Judul: Analisis Beban Kerja Kegiatan Penyemprotan Lahan dan Gudang Pertanian menggunakan Mesin Thermal Fogger Tipe TS-35A(E)
Abstrak: Abundance farms in Indonesia led to greater levels of pest attack. One of the method to control pest growth was pest fumigation. However, the use of thermal fogger machine must also consider the fatigue and workload received by the operator. This study will focus on physiological aspect of operator, ie the level of workload and total energy consumption while operating Thermal Fogger machine type TS-35A (E). Measurement of workload carried out with three repetitions. At the beginning of the measurement, and in each and every repetition punctuated by rest for approximately 10 minutes. The result for Qualitative Workload Levels (fatigue) for fumigation using Thermal Fogger type TS-35A(E) on field was categorized Very Heavy category with average IRHR 1769 ± 0140 meanwhile for warehouse was categorized in Heavy category with average IRHR 1.638 ± 0.128. This means that fogging activities on field heavier than activities on warehouse. The average energy consumption of the operator (Total Energy Cost) for fumigation using Thermal Fogger TS type 35A (E) on the field was 2247 ± 0373 kcal / min, while fumigation in warehouse was 2174 ± 0278 kcal / min. This means that the work done in the field use more energy per unit of time.
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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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Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix