Judul: Determinan dan Invers Matriks Skew Circulant dengan Entri Bilangan Pell
Abstrak: Matriks skew circulant adalah matriks persegi yang entrinya bergeser satu kolom ke kanan secara berurutan dengan seluruh entri sebelum diagonal utama akan bernilai negatif. Entri-entri dari matriks skew circulant dapat diisi dengan entri berbagai bilangan, salah satunya yaitu bilangan Pell. Pada karya ilmiah ini, determinan dan invers matriks skew circulant dengan entri bilangan Pell diformulasikan. Pembuktian formulasi determinan matriks skew circulant dengan entri bilangan Pell dilakukan berdasarkan serangkaian operasi baris dasar sehingga diperoleh matriks segitiga atas. Sedangkan pembuktian formulasi pada inversnya berlandaskan sifat-sifat ekuivalensi dari hasil kombinasi operasi baris dasar dan operasi kolom dasar., Skew circulant matrix is a square matrix whose entries are shifted one column to the right and all entries before the main diagonal will be negative.The entries of the circulant skew matrix can be filled in various numbers, one of which is the Pell number. In this scientific work, the determinant and inverse of skew circulant matrices with the entry of the Pell number are formulated. The substantiation of the determinant formulation of the circulant skew matrix with the entry of the Pell numbers is carried out on the basis of a series of elementary row operations so that an upper triangular matrix is obtained. Meanwhile, the proof of the formulation in the inverse is based on the equivalence proprties of the results of a combination of elementary row and column operations.
Keyword: circulant matrix, circulant skew matrix, determinant, inverse, Pell numbers

Judul: Determinant and Inverse Circulant Matrix with Pell Numbers Entries
Abstrak: Matriks circulant adalah matriks yang entrinya bergeser satu kolom ke kanan secara berurutan, sehingga untuk mengetahui seluruh entrinya dapat dilihat hanya dari kolom pertama. Salah satu sifat yang dimiliki matriks circulant adalah bahwa inversnya juga berupa circulant. Entri-entri matriks circulant dapat menggunakan entri berbagai bilangan, salah satunya adalah bilangan Pell. Pada karya ilmiah ini, determinan dan invers matriks circulant dengan entri bilangan Pell diformulasikan. Pembuktian formulasi determinan matriks circulant dengan entri bilangan Pell dilakukan berdasarkan serangkaian operasi baris dasar sehingga diperoleh mariks segitiga atas. Sedangkan pembuktian formulasi inversnya berlandaskan sifat-sifat ekuivalensi dari hasil kombinasi operasi baris dasar atau operasi kolom dasar., A circulant matrix is a matrix whose entries are shifted one column to the right in sequence, so to find out all the entries can be seen only from the first column. One of the properties of a circulant matrix is that its inverse is also a circulant. Circulant matrix entries can use entries of various numbers, one of which is Pell's number. In this scientific paper, the determinant and the inverse of the circulant matrix with Pell number entries formulated. Proof of the determinant formulation matrix circulant with Pell number entries performed based on a series of base row operations so that the upper triangular matrix is obtained. While the proof of the inverse formulation based on the equivalence properties of the result combination of base row operations or base column operations.
Keyword: circulant matrices, determinant, inverse,, Pell numbers

Judul: Mechanical Vibration and Noise Measurement on Thermal Fogger Machine Type TS-35A (E)
Abstrak: The high utilizing of thermal fogger machine in agriculture is giving an impact for operator’s health and comfortness. This is because of mechanical vibration and noise level which produced by thermal fogger machine disturbing operator activity. Measuring of vibration and noise on thermal fogger machine was conducted by using vibrationmeter and sound level meter. The measurement results show that the operator was exposed 99.4 dB(A) noise and 4.03 m/s2vibration. A hand arm vibration nomogram was employed with vibration factor 3 hours for comfortable level and 8 hours for safety level, concurently with noise standard provided by National Ministry of Labor. The result derived from noise analysis shows that daily exsposure time of the machne utilization is 15 – 30 minutes as the noise factor shows significant effect on the machine operation. As the preventing action to decreasing noise level, it can using ear muff and ear plug. Beside that, by covering the machine using foam rubber.
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