Judul: Rancang Bangun Sistem Sprayer Otomatis pada Kendaraan Tanpa Awak.
Abstrak: Sprayer merupakan aplikator pestisida untuk pengendalian hama dan penyakit tumbuhan. Penelitian sebelumnya hanya merancang bangun sistem kendali kendaraan tanpa awak. Tujuan dari penelitian ini adalah merancang sprayer otomatis pada kendaraan tanpa awak untuk meringankan beban dan meningkatkan kenyamanan operator. Metode penelitian terdiri dari identifikasi masalah, perancangan sprayer otomatis dengan mikrokontroler dan sensor ultrasonik, pembuatan program, analisis kebutuhan sprayer otomatis, pengujian fungsional, dan pengujian kinerja. Hasil dari Butiran semprotan halus yang digunakan adalah berukuran 990 μm, keseragaman (Coefficient of Variation) 0.624, dan tekanan 120 kPa. Mekanisme penyemprotan digunakan delay karena ada jarak antara nozzle dan sensor ultrasonik sebesar 1.825 detik supaya semprotan tepat mengenai tanaman. Pengujian debit penyemprotan ialah 0.498 liter/menit dan waktu penyemprotan sprayer disesuaikan dengan lebar tanaman dan kecepatan maju kendaraan. Hasil untuk kapasitas lapang efektif rata-rata ialah 0.06 ha/h dan teoritis ialah 0.23 ha/h sehingga rata-rata efisiensi lapangnya sebesar 26.27%.
Keyword: automatic sprayer,, nozzle, ultrasonic sensor, unmaned vehicle

Judul: Rancang Bangun Sistem Kendali untuk Kendaraan Sprayer Tanpa Awak Berbasis Jaringan.
Abstrak: Sprayer is commonly used in agro-chemical aplication in form of a mist. However, the exposure of agrochemical to operator on operating sprayer potentially causing risk to operator health. The objective of this research was to design a web-based control system for unmanned sprayer in order to improved health aspect of operator. Mini electric car was modified into web-based controlled was used as model for this research. Maximum range of radio control was 55 m and maximum range of web-based control (Wifi) was 110 m. Therefore, web based control was chosen because it has wider range. The average forward speed of model was 31.04 cm/s with 1% of slip for left rear wheel and 2% of slip for right rear wheel. The average turning radius of model was 210.4 cm for turning right and 290.9 cm for turning left. Controlling test conducted at straight path, turn right, and turn left with 3 kinds of different camera angle i.e. 72o, 77°, and 90°. According to data analysis result by using ANOVA could be concluded that camera angle significantly affected on controlling straight and left turn, but didn’t significantly affected on controlling turn right. The difference in significancy was due to the model just using motor in the right rear wheel for moving so the model tends to moved towards the left.
Keyword: agricultural chemicals, operator health, unmanned sprayer, web based control

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
Keyword: