Judul: Identifikasi Perubahan Tingkat Pengetahuan K3 Menggunakan Safety Game terhadap Pekerja Industri Mebel Kayu Jati di Jepara
Abstrak: Occupational Safety and Health (OSH) is one of the labor protection forms. The implementation of OSH in the forestry sector, especially for furniture industry workers in Jepara, is still weak, and this may pose a risk of never-ending OSH disruption that can be problematic for the furniture industry in Jepara in the long term. The high risk of OSH disruption in a small-scale industry was caused by the low level of worker’s knowledge in OSH. The objective of this research was to learn about a safety game performance as an instrument to improve worker’s knowledge in OSH to replace the conventional method. The study was conducted in a small-scale furniture industry in Mulyoharjo village of Jepara regency involving 45 workers from wood shaping, sanding and finishing. Based on the results, the safety games can be used as an instrument to improve worker’s knowledge in OSH because showed an increase of knowledge. The change in the level of knowledge before and after using the safety game was significant, meaning that the safety game had a good performance.
Keyword: safety game, knowledge increase, furniture industry workers, occupational safety and health

Judul: Identifikasi Tingkat Pengetahuan K3 dengan Instrumen Safety Game di TPK Tradisional
Abstrak: Occupational safety and health (OSH) disruption risk in timber harvesting activities is very high. One of the timber harvesting activities is activities in the lumberyard. This is occurs because the work environment condition are not in accordance with government regulations, and basic competence (knowledge) of workers and administrators (the employer) is still relatively low. So it requires a strategy to increase their knowledge with low cost, interesting, and usefull everytime, so it can use in traditional activities in the lumberyard condition in Jepara which is small business units. One of solution is using safety game which is an instrument that used to increase workers and administrators knowledge that created by Dr. Efi Yuliati Yovi, S.Hut, M.Life.Env.Sc. The enhancement of their knowledge about OSH after use the safety game at 1 replications were 14% during ±45 minutes and 3 replications were 33% during ±140 minutes.
Keyword: workers and administrators., safety game, knowledge about OSH, activities in the lumberyard

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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