Judul: Completion of the Lotka Volterra Model of Two Species Using the Homotopy Analysis Method
Abstrak: Dalam tulisan ini, model Lotka Volterra dua spesies yang bersaing dan dikembangkan oleh Bakare et.al (2018) diselesaikan dengan metode analisis homotopi. Dalam metode ini didefinisikan suatu persamaan deformasi dengan memperkenalkan suatu operator linear. Tujuan penelitian ini adalah menentukan penyelesaian semi-analitik dari model Lotka Volterra dengan menggunakan persamaan deformasi yang didefinisikan. Hampiran penyelesaian yang diperoleh ini cukup baik untuk mendekati penyelesaian model Lotka Volterra dua spesies. Beberapa tafsiran terhadap penyelesaian dari model untuk perubahan tingkat intrinsik spesies satu dan spesies dua, juga diberikan. Hasil simulasi menunjukkan bahwa penyelesaian tingkat intrinsik populasi spesies satu menghasilkan penurunan pada jumlah spesies kedua. Kata kunci: metode analisis homotopi, model Lotka Volterra, semi-analitik, In this paper, the competing two species Lotka Volterra model developed by Bakare et.al (2018) was completed using the homotopy analysis method. In this method a deformation equation is defined by introducing a linear operator. The purpose of this study was to determine the semi-analytic solution of the Lotka Volterra model using the defined deformation equation. The approximation of the obtained solution is good enough to approximate the completion of the two species Lotka Volterra model. Several interpretations of the completion of the model for changes in the intrinsic rate of species one and species two, are also given. The simulation results show that the completion of the intrinsic level of the population of one species results in a decreacse in the number of the second species. Keywords: homotopy analysis method, model Lotka Volterra, semi-analytic.
Keyword: metode analisis homotopi, model Lotka Volterra, semi-analitik

Judul: Penggunaan Metode Homotopi Pade' untuk Menyelesaikan Masalah Lotka–Volterra Logistik.
Abstrak: In this research, the problems of Lotka–Volterra and Lotka–Volterra with prey logistic growth models are solved by using homotopy and Pade' homotopy methods. The homotopy method is an analytical approach to solve non linear problems. The solution of homotopy method is common series. The solution of the problem using Pade' homotopy method is obtained by using the result of applying the homotopy method and then transforming the equation into the form of rational function. The results of homotopy and Pade' homotopy methods are compared with some numerical solutions. The result shows that in solving Lotka–Volterra and Lotka–Volterra with prey logistic growth, the Pade' homotopy method is better than homotopy method because the Pade' homotopy method covers a larger area of convergence and produces smaller errors.
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Judul: Photosensor producing based on ferroelectric material of Ba0,5Sr0,5TiO3 doped by Ferrium Oxide (Fe2O3) on a P-Type Silicon Substate Si (100) applied as a digital camera with a single pixel image sensor
Abstrak: Thin film Ba0,5Sr0,5TiO3 (BST) doped with Fe2O3 was grown on p-type silicon substrate (100) using chemical solution deposition (CSD). It used the solvent 2-methoxyethanol with annealing temperature of 850°C and the doping treatment Fe2O3 of 2.5, 5, 7.5, 10 % of the mass formed BST. Pure BST had the highest absorption of 600 nm of light wavelength. Additions Fe2O3 moves highest absorption in the range of 560 nm. Fe2O3 addition was strengthening thin film sensitivity to the effects of light. In general, doping Fe2O3 10% was result the best absorbance and current-voltage of BST thin film. Electrical properties of thin films BST include dielectric, photoconductivity, and dissipation energy. Based on the current-voltage (I-V) analysis, pure BST and doped BST showed photodiode properties. Dielectric values obtained in the range from 23.32 to 243. Based on electrical conductivity data and energy dissipation, BST thin films have shown photodiode characteristics and are therefore suitable as light sensors. The image sensor in a digital camera is also a light sensor. This BST thin film has been scientifically proven to be a light sensor and also it can be applied as an image sensor. This is a novelty image sensor based on thin film Ba0.5Sr0.5TiO3.
Keyword: barium strontium titanate, thin film, photodiode, image sensor, digital camera