out (FIFO). The basic queuing model is the Multiple Channel Queuing System.Keywords– Queue Theory, Multiple Channel Queuing System.

Model Matematika Penyebaran Penyakit Scabies pada Populasi Hewan dan Manusia Yani Sriyanti; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 4 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract — Scabies is a contagious skin disease caused by an infestation of the Sarcoptes Scabie mite which can spread quickly. This disease is spread in tropical areas where the level of hygiene, sanitation, and socio-economy is low and attacks all groups regardless of sex and age. The purpose of this research is to form a mathematical model, then the model is analyzed and interpreted. Based on the asumi and parameter values, a mathematical model of the spread of scabies in animal and human populations can be formed. The model that has been formed will then be analyzed using simulation. From the analysis obtained two points of equilibrium, which disease free and disease endemic. The simulation results show that scabies disease will continue to exist in the population because the equilibrium point at the endemic disease is unstable.Keywords— endemic, mathematical model, scabies, basic reproduction number.

Penentuan Cadangan PreminTahunan Retrospektif AsuransinJiwa Dwiguna Kasus JointnLife dengannMenggunakan Metode Fackler Noni Aryanti; Defri Ahmad
Journal of Mathematics UNP Vol 5, No 1 (2020): Journal Of Mathematics UNP
Publisher : UNIVERSITAS NEGERI PADANG

Abstract –The problem that insurance companies often face is that their small reserve premiums are acquired. The reserves will be used to pay compensation to insurance participants when a claim is made. As a effect, insurance companies will suffer losses. Therefore, it is discussed the determination of annual premium reserves of endowment insurance for joint life cases using the Fackler method with retrospective reserve. The Fackler method is used to calculate net premium reserves in the next few years in sequence. The calculationnof the reservenofnendowment insurance isndonenby forming a combined mortality table, determining the combined life annuity, a single premium, and an annual net premium. By using such calculation, the annual net premium formula and retrospective annual net premium reserve formulation are obtained. Keywords—premium reserves, retrospective, endowment insurance, joint life, Fackler method

Co-Authors Abdillah Janaki Daosti Ade Fauzan Akira Mikail Alya Anzira Amellia Fadjri annisa yovinda Aulia Fitri Fireza Defrisa Yoga Putra Deva Eliza Dina Agustina Dina Fitria Fadhilah Fitri Fridgo Tasman Ghaitsa Deiwa Karufa HAFIIZH, MOCHAMMAD Hafis Alrizal Indiko Prima Jazwinarti Jazwinarti Kefiano Fangelis Laksono Trisnantoro Media Rosha Melisa Melisa Mella Susriyanti Meria Ultra Gusteti Muhammad Fadhli Gusvino Muhammad Subhan Neneng Gusnela Noni Aryanti Nurul Hikmah Rahmawati Rara Sandhy Winanda Rara Sandy Winanda Rara Shandy Winanda Rida arifi Ronal Rifandi Saddam Al Aziz Suherman Suherman Suherman Suherman Syafriandi Syafriandi Tesa Nofri Handayani Ultari Femi Arshinta Vezalin, Stefanny Vita Kusumasari Wella Kurnia windi jelita Windy Septia Putri Yani Sriyanti Yani Sriyanti

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