Judul: Analisis Perancangan Modifikasi Dan Uji Kinerja Crawler Mesin Penggerak Fertilizer Applicator (Cfa01).
Abstrak: CFA01 adalah mesin yang penggerak aplicator pupuk butiran, mesin pemupuk ini dilengkapi dengan mekanisme pengangkat pelepah daun sehingga pupuk yang diberikan lebih tepat sasaran. Rancangan roda crawler mesin penggerak aplicator pupuk butiran CFA01 yang pernah didesain sebelumnya memiliki beberapa kekurangan. Penelitian ini bertujuan memodifikasi crawler mesin penggerak aplicator (CFA01) dengan penambahan mekanisme elevator sproket dan melakukan pengujian kinerja crawlernya. Rancangan crawler yang dihasilkan memiliki komponen fungsional yakni rangka, sproket dan rantai, roller, roller idler belakang dan sepatu trek. Hasil analisis struktural, pemilihan dan perencanaan bahan pada crawler sesuai dan dianggap baik karena bahan SC45 memiliki σb = 58 kg/mm2 lebih besar daripada tegangan geser dan tegangan bending yang diterima oleh bahan. Hasil analisis kinematik menunjukan kebutuhan daya untuk menggerakan crawler adalah 6.9 Hp. Untuk mengoptimalkan sebaran pupuk maka pengoperasian dilakukan pada tingkatan kecepatan maju L2 dengan kecepatan putar mesin 2000 rpm. Hasil simulasi beban statis menggunakan software solidworks menunjukkan bahwa bahan dan dimensi pada komponen rangka utama masih aman karena tegangan maksimum yang diterima oleh bahan lebih kecil dari tegangan izin bahan.
Keyword: crawler, kelapa sawit, mesin penggerak aplicator (CFA01), simulasi beban, Solidworks, uji kinerja

Judul: Rancangan Konseptual Mesin Penggerak Aplikator Pupuk Butiran dengan Mekanisme Pengangkat Pelepah Daun
Abstrak: Fertilizer application is one of activities on oil palm tree cultivation. Fertilizer application is applied in nursery, pre-production plant, and production plant. Inaccuracy of spreading is one of fertilization problem such as fertilizer which was dropped on oil palm frond, especially on pre-production plant. The objective of this research is to make conceptual design of prime mover of granular fertilizer applicator with frond lifting mechanism. The design criteria were the ground pressure of machine less than 90 kPa, maximum width machine was 250 cm and 220 cm of high. The result indicate that weight of machine without fertilizer applicator was 1205.55 kg, 19.59 kPa of ground pressure, 141.3 cm of width and 174.9 cm of high. The prime mover component consist of chassis, gearbox, crawler, roller, engine, control lever, seat, lifter conveyor, and cabin chassis. The chassis was made from canal UNP S45C. Based on engineering analysis, chassis has 3.03 N/m2 of maximum shear stress and 30.92 N/m2 of maximum bending stress. Frond lifting system slope was 53.45o and operated at 0.67 m/s of forward velocity with 1.13 m/s of lifting velocity. Based on result of load static simulation from SolidWorks software, the material which used in each component is safe because the value of stress is less than material yield strength.
Keyword: Bogor Agricultural University (IPB), SolidWorks, load simulation, conveyor, fertilization

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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