Judul: Identifikasi Kerusakan Komponen Chainsaw Serta Pengaruhnya Terhadap Produktivitas Penebangan Di PT Inhutani Ii Pulau Laut Kalimantan Selatan
Abstrak: Pengetahuan tentang pemakaian dan pemeliharaan chainsaw mutlak diperlukan bagi setiap operator. Penggunaan chainsaw yang tepat akan meningkatkan produktivitas dan penggunaan chainsaw yang tidak tepat akan menyebabkan kerugian berupa kecelakaan kerja, kerusakan alat serta penurunan produktivitas. Mengetahuai komponen-komponen chainsaw dan fungsi-fungsinya akan memudahkan operator dalam pemeliharaan chainsaw yang mereka miliki. Hasil analisis kerusakan komponen chainsaw menunjukkan bahwa komponen yang sering mengalami kerusakan adalah sprocket, busi, rantai, dan piston. Kerusakan dari komponen chainsaw dapat mempengaruhi besarnya waktu kerja tidak efektif sehingga akan membuat produktivitas yang dihasilkan menjadi kecil. Chainsaw merk Falcon tipe Pro 5800 memiliki produktivitas 2.45 m3/jam. Waktu efektif berkisar antara 0.2−0.4 jam dengan waktu rata-rata 0.3 jam dan waktu tidak efektif berkisar antara 0.18−0.24 jam dengan waktu rata-rata 0.21 jam.
Keyword: chainsaw, kerusakan, komponen, pengaruh, produktivitas

Judul: Analisis Kerusakan Komponen dan Produktivitas Gergaji Rantai di Perum Perhutani Divisi Regional Jawa Timur KPH Madiun
Abstrak: The correct usage of chainsaw will increase the logging productivity. In the other hand, the incorrect usage will cause loss such as decline of the productivity, damage to the chainsaw and also causing occupational accident for the operator. The objectives of this research to find out the damage component, the cause of the damage component in chainsaw and also to find out the effect of the damage component towards logging productivity. The data was collected by analyzing the damage component, the cause of the damage chainsaw component and also by analyzing the effect of the damage component towards logging productivity. The analysis of the damage chainsaw component show that the most frequently damage component are chain, spark plug, piston and sprocket. The lack of understanding about the correct maintenance and treatment way for the tools and the usage of non-original part is one of the factors that cause the damage. The damage of chainsaw component can influence the non-effective work hours which result in the size of productivity.
Keyword: Bogor Agricultural University (IPB), productivity, influence, damage, component, chainsaw

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model