Judul: Pengaruh Etnosentrisme, Sikap, dan Preferensi terhadap Perilaku Pembelian Buah Lokal di Perkotaan dan Perdesaan Bogor
Abstrak: The excess quantity of imported fruit in Indonesia has triggered business competition between local and import fruit. This research aimed to analyze the influence of ethnocentrism, attitude, and preference toward the purchasing behavior of local fruit in urban and rural. The design of this research used cross sectional study which involved 120 housewives. The result showed the significant positive relation between ethnocentrism, preference, and attitude. The age of respondent also relates positively to ethnocentrism and attitude. Ethnocentrism, attitude, and preference have no significant relation to the purchasing number of local fruit and local fruit expenditure. Based on multiple regression linear test, the education level of respondent and per capita income significantly positive influence toward the purchasing number of local fruit. The number of family member and per capita income also significantly positive influence toward local fruit expenditure.
Keyword: preference., local fruits, ethnocentrism, attitude

Judul: Pengaruh Citra, Preferensi, dan Sikap terhadap Perilaku Pembelian Buah Lokal
Abstrak: A good response to imported fruits by the public, impact to more competitiveness rivalry between the local and import fruits in the market. The aim of this study was to analyze the effect of image, preference, and attitude toward the purchase behavior of local fruits. The design of this study was cross sectional, and the research were located at Baranangsiang and Cihideung Ilir villages. The sample of this study was 120 households who buy fruits and selected by cluster. The result show significant differences between characteristic, images, attitude, and purchase behavior of local fruits on household in urban and rural area, but there is no distinction preference to local fruits on housewives in the urban and rural area. Factors that effect purchase behavior of local fruits by housewives are age, the number member of family, long education of the mother and the level of preference against local fruits.
Keyword: purchase on local fruits, preference, image, attitude

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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